2 <!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
3 <chapter xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" id="boost_contract" rev:last-revision="$Date: 2019/12/10 00:23:48 $">
5 <firstname>Lorenzo</firstname> <surname>Caminiti <email>lorcaminiti@gmail.com</email></surname>
7 <year>2008</year> <year>2009</year> <year>2010</year> <year>2011</year> <year>2012</year>
8 <year>2013</year> <year>2014</year> <year>2015</year> <year>2016</year> <year>2017</year>
9 <year>2018</year> <year>2019</year> <holder>Lorenzo Caminiti</holder>
10 </copyright><legalnotice id="boost_contract.legal">
12 Distributed under the Boost Software License, Version 1.0 (see accompanying
13 file LICENSE_1_0.txt or a copy at <ulink url="http://www.boost.org/LICENSE_1_0.txt">http://www.boost.org/LICENSE_1_0.txt</ulink>)
15 </legalnotice></chapterinfo>
16 <title>Boost.Contract 1.0.0</title>
19 <emphasis><quote>Our field needs more formality, but the profession has not
20 realized it yet.</quote></emphasis>
25 <emphasis>-- Bertrand Meyer (see <link linkend="Meyer97_anchor">[Meyer97]</link>
30 This library implements <ulink url="http://en.wikipedia.org/wiki/Design_by_contract">contract
31 programming</ulink> (a.k.a., Design by Contract or DbC) <footnote id="boost_contract.f0">
33 Design by Contract (DbC) is a registered trademark of the Eiffel Software company
34 and it was first introduced by the Eiffel programming language (see <link linkend="Meyer97_anchor">[Meyer97]</link>).
36 </footnote> for the C++ programming language. All contract programming features
37 are supported by this library: Subcontracting, class invariants (also for static
38 and volatile member functions), postconditions (with old and return values),
39 preconditions, customizable actions on assertion failure (e.g., terminate the
40 program or throw exceptions), optional compilation of assertions, disable assertions
41 while already checking other assertions (to avoid infinite recursion), and more
42 (see <link linkend="boost_contract.contract_programming_overview.feature_summary">Feature
45 <section id="boost_contract.introduction">
46 <title><link linkend="boost_contract.introduction">Introduction</link></title>
48 Contract programming allows to specify preconditions, postconditions, and class
49 invariants that are automatically checked when functions are executed at run-time.
50 These conditions assert program specifications within the source code itself
51 allowing to find bugs more quickly during testing, making the code self-documenting,
52 and increasing overall software quality (see <link linkend="boost_contract.contract_programming_overview">Contract
53 Programming Overview</link>).
56 For example, consider the following function <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">inc</phrase></computeroutput>
57 that increments its argument <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">x</phrase></computeroutput>
58 by <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="number">1</phrase></computeroutput> and let's write its contract
59 using code comments (see <ulink url="../../example/features/introduction_comments.cpp"><literal moreinfo="none">introduction_comments.cpp</literal></ulink>):
62 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">void</phrase> <phrase role="identifier">inc</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase><phrase role="special">&</phrase> <phrase role="identifier">x</phrase><phrase role="special">)</phrase>
63 <phrase role="comment">// Precondition: x < std::numeric_limit<int>::max()</phrase>
64 <phrase role="comment">// Postcondition: x == oldof(x) + 1</phrase>
65 <phrase role="special">{</phrase>
66 <phrase role="special">++</phrase><phrase role="identifier">x</phrase><phrase role="special">;</phrase> <phrase role="comment">// Function body.</phrase>
67 <phrase role="special">}</phrase>
71 The precondition states that at function entry the argument <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">x</phrase></computeroutput>
72 must be strictly smaller than the maximum allowable value of its type (so it
73 can be incremented by <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="number">1</phrase></computeroutput> without
74 overflowing). The postcondition states that at function exit the argument
75 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">x</phrase></computeroutput> must be incremented by <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="number">1</phrase></computeroutput> with respect to the <emphasis>old value</emphasis>
76 that <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">x</phrase></computeroutput> had before executing
77 the function (indicated here by <literal moreinfo="none"><emphasis>oldof</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">(</phrase><phrase role="identifier">x</phrase><phrase role="special">)</phrase></computeroutput>).
78 Note that postconditions shall be checked only when the execution of the function
79 body does not throw an exception.
82 Now let's program this function and its contract using this library (see <ulink url="../../example/features/introduction.cpp"><literal moreinfo="none">introduction.cpp</literal></ulink>
83 and <link linkend="boost_contract.tutorial.non_member_functions">Non-Member
87 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">contract</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">></phrase>
89 <phrase role="keyword">void</phrase> <phrase role="identifier">inc</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase><phrase role="special">&</phrase> <phrase role="identifier">x</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
90 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">></phrase> <phrase role="identifier">old_x</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">x</phrase><phrase role="special">);</phrase> <phrase role="comment">// Old value.</phrase>
91 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">function</phrase><phrase role="special">()</phrase>
92 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
93 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">x</phrase> <phrase role="special"><</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">numeric_limits</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">>::</phrase><phrase role="identifier">max</phrase><phrase role="special">());</phrase> <phrase role="comment">// Line 17.</phrase>
94 <phrase role="special">})</phrase>
95 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
96 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">x</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_x</phrase> <phrase role="special">+</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase> <phrase role="comment">// Line 20.</phrase>
97 <phrase role="special">})</phrase>
98 <phrase role="special">;</phrase>
100 <phrase role="special">++</phrase><phrase role="identifier">x</phrase><phrase role="special">;</phrase> <phrase role="comment">// Function body.</phrase>
101 <phrase role="special">}</phrase>
105 When the above function <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">inc</phrase></computeroutput>
106 is called, this library will:
111 First, execute the functor passed to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">(...)</phrase></computeroutput>
112 that asserts <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">inc</phrase></computeroutput> precondition.
117 Then, execute <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">inc</phrase></computeroutput> body
118 (i.e., all the code that follows the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="special">...</phrase></computeroutput> declaration).
123 Last, execute the functor passed to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">(...)</phrase></computeroutput>
124 that asserts <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">inc</phrase></computeroutput> postcondition
125 (unless <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">inc</phrase></computeroutput> body threw
131 For example, if there is a bug in the code calling <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">inc</phrase></computeroutput>
132 so that the function is called with <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">x</phrase></computeroutput>
133 equal to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">numeric_limits</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">>::</phrase><phrase role="identifier">max</phrase><phrase role="special">()</phrase></computeroutput> then the program will terminate with an error
134 message similar to the following (and it will be evident that the bug is in
137 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude">precondition assertion "x < std::numeric_limits<int>::max()" failed: file "introduction.cpp", line 17
140 Instead, if there is a bug in the implementation of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">inc</phrase></computeroutput>
141 so that <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">x</phrase></computeroutput> is not incremented
142 by <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="number">1</phrase></computeroutput> after the execution of the
143 function body then the program will terminate with an error message similar
144 to the following (and it will be evident that the bug is in <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">inc</phrase></computeroutput>
145 body): <footnote id="boost_contract.introduction.f0">
147 In this example the function body is composed of a single trivial instruction
148 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">++</phrase><phrase role="identifier">x</phrase></computeroutput>
149 so it easy to check by visual inspection that it does not contain any bug
150 and it will always increment <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">x</phrase></computeroutput>
151 by <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="number">1</phrase></computeroutput> thus the function postcondition
152 will never fail. In real production code, function bodies are rarely this
153 simple and can hide bugs which make checking postconditions useful.
157 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude">postcondition assertion "x == *old_x + 1" failed: file "introduction.cpp", line 20
160 By default, when an assertion fails this library prints an error message such
161 the ones above to the standard error <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">cerr</phrase></computeroutput> and
162 terminates the program calling <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">terminate</phrase></computeroutput>
163 (this behaviour can be customized to take any user-specified action including
164 throwing exceptions, see <link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__">Throw
165 on Failures</link>). Note that the error messages printed by this library contain
166 all the information necessary to easily and uniquely identify the point in
167 the code at which contract assertions fail. <footnote id="boost_contract.introduction.f1">
169 <emphasis role="bold">Rationale:</emphasis> The assertion failure message
170 printed by this library follows a format similar to the message printed by
171 Clang when the C-style <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">assert</phrase></computeroutput>
178 C++11 lambda functions are necessary to use this library without manually
179 writing a significant amount of boiler-plate code to program functors that
180 assert the contracts (see <link linkend="boost_contract.extras.no_lambda_functions__no_c__11_">No
181 Lambda Functions</link>). That said, this library implementation does not
182 use C++11 features and should work on most modern C++ compilers (see <link linkend="boost_contract.getting_started">Getting Started</link>).
186 In addition to contracts for non-member functions as shown the in the example
187 above, this library allows to program contracts for constructors, destructors,
188 and member functions. These can check class invariants and can also <emphasis>subcontract</emphasis>
189 inheriting and extending contracts from base classes (see <ulink url="../../example/features/introduction_public.cpp"><literal moreinfo="none">introduction_public.cpp</literal></ulink>
190 and <link linkend="boost_contract.tutorial.public_function_overrides__subcontracting_">Public
191 Function Overrides</link>): <footnote id="boost_contract.introduction.f2">
193 The <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">pushable</phrase></computeroutput> base class is
194 used in this example just to show subcontracting, it is somewhat arbitrary
195 and it will likely not appear in real production code.
200 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">></phrase>
201 <phrase role="keyword">class</phrase> <phrase role="identifier">vector</phrase>
202 <phrase role="preprocessor">#define</phrase> <phrase role="identifier">BASES</phrase> <phrase role="keyword">public</phrase> <phrase role="identifier">pushable</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase>
203 <phrase role="special">:</phrase> <phrase role="identifier">BASES</phrase>
204 <phrase role="special">{</phrase>
205 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
206 <phrase role="keyword">typedef</phrase> <phrase role="identifier">BOOST_CONTRACT_BASE_TYPES</phrase><phrase role="special">(</phrase><phrase role="identifier">BASES</phrase><phrase role="special">)</phrase> <phrase role="identifier">base_types</phrase><phrase role="special">;</phrase> <phrase role="comment">// For subcontracting.</phrase>
207 <phrase role="preprocessor">#undef</phrase> <phrase role="identifier">BASES</phrase>
209 <phrase role="keyword">void</phrase> <phrase role="identifier">invariant</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Checked in AND with base class invariants.</phrase>
210 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special"><=</phrase> <phrase role="identifier">capacity</phrase><phrase role="special">());</phrase>
211 <phrase role="special">}</phrase>
213 <phrase role="keyword">virtual</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">push_back</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">value</phrase><phrase role="special">,</phrase>
214 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="comment">/* override */</phrase> <phrase role="special">{</phrase> <phrase role="comment">// For virtuals.</phrase>
215 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">unsigned</phrase><phrase role="special">></phrase> <phrase role="identifier">old_size</phrase> <phrase role="special">=</phrase>
216 <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">size</phrase><phrase role="special">());</phrase> <phrase role="comment">// Old values for virtuals.</phrase>
217 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special"><</phrase> <phrase role="comment">// For overrides.</phrase>
218 <phrase role="identifier">override_push_back</phrase><phrase role="special">>(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="special">&</phrase><phrase role="identifier">vector</phrase><phrase role="special">::</phrase><phrase role="identifier">push_back</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">,</phrase> <phrase role="identifier">value</phrase><phrase role="special">)</phrase>
219 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Checked in OR with base preconditions.</phrase>
220 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special"><</phrase> <phrase role="identifier">max_size</phrase><phrase role="special">());</phrase>
221 <phrase role="special">})</phrase>
222 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Checked in AND with base postconditions.</phrase>
223 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_size</phrase> <phrase role="special">+</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase>
224 <phrase role="special">})</phrase>
225 <phrase role="special">;</phrase>
227 <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">push_back</phrase><phrase role="special">(</phrase><phrase role="identifier">value</phrase><phrase role="special">);</phrase>
228 <phrase role="special">}</phrase>
229 <phrase role="identifier">BOOST_CONTRACT_OVERRIDE</phrase><phrase role="special">(</phrase><phrase role="identifier">push_back</phrase><phrase role="special">)</phrase> <phrase role="comment">// Define `override_push_back` above.</phrase>
231 <phrase role="comment">// Could program contracts for those as well.</phrase>
232 <phrase role="keyword">unsigned</phrase> <phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase> <phrase role="keyword">return</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">size</phrase><phrase role="special">();</phrase> <phrase role="special">}</phrase>
233 <phrase role="keyword">unsigned</phrase> <phrase role="identifier">max_size</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase> <phrase role="keyword">return</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">max_size</phrase><phrase role="special">();</phrase> <phrase role="special">}</phrase>
234 <phrase role="keyword">unsigned</phrase> <phrase role="identifier">capacity</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase> <phrase role="keyword">return</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">capacity</phrase><phrase role="special">();</phrase> <phrase role="special">}</phrase>
236 <phrase role="keyword">private</phrase><phrase role="special">:</phrase>
237 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase> <phrase role="identifier">vect_</phrase><phrase role="special">;</phrase>
238 <phrase role="special">};</phrase>
241 <bridgehead renderas="sect3" id="boost_contract.introduction.h0">
242 <phrase id="boost_contract.introduction.language_support"/><link linkend="boost_contract.introduction.language_support">Language
246 The authors of this library advocate for contracts to be added to the core
247 language. Adding contract programming to the C++ standard has a number of advantages
248 over any library implementation (shorter and more concise syntax to program
249 contracts, specify contracts in declarations instead of definitions, enforce
250 contract constant-correctness, expected faster compile- and run-time, vendors
251 could develop static analysis tools to recognize and check contracts statically
252 when possible, compiler optimizations could be improved based on contract conditions,
256 The <link linkend="P0380_anchor">[P0380]</link> proposal supports basic contract
257 programming, it was accepted and it will be included in C++20. This is undoubtedly
258 a step in the right direction, but unfortunately <link linkend="P0380_anchor">[P0380]</link>
259 only supports pre- and postconditions while missing important features such
260 as class invariants and old values in postconditions, not to mention the lack
261 of more advanced features like subcontracting (more complete proposals like
262 <link linkend="N1962_anchor">[N1962]</link> were rejected by the C++ standard
263 committee). All contracting programming features are instead supported by this
264 library (see <link linkend="boost_contract.contract_programming_overview.feature_summary">Feature
265 Summary</link> for a detailed comparison between the features supported by
266 this library and the ones listed in different contract programming proposals,
267 see <link linkend="boost_contract.bibliography">Bibliography</link> for a list
268 of references considered during the design and implementation of this library,
269 including the vast majority of contract programming proposals submitted to
270 the C++ standard committee).
273 <section id="boost_contract.full_table_of_contents">
274 <title><link linkend="boost_contract.full_table_of_contents">Full Table of Contents</link></title>
275 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_contract.introduction">Introduction</link>
276 <link linkend="boost_contract.full_table_of_contents">Full Table of Contents</link>
277 <link linkend="boost_contract.getting_started">Getting Started</link>
278 <link linkend="boost_contract.getting_started.this_documentation">This Documentation</link>
279 <link linkend="boost_contract.getting_started.compilers_and_platforms">Compilers and Platforms</link>
280 <link linkend="boost_contract.getting_started.code_organization">Code Organization</link>
281 <link linkend="boost_contract.getting_started.build">Build</link>
282 <link linkend="boost_contract.contract_programming_overview">Contract Programming Overview</link>
283 <link linkend="boost_contract.contract_programming_overview.assertions">Assertions</link>
284 <link linkend="boost_contract.contract_programming_overview.benefits_and_costs">Benefits and Costs</link>
285 <link linkend="boost_contract.contract_programming_overview.function_calls">Function Calls</link>
286 <link linkend="boost_contract.contract_programming_overview.public_function_calls">Public Function Calls</link>
287 <link linkend="boost_contract.contract_programming_overview.constructor_calls">Constructor Calls</link>
288 <link linkend="boost_contract.contract_programming_overview.destructor_calls">Destructor Calls</link>
289 <link linkend="boost_contract.contract_programming_overview.constant_correctness">Constant-Correctness</link>
290 <link linkend="boost_contract.contract_programming_overview.specifications_vs__implementation">Specifications vs. Implementation</link>
291 <link linkend="boost_contract.contract_programming_overview.on_contract_failures">On Contract Failures</link>
292 <link linkend="boost_contract.contract_programming_overview.feature_summary">Feature Summary</link>
293 <link linkend="boost_contract.tutorial">Tutorial</link>
294 <link linkend="boost_contract.tutorial.non_member_functions">Non-Member Functions</link>
295 <link linkend="boost_contract.tutorial.preconditions">Preconditions</link>
296 <link linkend="boost_contract.tutorial.postconditions">Postconditions</link>
297 <link linkend="boost_contract.tutorial.return_values">Return Values</link>
298 <link linkend="boost_contract.tutorial.old_values">Old Values</link>
299 <link linkend="boost_contract.tutorial.exception_guarantees">Exception Guarantees</link>
300 <link linkend="boost_contract.tutorial.class_invariants">Class Invariants</link>
301 <link linkend="boost_contract.tutorial.constructors">Constructors</link>
302 <link linkend="boost_contract.tutorial.destructors">Destructors</link>
303 <link linkend="boost_contract.tutorial.public_functions">Public Functions</link>
304 <link linkend="boost_contract.tutorial.virtual_public_functions">Virtual Public Functions</link>
305 <link linkend="boost_contract.tutorial.public_function_overrides__subcontracting_">Public Function Overrides (Subcontracting)</link>
306 <link linkend="boost_contract.tutorial.base_classes__subcontracting_">Base Classes (Subcontracting)</link>
307 <link linkend="boost_contract.tutorial.static_public_functions">Static Public Functions</link>
308 <link linkend="boost_contract.advanced">Advanced</link>
309 <link linkend="boost_contract.advanced.pure_virtual_public_functions">Pure Virtual Public Functions</link>
310 <link linkend="boost_contract.advanced.optional_return_values">Optional Return Values</link>
311 <link linkend="boost_contract.advanced.private_and_protected_functions">Private and Protected Functions</link>
312 <link linkend="boost_contract.advanced.friend_functions">Friend Functions</link>
313 <link linkend="boost_contract.advanced.function_overloads">Function Overloads</link>
314 <link linkend="boost_contract.advanced.lambdas__loops__code_blocks__and__constexpr__">Lambdas, Loops, Code Blocks (and <computeroutput><phrase role="keyword">constexpr</phrase></computeroutput>)</link>
315 <link linkend="boost_contract.advanced.implementation_checks">Implementation Checks</link>
316 <link linkend="boost_contract.advanced.old_values_copied_at_body">Old Values Copied at Body</link>
317 <link linkend="boost_contract.advanced.named_overrides">Named Overrides</link>
318 <link linkend="boost_contract.advanced.access_specifiers">Access Specifiers</link>
319 <link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__">Throw on Failures (and <computeroutput><phrase role="keyword">noexcept</phrase></computeroutput>)</link>
320 <link linkend="boost_contract.extras">Extras</link>
321 <link linkend="boost_contract.extras.old_value_requirements__templates_">Old Value Requirements (Templates)</link>
322 <link linkend="boost_contract.extras.assertion_requirements__templates_">Assertion Requirements (Templates)</link>
323 <link linkend="boost_contract.extras.volatile_public_functions">Volatile Public Functions</link>
324 <link linkend="boost_contract.extras.move_operations">Move Operations</link>
325 <link linkend="boost_contract.extras.unions">Unions</link>
326 <link linkend="boost_contract.extras.assertion_levels">Assertion Levels</link>
327 <link linkend="boost_contract.extras.disable_contract_checking">Disable Contract Checking</link>
328 <link linkend="boost_contract.extras.disable_contract_compilation__macro_interface_">Disable Contract Compilation (Macro Interface)</link>
329 <link linkend="boost_contract.extras.separate_body_implementation">Separate Body Implementation</link>
330 <link linkend="boost_contract.extras.no_lambda_functions__no_c__11_">No Lambda Functions (No C++11)</link>
331 <link linkend="boost_contract.extras.no_macros__and_no_variadic_macros_">No Macros (and No Variadic Macros)</link>
332 <link linkend="boost_contract.examples">Examples</link>
333 <ulink url="reference.html">Reference</ulink>
334 <link linkend="boost_contract.release_notes">Release Notes</link>
335 <link linkend="boost_contract.bibliography">Bibliography</link>
336 <link linkend="boost_contract.acknowledgments">Acknowledgments</link>
339 <section id="boost_contract.getting_started">
340 <title><link linkend="boost_contract.getting_started">Getting Started</link></title>
342 This section shows how to setup and start using this library.
344 <section id="boost_contract.getting_started.this_documentation">
345 <title><link linkend="boost_contract.getting_started.this_documentation">This
346 Documentation</link></title>
348 Programmers should be able to start using this library after reading the
349 <link linkend="boost_contract.introduction">Introduction</link>, <link linkend="boost_contract.getting_started">Getting
350 Started</link>, and <link linkend="boost_contract.tutorial">Tutorial</link>.
351 Other sections of this documentation (e.g., <link linkend="boost_contract.advanced">Advanced</link>
352 and <link linkend="boost_contract.extras">Extras</link>) can be consulted
353 at a later point to gain a more in-depth knowledge of the library. <link linkend="boost_contract.contract_programming_overview">Contract Programming
354 Overview</link> can be skipped by programmers that are already familiar with
355 the contract programming methodology.
358 Some of the source code listed in this documentation contains special code
359 comments of the form <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="comment">//[...</phrase></computeroutput>
360 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="comment">//]</phrase></computeroutput>. These mark sections
361 of the code that are automatically extracted from the source code and presented
362 as part of this documentation. <footnote id="boost_contract.getting_started.this_documentation.f0">
364 <emphasis role="bold">Rationale:</emphasis> This allows to make sure that
365 most of the example code presented in this documentation is always up-to-date,
366 builds and runs with the latest implementation of the library.
368 </footnote> It should be noted that the purpose of all examples of this documentation
369 is to illustrate how to use this library and not to show real production
373 Some footnotes are marked by the word "<emphasis role="bold">Rationale</emphasis>".
374 These explain some of the decisions made during the design and implementation
378 <section id="boost_contract.getting_started.compilers_and_platforms">
379 <title><link linkend="boost_contract.getting_started.compilers_and_platforms">Compilers
380 and Platforms</link></title>
382 In general, this library requires C++ compilers with a sound implementation
383 of SFINAE and other template meta-programming techniques supported by the
384 C++03 standard. It is possible to use this library without C++11 lambda functions
385 but a large amount of boiler-plate code is required to manually program separate
386 functors to specify preconditions, postconditions, etc. (so using this library
387 without C++11 lambda functions is possible but not recommended, see <link linkend="boost_contract.extras.no_lambda_functions__no_c__11_">No Lambda
388 Functions</link>). It is also possible to use this library without variadic
389 macros by manually programming a small amount of boiler-plate code (but most
390 if not all modern C++ compilers support variadic macros even before C++99
391 and C++11 so this should never be needed in practice, see <link linkend="boost_contract.extras.no_macros__and_no_variadic_macros_">No
395 Some parts of this documentation use the syntax <literal moreinfo="none"><emphasis>type-of</emphasis>(...)</literal>
396 to indicate an operator logically equivalent to C++11 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">decltype</phrase><phrase role="special">(...)</phrase></computeroutput>. However, this library implementation
397 does not actually use type deduction in these cases (because the library
398 internally already knows the types in question) so support for C++11 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">decltype</phrase></computeroutput> and other type-of implementations
399 are not actually required (that is why <literal moreinfo="none"><emphasis>type-of</emphasis></literal>
400 and not the real <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">decltype</phrase></computeroutput> operator
401 is used in this documentation).
404 This library has been developed and tested using:
409 Visual Studio 2015 on Windows (MSVC <literal moreinfo="none">cl</literal> version 19.00.24215.1).
414 GCC version 5.4.0 on Cygwin (with C++11 features enabled <literal moreinfo="none">-std=c++11</literal>).
419 Clang version 3.8.1 on Cygwin (with C++11 features enabled <literal moreinfo="none">-std=c++11</literal>).
424 For information on other compilers and platforms see the library <ulink url="http://www.boost.org/development/tests/master/developer/contract.html">regression
425 tests</ulink>. The development and maintenance of this library is hosted
426 on <ulink url="https://github.com/boostorg/contract">GitHub</ulink>.
429 <section id="boost_contract.getting_started.code_organization">
430 <title><link linkend="boost_contract.getting_started.code_organization">Code
431 Organization</link></title>
433 Let <literal moreinfo="none"><emphasis>boost-root</emphasis></literal> be the directory where
434 Boost source files were installed. This library flies are organized as follows:
436 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><emphasis>boost-root</emphasis>/libs/contract # Directory where this library files are.
437 build/ # Build files (using BJam).
438 doc/ # Documentation (using Boost.QuickBook).
439 example/ # Examples (also those listed in this documentation).
440 include/ # DO NOT USE: Use copies of these files from
441 boost/ # <emphasis>boost-root</emphasis>/boost/ instead:
442 contract.hpp # - Include all headers at once.
443 contract_macro.hpp # - Include library macro interface.
444 contract/ # - Header files that can be included one-by-one.
445 core/ # - Fundamental headers (usually indirectly included by other headers).
446 detail/ # - Implementation code (should never be included or used directly).
447 src/ # Library source code to be compiled.
451 All headers required by this library can be included at once by:
453 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">contract</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">></phrase>
456 Or, by the following when using the library macro interface (see <link linkend="boost_contract.extras.disable_contract_compilation__macro_interface_">Disable
457 Contract Compilation</link>):
459 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">contract_macro</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">></phrase>
462 Alternatively, all <literal moreinfo="none">boost/contract/*.hpp</literal> headers are independent
463 from one another and they can be selectively included one-by-one based on
464 the specific functionality of this library being used (but this was measured
465 to not make an appreciable difference in compile-time so <literal moreinfo="none">boost/contract.hpp</literal>
466 can be included directly in most cases). The <literal moreinfo="none">boost/contract/core/*.hpp</literal>
467 headers are not independent from other headers and they do not need to be
468 directly included in user code when <literal moreinfo="none">boost/contract.hpp</literal>
469 or <literal moreinfo="none">boost/contract/*.hpp</literal> headers are included already.
472 All files under <literal moreinfo="none">boost/contract/detail/</literal>, names in the
473 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">detail</phrase></computeroutput> namespace, macros starting with
474 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">BOOST_CONTRACT_DETAIL</phrase><phrase role="special">...</phrase></computeroutput>,
475 and all names starting with <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost_contract_detail</phrase><phrase role="special">...</phrase></computeroutput> (in any namespace, including user-defined
476 namespaces) are part of this library implementation and should never be used
477 directly in user code. Names starting with <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">BOOST_CONTRACT_ERROR</phrase><phrase role="special">...</phrase></computeroutput> are used by this library to report some
478 compile-time errors (so spotting these names in compiler error messages might
479 help troubleshooting).
482 <section id="boost_contract.getting_started.build">
483 <title><link linkend="boost_contract.getting_started.build">Build</link></title>
485 Let <literal moreinfo="none"><emphasis>boost-root</emphasis></literal> be the directory where
486 Boost source files were installed. This library is installed and compiled
487 as part of Boost using BJam.
491 It is strongly recommended to compile and use this library as a shared
492 library (a.k.a., Dynamically Linked Library or DLL) by defining the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">BOOST_ALL_DYN_LINK</phrase></computeroutput> macro (or at least
493 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_DYN_LINK">BOOST_CONTRACT_DYN_LINK</link></computeroutput>)
494 when building Boost. When using BJam to build Boost, this can be achieved
495 by the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">link</phrase><phrase role="special">=</phrase><phrase role="identifier">shared</phrase></computeroutput> parameter (which is already the
496 default so no extra parameter is actually needed for <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">bjam</phrase></computeroutput>).
499 It is also possible to compile and use this library as a static library
500 (by defining the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_STATIC_LINK">BOOST_CONTRACT_STATIC_LINK</link></computeroutput>
501 macro) or as a header-only library (by leaving both <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_DYN_LINK">BOOST_CONTRACT_DYN_LINK</link></computeroutput>
502 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_STATIC_LINK">BOOST_CONTRACT_STATIC_LINK</link></computeroutput>
503 undefined). However, this library is not guaranteed to always work correctly
504 in these cases. Specifically, this library might not correctly disable
505 contracts while checking other contracts and call the correct user-defined
506 contract failure handlers unless it is compiled as a shared library when
507 it is used across different program units (different programs, different
508 shared libraries in the same program, etc.).
511 <bridgehead renderas="sect4" id="boost_contract.getting_started.build.h0">
512 <phrase id="boost_contract.getting_started.build.linux_based_systems"/><link linkend="boost_contract.getting_started.build.linux_based_systems">Linux-Based
516 For example, to build all Boost libraries including this one (as shared libraries,
517 see also <ulink url="https://www.boost.org/doc/libs/1_70_0/more/getting_started">Boost
518 documentation</ulink>):
520 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude">$ cd <emphasis>boost-root</emphasis>
525 To compile and run the <ulink url="../../example/features/introduction.cpp"><literal moreinfo="none"><emphasis>boost-root</emphasis>/libs/contract/example/features/introduction.cpp</literal></ulink>
528 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude">$ cd <emphasis>boost-root</emphasis>/libs/contract/example
529 $ ../../../bjam features-introduction
532 To compile and run all this library's tests (this might take while):
534 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude">$ cd <emphasis>boost-root</emphasis>/libs/contract/test
538 To compile and run code that uses this library but without BJam (similarly
541 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude">$ cd /tmp
542 $ g++ -std=c++11 -D BOOST_CONTRACT_DYN_LINK -I <emphasis>boost-root</emphasis> <emphasis>boost-root</emphasis>/stage/lib/<emphasis>system-prefix</emphasis>boost_contract.dll <emphasis>boost-root</emphasis>/libs/contract/example/features/introduction.cpp -o introduction
543 $ export PATH=$PATH:<emphasis>boost-root</emphasis>/stage/lib
546 <bridgehead renderas="sect4" id="boost_contract.getting_started.build.h1">
547 <phrase id="boost_contract.getting_started.build.windows_based_systems"/><link linkend="boost_contract.getting_started.build.windows_based_systems">Windows-Based
551 For example, to build all Boost libraries including this one (as DLLs, see
552 also <ulink url="https://www.boost.org/doc/libs/1_70_0/more/getting_started">Boost
553 documentation</ulink>):
555 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude">>cd <emphasis>boost-root</emphasis>
560 To compile and run the <ulink url="../../example/features/introduction.cpp"><literal moreinfo="none"><emphasis>boost-root</emphasis>/libs/contract/example/features/introduction.cpp</literal></ulink>
563 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude">>cd <emphasis>boost-root</emphasis>\libs\contract\example
564 >..\..\..\bjam features-introduction
567 To compile and run all this library's tests (this might take while):
569 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude">>cd <emphasis>boost-root</emphasis>\libs\contract\test
573 To compile and run code that uses this library but without BJam:
575 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude">>cd C:\Temp
576 >cl /MDd /EHs /std:c++11 /D BOOST_CONTRACT_DYN_LINK /I <emphasis>boost-root</emphasis> /link /DLL /LIBPATH:<emphasis>boost-root</emphasis>\stage\lib <emphasis>boost-root</emphasis>\libs\contract\example\features\introduction.cpp /out:introduction
577 >set PATH=%PATH%;<emphasis>boost-root</emphasis>/stage/lib
582 <section id="boost_contract.contract_programming_overview">
583 <title><link linkend="boost_contract.contract_programming_overview">Contract
584 Programming Overview</link></title>
587 <emphasis><quote>It is absurd to make elaborate security checks on debugging
588 runs, when no trust is put in the results, and then remove them in production
589 runs, when an erroneous result could be expensive or disastrous. What would
590 we think of a sailing enthusiast who wears his life-jacket when training
591 on dry land but takes it off as soon as he goes to sea?</quote></emphasis>
596 <emphasis>-- Charles Antony Richard Hoare (see <link linkend="Hoare73_anchor">[Hoare73]</link>)</emphasis>
600 This section gives an overview of contract programming (see <link linkend="Meyer97_anchor">[Meyer97]</link>,
601 <link linkend="Mitchell02_anchor">[Mitchell02]</link>, and <link linkend="N1613_anchor">[N1613]</link>
602 for more extensive introductions to contract programming). Readers that already
603 have a basic understanding of contract programming can skip this section and
604 maybe come back to it after reading the <link linkend="boost_contract.tutorial">Tutorial</link>.
608 The objective of this library is not to convince programmers to use contract
609 programming. It is assumed that programmes understand the benefits and trade-offs
610 associated with contract programming and they have already decided to use
611 this methodology in their code. Then, this library aims to be the best and
612 more complete contract programming library for C++ (without using programs
613 and tools external to the C++ language and its preprocessor).
616 <section id="boost_contract.contract_programming_overview.assertions">
617 <title><link linkend="boost_contract.contract_programming_overview.assertions">Assertions</link></title>
619 Contract programming is characterized by the following assertion mechanisms:
624 <emphasis>Preconditions</emphasis>: These are logical conditions that
625 programmers expect to be true when a function is called (e.g., to check
626 constraints on function arguments). Operations that logically have no
627 preconditions (i.e., that are always well-defined for the entire domain
628 of their inputs) are also referred to as having a <emphasis>wide contract</emphasis>.
629 This is in contrast to operations that have preconditions which are also
630 referred to as having a <emphasis>narrow contract</emphasis> (note that
631 operations with truly narrow contracts are also expected to never throw
632 exceptions because the implementation body of these operations is always
633 expected to succeed after its preconditions are checked to be true).
634 <footnote id="boost_contract.contract_programming_overview.assertions.f0">
636 The nomenclature of wide and narrow contracts has gained some popularity
637 in recent years in the C++ community (appearing in a number of more
638 recent proposals to add contract programming to the C++ standard, see
639 <link linkend="boost_contract.bibliography">Bibliography</link>). This
640 nomenclature is perfectly reasonable but it is not often used in this
641 document just because the authors usually prefer to explicitly say
642 "this operation has no preconditions..." or "this operation
643 has preconditions..." (this is just a matter of taste).
650 <emphasis>Postconditions</emphasis>: These are logical conditions that
651 programmers expect to be true when a function exits without throwing
652 an exception (e.g., to check the result and any side effect that a function
653 might have). Postconditions can access the function return value (for
654 non-void functions) and also <emphasis>old values</emphasis> (which are
655 the values that expressions had before the function implementation was
661 <emphasis>Exception guarantees</emphasis>: These are logical conditions
662 that programmers except to be true when a function exits throwing an
663 exception. Exception guarantees can access old values (but not the function
664 return value). <footnote id="boost_contract.contract_programming_overview.assertions.f1">
666 <emphasis role="bold">Rationale:</emphasis> Contract assertions for
667 exception guarantees were first introduced by this library, they are
668 not part of <link linkend="N1962_anchor">[N1962]</link> or other references
669 listed in the <link linkend="boost_contract.bibliography">Bibliography</link>
670 (even if exception safety guarantees have long been part of C++ STL
678 <emphasis>Class invariants</emphasis>: These are logical conditions that
679 programmers expect to be true after a constructor exits without throwing
680 an exception, before and after the execution of every non-static public
681 function (even if they throw exceptions), before the destructor is executed
682 (and also after the destructor is executed but only when the destructor
683 throws an exception). Class invariants define valid states for all objects
684 of a given class. It is possible to specify a different set of class
685 invariants for volatile public functions, namely <emphasis>volatile class
686 invariants</emphasis>. It is also possible to specify <emphasis>static
687 class invariants</emphasis> which are excepted to be true before and
688 after the execution of any constructor, destructor (even if it does not
689 throw an exception), and public function (even if static). <footnote id="boost_contract.contract_programming_overview.assertions.f2">
691 <emphasis role="bold">Rationale:</emphasis> Static and volatile class
692 invariants were first introduced by this library (simply to reflect
693 the fact that C++ supports also static and volatile public functions),
694 they are not part of <link linkend="N1962_anchor">[N1962]</link> or
695 other references listed in the <link linkend="boost_contract.bibliography">Bibliography</link>.
702 <emphasis>Subcontracting</emphasis>: This indicates that preconditions
703 cannot be strengthen, while postconditions and class invariants cannot
704 be weaken when a public function in a derived class overrides public
705 functions in one or more of its base classes (this is formally defined
706 according to the <ulink url="http://en.wikipedia.org/wiki/Liskov_substitution_principle">substitution
712 The actual function implementation code, that remains outside of these contract
713 assertions, is often referred to as the <emphasis>function body</emphasis>
714 in contract programming.
717 Class invariants can also be used to specify <emphasis>basic</emphasis> exception
718 safety guarantees for an object (because they are checked at exit of public
719 functions even when those throw exceptions). Contract assertions for exception
720 guarantees can be used to specify <emphasis>strong</emphasis> exception safety
721 guarantees for a given operation on the same object.
724 It is also a common requirement for contract programming to automatically
725 disable contract checking while already checking assertions from another
726 contract (in order to avoid infinite recursion while checking contract assertions).
730 This library implements this requirement but in order to globally disable
731 assertions while checking another assertion some kind of global arbitrating
732 variable needs to be used by this library implementation. This library
733 will automatically protect such a global variable from race conditions
734 in multi-threated programs, but this will effectively introduce a global
735 lock in the program (the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394999743888">BOOST_CONTRACT_DISABLE_THREADS</link></computeroutput>
736 macro can be defined to disable this global lock but at the risk of incurring
737 in race conditions). <footnote id="boost_contract.contract_programming_overview.assertions.f3">
739 <emphasis role="bold">Rationale:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394999743888">BOOST_CONTRACT_DISABLE_THREADS</link></computeroutput>
740 is named after <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">BOOST_DISABLE_THREADS</phrase></computeroutput>.
746 In general, it is recommended to specify different contract conditions using
747 separate assertion statements and not to group them together into a single
748 condition using logical operators (<computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">&&</phrase></computeroutput>,
749 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">||</phrase></computeroutput>, etc.). This is because when
750 contract conditions are programmed together in a single assertion using logical
751 operators, it might not be clear which condition actually failed in case
752 the entire assertion fails at run-time.
754 <bridgehead renderas="sect4" id="boost_contract.contract_programming_overview.assertions.h0">
755 <phrase id="boost_contract.contract_programming_overview.assertions.c_style_assertions"/><link linkend="boost_contract.contract_programming_overview.assertions.c_style_assertions">C-Style
759 A limited form of contract programming (typically some form of precondition
760 and basic postcondition checking) can be achieved using the C-style <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">assert</phrase></computeroutput> macro. Using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">assert</phrase></computeroutput>
761 is common practice for many programmers but it suffers of the following limitations:
766 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">assert</phrase></computeroutput> does not distinguish
767 between preconditions and postconditions. In well-tested production code,
768 postconditions can usually be disabled trusting the correctness of the
769 implementation while preconditions might still need to remain enabled
770 because of possible changes in the calling code (e.g., postconditions
771 of a given library could be disabled after testing while keeping the
772 library preconditions enabled given that future changes in the user code
773 that calls the library cannot be anticipated). Using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">assert</phrase></computeroutput>
774 it is not possible to selectively disable only postconditions and all
775 assertions must be disabled at once.
780 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">assert</phrase></computeroutput> requires to manually
781 program extra code to correctly check postconditions (specifically to
782 handle functions with multiple return statements, to not check postconditions
783 when functions throw exceptions, and to implement old values).
788 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">assert</phrase></computeroutput> requires to manually
789 program extra code to check class invariants (extra member functions,
795 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">assert</phrase></computeroutput> does not support
801 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">assert</phrase></computeroutput> calls are usually
802 scattered within function implementations thus the asserted conditions
803 are not immediately visible in their entirety by programmers (as they
804 are instead when the assertions appear in the function declaration or
805 at least at the very top of the function definition).
810 Contract programming does not suffer of these limitations.
813 <section id="boost_contract.contract_programming_overview.benefits_and_costs">
814 <title><link linkend="boost_contract.contract_programming_overview.benefits_and_costs">Benefits
815 and Costs</link></title>
816 <bridgehead renderas="sect4" id="boost_contract.contract_programming_overview.benefits_and_costs.h0">
817 <phrase id="boost_contract.contract_programming_overview.benefits_and_costs.benefits"/><link linkend="boost_contract.contract_programming_overview.benefits_and_costs.benefits">Benefits</link>
820 The main use of contract programming is to improve software quality. <link linkend="Meyer97_anchor">[Meyer97]</link> discusses how contract programming
821 can be used as the basic tool to write <quote>correct</quote> software.
822 <link linkend="Stroustrup94_anchor">[Stroustrup94]</link> discusses the key
823 importance of class invariants plus advantages and disadvantages of preconditions
827 The following is a short summary of benefits associated with contract programming
828 inspired mainly by <link linkend="N1613_anchor">[N1613]</link>:
833 Preconditions and postconditions: Using function preconditions and postconditions,
834 programmers can give a precise semantic description of what a function
835 requires at its entry and what it ensures at its exit (if it does not
836 throw an exception). In particular, using postcondition old values, contract
837 programming provides a mechanism that allows programmers to compare values
838 of an expression before and after the function body execution. This mechanism
839 is powerful enough to enable programmers to express many correctness
840 constraints within the code itself, constraints that would otherwise
841 have to be captured at best only informally by documentation.
846 Class invariants: Using class invariants, programmers can describe what
847 to expect from a class and the logic dependencies between the class members.
848 It is the job of the constructor to ensure that the class invariants
849 are satisfied when the object is first created. Then the implementation
850 of the member functions can be largely simplified as they can be written
851 knowing that the class invariants are satisfied because contract programming
852 checks them before and after the execution of every public function.
853 Finally, the destructor makes sure that the class invariants held for
854 the entire life of the object checking the class invariants one last
855 time before the object is destructed. Class invariants can also be used
856 as a criteria for good abstractions: If it is not possible to specify
857 an invariant, it might be an indication that the design abstraction maybe
858 be poor and it should not have been made into a class (maybe a namespace
859 would have sufficed instead).
864 Self-documenting code: Contracts are part of the source code, they are
865 checked at run-time so they are always up-to-date with the code itself.
866 Therefore program specifications, as documented by the contracts, can
867 be trusted to always be up-to-date with the implementation.
872 Easier debugging: Contract programming can provide a powerful debugging
873 facility because, if contracts are well-written, bugs will cause contract
874 assertions to fail exactly where the problem first occurs instead than
875 at some later stage of the program execution in an apparently unrelated
876 (and often hard to debug) manner. Note that a precondition failure points
877 to a bug in the function caller, a postcondition failure points instead
878 to a bug in the function implementation. <footnote id="boost_contract.contract_programming_overview.benefits_and_costs.f0">
880 Of course, if contracts are ill-written then contract programming is
881 of little use. However, it is less likely to have a bug in both the
882 function body and the contract than in the function body alone. For
883 example, consider the validation of a result in postconditions. Validating
884 the return value might seem redundant, but in this case we actually
885 want that redundancy. When programmers write a function, there is a
886 certain probability that they make a mistake in implementing the function
887 body. When programmers specify the result of the function in the postconditions,
888 there is also a certain probability that they make a mistake in writing
889 the contract. However, the probability that programmers make a mistake
890 twice (in both the body <emphasis>and</emphasis> the contract) is in
891 general lower than the probability that the mistake is made only once
892 (in either the body <emphasis>or</emphasis> the contract).
899 Easier testing: Contract programming facilitates testing because a contract
900 naturally specifies what a test should check. For example, preconditions
901 of a function state which inputs cause the function to fail and postconditions
902 state which outputs are produced by the function on successful exit (contract
903 programming should be seen as a tool to complement and guide, but obviously
904 not to replace, testing).
909 Formal design: Contract programming can serve to reduce the gap between
910 designers and programmers by providing a precise and unambiguous specification
911 language in terms of contract assertions. Moreover, contracts can make
912 code reviews easier by clarifying some of the semantics and usage of
918 Formalize inheritance: Contract programming formalizes the virtual function
919 overriding mechanism using subcontracting as justified by the <ulink url="http://en.wikipedia.org/wiki/Liskov_substitution_principle">substitution
920 principle</ulink>. This keeps the base class programmers in control as
921 overriding functions always have to fully satisfy the contracts of their
927 Replace defensive programming: Contract programming assertions can replace
928 <ulink url="http://en.wikipedia.org/wiki/Defensive_programming">defensive
929 programming</ulink> checks localizing these checks within the contracts
930 and making the code more readable.
935 Of course, not all formal contract specifications can be asserted in C++.
936 For example, in C++ is it not possible to assert the validity of an iterator
937 range in the general case (because the only way to check if two iterators
938 form a valid range is to keep incrementing the first iterator until it reaches
939 the second iterator, but if the iterator range is invalid then such a code
940 would render undefined behaviour or run forever instead of failing an assertion).
941 Nevertheless, a large amount of contract assertions can be successfully programmed
942 in C++ as illustrated by the numerous examples in this documentation and
943 from the literature (for example see how much of STL <link linkend="N1962_vector_anchor"><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">vector</phrase></computeroutput></link> contract assertions can actually
944 be programmed in C++ using this library).
946 <bridgehead renderas="sect4" id="boost_contract.contract_programming_overview.benefits_and_costs.h1">
947 <phrase id="boost_contract.contract_programming_overview.benefits_and_costs.costs"/><link linkend="boost_contract.contract_programming_overview.benefits_and_costs.costs">Costs</link>
950 In general, contract programming benefits come at the cost of performance
951 as discussed in detail by both <link linkend="Stroustrup94_anchor">[Stroustrup94]</link>
952 and <link linkend="Meyer97_anchor">[Meyer97]</link>. While performance trade-offs
953 should be carefully considered depending on the specific application domain,
954 software quality cannot be sacrificed: It is difficult to see value in software
955 that quickly and efficiently provides incorrect results.
958 The run-time performances are negatively impacted by contract programming
959 mainly because of extra time require to:
964 Check the asserted conditions.
969 Copy old values when these are used in postconditions or exception guarantees.
974 Call additional functors that check preconditions, postconditions, exception
975 guarantees, class invariants, etc. (these can add up to many extra calls
976 especially when using subcontracting).
982 In general, contracts introduce at least three extra functor calls to check
983 preconditions, postconditions, and exception guarantees for any given non-member
984 function call. Public functions introduce also two more function calls
985 to check class invariants (at entry and at exit). For subcontracting, these
986 extra calls (some of which become virtual calls) are repeated for the number
987 of functions being overridden from the base classes (possibly deep in the
988 inheritance tree). In addition to that, this library introduces a number
989 of function calls internal to its implementation in order to properly check
994 To mitigate the run-time performance impact, programmers can selectively
995 disable run-time checking of some of the contract assertions. Programmers
996 will have to decide based on the performance trade-offs required by their
997 specific applications, but a reasonable approach often is to (see <link linkend="boost_contract.extras.disable_contract_checking">Disable
998 Contract Checking</link>):
1003 Always write contracts to clarify the semantics of the design embedding
1004 the specifications directly in the code and making the code self-documenting.
1009 Check preconditions, postconditions, class invariants, and maybe even
1010 exception guarantees during initial testing.
1015 Check only preconditions (and maybe class invariants, but not postconditions
1016 and exception guarantees) during release testing and for the final release.
1021 This approach is usually reasonable because in well-tested production code,
1022 validating the function body implementation using postconditions is rarely
1023 needed since the function has shown itself to be <quote>correct</quote> during
1024 testing. On the other hand, checking function arguments using preconditions
1025 is always needed because of changes that can be made to the calling code
1026 (without having to necessarily re-test and re-release the called code). Furthermore,
1027 postconditions and also exception guarantees, with related old value copies,
1028 are often computationally more expensive to check than preconditions and
1032 <section id="boost_contract.contract_programming_overview.function_calls">
1033 <title><link linkend="boost_contract.contract_programming_overview.function_calls">Function
1034 Calls</link></title>
1035 <bridgehead renderas="sect4" id="boost_contract.contract_programming_overview.function_calls.h0">
1036 <phrase id="boost_contract.contract_programming_overview.function_calls.non_member_functions"/><link linkend="boost_contract.contract_programming_overview.function_calls.non_member_functions">Non-Member
1040 A call to a non-member function with a contract executes the following steps
1041 (see <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.function">boost::contract::function</link></computeroutput>):
1043 <orderedlist inheritnum="ignore" continuation="restarts">
1046 Check function preconditions.
1051 Execute the function body.
1056 If the body did not throw an exception, check function postconditions.
1061 Else, check function exception guarantees.
1065 <bridgehead renderas="sect4" id="boost_contract.contract_programming_overview.function_calls.h1">
1066 <phrase id="boost_contract.contract_programming_overview.function_calls.private_and_protected_functions"/><link linkend="boost_contract.contract_programming_overview.function_calls.private_and_protected_functions">Private
1067 and Protected Functions</link>
1070 Private and protected functions do not have to satisfy class invariants because
1071 these functions are part of the class implementation and not of the class
1072 public interface. Furthermore, the <ulink url="http://en.wikipedia.org/wiki/Liskov_substitution_principle">substitution
1073 principle</ulink> does not apply to private and protected functions because
1074 these functions are not accessible to the user at the calling site where
1075 the <ulink url="http://en.wikipedia.org/wiki/Liskov_substitution_principle">substitution
1076 principle</ulink> applies.
1079 Therefore, calls to private and protected functions with contracts execute
1080 the same steps as the ones indicated above for non-member functions (checking
1081 only preconditions and postconditions, without checking class invariants
1082 and without subcontracting).
1085 <section id="boost_contract.contract_programming_overview.public_function_calls">
1086 <title><link linkend="boost_contract.contract_programming_overview.public_function_calls">Public
1087 Function Calls</link></title>
1088 <bridgehead renderas="sect4" id="boost_contract.contract_programming_overview.public_function_calls.h0">
1089 <phrase id="boost_contract.contract_programming_overview.public_function_calls.overriding_public_functions"/><link linkend="boost_contract.contract_programming_overview.public_function_calls.overriding_public_functions">Overriding
1090 Public Functions</link>
1093 Let's consider a public function in a derived class that overrides public
1094 virtual functions declared by its public base classes (because of C++ multiple
1095 inheritance, the function could override from more than one of its base classes).
1096 We refer to the function in the derived class as the <emphasis>overriding
1097 function</emphasis>, and to the set of base classes containing all the <emphasis>overridden
1098 functions</emphasis> as <emphasis>overridden bases</emphasis>.
1101 When subcontracting, overridden functions are searched (at compile-time)
1102 deeply in all public branches of the inheritance tree (i.e., not just the
1103 derived class' direct public parents are inspected, but also all its public
1104 grandparents, etc.). In case of multiple inheritance, this search also extends
1105 (at compile-time) widely to all public trees of the multiple inheritance
1106 forest (multiple public base classes are searched following their order of
1107 declaration in the derived class' inheritance list). As usual with C++ multiple
1108 inheritance, this search could result in multiple overridden functions and
1109 therefore in subcontracting from multiple public base classes. Note that
1110 only public base classes are considered for subcontracting because private
1111 and protected base classes are not accessible to the user at the calling
1112 site where the <ulink url="http://en.wikipedia.org/wiki/Liskov_substitution_principle">substitution
1113 principle</ulink> applies.
1116 A call to the overriding public function with a contract executes the following
1117 steps (see <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>):
1119 <orderedlist inheritnum="ignore" continuation="restarts">
1122 Check static class invariants <link linkend="and_anchor"><literal moreinfo="none"><emphasis>AND</emphasis></literal></link>
1123 non-static class invariants for all overridden bases, <link linkend="and_anchor"><literal moreinfo="none"><emphasis>AND</emphasis></literal></link>
1124 then check the derived class static <link linkend="and_anchor"><literal moreinfo="none"><emphasis>AND</emphasis></literal></link>
1125 non-static invariants.
1130 Check preconditions of overridden public functions from all overridden
1131 bases in <link linkend="or_anchor"><literal moreinfo="none"><emphasis>OR</emphasis></literal></link>
1132 with each other, <link linkend="or_anchor"><literal moreinfo="none"><emphasis>OR</emphasis></literal></link>
1133 else check the overriding function preconditions in the derived class.
1138 Execute the overriding function body.
1143 Check static class invariants <link linkend="and_anchor"><literal moreinfo="none"><emphasis>AND</emphasis></literal></link>
1144 non-static class invariants for all overridden bases, <link linkend="and_anchor"><literal moreinfo="none"><emphasis>AND</emphasis></literal></link>
1145 then check the derived class static <link linkend="and_anchor"><literal moreinfo="none"><emphasis>AND</emphasis></literal></link>
1146 non-static invariants (even if the body threw an exception).
1151 If the body did not throw an exception, check postconditions of overridden
1152 public functions from all overridden bases in <link linkend="and_anchor"><literal moreinfo="none"><emphasis>AND</emphasis></literal></link>
1153 with each other, <link linkend="and_anchor"><literal moreinfo="none"><emphasis>AND</emphasis></literal></link>
1154 then check the overriding function postconditions in the derived class.
1159 Else, check exception guarantees of overridden public functions from
1160 all overridden bases in <link linkend="and_anchor"><literal moreinfo="none"><emphasis>AND</emphasis></literal></link>
1161 with each other, <link linkend="and_anchor"><literal moreinfo="none"><emphasis>AND</emphasis></literal></link>
1162 then check the overriding function exception guarantees in the derived
1168 Volatile public functions check static class invariants <link linkend="and_anchor"><literal moreinfo="none"><emphasis>AND</emphasis></literal></link>
1169 volatile class invariants instead. Preconditions and postconditions of volatile
1170 public functions and volatile class invariants access the object as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">volatile</phrase></computeroutput>.
1173 Class invariants are checked before preconditions and postconditions so programming
1174 precondition and postcondition assertions can be simplified assuming that
1175 class invariants are satisfied already (e.g., if class invariants assert
1176 that a pointer cannot be null then preconditions and postconditions can safety
1177 dereference that pointer without additional checking). Similarly, static
1178 class invariants are checked before non-static class invariants so programming
1179 non-static class invariant (volatile and non) can be simplified assuming
1180 that static class invariants are satisfied already. Furthermore, subcontracting
1181 checks contracts of public base classes before checking the derived class
1182 contracts so programming derived class contract assertions can be simplified
1183 by assuming that public base class contracts are satisfied already.
1187 <anchor id="and_anchor"/><anchor id="or_anchor"/>In this documentation
1188 <link linkend="and_anchor"><literal moreinfo="none"><emphasis>AND</emphasis></literal></link>
1189 and <link linkend="or_anchor"><literal moreinfo="none"><emphasis>OR</emphasis></literal></link>
1190 indicate the logic <emphasis>and</emphasis> and <emphasis>or</emphasis>
1191 operations evaluated in <emphasis>short-circuit</emphasis>. For example:
1192 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">p</phrase></computeroutput> <link linkend="and_anchor"><literal moreinfo="none"><emphasis>AND</emphasis></literal></link>
1193 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">q</phrase></computeroutput> is true if and only if
1194 both <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">p</phrase></computeroutput> and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">q</phrase></computeroutput> are true, but <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">q</phrase></computeroutput>
1195 is never evaluated when <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">p</phrase></computeroutput>
1196 is false; <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">p</phrase></computeroutput> <link linkend="or_anchor"><literal moreinfo="none"><emphasis>OR</emphasis></literal></link>
1197 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">q</phrase></computeroutput> is true if and only if
1198 either <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">p</phrase></computeroutput> or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">q</phrase></computeroutput> are true, but <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">q</phrase></computeroutput>
1199 is never evaluated when <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">p</phrase></computeroutput>
1203 As indicated by the steps above and in accordance with the <ulink url="http://en.wikipedia.org/wiki/Liskov_substitution_principle">substitution
1204 principle</ulink>, subcontracting checks preconditions in <link linkend="or_anchor"><literal moreinfo="none"><emphasis>OR</emphasis></literal></link>
1205 while class invariants, postconditions, and exceptions guarantees are checked
1206 in <link linkend="and_anchor"><literal moreinfo="none"><emphasis>AND</emphasis></literal></link>
1207 with preconditions, class invariants, postconditions, and exceptions guarantees
1208 of base classes respectively.
1211 <bridgehead renderas="sect4" id="boost_contract.contract_programming_overview.public_function_calls.h1">
1212 <phrase id="boost_contract.contract_programming_overview.public_function_calls.non_overriding_public_functions"/><link linkend="boost_contract.contract_programming_overview.public_function_calls.non_overriding_public_functions">Non-Overriding
1213 Public Functions</link>
1216 A call to a non-static public function with a contract (that does not override
1217 functions from any of its public base classes) executes the following steps
1218 (see <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>):
1220 <orderedlist inheritnum="ignore" continuation="restarts">
1223 Check class static <link linkend="and_anchor"><literal moreinfo="none"><emphasis>AND</emphasis></literal></link>
1224 non-static invariants (but none of the invariants from base classes).
1229 Check function preconditions (but none of the preconditions from functions
1235 Execute the function body.
1240 Check the class static <link linkend="and_anchor"><literal moreinfo="none"><emphasis>AND</emphasis></literal></link>
1241 non-static invariants (even if the body threw an exception, but none
1242 of the invariants from base classes).
1247 If the body did not throw an exception, check function postconditions
1248 (but none of the postconditions from functions in base classes).
1253 Else, check function exception guarantees (but none of the exception
1254 guarantees from functions in base classes).
1259 Volatile public functions check static class invariants <link linkend="and_anchor"><literal moreinfo="none"><emphasis>AND</emphasis></literal></link>
1260 volatile class invariants instead. Preconditions and postconditions of volatile
1261 functions and volatile class invariants access the object as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">volatile</phrase></computeroutput>.
1264 Class invariants are checked because this function is part of the class public
1265 interface. However, none of the contracts of the base classes are checked
1266 because this function does not override any functions from any of the public
1267 base classes (so the <ulink url="http://en.wikipedia.org/wiki/Liskov_substitution_principle">substitution
1268 principle</ulink> does not require to subcontract in this case).
1270 <bridgehead renderas="sect4" id="boost_contract.contract_programming_overview.public_function_calls.h2">
1271 <phrase id="boost_contract.contract_programming_overview.public_function_calls.static_public_functions"/><link linkend="boost_contract.contract_programming_overview.public_function_calls.static_public_functions">Static
1272 Public Functions</link>
1275 A call to a static public function with a contract executes the following
1276 steps (see <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>):
1278 <orderedlist inheritnum="ignore" continuation="restarts">
1281 Check static class invariants (but not the non-static invariants and
1282 none of the invariants from base classes).
1287 Check function preconditions (but none of the preconditions from functions
1293 Execute the function body.
1298 Check static class invariants (even if the body threw an exception, but
1299 not the non-static invariants and none of the invariants from base classes).
1304 If the body did not throw an exception, check function postconditions
1305 (but none of the postconditions from functions in base classes).
1310 Else, check function exception guarantees (but none of the exception
1311 guarantees from functions in base classes).
1316 Class invariants are checked because this function is part of the class public
1317 interface, but only static class invariants can be checked (because this
1318 is a static function so it cannot access the object that would instead be
1319 required to check non-static class invariants, volatile or not). Furthermore,
1320 static functions cannot override any function so the <ulink url="http://en.wikipedia.org/wiki/Liskov_substitution_principle">substitution
1321 principle</ulink> does not apply and they do not subcontract.
1324 Preconditions and postconditions of static functions and static class invariants
1325 cannot access the object (because they are checked from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">static</phrase></computeroutput>
1329 <section id="boost_contract.contract_programming_overview.constructor_calls">
1330 <title><link linkend="boost_contract.contract_programming_overview.constructor_calls">Constructor
1331 Calls</link></title>
1333 A call to a constructor with a contract executes the following steps (see
1334 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.constructor_precondition">boost::contract::constructor_precondition</link></computeroutput>
1335 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.constructor">boost::contract::constructor</link></computeroutput>):
1337 <orderedlist inheritnum="ignore" continuation="restarts">
1340 Check constructor preconditions (but these cannot access the object because
1341 the object is not constructed yet).
1346 Execute the constructor member initialization list (if present).
1347 <orderedlist inheritnum="ignore" continuation="restarts">
1350 Construct any base class (public or not) according with C++ construction
1351 mechanism and also check the contracts of these base constructors
1352 (according with steps similar to the ones listed here).
1360 Check static class invariants (but not the non-static or volatile class
1361 invariants, because the object is not constructed yet).
1366 Execute the constructor body.
1371 Check static class invariants (even if the body threw an exception).
1376 If the body did not throw an exception:
1377 <orderedlist inheritnum="ignore" continuation="restarts">
1380 Check non-static <link linkend="and_anchor"><literal moreinfo="none"><emphasis>AND</emphasis></literal></link>
1381 volatile class invariants (because the object is now successfully
1387 Check constructor postconditions (but these cannot access the object
1388 old value <literal moreinfo="none"><emphasis>oldof</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">(*</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase></computeroutput> because the object was not constructed
1389 before the execution of the constructor body).
1397 Else, check constructor exception guarantees (but these cannot access
1398 the object old value <literal moreinfo="none"><emphasis>oldof</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">(*</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase></computeroutput> because the object was not constructed
1399 before the execution of the constructor body, plus they can only access
1400 class' static members because the object has not been successfully constructed
1401 given the constructor body threw an exception in this case).
1406 Constructor preconditions are checked before executing the member initialization
1407 list so programming these initializations can be simplified assuming the
1408 constructor preconditions are satisfied (e.g., constructor arguments can
1409 be validated by the constructor preconditions before they are used to initialize
1410 base classes and data members).
1413 As indicated in step 2.a. above, C++ object construction mechanism will automatically
1414 check base class contracts when these bases are initialized (no explicit
1415 subcontracting behaviour is required here).
1418 <section id="boost_contract.contract_programming_overview.destructor_calls">
1419 <title><link linkend="boost_contract.contract_programming_overview.destructor_calls">Destructor
1420 Calls</link></title>
1422 A call to a destructor with a contract executes the following steps (see
1423 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.destructor">boost::contract::destructor</link></computeroutput>):
1425 <orderedlist inheritnum="ignore" continuation="restarts">
1428 Check static class invariants <link linkend="and_anchor"><literal moreinfo="none"><emphasis>AND</emphasis></literal></link>
1429 non-static <link linkend="and_anchor"><literal moreinfo="none"><emphasis>AND</emphasis></literal></link>
1430 volatile class invariants.
1435 Execute the destructor body (destructors have no parameters and they
1436 can be called at any time after object construction so they have no preconditions).
1441 Check static class invariants (even if the body threw an exception).
1446 If the body did not throw an exception:
1447 <orderedlist inheritnum="ignore" continuation="restarts">
1450 Check destructor postconditions (but these can only access class'
1451 static members and the object old value <literal moreinfo="none"><emphasis>oldof</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">(*</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase></computeroutput> because the object has been destroyed
1452 after successful execution of the destructor body). <footnote id="boost_contract.contract_programming_overview.destructor_calls.f0">
1454 <emphasis role="bold">Rationale:</emphasis> Postconditions for
1455 destructors are not part of <link linkend="N1962_anchor">[N1962]</link>
1456 or other references listed in the <link linkend="boost_contract.bibliography">Bibliography</link>
1457 (but with respect to <link linkend="Meyer97_anchor">[Meyer97]</link>
1458 it should be noted that Eiffel does not support static data members
1459 and that might by why destructors do not have postconditions
1460 in Eiffel). However, in principle there could be uses for destructor
1461 postconditions so this library supports postconditions for destructors
1462 (e.g., a class that counts object instances could use destructor
1463 postconditions to assert that an instance counter stored in a
1464 static data member is decreased by <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="number">1</phrase></computeroutput>
1465 because the object has been destructed).
1472 Destroy any base class (public or not) according with C++ destruction
1473 mechanism and also check the contracts of these base destructors
1474 (according with steps similar to the ones listed here).
1482 Else (even if destructors should rarely, if ever, be allowed to throw
1484 <orderedlist inheritnum="ignore" continuation="restarts">
1487 Check non-static <link linkend="and_anchor"><literal moreinfo="none"><emphasis>AND</emphasis></literal></link>
1488 volatile class invariants (because the object was not successfully
1489 destructed so it still exists and should satisfy its invariants).
1494 Check destructor exception guarantees.
1502 As indicated in step 4.b. above, C++ object destruction mechanism will automatically
1503 check base class contracts when the destructor exits without throwing an
1504 exception (no explicit subcontracting behaviour is required here).
1508 Given that C++ allows destructors to throw, this library handles the case
1509 when the destructor body throws an exception as indicated above. However,
1510 in order to comply with STL exception safety guarantees and good C++ programming
1511 practices, programmers should implement destructor bodies to rarely, if
1512 ever, throw exceptions (in fact destructors are implicitly declared <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">noexcept</phrase></computeroutput> in C++11).
1516 <section id="boost_contract.contract_programming_overview.constant_correctness">
1517 <title><link linkend="boost_contract.contract_programming_overview.constant_correctness">Constant-Correctness</link></title>
1519 Contracts should not be allowed to modify the program state because they
1520 are only responsible to check (and not to change) the program state in order
1521 to verify its compliance with the specifications. Therefore, contracts should
1522 only access objects, function arguments, function return values, old values,
1523 and all other program variables in <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase></computeroutput>
1524 context (via <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase><phrase role="special">&</phrase></computeroutput>,
1525 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase><phrase role="special">*</phrase>
1526 <phrase role="keyword">const</phrase></computeroutput>, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase>
1527 <phrase role="keyword">volatile</phrase></computeroutput>, etc.).
1530 Whenever possible (e.g., class invariants and postcondition old values),
1531 this library automatically enforces this <emphasis>constant-correctness constraint</emphasis>
1532 at compile-time using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase></computeroutput>.
1533 However, this library cannot automatically enforce this constraint in all
1534 cases (for preconditions and postconditions of mutable member functions,
1535 for global variables, etc.). See <link linkend="boost_contract.extras.no_lambda_functions__no_c__11_">No
1536 Lambda Functions</link> for ways of using this library that enforce the constant-correctness
1537 constraint at compile-time (but at the cost of significant boiler-plate code
1538 to be programmed manually so not recommended in general).
1542 In general, it is the responsibility of the programmers to code assertions
1543 that only check, and do not change, program variables. <footnote id="boost_contract.contract_programming_overview.constant_correctness.f0">
1545 Note that this is true when using C-style <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">assert</phrase></computeroutput>
1552 <section id="boost_contract.contract_programming_overview.specifications_vs__implementation">
1553 <title><link linkend="boost_contract.contract_programming_overview.specifications_vs__implementation">Specifications
1554 vs. Implementation</link></title>
1556 Contracts are part of the program specification and not of its implementation.
1557 Therefore, contracts should ideally be programmed within C++ declarations,
1558 and not within definitions.
1561 In general, this library cannot satisfy this requirement. However, even when
1562 contracts are programmed together with the body in the function definition,
1563 it is still fairly easy for users to identify and read just the contract
1564 portion of the function definition (because the contract code must always
1565 be programmed at the very top of the function definition). See <link linkend="boost_contract.extras.separate_body_implementation">Separate
1566 Body Implementation</link> for ways of using this library to program contract
1567 specifications outside of the body implementation (but at the cost of writing
1568 one extra function for any given function so not recommended in general).
1571 Furthermore, contracts are most useful when they assert conditions only using
1572 public members (in most cases, the need for using non-public members to check
1573 contracts, especially in preconditions, indicates an error in the class design).
1574 For example, the caller of a public function cannot in general make sure
1575 that the function preconditions are satisfied if the precondition assertions
1576 use private members that are not callable by the caller (therefore, a failure
1577 in the preconditions will not necessarily indicate a bug in the caller given
1578 that the caller was made unable to fully check the preconditions in the first
1579 place). However, given that C++ provides programmers ways around access level
1580 restrictions (<computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">friend</phrase></computeroutput>, function
1581 pointers, etc.), this library leaves it up to programmers to make sure that
1582 only public members are used in contract assertions (especially in preconditions).
1583 (<link linkend="N1962_anchor">[N1962]</link> follows the same approach not
1584 restricting contracts to only use public members, Eiffel instead generates
1585 a compile-time error if preconditions are asserted using non-public members.)
1586 <footnote id="boost_contract.contract_programming_overview.specifications_vs__implementation.f0">
1588 <emphasis role="bold">Rationale:</emphasis> Out of curiosity, if C++ <ulink url="http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#45">defect
1589 45</ulink> had not been fixed, this library could have been implemented
1590 to generate a compile-time error when precondition assertions use non-public
1591 members more similarly to Eiffel's implementation (but still, not necessary
1592 the best approach for C++).
1597 <section id="boost_contract.contract_programming_overview.on_contract_failures">
1598 <title><link linkend="boost_contract.contract_programming_overview.on_contract_failures">On
1599 Contract Failures</link></title>
1601 If preconditions, postconditions, exception guarantees, or class invariants
1602 are either checked to be false or their evaluation throws an exception at
1603 run-time then this library will call specific <emphasis>failure handler functions</emphasis>.
1604 <footnote id="boost_contract.contract_programming_overview.on_contract_failures.f0">
1606 <emphasis role="bold">Rationale:</emphasis> If the evaluation of a contract
1607 assertion throws an exception, the assertion cannot be checked to be true
1608 so the only safe thing to assume is that the assertion failed (indeed the
1609 contract assertion checking failed) and call the contract failure handler
1615 By default, these failure handler functions print a message to the standard
1616 error <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">cerr</phrase></computeroutput> (with detailed information about the
1617 failure) and then terminate the program calling <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">terminate</phrase></computeroutput>.
1618 However, using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.set_precondition_failure">boost::contract::set_precondition_failure</link></computeroutput>,
1619 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.set_postcondition_failure">boost::contract::set_postcondition_failure</link></computeroutput>,
1620 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.set_except_failure">boost::contract::set_except_failure</link></computeroutput>,
1621 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.set_invariant_failure">boost::contract::set_invariant_failure</link></computeroutput>,
1622 etc. programmers can define their own failure handler functions that can
1623 take any user-specified action (throw an exception, exit the program with
1624 an error code, etc., see <link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__">Throw
1625 on Failures</link>). <footnote id="boost_contract.contract_programming_overview.on_contract_failures.f1">
1627 <emphasis role="bold">Rationale:</emphasis> This customizable failure handling
1628 mechanism is similar to the one used by C++ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">terminate</phrase></computeroutput>
1629 and also to the one proposed in <link linkend="N1962_anchor">[N1962]</link>.
1635 In C++ there are a number of issues with programming contract failure handlers
1636 that throw exceptions instead of terminating the program. Specifically,
1637 destructors check class invariants so they will throw if programmers change
1638 class invariant failure handlers to throw instead of terminating the program,
1639 but in general destructors should not throw in C++ (to comply with STL
1640 exception safety, C++11 implicit <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">noexcept</phrase></computeroutput>
1641 declarations for destructors, etc.). Furthermore, programming a failure
1642 handler that throws on exception guarantee failures results in throwing
1643 an exception (the one reporting the contract failure) while there is already
1644 an active exception (the one that caused the exception guarantees to be
1645 checked in the first place), and this will force C++ to terminate the program
1650 Therefore, it is recommended to terminate the program at least for contract
1651 failures from destructors and exception guarantees (if not in all other cases
1652 of contract failures as it is done by default by this library). The contract
1653 failure handler functions programmed using this library have information
1654 about the failed contract (preconditions, postconditions, etc.) and the operation
1655 that was checking the contract (constructor, destructor, etc.) so programmers
1656 can granularly distinguish all cases and decide when it is appropriate to
1657 terminate, throw, or take some other user-specific action.
1660 <section id="boost_contract.contract_programming_overview.feature_summary">
1661 <title><link linkend="boost_contract.contract_programming_overview.feature_summary">Feature
1662 Summary</link></title>
1664 The contract programming features supported by this library are largely based
1665 on <link linkend="N1962_anchor">[N1962]</link> and on the Eiffel programming
1669 The following table compares contract programming features among this library,
1670 <link linkend="N1962_anchor">[N1962]</link> (unfortunately the C++ standard
1671 committee rejected this proposal commenting on a lack of interest in adding
1672 contract programming to C++ at that time, even if <link linkend="N1962_anchor">[N1962]</link>
1673 itself is sound), a more recent proposal <link linkend="P0380_anchor">[P0380]</link>
1674 (which was accepted in the C++20 standard but unfortunately only supports
1675 preconditions and postconditions, while does not support class invariants,
1676 old values, and subcontracting), the Eiffel and D programming languages.
1677 Some of the items listed in this summary table will become clear in detail
1678 after reading the remaining sections of this documentation.
1680 <informaltable frame="all">
1696 <link linkend="N1962_anchor">[N1962]</link> Proposal (not accepted
1702 C++20 (see <link linkend="P0380_anchor">[P0380]</link>)
1707 ISE Eiffel 5.4 (see <link linkend="Meyer97_anchor">[Meyer97]</link>)
1712 D (see <link linkend="Bright04_anchor">[Bright04]</link>)
1721 <emphasis>Keywords and specifiers</emphasis>
1726 Specifiers: <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">precondition</phrase></computeroutput>,
1727 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">postcondition</phrase></computeroutput>,
1728 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">invariant</phrase></computeroutput>, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">static_invariant</phrase></computeroutput>, and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">base_types</phrase></computeroutput>. The last three specifiers
1729 appear in user code so their names can be referred to or changed
1730 using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_INVARIANT">BOOST_CONTRACT_INVARIANT</link></computeroutput>,
1731 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394998621472">BOOST_CONTRACT_STATIC_INVARIANT</link></computeroutput>,
1732 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394999732400">BOOST_CONTRACT_BASES_TYPEDEF</link></computeroutput>
1733 macros respectively to avoid name clashes.
1738 Keywords: <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">precondition</phrase></computeroutput>,
1739 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">postcondition</phrase></computeroutput>,
1740 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">oldof</phrase></computeroutput>, and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">invariant</phrase></computeroutput>.
1745 Attributes: <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">[[</phrase><phrase role="identifier">expects</phrase><phrase role="special">]]</phrase></computeroutput> and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">[[</phrase><phrase role="identifier">ensures</phrase><phrase role="special">]]</phrase></computeroutput>.
1750 Keywords: <literal moreinfo="none">require</literal>, <literal moreinfo="none">require else</literal>,
1751 <literal moreinfo="none">ensure</literal>, <literal moreinfo="none">ensure then</literal>, <literal moreinfo="none">old</literal>,
1752 <literal moreinfo="none">result</literal>, <literal moreinfo="none">do</literal>, and <literal moreinfo="none">invariant</literal>.
1757 Keywords: <literal moreinfo="none">in</literal>, <literal moreinfo="none">out</literal>, <literal moreinfo="none">do</literal>,
1758 <literal moreinfo="none">assert</literal>, and <literal moreinfo="none">invariant</literal>.
1765 <emphasis>On contract failures</emphasis>
1770 Print an error to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">cerr</phrase></computeroutput>
1771 and call <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">terminate</phrase></computeroutput> (but can be customized
1772 to throw exceptions, exit with an error code, etc.).
1777 Call <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">terminate</phrase></computeroutput> (but can be customized
1778 to throw exceptions, exit with an error code, etc.).
1783 Call <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">abort</phrase></computeroutput> (but can be customized
1784 to throw exceptions, exit with an error code, etc.).
1801 <emphasis>Return values in postconditions</emphasis>
1806 Yes, captured by or passed as a parameter to (for virtual functions)
1807 the postcondition functor.
1812 Yes, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">postcondition</phrase><phrase role="special">(</phrase></computeroutput><literal moreinfo="none"><emphasis>result-variable-name</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">)</phrase></computeroutput>.
1817 Yes, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">[[</phrase><phrase role="identifier">ensures</phrase>
1818 </computeroutput><literal moreinfo="none"><emphasis>result-variable-name</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">:</phrase> <phrase role="special">...]]</phrase></computeroutput>.
1823 Yes, <literal moreinfo="none">result</literal> keyword.
1828 Yes, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">out</phrase><phrase role="special">(</phrase></computeroutput><literal moreinfo="none"><emphasis>result-variable-name</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">)</phrase></computeroutput>.
1835 <emphasis>Old values in postconditions</emphasis>
1840 Yes, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_OLDOF">BOOST_CONTRACT_OLDOF</link></computeroutput>
1841 macro and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.old_ptr">boost::contract::old_ptr</link></computeroutput>
1842 (but copied before preconditions unless <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">old</phrase><phrase role="special">(...)</phrase></computeroutput>
1843 is used as shown in <link linkend="boost_contract.advanced.old_values_copied_at_body">Old
1844 Values Copied at Body</link>). For templates, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.old_ptr_if_copyable">boost::contract::old_ptr_if_copyable</link></computeroutput>
1845 skips old value copies for non-copyable types and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.condition_if">boost::contract::condition_if</link></computeroutput>
1846 skips old value copies selectively based on old expression type
1847 requirements (on compilers that do not support <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">if</phrase>
1848 <phrase role="keyword">constexpr</phrase></computeroutput>).
1853 Yes, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">oldof</phrase></computeroutput> keyword
1854 (copied right after preconditions). (Never skipped, not even in
1855 templates for non-copyable types.)
1865 Yes, <literal moreinfo="none">old</literal> keyword (copied right after preconditions).
1866 (Never skipped, but all types are copyable in Eiffel.)
1878 <emphasis>Class invariants</emphasis>
1883 Yes, checked at constructor exit, at destructor entry and throw,
1884 and at public function entry, exit, and throw. Same for volatile
1885 class invariants. Static class invariants checked at entry, exit,
1886 and throw for constructors, destructors, and any (also <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">static</phrase></computeroutput>) public function.
1891 Yes, checked at constructor exit, at destructor entry and throw,
1892 and at public function entry, exit, and throw. (Volatile and static
1893 class invariants not supported.)
1903 Yes, checked at constructor exit, and around public functions.
1904 (Volatile and static class invariants do not apply to Eiffel.)
1909 Yes, checked at constructor exit, at destructor entry, and around
1910 public functions. However, invariants cannot call public functions
1911 (to avoid infinite recursion because D does not disable contracts
1912 while checking other contracts). (Volatile and static class invariants
1913 not supported, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">volatile</phrase></computeroutput>
1914 was deprecated all together in D.)
1921 <emphasis>Subcontracting</emphasis>
1926 Yes, also supports subcontracting for multiple inheritance (<computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_BASE_TYPES">BOOST_CONTRACT_BASE_TYPES</link></computeroutput>,
1927 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_OVERRIDE">BOOST_CONTRACT_OVERRIDE</link></computeroutput>,
1928 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.virtual_">boost::contract::virtual_</link></computeroutput>
1929 are used to declare base classes, overrides and virtual public
1930 functions respectively).
1935 Yes, also supports subcontracting for multiple inheritance, but
1936 preconditions cannot be subcontracted. <footnote id="boost_contract.contract_programming_overview.feature_summary.f0">
1938 <emphasis role="bold">Rationale:</emphasis> The authors of <link linkend="N1962_anchor">[N1962]</link> decided to forbid derived
1939 classes from subcontracting preconditions because they found
1940 that such a feature was rarely, if ever, used (see <ulink url="http://lists.boost.org/Archives/boost/2010/04/164862.php">Re:
1941 [boost] [contract] diff n1962</ulink>). Still, it should be noted
1942 that even in <link linkend="N1962_anchor">[N1962]</link> if a
1943 derived class overrides two functions with preconditions coming
1944 from two different base classes via multiple inheritance, the
1945 overriding function contract will check preconditions from its
1946 two base class functions in <link linkend="or_anchor"><literal moreinfo="none"><emphasis>OR</emphasis></literal></link>
1947 (so even in <link linkend="N1962_anchor">[N1962]</link> preconditions
1948 can indirectly subcontract when multiple inheritance is used).
1949 Furthermore, subcontracting preconditions is soundly defined
1950 by the <ulink url="http://en.wikipedia.org/wiki/Liskov_substitution_principle">substitution
1951 principle</ulink> so this library allows to subcontract preconditions
1952 as Eiffel does (users can always avoid using this feature if
1953 they have no need for it). (This is essentially the only feature
1954 on which this library deliberately differs from <link linkend="N1962_anchor">[N1962]</link>.)
1978 <emphasis>Contracts for pure virtual functions</emphasis>
1983 Yes (programmed via out-of-line functions as always in C++ with
1984 pure virtual function definitions).
1994 No (because no subcontracting).
1999 Yes (contracts for abstract functions).
2011 <emphasis>Arbitrary code in contracts</emphasis>
2016 Yes (but users are generally recommended to only program assertions
2017 using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_ASSERT">BOOST_CONTRACT_ASSERT</link></computeroutput>
2018 and if-guard statements within contracts to avoid introducing bugs
2019 and expensive code in contracts, and also to only use public functions
2020 to program preconditions).
2025 No, assertions only (use of only public functions to program preconditions
2026 is recommended but not prescribed).
2031 No, assertions only (in addition contracts of public, protected,
2032 and private members can only use other public, public/protected,
2033 and public/protected/private members respectively).
2038 No, assertions only (in addition only public members can be used
2051 <emphasis>Constant-correctness</emphasis>
2056 No, enforced only for class invariants and old values (making also
2057 preconditions and postconditions constant-correct is possible but
2058 requires users to program a fare amount of boiler-plate code).
2068 Yes (side effects in contracts lead to undefined behaviour).
2078 No, enforced only for class invariants.
2085 <emphasis>Contracts in specifications</emphasis>
2090 No, in function definitions instead (unless programmers manually
2091 write an extra function for any given function).
2096 Yes (in function declarations).
2101 Yes (in function declarations).
2118 <emphasis>Function code ordering</emphasis>
2123 Preconditions, postconditions, exception guarantees, body.
2128 Preconditions, postconditions, body.
2133 Preconditions, postconditions, body.
2138 Preconditions, body, postconditions.
2143 Preconditions, postconditions, body.
2150 <emphasis>Disable assertion checking within assertions checking
2151 (to avoid infinite recursion when checking contracts)</emphasis>
2156 Yes, but use <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394999685184">BOOST_CONTRACT_PRECONDITIONS_DISABLE_NO_ASSERTION</link></computeroutput>
2157 to disable no assertion while checking preconditions (see also
2158 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394999679376">BOOST_CONTRACT_ALL_DISABLE_NO_ASSERTION</link></computeroutput>).
2159 <footnote id="boost_contract.contract_programming_overview.feature_summary.f1">
2161 <emphasis role="bold">Rationale:</emphasis> Technically, it can
2162 be shown that an invalid argument can reach the function body
2163 when assertion checking is disabled while checking preconditions
2164 (that is why <link linkend="N1962_anchor">[N1962]</link> does
2165 not disable any assertion while checking preconditions, see
2166 <ulink url="http://lists.boost.org/Archives/boost/2010/04/164862.php">Re:
2167 [boost] [contract] diff n1962</ulink>). However, this can only
2168 happen while checking contracts when an invalid argument passed
2169 to the body, which should results in the body either throwing
2170 an exception or returning an incorrect result, will in turn fail
2171 the contract assertion being checked by the caller of the body
2172 and invoke the related contract failure handler as desired in
2173 the first place. Furthermore, not disabling assertions while
2174 checking preconditions (like <link linkend="N1962_anchor">[N1962]</link>
2175 does) makes it possible to have infinite recursion while checking
2176 preconditions. Therefore, this library by default disables assertion
2177 checking also while checking preconditions (like Eiffel does),
2178 but it also provides the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394999685184">BOOST_CONTRACT_PRECONDITIONS_DISABLE_NO_ASSERTION</link></computeroutput>
2179 configuration macro so users can change this behaviour to match
2180 <link linkend="N1962_anchor">[N1962]</link> if needed.
2182 </footnote> (In multi-threaded programs this introduces a global
2183 lock, see <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394999743888">BOOST_CONTRACT_DISABLE_THREADS</link></computeroutput>.)
2188 Yes for class invariants and postconditions, but preconditions
2189 disable no assertion.
2211 <emphasis>Nested member function calls</emphasis>
2216 Disable nothing. <footnote id="boost_contract.contract_programming_overview.feature_summary.f2">
2218 <emphasis role="bold">Rationale:</emphasis> Older versions of
2219 this library defined a data member in the user class that was
2220 automatically used to disable checking of class invariants within
2221 nested member function calls (similarly to Eiffel). This feature
2222 was required by older revisions of <link linkend="N1962_anchor">[N1962]</link>
2223 but it is no longer required by <link linkend="N1962_anchor">[N1962]</link>
2224 (because it seems to be motivated purely by optimization reasons
2225 while similar performances can be achieved by disabling invariants
2226 for release builds). Furthermore, in multi-threaded programs
2227 this feature would introduce a lock that synchronizes all member
2228 functions calls for a given object. Therefore, this feature was
2229 removed in the current revision of this library.
2246 Disable all contract assertions.
2258 <emphasis>Disable contract checking</emphasis>
2263 Yes, contract checking can be skipped at run-time by defining combinations
2264 of the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394999662416">BOOST_CONTRACT_NO_PRECONDITIONS</link></computeroutput>,
2265 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394999656032">BOOST_CONTRACT_NO_POSTCONDITIONS</link></computeroutput>,
2266 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394999622032">BOOST_CONTRACT_NO_INVARIANTS</link></computeroutput>,
2267 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394999637264">BOOST_CONTRACT_NO_ENTRY_INVARIANTS</link></computeroutput>,
2268 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394999629648">BOOST_CONTRACT_NO_EXIT_INVARIANTS</link></computeroutput>
2269 macros (completely removing contract code from compiled object
2270 code is also possible but requires using macros as shown in <link linkend="boost_contract.extras.disable_contract_compilation__macro_interface_">Disable
2271 Contract Compilation</link>).
2276 Yes (contract code also removed from compiled object code, but
2277 details are compiler-implementation specific).
2282 Yes (contract code also removed from compiled object code, but
2283 details are compiler-implementation specific).
2288 Yes, but only predefined combinations of preconditions, postconditions,
2289 and class invariants can be disabled (contract code also removed
2290 from compiled object code).
2302 <emphasis>Assertion levels</emphasis>
2307 Yes, predefined default, audit, and axiom, in addition programmers
2308 can also define their own levels.
2313 No (but a previous revision of this proposal considered adding
2314 assertion levels under the name of "assertion ordering").
2319 Yes, predefined default, audit, and axiom.
2337 The authors of this library consulted the following references that implement
2338 contract programming for C++ (but usually for only a limited set of features,
2339 or using preprocessing tools other than the C++ preprocessor and external
2340 to the language itself) and for other languages (see <link linkend="boost_contract.bibliography">Bibliography</link>
2341 for a complete list of all references consulted during the design and development
2344 <informaltable frame="all">
2369 <link linkend="Bright04b_anchor">[Bright04b]</link>
2379 The Digital Mars C++ compiler extends C++ adding contract programming
2380 language support (among many other features).
2387 <link linkend="Maley99_anchor">[Maley99]</link>
2397 This supports contract programming including subcontracting but
2398 with limitations (e.g., programmers need to manually build an inheritance
2399 tree using artificial template parameters), it does not use macros
2400 but programmers are required to write by hand a significant amount
2401 of boiler-plate code. (The authors have found this work very inspiring
2402 when developing initial revisions of this library especially for
2403 its attempt to support subcontracting.)
2410 <link linkend="Lindrud04_anchor">[Lindrud04]</link>
2420 This supports class invariants and old values but it does not support
2421 subcontracting (contracts are specified within definitions instead
2422 of declarations and assertions are not constant-correct).
2429 <link linkend="Tandin04_anchor">[Tandin04]</link>
2439 Interestingly, these contract macros automatically generate Doxygen
2440 documentation <footnote id="boost_contract.contract_programming_overview.feature_summary.f3">
2442 <emphasis role="bold">Rationale:</emphasis> Older versions of
2443 this library also automatically generated Doxygen documentation
2444 from contract definition macros. This functionality was abandoned
2445 for a number of reasons: This library no longer uses macros to
2446 program contracts; even before that, the implementation of this
2447 library macros became too complex and the Doxygen preprocessor
2448 was no longer able to expand them; the Doxygen documentation
2449 was just a repeat of the contract code (so programmers could
2450 directly look at contracts in the source code); Doxygen might
2451 not necessarily be the documentation tool used by all C++ programmers.
2453 </footnote> but old values, class invariants, and subcontracting
2454 are not supported (plus contracts are specified within definitions
2455 instead of declarations and assertions are not constant-correct).
2462 <link linkend="Nana_anchor">[Nana]</link>
2472 This uses macros but it only works on GCC (and maybe Clang, but
2473 it does not work on MSVC, etc.). It does not support subcontracting.
2474 It requires extra care to program postconditions for functions
2475 with multiple return statements. It seems that it might not check
2476 class invariants when functions throw exceptions (unless the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">END</phrase></computeroutput> macro does that...). (In
2477 addition, it provides tools for logging and integration with GDB.)
2484 <link linkend="C2_anchor">[C2]</link>
2494 This uses an external preprocessing tool (the authors could no
2495 longer find this project's code to evaluate it).
2502 <link linkend="iContract_anchor">[iContract]</link>
2512 This uses an external preprocessing tool.
2519 <link linkend="Jcontract_anchor">[Jcontract]</link>
2529 This uses an external preprocessing tool.
2536 <link linkend="CodeContracts_anchor">[CodeContracts]</link>
2546 Microsoft contract programming for .NET programming languages.
2553 <link linkend="SpecSharp_anchor">[SpecSharp]</link>
2563 This is a C# extension with contract programming language support.
2570 <link linkend="Chrome_anchor">[Chrome]</link>
2580 This is the .NET version of Object Pascal and it has language support
2581 for contract programming.
2588 <link linkend="SPARKAda_anchor">[SPARKAda]</link>
2598 This is an Ada-like programming language with support for contract
2607 To the best knowledge of the authors, this the only library that fully supports
2608 all contract programming features for C++ (without using preprocessing tools
2609 external to the language itself). In general:
2614 Implementing preconditions and postconditions in C++ is not difficult
2615 (e.g., using some kind of RAII object).
2620 Implementing postcondition old values is also not too difficult (usually
2621 requiring programmers to copy old values into local variables), but it
2622 is already somewhat more difficult to ensure such copies are not performed
2623 when postconditions are disabled. <footnote id="boost_contract.contract_programming_overview.feature_summary.f4">
2625 For example, the following pseudocode attempts to emulate old values
2626 in <link linkend="P0380_anchor">[P0380]</link>:
2627 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">struct</phrase> <phrase role="identifier">scope_exit</phrase> <phrase role="special">{</phrase> <phrase role="comment">// RAII.</phrase>
2628 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">F</phrase><phrase role="special">></phrase>
2629 <phrase role="keyword">explicit</phrase> <phrase role="identifier">scope_exit</phrase><phrase role="special">(</phrase><phrase role="identifier">F</phrase> <phrase role="identifier">f</phrase><phrase role="special">)</phrase> <phrase role="special">:</phrase> <phrase role="identifier">f_</phrase><phrase role="special">(</phrase><phrase role="identifier">f</phrase><phrase role="special">)</phrase> <phrase role="special">{}</phrase>
2630 <phrase role="special">~</phrase><phrase role="identifier">scope_exit</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase> <phrase role="identifier">f_</phrase><phrase role="special">();</phrase> <phrase role="special">}</phrase>
2632 <phrase role="identifier">scope_exit</phrase><phrase role="special">(</phrase><phrase role="identifier">scope_exit</phrase> <phrase role="keyword">const</phrase><phrase role="special">&)</phrase> <phrase role="special">=</phrase> <phrase role="keyword">delete</phrase><phrase role="special">;</phrase>
2633 <phrase role="identifier">scope_exit</phrase><phrase role="special">&</phrase> <phrase role="keyword">operator</phrase><phrase role="special">=(</phrase><phrase role="identifier">scope_exit</phrase> <phrase role="keyword">const</phrase><phrase role="special">&)</phrase> <phrase role="special">=</phrase> <phrase role="keyword">delete</phrase><phrase role="special">;</phrase>
2634 <phrase role="keyword">private</phrase><phrase role="special">:</phrase>
2635 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">function</phrase><phrase role="special"><</phrase><phrase role="keyword">void</phrase> <phrase role="special">()></phrase> <phrase role="identifier">f_</phrase><phrase role="special">;</phrase>
2636 <phrase role="special">};</phrase>
2638 <phrase role="keyword">void</phrase> <phrase role="identifier">fswap</phrase><phrase role="special">(</phrase><phrase role="identifier">file</phrase><phrase role="special">&</phrase> <phrase role="identifier">x</phrase><phrase role="special">,</phrase> <phrase role="identifier">file</phrase><phrase role="special">&</phrase> <phrase role="identifier">y</phrase><phrase role="special">)</phrase>
2639 <phrase role="special">[[</phrase><phrase role="identifier">expects</phrase><phrase role="special">:</phrase> <phrase role="identifier">x</phrase><phrase role="special">.</phrase><phrase role="identifier">closed</phrase><phrase role="special">()]]</phrase>
2640 <phrase role="special">[[</phrase><phrase role="identifier">expects</phrase><phrase role="special">:</phrase> <phrase role="identifier">y</phrase><phrase role="special">.</phrase><phrase role="identifier">closed</phrase><phrase role="special">()]]</phrase>
2641 <phrase role="comment">// Cannot use [[ensures]] for postconditions so to emulate old values.</phrase>
2642 <phrase role="special">{</phrase>
2643 <phrase role="identifier">file</phrase> <phrase role="identifier">old_x</phrase> <phrase role="special">=</phrase> <phrase role="identifier">x</phrase><phrase role="special">;</phrase> <phrase role="comment">// Emulate old values with local copies (not disabled).</phrase>
2644 <phrase role="identifier">file</phrase> <phrase role="identifier">old_y</phrase> <phrase role="special">=</phrase> <phrase role="identifier">y</phrase><phrase role="special">;</phrase>
2645 <phrase role="identifier">scope_exit</phrase> <phrase role="identifier">ensures</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Check after local objects destroyed.</phrase>
2646 <phrase role="keyword">if</phrase><phrase role="special">(</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">uncaught_exceptions</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Check only if no throw.</phrase>
2647 <phrase role="special">[[</phrase><phrase role="identifier">assert</phrase><phrase role="special">:</phrase> <phrase role="identifier">x</phrase><phrase role="special">.</phrase><phrase role="identifier">closed</phrase><phrase role="special">()]]</phrase>
2648 <phrase role="special">[[</phrase><phrase role="identifier">assert</phrase><phrase role="special">:</phrase> <phrase role="identifier">y</phrase><phrase role="special">.</phrase><phrase role="identifier">closed</phrase><phrase role="special">()]]</phrase>
2649 <phrase role="special">[[</phrase><phrase role="identifier">assert</phrase><phrase role="special">:</phrase> <phrase role="identifier">x</phrase> <phrase role="special">==</phrase> <phrase role="identifier">old_y</phrase><phrase role="special">]]</phrase>
2650 <phrase role="special">[[</phrase><phrase role="identifier">assert</phrase><phrase role="special">:</phrase> <phrase role="identifier">y</phrase> <phrase role="special">==</phrase> <phrase role="identifier">old_x</phrase><phrase role="special">]]</phrase>
2651 <phrase role="special">}</phrase>
2652 <phrase role="special">});</phrase>
2654 <phrase role="identifier">x</phrase><phrase role="special">.</phrase><phrase role="identifier">open</phrase><phrase role="special">();</phrase>
2655 <phrase role="identifier">scope_exit</phrase> <phrase role="identifier">close_x</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase> <phrase role="identifier">x</phrase><phrase role="special">.</phrase><phrase role="identifier">close</phrase><phrase role="special">();</phrase> <phrase role="special">});</phrase>
2656 <phrase role="identifier">y</phrase><phrase role="special">.</phrase><phrase role="identifier">open</phrase><phrase role="special">();</phrase>
2657 <phrase role="identifier">scope_exit</phrase> <phrase role="identifier">close_y</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase> <phrase role="identifier">y</phrase><phrase role="special">.</phrase><phrase role="identifier">close</phrase><phrase role="special">();</phrase> <phrase role="special">});</phrase>
2658 <phrase role="identifier">file</phrase> <phrase role="identifier">z</phrase> <phrase role="special">=</phrase> <phrase role="identifier">file</phrase><phrase role="special">::</phrase><phrase role="identifier">temp</phrase><phrase role="special">();</phrase>
2659 <phrase role="identifier">z</phrase><phrase role="special">.</phrase><phrase role="identifier">open</phrase><phrase role="special">;</phrase>
2660 <phrase role="identifier">scope_exit</phrase> <phrase role="identifier">close_z</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase> <phrase role="identifier">z</phrase><phrase role="special">.</phrase><phrase role="identifier">close</phrase><phrase role="special">();</phrase> <phrase role="special">});</phrase>
2662 <phrase role="identifier">x</phrase><phrase role="special">.</phrase><phrase role="identifier">mv</phrase><phrase role="special">(</phrase><phrase role="identifier">z</phrase><phrase role="special">);</phrase>
2663 <phrase role="identifier">y</phrase><phrase role="special">.</phrase><phrase role="identifier">mv</phrase><phrase role="special">(</phrase><phrase role="identifier">x</phrase><phrase role="special">);</phrase>
2664 <phrase role="identifier">z</phrase><phrase role="special">.</phrase><phrase role="identifier">mv</phrase><phrase role="special">(</phrase><phrase role="identifier">y</phrase><phrase role="special">);</phrase>
2665 <phrase role="special">}</phrase>
2667 This requires boiler-plate code to make sure postconditions are correctly
2668 checked only if the function did not throw an exception and in a <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">scope_exit</phrase></computeroutput> RAII object after all
2669 other local objects have been destroyed (because some of these destructors
2670 contribute to establishing the postconditions). Still, it never disables
2671 old value copies (not even if postconditions are disabled in release
2672 builds, this would require adding even more boiler-plate code using
2673 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#ifdef</phrase></computeroutput>, etc.).
2680 Implementing class invariants is more involved (especially if done automatically,
2681 without requiring programmers to manually invoke extra functions to check
2682 the invariants). <footnote id="boost_contract.contract_programming_overview.feature_summary.f5">
2684 For example, the following pseudocode attempts to emulation of class
2685 invariants in <link linkend="P0380_anchor">[P0380]</link>:
2686 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">></phrase>
2687 <phrase role="keyword">class</phrase> <phrase role="identifier">vector</phrase> <phrase role="special">{</phrase>
2688 <phrase role="keyword">bool</phrase> <phrase role="identifier">invariant</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Check invariants at...</phrase>
2689 <phrase role="special">[[</phrase><phrase role="identifier">assert</phrase><phrase role="special">:</phrase> <phrase role="identifier">empty</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">0</phrase><phrase role="special">)]]</phrase>
2690 <phrase role="special">[[</phrase><phrase role="identifier">assert</phrase><phrase role="special">:</phrase> <phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special"><=</phrase> <phrase role="identifier">capacity</phrase><phrase role="special">()]]</phrase>
2691 <phrase role="keyword">return</phrase> <phrase role="keyword">true</phrase><phrase role="special">;</phrase>
2692 <phrase role="special">}</phrase>
2694 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
2695 <phrase role="identifier">vector</phrase><phrase role="special">()</phrase>
2696 <phrase role="special">[[</phrase><phrase role="identifier">ensures</phrase><phrase role="special">:</phrase> <phrase role="identifier">invariant</phrase><phrase role="special">()]]</phrase> <phrase role="comment">// ...constructor exit (only if no throw).</phrase>
2697 <phrase role="special">{</phrase> <phrase role="special">...</phrase> <phrase role="special">}</phrase>
2699 <phrase role="special">~</phrase><phrase role="identifier">vector</phrase><phrase role="special">()</phrase> <phrase role="keyword">noexcept</phrase>
2700 <phrase role="special">[[</phrase><phrase role="identifier">expects</phrase><phrase role="special">:</phrase> <phrase role="identifier">invariant</phrase><phrase role="special">()]]</phrase> <phrase role="comment">// ...destructor entry.</phrase>
2701 <phrase role="special">{</phrase> <phrase role="special">...</phrase> <phrase role="special">}</phrase>
2703 <phrase role="keyword">void</phrase> <phrase role="identifier">push_back</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">value</phrase><phrase role="special">)</phrase>
2704 <phrase role="special">[[</phrase><phrase role="identifier">expects</phrase><phrase role="special">:</phrase> <phrase role="identifier">invariant</phrase><phrase role="special">()]]</phrase> <phrase role="comment">// ...public function entry.</phrase>
2705 <phrase role="special">[[</phrase><phrase role="identifier">ensures</phrase><phrase role="special">:</phrase> <phrase role="identifier">invariant</phrase><phrase role="special">()]]</phrase> <phrase role="comment">// ...public function exit (if no throw).</phrase>
2706 <phrase role="keyword">try</phrase> <phrase role="special">{</phrase>
2707 <phrase role="special">...</phrase> <phrase role="comment">// Function body.</phrase>
2708 <phrase role="special">}</phrase> <phrase role="keyword">catch</phrase><phrase role="special">(...)</phrase> <phrase role="special">{</phrase>
2709 <phrase role="identifier">invariant</phrase><phrase role="special">();</phrase> <phrase role="comment">// ...public function exit (if throw).</phrase>
2710 <phrase role="keyword">throw</phrase><phrase role="special">;</phrase>
2711 <phrase role="special">}</phrase>
2713 <phrase role="special">...</phrase>
2714 <phrase role="special">};</phrase>
2716 This requires boiler-plate code to manually invoke the function that
2717 checks the invariants (note that invariants are checked at public function
2718 exit regardless of exceptions being thrown while postconditions are
2719 not). In case the destructor can throw (e.g., it is declared <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">noexcept</phrase><phrase role="special">(</phrase><phrase role="keyword">false</phrase><phrase role="special">)</phrase></computeroutput>),
2720 the destructor also requires a <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">try</phrase><phrase role="special">-</phrase><phrase role="keyword">catch</phrase></computeroutput>
2721 statement similar to the one programmed for <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">push_back</phrase></computeroutput>
2722 to check class invariants at destructor exit when it throws exceptions.
2723 Still, an outstanding issue remains to avoid infinite recursion if
2724 also <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">empty</phrase></computeroutput> and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">size</phrase></computeroutput> are public functions programmed
2725 to check class invariants (because <link linkend="P0380_anchor">[P0380]</link>
2726 does not automatically disable assertions while checking other assertions).
2728 </footnote> In addition, all references reviewed by the authors seem
2729 to not consider static and volatile functions not supporting static and
2730 volatile invariants respectively.
2735 Implementing subcontracting involves a significant amount of complexity
2736 and it seems to not be properly supported by any C++ library other than
2737 this one (especially when handling multiple inheritance, correctly copying
2738 postcondition old values across all overridden contracts deep in the
2739 inheritance tree, and correctly reporting the return value to the postconditions
2740 of overridden virtual functions in base classes). <footnote id="boost_contract.contract_programming_overview.feature_summary.f6">
2742 For example, it is not really possible to sketch pseudocode based on
2743 <link linkend="P0380_anchor">[P0380]</link> that emulates subcontracting
2744 in the general case.
2752 <section id="boost_contract.tutorial">
2753 <title><link linkend="boost_contract.tutorial">Tutorial</link></title>
2755 This section is a guide to basic usage of this library.
2757 <section id="boost_contract.tutorial.non_member_functions">
2758 <title><link linkend="boost_contract.tutorial.non_member_functions">Non-Member
2759 Functions</link></title>
2761 Contracts for non-member functions are programmed using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.function">boost::contract::function</link></computeroutput>.
2762 For example (see <ulink url="../../example/features/non_member.cpp"><literal moreinfo="none">non_member.cpp</literal></ulink>):
2765 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">contract</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">></phrase>
2767 <phrase role="comment">// Contract for a non-member function.</phrase>
2768 <phrase role="keyword">int</phrase> <phrase role="identifier">inc</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase><phrase role="special">&</phrase> <phrase role="identifier">x</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
2769 <phrase role="keyword">int</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
2770 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">></phrase> <phrase role="identifier">old_x</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">x</phrase><phrase role="special">);</phrase>
2771 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">function</phrase><phrase role="special">()</phrase>
2772 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
2773 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">x</phrase> <phrase role="special"><</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">numeric_limits</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">>::</phrase><phrase role="identifier">max</phrase><phrase role="special">());</phrase>
2774 <phrase role="special">})</phrase>
2775 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
2776 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">x</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_x</phrase> <phrase role="special">+</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase>
2777 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">result</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_x</phrase><phrase role="special">);</phrase>
2778 <phrase role="special">})</phrase>
2779 <phrase role="special">.</phrase><phrase role="identifier">except</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
2780 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">x</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_x</phrase><phrase role="special">);</phrase>
2781 <phrase role="special">})</phrase>
2782 <phrase role="special">;</phrase>
2784 <phrase role="keyword">return</phrase> <phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="identifier">x</phrase><phrase role="special">++;</phrase> <phrase role="comment">// Function body.</phrase>
2785 <phrase role="special">}</phrase>
2789 All necessary header files of this library are included by <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">contract</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">></phrase></computeroutput>.
2790 Alternatively, programmers can selectively include only the header files
2791 they actually need among <literal moreinfo="none">boost/contract/*.hpp</literal> (see <link linkend="boost_contract.getting_started">Getting Started</link>).
2794 It is possible to specify preconditions, postconditions, and exception guarantees
2795 for non-member functions (see <link linkend="boost_contract.tutorial.preconditions">Preconditions</link>,
2796 <link linkend="boost_contract.tutorial.postconditions">Postconditions</link>,
2797 and <link linkend="boost_contract.tutorial.exception_guarantees">Exception
2801 The <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.function">boost::contract::function</link></computeroutput>
2802 function returns an RAII object that must always be assigned to a local variable
2803 of type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.check">boost::contract::check</link></computeroutput>
2804 (otherwise this library will generate a run-time error, see <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394999694064">BOOST_CONTRACT_ON_MISSING_CHECK_DECL</link></computeroutput>).
2805 <footnote id="boost_contract.tutorial.non_member_functions.f0">
2807 The name of this local variable is arbitrary, but <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">c</phrase></computeroutput>
2808 is often used in this documentation for <quote>c</quote>heck or <quote>c</quote>aminiti
2809 <literal moreinfo="none">;-)</literal> .
2811 </footnote> Furthermore, C++11 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">auto</phrase></computeroutput>
2812 declarations cannot be used here and the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.check">boost::contract::check</link></computeroutput>
2813 type must be explicitly specified (otherwise this library will generate a
2814 compile-time error prior C++17 and a run-time error post C++17). <footnote id="boost_contract.tutorial.non_member_functions.f1">
2816 <emphasis role="bold">Rationale:</emphasis> C++17 guaranteed copy elision
2817 on function return value voids the trick this library uses to force a compile-time
2818 error when <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">auto</phrase></computeroutput> is incorrectly
2819 used instead of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.check">boost::contract::check</link></computeroutput>.
2820 The library still generates a run-time error in this case (also on C++17).
2821 In any case, after reading this documentation it should be evident to programmers
2822 that <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">auto</phrase></computeroutput> should not be used
2823 in <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.check">boost::contract::check</link></computeroutput>
2824 declarations so this misuse of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">auto</phrase></computeroutput>
2825 should not be an issue in practice.
2827 </footnote> The function body is programmed right after the declaration of
2832 In some cases, it might be necessary to program some code before the contract.
2833 For example for acquiring resources that will be used while checking the
2834 contract like old values, but also to lock mutexes (or other synchronization
2835 mechanisms) in multi-threaded programs.
2839 At construction, the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.check">boost::contract::check</link></computeroutput>
2840 RAII object for non-member functions does the following (enclosing function
2843 <orderedlist inheritnum="ignore" continuation="restarts">
2846 Check preconditions, by calling the nullary functor <literal moreinfo="none"><emphasis>r</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">()</phrase></computeroutput> passed to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">(</phrase></computeroutput><literal moreinfo="none"><emphasis>r</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">)</phrase></computeroutput>.
2851 At destruction instead (enclosing function exit):
2853 <orderedlist inheritnum="ignore" continuation="restarts">
2856 If the function body did not throw an exception:
2857 <orderedlist inheritnum="ignore" continuation="restarts">
2860 Check postconditions, by calling the nullary functor <literal moreinfo="none"><emphasis>s</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">()</phrase></computeroutput> passed to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">(</phrase></computeroutput><literal moreinfo="none"><emphasis>s</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">)</phrase></computeroutput>.
2869 <orderedlist inheritnum="ignore" continuation="restarts">
2872 Check exception guarantees, by calling the nullary functor <literal moreinfo="none"><emphasis>e</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">()</phrase></computeroutput> passed to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">except</phrase><phrase role="special">(</phrase></computeroutput><literal moreinfo="none"><emphasis>e</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">)</phrase></computeroutput>.
2880 This ensures that non-member function contracts are correctly checked at
2881 run-time (see <link linkend="boost_contract.contract_programming_overview.function_calls">Function
2882 Calls</link>). (Also note that functions will correctly check their contracts
2883 even when they are called via function pointers, function objects, etc.)
2887 A non-member function can avoid calling <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.function">boost::contract::function</link></computeroutput>
2888 for efficiency but only when it has no preconditions, no postconditions,
2889 and no exception guarantees.
2893 <section id="boost_contract.tutorial.preconditions">
2894 <title><link linkend="boost_contract.tutorial.preconditions">Preconditions</link></title>
2896 When preconditions are specified, they are programmed using a functor <literal moreinfo="none"><emphasis>r</emphasis></literal>
2897 passed to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">(</phrase></computeroutput><literal moreinfo="none"><emphasis>r</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">)</phrase></computeroutput> that can be called with no parameters as
2898 in <literal moreinfo="none"><emphasis>r</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">()</phrase></computeroutput>.
2899 Contracts that do not have preconditions simply do not call <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">(...)</phrase></computeroutput>. Preconditions must appear before postconditions
2900 and exception guarantees when these are all present (see <link linkend="boost_contract.tutorial.postconditions">Postconditions</link>
2901 and <link linkend="boost_contract.tutorial.exception_guarantees">Exception
2905 C++11 lambda functions are convenient to program preconditions, but any other
2906 nullary functor can be used (see <link linkend="boost_contract.extras.no_lambda_functions__no_c__11_">No
2907 Lambda Functions</link>). <footnote id="boost_contract.tutorial.preconditions.f0">
2909 Lambda functions with no parameters can be programmed in C++11 as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">[...]</phrase> <phrase role="special">()</phrase> <phrase role="special">{</phrase> <phrase role="special">...</phrase> <phrase role="special">}</phrase></computeroutput>
2910 but also equivalently as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">[...]</phrase> <phrase role="special">{</phrase> <phrase role="special">...</phrase> <phrase role="special">}</phrase></computeroutput>.
2911 This second from is often used in this documentation omitting the empty
2912 parameter list <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">()</phrase></computeroutput> for brevity.
2914 </footnote> For example, for <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.function">boost::contract::function</link></computeroutput>
2915 (similarly for public functions, instead destructors do not have preconditions
2916 and constructors use <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.constructor_precondition">boost::contract::constructor_precondition</link></computeroutput>,
2917 see <link linkend="boost_contract.tutorial.public_functions">Public Functions</link>,
2918 <link linkend="boost_contract.tutorial.destructors">Destructors</link>, and
2919 <link linkend="boost_contract.tutorial.constructors">Constructors</link>):
2921 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">void</phrase> <phrase role="identifier">f</phrase><phrase role="special">(...)</phrase> <phrase role="special">{</phrase>
2922 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">function</phrase><phrase role="special">()</phrase> <phrase role="comment">// Same for all other contracts.</phrase>
2923 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Capture by reference or value...</phrase>
2924 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(...);</phrase> <phrase role="comment">// ...and should not modify captures.</phrase>
2925 <phrase role="special">...</phrase>
2926 <phrase role="special">})</phrase>
2927 <phrase role="special">...</phrase>
2928 <phrase role="special">;</phrase>
2930 <phrase role="special">...</phrase>
2931 <phrase role="special">}</phrase>
2934 The precondition functor should capture all the variables that it needs to
2935 assert the preconditions. These variables can be captured by value when the
2936 overhead of copying such variables is acceptable. <footnote id="boost_contract.tutorial.preconditions.f1">
2938 In this documentation preconditions often capture variables by reference
2939 to avoid extra copies.
2941 </footnote> In any case, programmers should not write precondition assertions
2942 that modify the value of the captured variables, even when those are captured
2943 by reference (see <link linkend="boost_contract.contract_programming_overview.constant_correctness">Constant-Correctness</link>).
2946 Any code can be programmed in the precondition functor, but it is recommended
2947 to keep this code simple using mainly assertions and if-statements (to avoid
2948 programming complex preconditions that might be buggy and also slow to check
2949 at run-time). It is also recommended to use <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_ASSERT">BOOST_CONTRACT_ASSERT</link></computeroutput>
2950 to program precondition assertions because that enables this library to print
2951 informative error messages when the asserted conditions are evaluated to
2952 be false (note that this is not a variadic macro, see <link linkend="boost_contract.extras.no_macros__and_no_variadic_macros_">No
2955 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><literal moreinfo="none"><emphasis>boolean-condition</emphasis></literal><phrase role="special">)</phrase>
2956 <phrase role="comment">// Or, if `boolean-condition` contains commas `,` not already within parenthesis `()`...</phrase>
2957 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">((</phrase><literal moreinfo="none"><emphasis>boolean-condition</emphasis></literal><phrase role="special">))</phrase> <phrase role="comment">// ...use extra parenthesis (not a variadic macro).</phrase>
2960 This library will automatically call the failure handler <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.precondition_failure">boost::contract::precondition_failure</link></computeroutput>
2961 if any of the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_ASSERT">BOOST_CONTRACT_ASSERT</link></computeroutput>
2962 conditions are false or, more in general, if calling the functor specified
2963 via <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">(...)</phrase></computeroutput> throws any exception. By default, this
2964 failure handler prints an error message to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">cerr</phrase></computeroutput>
2965 and terminates the program calling <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">terminate</phrase></computeroutput>
2966 (see <link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__">Throw
2967 on Failures</link> to change the failure handler to throw exceptions, exit
2968 the program with an error code, etc.).
2972 Contracts are most useful when their assertions only use public members
2973 that are accessible to the caller so the caller can properly check and
2974 use the contract. In particular, preconditions of a public function or
2975 constructor that use non-public members are essentially incorrect because
2976 they cannot be fully checked by the caller (in fact, Eiffel generates a
2977 compile-time error in this case). However, this library does not enforce
2978 such a constraint and it leaves it up to programmers to only use public
2979 members when programming contracts, especially when asserting preconditions
2980 (see <link linkend="boost_contract.contract_programming_overview.specifications_vs__implementation">Specifications
2981 vs. Implementation</link>).
2985 <section id="boost_contract.tutorial.postconditions">
2986 <title><link linkend="boost_contract.tutorial.postconditions">Postconditions</link></title>
2988 When postconditions are specified, they are programmed using a functor <literal moreinfo="none"><emphasis>s</emphasis></literal>
2989 passed to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">(</phrase></computeroutput><literal moreinfo="none"><emphasis>s</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">)</phrase></computeroutput> that can be called with no parameters as
2990 in <literal moreinfo="none"><emphasis>s</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">()</phrase></computeroutput>.
2991 Contracts that do not have postconditions simply do not call <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">(...)</phrase></computeroutput>. Postconditions must appear after preconditions
2992 but before exception guarantees when these are all present (see <link linkend="boost_contract.tutorial.preconditions">Preconditions</link>
2993 and <link linkend="boost_contract.tutorial.exception_guarantees">Exception
2997 C++11 lambda functions are convenient to program postconditions, but any
2998 other nullary functor can be used (see <link linkend="boost_contract.extras.no_lambda_functions__no_c__11_">No
2999 Lambda Functions</link>). For example, for <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.function">boost::contract::function</link></computeroutput>
3000 (similarly for all other contracts):
3002 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">void</phrase> <phrase role="identifier">f</phrase><phrase role="special">(...)</phrase> <phrase role="special">{</phrase>
3003 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">function</phrase><phrase role="special">()</phrase> <phrase role="comment">// Same for all other contracts.</phrase>
3004 <phrase role="special">...</phrase>
3005 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Capture by reference...</phrase>
3006 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(...);</phrase> <phrase role="comment">// ...but should not modify captures.</phrase>
3007 <phrase role="special">...</phrase>
3008 <phrase role="special">})</phrase>
3009 <phrase role="special">...</phrase>
3010 <phrase role="special">;</phrase>
3012 <phrase role="special">...</phrase>
3013 <phrase role="special">}</phrase>
3016 The postcondition functor should capture all the variables that it needs
3017 to assert the postconditions. In general, these variables should be captured
3018 by reference and not by value (because postconditions need to access the
3019 value that these variables will have at function exit, and not the value
3020 these variables had when the postcondition functor was first declared). Postconditions
3021 can also capture return and old values (see <link linkend="boost_contract.tutorial.return_values">Return
3022 Values</link> and <link linkend="boost_contract.tutorial.old_values">Old
3023 Values</link>). In any case, programmers should not write postcondition assertions
3024 that modify the value of the captured variables, even when those are captured
3025 by reference (see <link linkend="boost_contract.contract_programming_overview.constant_correctness">Constant-Correctness</link>).
3028 Any code can be programmed in the postcondition functor, but it is recommended
3029 to keep this code simple using mainly assertions and if-statements (to avoid
3030 programming complex postconditions that might be buggy and slow to check
3031 at run-time). It is also recommended to use <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_ASSERT">BOOST_CONTRACT_ASSERT</link></computeroutput>
3032 to program postcondition assertions because that enables this library to
3033 print informative error messages when the asserted conditions are evaluated
3034 to be false (note that this is not a variadic macro, see <link linkend="boost_contract.extras.no_macros__and_no_variadic_macros_">No
3037 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><literal moreinfo="none"><emphasis>boolean-condition</emphasis></literal><phrase role="special">)</phrase>
3038 <phrase role="comment">// Or, if `boolean-condition` has commas `,` not already within parenthesis `()`...</phrase>
3039 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">((</phrase><literal moreinfo="none"><emphasis>boolean-condition</emphasis></literal><phrase role="special">))</phrase> <phrase role="comment">// ...use extra parenthesis (not a variadic macro).</phrase>
3042 This library will automatically call the failure handler <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.postcondition_failure">boost::contract::postcondition_failure</link></computeroutput>
3043 if any of the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_ASSERT">BOOST_CONTRACT_ASSERT</link></computeroutput>
3044 conditions are false or, more in general, if calling the functor specified
3045 via <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">(...)</phrase></computeroutput> throws any exception. By default, this
3046 failure handler prints an error message to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">cerr</phrase></computeroutput>
3047 and terminates the program calling <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">terminate</phrase></computeroutput>
3048 (see <link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__">Throw
3049 on Failures</link> to change the failure handler to throw exceptions, exit
3050 the program with an error code, etc.).
3053 For non-void virtual public functions and non-void public function overrides,
3054 the functor <literal moreinfo="none"><emphasis>s</emphasis></literal> passed to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">(</phrase></computeroutput><literal moreinfo="none"><emphasis>s</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">)</phrase></computeroutput> is not a nullary functor, instead it is
3055 a unary functor taking a variable holding the return value as its one parameter
3056 <literal moreinfo="none"><emphasis>s</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">(</phrase></computeroutput><literal moreinfo="none"><emphasis>result</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">)</phrase></computeroutput> (this is to properly support subcontracting,
3057 see <link linkend="boost_contract.tutorial.virtual_public_functions">Virtual
3058 Public Functions</link> and <link linkend="boost_contract.tutorial.public_function_overrides__subcontracting_">Public
3059 Function Overrides</link>).
3062 <section id="boost_contract.tutorial.return_values">
3063 <title><link linkend="boost_contract.tutorial.return_values">Return Values</link></title>
3065 In non-void functions, postconditions might need to access the function return
3066 value to program assertions. In these cases, programmers are responsible
3067 to declare a local variable before the contract and to assign it to the return
3068 value at function exit (when the function does not throw an exception).
3069 <footnote id="boost_contract.tutorial.return_values.f0">
3071 The name of the local variable that holds the return value is arbitrary,
3072 but <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">result</phrase></computeroutput> is often used
3073 in this documentation.
3075 </footnote> For example, for <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.function">boost::contract::function</link></computeroutput>
3076 (similarly for all other contracts):
3078 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">return_type</phrase> <phrase role="identifier">f</phrase><phrase role="special">(...)</phrase> <phrase role="special">{</phrase>
3079 <phrase role="identifier">return_type</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase> <phrase role="comment">// Must be later assigned to return value.</phrase>
3080 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">function</phrase><phrase role="special">()</phrase> <phrase role="comment">// Same for all other contracts.</phrase>
3081 <phrase role="special">...</phrase>
3082 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Also capture `result` reference...</phrase>
3083 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">result</phrase> <phrase role="special">==</phrase> <phrase role="special">...);</phrase> <phrase role="comment">// ...but should not modify captures.</phrase>
3084 <phrase role="special">...</phrase>
3085 <phrase role="special">})</phrase>
3086 <phrase role="special">...</phrase>
3087 <phrase role="special">;</phrase>
3089 <phrase role="special">...</phrase>
3090 <phrase role="keyword">return</phrase> <phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="special">...;</phrase> <phrase role="comment">// Assign `result` at each return.</phrase>
3091 <phrase role="special">}</phrase>
3094 At any point where the enclosing function returns, programmers are responsible
3095 to assign the result variable to the expression being returned. This can
3096 be done ensuring that <emphasis>all</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">return</phrase></computeroutput>
3097 statements in the function are of the form:
3099 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><literal moreinfo="none"><emphasis>return-type</emphasis></literal> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
3100 <phrase role="special">...</phrase>
3101 <phrase role="keyword">return</phrase> <phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <literal moreinfo="none"><emphasis>return-expression</emphasis></literal><phrase role="special">;</phrase> <phrase role="comment">// Assign `result` at each return.</phrase>
3104 The functor used to program postconditions should capture the result variable
3105 by reference and not by value (because postconditions must access the value
3106 the result variable will have at function exit, and not the value the result
3107 variable had when the postcondition functor was first declared). The return
3108 value should never be used in preconditions, old value copies, or exception
3109 guarantees (because the return value is not yet correctly evaluated and set
3110 when preconditions are checked, old values are copied, or if the function
3111 throws an exception). In any case, programmers should not modify the result
3112 variable in the contract assertions (see <link linkend="boost_contract.contract_programming_overview.constant_correctness">Constant-Correctness</link>).
3115 It is also possible to declared the result variable using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">optional</phrase></computeroutput>
3116 when the function return type does not have a default constructor, or if
3117 the default constructor is too expensive or undesirable to execute when first
3118 declaring the result variable (see <link linkend="boost_contract.advanced.optional_return_values">Optional
3119 Return Values</link>).
3122 Non-void virtual public functions and non-void public function overrides
3123 must always declare and use a result variable even when postconditions do
3124 not directly use the function return value (this is to properly support subcontracting,
3125 see <link linkend="boost_contract.tutorial.virtual_public_functions">Virtual
3126 Public Functions</link> and <link linkend="boost_contract.tutorial.public_function_overrides__subcontracting_">Public
3127 Function Overrides</link>).
3130 <section id="boost_contract.tutorial.old_values">
3131 <title><link linkend="boost_contract.tutorial.old_values">Old Values</link></title>
3133 When old values are used in postconditions or in exception guarantees, programmes
3134 are responsible to declare local variables before the contract and to assign
3135 them to related old value expressions using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_OLDOF">BOOST_CONTRACT_OLDOF</link></computeroutput>.
3136 <footnote id="boost_contract.tutorial.old_values.f0">
3138 The name of a local variable that holds an old value is arbitrary, but
3139 <literal moreinfo="none">old_<emphasis>variable-name</emphasis></literal> is often used
3140 in this documentation.
3142 </footnote> For example, for <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.function">boost::contract::function</link></computeroutput>
3143 (similarly for all other contracts):
3145 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">void</phrase> <phrase role="identifier">f</phrase><phrase role="special">(...)</phrase> <phrase role="special">{</phrase>
3146 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="identifier">old_type</phrase><phrase role="special">></phrase> <phrase role="identifier">old_var</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">old_expr</phrase><phrase role="special">);</phrase>
3147 <phrase role="special">...</phrase> <phrase role="comment">// More old value declarations here if needed.</phrase>
3148 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">function</phrase><phrase role="special">()</phrase> <phrase role="comment">// Same for all other contracts.</phrase>
3149 <phrase role="special">...</phrase> <phrase role="comment">// Preconditions shall not use old values.</phrase>
3150 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Capture by reference...</phrase>
3151 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(*</phrase><phrase role="identifier">old_var</phrase> <phrase role="special">==</phrase> <phrase role="special">...);</phrase> <phrase role="comment">// ...but should not modify captures.</phrase>
3152 <phrase role="special">...</phrase>
3153 <phrase role="special">})</phrase>
3154 <phrase role="special">.</phrase><phrase role="identifier">except</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Capture by reference...</phrase>
3155 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">old_var</phrase><phrase role="special">->...);</phrase> <phrase role="comment">// ...but should not modify captures.</phrase>
3156 <phrase role="special">...</phrase>
3157 <phrase role="special">})</phrase>
3158 <phrase role="special">;</phrase>
3160 <phrase role="special">...</phrase>
3161 <phrase role="special">}</phrase>
3164 Old values are handled by this library using the smart pointer class template
3165 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.old_ptr">boost::contract::old_ptr</link></computeroutput>
3166 (so programmers do not directly manage allocation and deallocation of the
3167 pointed memory). <footnote id="boost_contract.tutorial.old_values.f1">
3169 <emphasis role="bold">Rationale:</emphasis> Old values have to be optional
3170 values because they need to be left uninitialized when they are not used
3171 because both postconditions and exception guarantees are disabled (defining
3172 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394999656032">BOOST_CONTRACT_NO_POSTCONDITIONS</link></computeroutput>
3173 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_NO_EXCEPTS">BOOST_CONTRACT_NO_EXCEPTS</link></computeroutput>).
3174 That is to avoid old value copies when old values are not used, either
3175 a pointer or (better) a <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">optional</phrase></computeroutput>
3176 could have been used to achieve that. In addition, old values need to be
3177 pointers internally allocated by this library so that they are never copied
3178 twice even when calling an overridden function multiple times to check
3179 preconditions, postconditions, etc. to implement subcontracting, so a smart
3180 pointer class template was used.
3182 </footnote> The pointed old value type is automatically qualified as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase></computeroutput> (so old values cannot be mistakenly
3183 changed by contract assertions, see <link linkend="boost_contract.contract_programming_overview.constant_correctness">Constant-Correctness</link>).
3184 This library ensures that old value pointers are always not null by the time
3185 postconditions and exception guarantees are checked (so programmers can safely
3186 dereference and use these pointers in postcondition and exception guarantee
3187 assertions using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">operator</phrase><phrase role="special">*</phrase></computeroutput>
3188 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">operator</phrase><phrase role="special">-></phrase></computeroutput>
3189 without having to check if old value pointers are not null first).
3192 Old values should not be used in preconditions and this library does not
3193 guarantee that old value pointers are always not null when preconditions
3194 are checked. <footnote id="boost_contract.tutorial.old_values.f2">
3196 For example, old value pointers might be null in preconditions when postconditions
3197 and exception guarantees are disabled defining <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394999656032">BOOST_CONTRACT_NO_POSTCONDITIONS</link></computeroutput>
3198 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_NO_EXCEPTS">BOOST_CONTRACT_NO_EXCEPTS</link></computeroutput>
3199 (but also when checking an overridden virtual public function contract
3200 via subcontracting, etc.).
3202 </footnote> See <link linkend="boost_contract.advanced.old_values_copied_at_body">Old
3203 Values Copied at Body</link> for delaying the copy of old values until after
3204 class invariants (for constructors, destructors, and public functions) and
3205 preconditions are checked (when necessary, this allows to program old value
3206 expressions under the simplifying assumption that class invariant and precondition
3207 assertions are satisfied already).
3210 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_OLDOF">BOOST_CONTRACT_OLDOF</link></computeroutput> is
3211 a variadic macro and it takes an extra parameter when used in virtual public
3212 functions or public function overrides (see <link linkend="boost_contract.tutorial.virtual_public_functions">Virtual
3213 Public Functions</link> and <link linkend="boost_contract.tutorial.public_function_overrides__subcontracting_">Public
3214 Function Overrides</link>). C++11 auto declarations can be used with <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_OLDOF">BOOST_CONTRACT_OLDOF</link></computeroutput> for brevity
3215 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">auto</phrase> </computeroutput><literal moreinfo="none">old_<emphasis>variable-name</emphasis>
3216 = BOOST_CONTRACT_OLDOF(<emphasis>expression</emphasis>)</literal> (but see
3217 also <link linkend="boost_contract.extras.old_value_requirements__templates_">Old
3218 Value Requirements</link>). See <link linkend="boost_contract.extras.no_macros__and_no_variadic_macros_">No
3219 Macros</link> to program old values without using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_OLDOF">BOOST_CONTRACT_OLDOF</link></computeroutput>
3220 (e.g., on compilers that do not support variadic macros).
3224 This library ensures that old values are copied only once. This library
3225 also ensures that old values are never copied when postconditions and exception
3226 guarantees are disabled defining both <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394999656032">BOOST_CONTRACT_NO_POSTCONDITIONS</link></computeroutput>
3227 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_NO_EXCEPTS">BOOST_CONTRACT_NO_EXCEPTS</link></computeroutput>
3228 (note that both these two macros must be defined, defining only <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394999656032">BOOST_CONTRACT_NO_POSTCONDITIONS</link></computeroutput>
3229 or only <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_NO_EXCEPTS">BOOST_CONTRACT_NO_EXCEPTS</link></computeroutput>
3230 is not sufficient to prevent the run-time cost of old value copies).
3234 <section id="boost_contract.tutorial.exception_guarantees">
3235 <title><link linkend="boost_contract.tutorial.exception_guarantees">Exception
3236 Guarantees</link></title>
3238 When exception guarantees are specified, they are programmed using a functor
3239 <literal moreinfo="none"><emphasis>e</emphasis></literal> passed to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">except</phrase><phrase role="special">(</phrase></computeroutput><literal moreinfo="none"><emphasis>e</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">)</phrase></computeroutput> that can be called with no parameters as
3240 in <literal moreinfo="none"><emphasis>e</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">()</phrase></computeroutput>.
3241 Contracts that do not have exception guarantees simply do not call <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">except</phrase><phrase role="special">(...)</phrase></computeroutput>. Exception guarantees must appear after
3242 both preconditions and postconditions when these are all present (see <link linkend="boost_contract.tutorial.preconditions">Preconditions</link> and
3243 <link linkend="boost_contract.tutorial.postconditions">Postconditions</link>).
3246 C++11 lambda functions are convenient to program exception guarantees, but
3247 any other nullary functor can be used (see <link linkend="boost_contract.extras.no_lambda_functions__no_c__11_">No
3248 Lambda Functions</link>). For example, for <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.function">boost::contract::function</link></computeroutput>
3249 (similarly for all other contracts):
3251 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">void</phrase> <phrase role="identifier">f</phrase><phrase role="special">(...)</phrase> <phrase role="special">{</phrase>
3252 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">function</phrase><phrase role="special">()</phrase> <phrase role="comment">// Same for all other contracts.</phrase>
3253 <phrase role="special">...</phrase>
3254 <phrase role="special">.</phrase><phrase role="identifier">except</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Capture by reference...</phrase>
3255 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(...);</phrase> <phrase role="comment">// ...but should not modify captures.</phrase>
3256 <phrase role="special">...</phrase>
3257 <phrase role="special">})</phrase>
3258 <phrase role="special">;</phrase>
3260 <phrase role="special">...</phrase>
3261 <phrase role="special">}</phrase>
3264 The exception guarantee functor should capture all the variables that it
3265 needs to assert the exception guarantees. In general, these variables should
3266 be captured by reference and not by value (because exception guarantees need
3267 to access the value that these variables will have when the function throws,
3268 and not the value these variables had when the exception guarantee functor
3269 was first declared). Exception guarantees can also capture old values (see
3270 <link linkend="boost_contract.tutorial.old_values">Old Values</link>) but
3271 they should not access the function return value instead (because the return
3272 value is not be properly set when the function throws an exception). In any
3273 case, programmers should not write exception guarantee assertions that modify
3274 the value of the captured variables, even when those are captured by reference
3275 (see <link linkend="boost_contract.contract_programming_overview.constant_correctness">Constant-Correctness</link>).
3279 In real production code, it might be difficult to program meaningful exception
3280 guarantees without resorting to expensive old value copies that will slow
3281 down execution. Therefore, the authors recognize that exception guarantees,
3282 even if supported by this library, might not be used often in practice
3283 (and they are not used in most of the examples listed in the rest of this
3284 documentation). In any case, these performance considerations are ultimately
3285 left to programmers and their specific application domains.
3289 Any code can be programmed in the exception guarantee functor, but it is
3290 recommended to keep this code simple using mainly assertions and if-statements
3291 (to avoid programming complex exception guarantees that might be buggy and
3292 slow to check at run-time). It is also recommended to use <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_ASSERT">BOOST_CONTRACT_ASSERT</link></computeroutput>
3293 to program exception guarantee assertions because that enables this library
3294 to print informative error messages when the asserted conditions are evaluated
3295 to be false (note that this is not a variadic macro, see <link linkend="boost_contract.extras.no_macros__and_no_variadic_macros_">No
3298 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><literal moreinfo="none"><emphasis>boolean-condition</emphasis></literal><phrase role="special">)</phrase>
3299 <phrase role="comment">// Or, if `boolean-condition` has commas `,` not already within parenthesis `()`...</phrase>
3300 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">((</phrase><literal moreinfo="none"><emphasis>boolean-condition</emphasis></literal><phrase role="special">))</phrase> <phrase role="comment">// ...use extra parenthesis (not a variadic macro).</phrase>
3303 This library will automatically call the failure handler <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.except_failure">boost::contract::except_failure</link></computeroutput>
3304 if any of the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_ASSERT">BOOST_CONTRACT_ASSERT</link></computeroutput>
3305 conditions are false or, more in general, if calling the functor specified
3306 via <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">except</phrase><phrase role="special">(...)</phrase></computeroutput> throws any exception. By default, this
3307 failure handler prints an error message to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">cerr</phrase></computeroutput>
3308 and terminates the program calling <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">terminate</phrase></computeroutput>
3309 (see <link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__">Throw
3310 on Failures</link> to change the failure handler to exit the program with
3311 an error code or to take some other custom action).
3315 While it is technically possible for programmers to specify an exception
3316 guarantee handler that throws an exception in case of an exception guarantee
3317 failure, this will force C++ to terminate the program. That is because
3318 the handler will throw an exception while there is already an active exception
3319 on the stack (the exception thrown by the function body that caused the
3320 exception guarantees to be checked in the first place). Therefore, programmers
3321 should not change the exception guarantee failure handler to throw exceptions.
3325 <section id="boost_contract.tutorial.class_invariants">
3326 <title><link linkend="boost_contract.tutorial.class_invariants">Class Invariants</link></title>
3328 Public member functions, constructors, and destructors can be programmed
3329 to also check class invariants. When class invariants are specified, they
3330 are programmed in a public <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase></computeroutput>
3331 function named <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">invariant</phrase></computeroutput>
3332 taking no argument and returning <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">void</phrase></computeroutput>.
3333 Classes that do not have invariants, simply do not declare the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">invariant</phrase></computeroutput> function. <footnote id="boost_contract.tutorial.class_invariants.f0">
3335 This library uses template meta-programming (SFINAE-based introspection
3336 techniques) to check invariants only for classes that declare a member
3337 function named by <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394999724496">BOOST_CONTRACT_INVARIANT_FUNC</link></computeroutput>.
3339 </footnote> For example:
3341 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">class</phrase> <phrase role="identifier">u</phrase> <phrase role="special">{</phrase>
3342 <phrase role="keyword">public</phrase><phrase role="special">:</phrase> <phrase role="comment">// Must be public.</phrase>
3343 <phrase role="keyword">void</phrase> <phrase role="identifier">invariant</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Must be const.</phrase>
3344 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(...);</phrase>
3345 <phrase role="special">...</phrase>
3346 <phrase role="special">}</phrase>
3348 <phrase role="special">...</phrase>
3349 <phrase role="special">};</phrase>
3352 This member function must be <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase></computeroutput>
3353 because contracts should not modify the object state (see <link linkend="boost_contract.contract_programming_overview.constant_correctness">Constant-Correctness</link>).
3354 This library will generate a compile-time error if the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase></computeroutput>
3355 qualifier is missing (unless <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_PERMISSIVE">BOOST_CONTRACT_PERMISSIVE</link></computeroutput>
3359 Any code can be programmed in the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">invariant</phrase></computeroutput>
3360 function, but it is recommended to keep this code simple using mainly assertions
3361 and if-statements (to avoid programming complex invariants that might be
3362 buggy and slow to check at run-time). It is also recommended to use <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_ASSERT">BOOST_CONTRACT_ASSERT</link></computeroutput> to program
3363 class invariant assertions because that enables this library to print informative
3364 error messages when the asserted conditions are evaluated to be false (note
3365 that this is not a variadic macro, see <link linkend="boost_contract.extras.no_macros__and_no_variadic_macros_">No
3368 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><literal moreinfo="none"><emphasis>boolean-condition</emphasis></literal><phrase role="special">)</phrase>
3369 <phrase role="comment">// Or, if `boolean-condition` has commas `,` not already within parenthesis `()`...</phrase>
3370 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">((</phrase><literal moreinfo="none"><emphasis>boolean-condition</emphasis></literal><phrase role="special">))</phrase> <phrase role="comment">// ...use extra parenthesis (not a variadic macro).</phrase>
3373 This library will automatically call failure handlers <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.entry_invariant_failure">boost::contract::entry_invariant_failure</link></computeroutput>
3374 or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.exit_invariant_failure">boost::contract::exit_invariant_failure</link></computeroutput>
3375 if any of the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_ASSERT">BOOST_CONTRACT_ASSERT</link></computeroutput>
3376 conditions are false or, more in general, if the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">invariant</phrase></computeroutput>
3377 function throws an exception when invariants are checked at function entry
3378 or exit respectively. By default, these handlers print an error message to
3379 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">cerr</phrase></computeroutput> and terminate the program calling
3380 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">terminate</phrase></computeroutput> (see <link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__">Throw
3381 on Failures</link> to change these failure handlers to throw exceptions,
3382 exit the program with an error code, etc.).
3385 See <link linkend="boost_contract.advanced.access_specifiers">Access Specifiers</link>
3386 to avoid making the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">invariant</phrase></computeroutput>
3387 member function <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">public</phrase></computeroutput>. <footnote id="boost_contract.tutorial.class_invariants.f1">
3389 In this documentation the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">invariant</phrase></computeroutput>
3390 member function is often declared <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">public</phrase></computeroutput>
3391 for simplicity. However, in production code it might not be acceptable
3392 to augment the public members of a class adding the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">invariant</phrase></computeroutput>
3393 function (and that can be avoided using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.access">boost::contract::access</link></computeroutput>
3394 as explained in <link linkend="boost_contract.advanced.access_specifiers">Access
3397 </footnote> See <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394999724496">BOOST_CONTRACT_INVARIANT_FUNC</link></computeroutput>
3398 to use a name different from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">invariant</phrase></computeroutput>
3399 (e.g., because <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">invariant</phrase></computeroutput>
3400 clashes with other names in user-defined classes).
3404 Contract assertions are not checked (not even class invariants) when data
3405 members are accessed directly (this is different from Eiffel where even
3406 accessing public data members checks class invariants). Therefore, it might
3407 be best for both <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">class</phrase></computeroutput>es and
3408 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">struct</phrase></computeroutput>s (and also <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">union</phrase></computeroutput>s, see <link linkend="boost_contract.extras.unions">Unions</link>)
3409 that have invariants to have no mutable public data members and to access
3410 data members publicly only via appropriate public functions (e.g., setters
3411 and getters) that can be programmed to check the class invariants using
3416 See <link linkend="boost_contract.extras.volatile_public_functions">Volatile
3417 Public Functions</link> to program invariants for classes with <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">volatile</phrase></computeroutput> public functions.
3419 <bridgehead renderas="sect4" id="boost_contract.tutorial.class_invariants.h0">
3420 <phrase id="boost_contract.tutorial.class_invariants.static_class_invariants"/><link linkend="boost_contract.tutorial.class_invariants.static_class_invariants">Static
3421 Class Invariants</link>
3424 Static public functions can be programmed to check static class invariants.
3425 When static class invariants are specified, they are programmed in a public
3426 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">static</phrase></computeroutput> function named <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">static_invariant</phrase></computeroutput> taking no argument and
3427 returning <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">void</phrase></computeroutput>. Classes that
3428 do not have static class invariants, simply do not declare the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">static_invariant</phrase></computeroutput> function. <footnote id="boost_contract.tutorial.class_invariants.f2">
3430 This library uses template meta-programming (SFINAE-based introspection
3431 techniques) to check static invariants only for classes that declare a
3432 member function named by <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394999714768">BOOST_CONTRACT_STATIC_INVARIANT_FUNC</link></computeroutput>.
3434 </footnote> For example:
3436 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">class</phrase> <phrase role="identifier">u</phrase> <phrase role="special">{</phrase>
3437 <phrase role="keyword">public</phrase><phrase role="special">:</phrase> <phrase role="comment">// Must be public.</phrase>
3438 <phrase role="keyword">static</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">static_invariant</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Must be static.</phrase>
3439 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(...);</phrase>
3440 <phrase role="special">...</phrase>
3441 <phrase role="special">}</phrase>
3443 <phrase role="special">...</phrase>
3444 <phrase role="special">};</phrase>
3447 This member function must be <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">static</phrase></computeroutput>
3448 (and it correctly cannot access the object <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">this</phrase></computeroutput>).
3449 This library will generate a compile-time error if the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">static</phrase></computeroutput>
3450 classifier is missing (unless the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_PERMISSIVE">BOOST_CONTRACT_PERMISSIVE</link></computeroutput>
3454 Any code can be programmed in the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">static_invariant</phrase></computeroutput>
3455 function, but it is recommended to keep this code simple using mainly assertions
3456 and if-statements (to avoid programming complex static invariants that might
3457 be buggy and slow to check at run-time). It is also recommended to use <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_ASSERT">BOOST_CONTRACT_ASSERT</link></computeroutput> to program
3458 the assertions because that enables this library to print informative error
3459 messages when the asserted conditions are evaluated to be false (note that
3460 this is not a variadic macro, see <link linkend="boost_contract.extras.no_macros__and_no_variadic_macros_">No
3463 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><literal moreinfo="none"><emphasis>boolean-condition</emphasis></literal><phrase role="special">)</phrase>
3464 <phrase role="comment">// Or, if `boolean-condition` has commas `,` not already within parenthesis `()`...</phrase>
3465 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">((</phrase><literal moreinfo="none"><emphasis>boolean-condition</emphasis></literal><phrase role="special">))</phrase> <phrase role="comment">// ...use extra parenthesis (not a variadic macro).</phrase>
3468 This library will automatically call failure handlers <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.entry_invariant_failure">boost::contract::entry_invariant_failure</link></computeroutput>
3469 or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.exit_invariant_failure">boost::contract::exit_invariant_failure</link></computeroutput>
3470 if any of the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_ASSERT">BOOST_CONTRACT_ASSERT</link></computeroutput>
3471 conditions are false or, more in general, if the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">static_invariant</phrase></computeroutput>
3472 function throws an exception when invariants are checked at function entry
3473 or exit respectively. By default, these handlers print an error message to
3474 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">cerr</phrase></computeroutput> and terminate the program calling
3475 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">terminate</phrase></computeroutput> (see <link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__">Throw
3476 on Failures</link> to change these failure handlers to throw exceptions,
3477 exit the program with an error code, etc.).
3480 See <link linkend="boost_contract.advanced.access_specifiers">Access Specifiers</link>
3481 to avoid making <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">static_invariant</phrase></computeroutput>
3482 member function <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">public</phrase></computeroutput>. <footnote id="boost_contract.tutorial.class_invariants.f3">
3484 In this documentation the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">static_invariant</phrase></computeroutput>
3485 member function is often declared <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">public</phrase></computeroutput>
3486 for simplicity. However, in production code it might not be acceptable
3487 to augment the public members of a class adding the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">static_invariant</phrase></computeroutput>
3488 function (and that can be avoided using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.access">boost::contract::access</link></computeroutput>
3489 as explained in <link linkend="boost_contract.advanced.access_specifiers">Access
3492 </footnote> See <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394999714768">BOOST_CONTRACT_STATIC_INVARIANT_FUNC</link></computeroutput>
3493 to use a name different from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">static_invariant</phrase></computeroutput>
3494 (e.g., because <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">static_invariant</phrase></computeroutput>
3495 clashes with other names in user-defined classes). <footnote id="boost_contract.tutorial.class_invariants.f4">
3497 <emphasis role="bold">Rationale:</emphasis> In C++, it is not possible
3498 to overload a member function based on the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">static</phrase></computeroutput>
3499 classifier. Therefore, this library has to use different names for the
3500 member functions checking non-static and static class invariants (namely
3501 for <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394999724496">BOOST_CONTRACT_INVARIANT_FUNC</link></computeroutput>
3502 and for <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394999714768">BOOST_CONTRACT_STATIC_INVARIANT_FUNC</link></computeroutput>).
3507 <section id="boost_contract.tutorial.constructors">
3508 <title><link linkend="boost_contract.tutorial.constructors">Constructors</link></title>
3510 Contracts for constructors are programmed using the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.constructor">boost::contract::constructor</link></computeroutput>
3511 function and the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.constructor_precondition">boost::contract::constructor_precondition</link></computeroutput>
3512 base class. For example (see <ulink url="../../example/features/public.cpp"><literal moreinfo="none">public.cpp</literal></ulink>):
3515 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">class</phrase> <phrase role="identifier">unique_identifiers</phrase> <phrase role="special">:</phrase>
3516 <phrase role="keyword">private</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor_precondition</phrase><phrase role="special"><</phrase><phrase role="identifier">unique_identifiers</phrase><phrase role="special">></phrase>
3517 <phrase role="special">{</phrase>
3518 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
3519 <phrase role="keyword">void</phrase> <phrase role="identifier">invariant</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
3520 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">>=</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase>
3521 <phrase role="special">}</phrase>
3525 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">public</phrase><phrase role="special">:</phrase>
3526 <phrase role="comment">// Contract for a constructor.</phrase>
3527 <phrase role="identifier">unique_identifiers</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">from</phrase><phrase role="special">,</phrase> <phrase role="keyword">int</phrase> <phrase role="identifier">to</phrase><phrase role="special">)</phrase> <phrase role="special">:</phrase>
3528 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor_precondition</phrase><phrase role="special"><</phrase><phrase role="identifier">unique_identifiers</phrase><phrase role="special">>([&]</phrase> <phrase role="special">{</phrase>
3529 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">from</phrase> <phrase role="special">>=</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase>
3530 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">to</phrase> <phrase role="special">>=</phrase> <phrase role="identifier">from</phrase><phrase role="special">);</phrase>
3531 <phrase role="special">})</phrase>
3532 <phrase role="special">{</phrase>
3533 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
3534 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
3535 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">(</phrase><phrase role="identifier">to</phrase> <phrase role="special">-</phrase> <phrase role="identifier">from</phrase> <phrase role="special">+</phrase> <phrase role="number">1</phrase><phrase role="special">));</phrase>
3536 <phrase role="special">})</phrase>
3537 <phrase role="special">;</phrase>
3539 <phrase role="comment">// Constructor body.</phrase>
3540 <phrase role="keyword">for</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">id</phrase> <phrase role="special">=</phrase> <phrase role="identifier">from</phrase><phrase role="special">;</phrase> <phrase role="identifier">id</phrase> <phrase role="special"><=</phrase> <phrase role="identifier">to</phrase><phrase role="special">;</phrase> <phrase role="special">++</phrase><phrase role="identifier">id</phrase><phrase role="special">)</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">push_back</phrase><phrase role="special">(</phrase><phrase role="identifier">id</phrase><phrase role="special">);</phrase>
3541 <phrase role="special">}</phrase>
3545 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="comment">/* ... */</phrase>
3546 <phrase role="special">};</phrase>
3550 It is not possible to specify preconditions using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">(...)</phrase></computeroutput>
3551 for constructors (this library will generate a compile-time error if <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">(...)</phrase></computeroutput> is used on the object returned by <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.constructor">boost::contract::constructor</link></computeroutput>).
3552 Constructor preconditions are specified using the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.constructor_precondition">boost::contract::constructor_precondition</link></computeroutput>
3553 base class instead (same considerations as the ones made in <link linkend="boost_contract.tutorial.preconditions">Preconditions</link>
3554 apply also to the precondition functor passed to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.constructor_precondition">boost::contract::constructor_precondition</link></computeroutput>).
3555 Programmes should not access the object <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">*</phrase><phrase role="keyword">this</phrase></computeroutput> from constructor preconditions (because
3556 the object does not exists yet before the constructor body is executed).
3557 <footnote id="boost_contract.tutorial.constructors.f0">
3559 See <link linkend="boost_contract.extras.no_lambda_functions__no_c__11_">No
3560 Lambda Functions</link> to enforce this constraint at compile-time (but
3561 not recommended because of extra boiler-plate code).
3563 </footnote> Constructors without preconditions simply do not explicitly initialize
3564 the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.constructor_precondition">boost::contract::constructor_precondition</link></computeroutput>
3565 base (because <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.constructor_precondition">boost::contract::constructor_precondition</link></computeroutput>
3566 default constructor checks no contract). When the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.constructor_precondition">boost::contract::constructor_precondition</link></computeroutput>
3567 base class is used: <footnote id="boost_contract.tutorial.constructors.f1">
3569 There is a MSVC bug that was fixed in MSVC 2013 for which lambdas cannot
3570 be used in constructor member initialization lists for templates. On MSVC
3571 compilers with that bug, an extra (static) member function can be used
3572 (together with <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">bind</phrase></computeroutput> and
3573 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">cref</phrase></computeroutput> as needed) to program
3574 constructor preconditions instead of using lambdas (see <link linkend="boost_contract.extras.no_lambda_functions__no_c__11_">No
3575 Lambda Functions</link>).
3582 It should be specified as the <emphasis>first</emphasis> class in the
3583 inheritance list (so constructor preconditions are checked before initializing
3584 any other base class or data member).
3589 Its inheritance access specifier should always be <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">private</phrase></computeroutput>
3590 (so this extra base class does not alter the public inheritance tree
3591 of its derived classes).
3596 It should never be declared as a <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">virtual</phrase></computeroutput>
3597 base (because virtual bases are initialized only once across the entire
3598 inheritance hierarchy preventing preconditions of other base classes
3599 from being checked).
3604 It takes the derived class as template parameter. <footnote id="boost_contract.tutorial.constructors.f2">
3606 <emphasis role="bold">Rationale:</emphasis> The <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.constructor_precondition">boost::contract::constructor_precondition</link></computeroutput>
3607 takes the derived class as its template parameter (using the Curiously
3608 Recursive Template Pattern, CRTP) so the instantiated template type
3609 is unique for each derived class. This always avoids base class ambiguity
3610 resolution errors even when multiple inheritance is used. Note that,
3611 as already mentioned, virtual inheritance could not be used instead
3612 of the template parameter here to resolve ambiguities (because virtual
3613 bases are initialized only once by the outer-most derived class, and
3614 that would not allow to properly check preconditions of all base classes).
3622 A class can avoid inheriting from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.constructor_precondition">boost::contract::constructor_precondition</link></computeroutput>
3623 for efficiency but only when all its constructors have no preconditions.
3627 It is possible to specify postconditions for constructors (see <link linkend="boost_contract.tutorial.postconditions">Postconditions</link>),
3628 but programmers should not access the old value of the object <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">*</phrase><phrase role="keyword">this</phrase></computeroutput> in constructor
3629 postconditions (because the object did not exist yet before the constructor
3630 body was executed). <footnote id="boost_contract.tutorial.constructors.f3">
3632 See <link linkend="boost_contract.extras.no_lambda_functions__no_c__11_">No
3633 Lambda Functions</link> to enforce this constraint at compile-time (but
3634 not recommended because of extra boiler-plate code).
3636 </footnote> It is also possible to specify exceptions guarantees for constructors
3637 (see <link linkend="boost_contract.tutorial.exception_guarantees">Exception
3638 Guarantees</link>), but programmers should not access the object <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">*</phrase><phrase role="keyword">this</phrase></computeroutput> or its
3639 old value in constructor exception guarantees (because the object did not
3640 exist before executing the constructor body and it was not properly constructed
3641 given the constructor body threw an exception). <footnote id="boost_contract.tutorial.constructors.f4">
3643 See <link linkend="boost_contract.extras.no_lambda_functions__no_c__11_">No
3644 Lambda Functions</link> to enforce these constraints at compile-time (but
3645 not recommended because of extra boiler-plate code).
3647 </footnote> The <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.constructor">boost::contract::constructor</link></computeroutput>
3648 function takes <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">this</phrase></computeroutput> as a parameter
3649 (because constructors check class invariants, see <link linkend="boost_contract.tutorial.class_invariants">Class
3653 The <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.constructor">boost::contract::constructor</link></computeroutput>
3654 function returns an RAII object that must always be assigned to a local variable
3655 of type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.check">boost::contract::check</link></computeroutput>
3656 (otherwise this library will generate a run-time error, see <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394999694064">BOOST_CONTRACT_ON_MISSING_CHECK_DECL</link></computeroutput>).
3657 Furthermore, C++11 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">auto</phrase></computeroutput> declarations
3658 cannot be used here and the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.check">boost::contract::check</link></computeroutput>
3659 type must be explicitly specified (otherwise this library will generate a
3660 compile-time error prior C++17 and a run-time error post C++17). The constructor
3661 body is programmed right after the declaration of this RAII object.
3664 At construction, the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.check">boost::contract::check</link></computeroutput>
3665 RAII object for constructors does the following (enclosing constructor entry):
3667 <orderedlist inheritnum="ignore" continuation="restarts">
3670 Check static class invariants, by calling <literal moreinfo="none"><emphasis>type-of</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">(*</phrase><phrase role="keyword">this</phrase><phrase role="special">)::</phrase><phrase role="identifier">static_invariant</phrase><phrase role="special">()</phrase></computeroutput> (but not non-static class invariants
3671 because the object does not exist yet).
3676 At destruction instead (enclosing constructor exit):
3678 <orderedlist inheritnum="ignore" continuation="restarts">
3681 Check static class invariants, by calling <literal moreinfo="none"><emphasis>type-of</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">(*</phrase><phrase role="keyword">this</phrase><phrase role="special">)::</phrase><phrase role="identifier">static_invariant</phrase><phrase role="special">()</phrase></computeroutput>.
3686 If the constructor body did not throw an exception:
3687 <orderedlist inheritnum="ignore" continuation="restarts">
3690 Check non-static class invariants, by calling <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">this</phrase><phrase role="special">-></phrase><phrase role="identifier">invariant</phrase><phrase role="special">()</phrase></computeroutput>.
3695 Check postconditions, by calling the nullary functor <literal moreinfo="none"><emphasis>s</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">()</phrase></computeroutput> passed to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">(</phrase></computeroutput><literal moreinfo="none"><emphasis>s</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">)</phrase></computeroutput>.
3704 <orderedlist inheritnum="ignore" continuation="restarts">
3707 Check exception guarantees, by calling the nullary functor <literal moreinfo="none"><emphasis>e</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">()</phrase></computeroutput> passed to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">except</phrase><phrase role="special">(</phrase></computeroutput><literal moreinfo="none"><emphasis>e</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">)</phrase></computeroutput>.
3715 This together with C++ object construction mechanism of base classes and
3716 the use of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.constructor_precondition">boost::contract::constructor_precondition</link></computeroutput>
3717 ensures that the constructor contracts are correctly checked at run-time
3718 (see <link linkend="boost_contract.contract_programming_overview.constructor_calls">Constructor
3723 A constructor can avoid calling <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.constructor">boost::contract::constructor</link></computeroutput>
3724 for efficiency but only when it has no postconditions, no exception guarantees,
3725 and its class has no invariants (even if <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.constructor">boost::contract::constructor</link></computeroutput>
3726 is not used by a derived class, contracts of base class constructors will
3727 still be correctly checked by C++ object construction mechanism).
3730 The default constructor and copy constructor automatically generated by
3731 C++ will not check contracts. Therefore, unless these constructors are
3732 not public or they have no preconditions, no postconditions, no exception
3733 guarantees, and their class has no invariants, programmers should manually
3734 define them using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.constructor">boost::contract::constructor</link></computeroutput>
3735 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.constructor_precondition">boost::contract::constructor_precondition</link></computeroutput>.
3736 Similar considerations apply to all other constructors automatically generated
3737 by C++ (e.g., the move constructor).
3740 <bridgehead renderas="sect4" id="boost_contract.tutorial.constructors.h0">
3741 <phrase id="boost_contract.tutorial.constructors.private_and_protected_constructors"/><link linkend="boost_contract.tutorial.constructors.private_and_protected_constructors">Private
3742 and Protected Constructors</link>
3745 Private and protected constructors can omit <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.constructor">boost::contract::constructor</link></computeroutput>
3746 (because they are not part of the public interface of the class so they are
3747 not required to check class invariants, see <link linkend="boost_contract.contract_programming_overview.constructor_calls">Constructor
3748 Calls</link>). They could still use <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.constructor_precondition">boost::contract::constructor_precondition</link></computeroutput>
3749 to check preconditions before member initializations, and even use <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.function">boost::contract::function</link></computeroutput>
3750 (but not <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.constructor">boost::contract::constructor</link></computeroutput>)
3751 to only check postconditions and exception guarantees without checking class
3752 invariants and without calling <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">(...)</phrase></computeroutput>
3753 (see <link linkend="boost_contract.advanced.private_and_protected_functions">Private
3754 and Protected Functions</link>). For example:
3756 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">class</phrase> <phrase role="identifier">u</phrase> <phrase role="special">:</phrase> <phrase role="keyword">private</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor_precondition</phrase><phrase role="special"><</phrase><phrase role="identifier">u</phrase><phrase role="special">></phrase> <phrase role="special">{</phrase>
3757 <phrase role="keyword">protected</phrase><phrase role="special">:</phrase>
3758 <phrase role="comment">// Contract for a protected constructor (same for private constructors).</phrase>
3759 <phrase role="identifier">u</phrase><phrase role="special">()</phrase> <phrase role="special">:</phrase> <phrase role="comment">// Still use this base class to check constructor preconditions.</phrase>
3760 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor_precondition</phrase><phrase role="special"><</phrase><phrase role="identifier">u</phrase><phrase role="special">>([&]</phrase> <phrase role="special">{</phrase>
3761 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(...);</phrase>
3762 <phrase role="special">...</phrase>
3763 <phrase role="special">})</phrase>
3764 <phrase role="special">{</phrase>
3765 <phrase role="comment">// Following will correctly not check class invariants.</phrase>
3766 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">function</phrase><phrase role="special">()</phrase>
3767 <phrase role="comment">// Do not use `.precondition(...)` here.</phrase>
3768 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
3769 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(...);</phrase>
3770 <phrase role="special">...</phrase>
3771 <phrase role="special">})</phrase>
3772 <phrase role="special">.</phrase><phrase role="identifier">except</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
3773 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(...);</phrase>
3774 <phrase role="special">...</phrase>
3775 <phrase role="special">})</phrase>
3776 <phrase role="special">;</phrase>
3778 <phrase role="special">...</phrase> <phrase role="comment">// Constructor body.</phrase>
3779 <phrase role="special">}</phrase>
3781 <phrase role="special">...</phrase>
3782 <phrase role="special">};</phrase>
3785 <section id="boost_contract.tutorial.destructors">
3786 <title><link linkend="boost_contract.tutorial.destructors">Destructors</link></title>
3788 Contracts for destructors are programmed using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.destructor">boost::contract::destructor</link></computeroutput>.
3789 For example (see <ulink url="../../example/features/public.cpp"><literal moreinfo="none">public.cpp</literal></ulink>):
3792 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">class</phrase> <phrase role="identifier">unique_identifiers</phrase> <phrase role="special">:</phrase>
3793 <phrase role="keyword">private</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor_precondition</phrase><phrase role="special"><</phrase><phrase role="identifier">unique_identifiers</phrase><phrase role="special">></phrase>
3794 <phrase role="special">{</phrase>
3795 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
3796 <phrase role="keyword">void</phrase> <phrase role="identifier">invariant</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
3797 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">>=</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase>
3798 <phrase role="special">}</phrase>
3802 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">public</phrase><phrase role="special">:</phrase>
3803 <phrase role="comment">// Contract for a destructor.</phrase>
3804 <phrase role="keyword">virtual</phrase> <phrase role="special">~</phrase><phrase role="identifier">unique_identifiers</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
3805 <phrase role="comment">// Following contract checks class invariants.</phrase>
3806 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">destructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
3808 <phrase role="comment">// Destructor body here... (do nothing in this example).</phrase>
3809 <phrase role="special">}</phrase>
3813 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="comment">/* ... */</phrase>
3814 <phrase role="special">};</phrase>
3818 It is not possible to specify preconditions for destructors (this library
3819 will generate a compile-time error if <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">(...)</phrase></computeroutput>
3820 is used here and that is because destructors can be called at any time after
3821 construction so they have no precondition). It is possible to specify postconditions
3822 for destructors (see <link linkend="boost_contract.tutorial.postconditions">Postconditions</link>,
3823 and also <link linkend="boost_contract.tutorial.static_public_functions">Static
3824 Public Functions</link> for an example), but programmers should not access
3825 the object <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">*</phrase><phrase role="keyword">this</phrase></computeroutput>
3826 in destructor postconditions (because the object no longer exists after the
3827 destructor body has been executed). <footnote id="boost_contract.tutorial.destructors.f0">
3829 See <link linkend="boost_contract.extras.no_lambda_functions__no_c__11_">No
3830 Lambda Functions</link> to enforce this constraint at compile-time (but
3831 not recommended because of extra boiler-plate code).
3833 </footnote> It is also possible to specify exceptions guarantees for destructors
3834 (see <link linkend="boost_contract.tutorial.exception_guarantees">Exception
3835 Guarantees</link>, even if destructors should usually be programmed to not
3836 throw exceptions in C++, in fact destructors are implicitly declared <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">noexcept</phrase></computeroutput> since C++11). <footnote id="boost_contract.tutorial.destructors.f1">
3838 Exceptions guarantees in destructors can access both the object <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">*</phrase><phrase role="keyword">this</phrase></computeroutput> and
3839 its old value because the object existed before executing the destructor
3840 body and it still exists given the destructor body failed throwing an exception
3841 so technically the object should still be properly constructed and satisfy
3842 its class invariants.
3844 </footnote> The <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.destructor">boost::contract::destructor</link></computeroutput>
3845 function takes <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">this</phrase></computeroutput> as a parameter
3846 (because destructors check class invariants, see <link linkend="boost_contract.tutorial.class_invariants">Class
3850 The <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.destructor">boost::contract::destructor</link></computeroutput>
3851 function returns an RAII object that must always be assigned to a local variable
3852 of type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.check">boost::contract::check</link></computeroutput>
3853 (otherwise this library will generate a run-time error, see <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394999694064">BOOST_CONTRACT_ON_MISSING_CHECK_DECL</link></computeroutput>).
3854 Furthermore, C++11 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">auto</phrase></computeroutput> declarations
3855 cannot be used here and the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.check">boost::contract::check</link></computeroutput>
3856 type must be explicitly specified (otherwise this library will generate a
3857 compile-time error prior C++17 and a run-time error post C++17). The destructor
3858 body is programmed right after the declaration of this RAII object.
3861 At construction, the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.check">boost::contract::check</link></computeroutput>
3862 RAII object for destructors does the following (enclosing destructor entry):
3864 <orderedlist inheritnum="ignore" continuation="restarts">
3867 Check static and non-static class invariants, by calling <emphasis><literal moreinfo="none">type-of</literal></emphasis><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">(*</phrase><phrase role="keyword">this</phrase><phrase role="special">)::</phrase><phrase role="identifier">static_invariant</phrase><phrase role="special">()</phrase></computeroutput> <link linkend="and_anchor"><literal moreinfo="none"><emphasis>AND</emphasis></literal></link>
3868 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">this</phrase><phrase role="special">-></phrase><phrase role="identifier">invariant</phrase><phrase role="special">()</phrase></computeroutput>.
3873 At destruction instead (enclosing destructor exit):
3875 <orderedlist inheritnum="ignore" continuation="restarts">
3878 Check static class invariants, by calling <literal moreinfo="none"><emphasis>type-of</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">(*</phrase><phrase role="keyword">this</phrase><phrase role="special">)::</phrase><phrase role="identifier">static_invariant</phrase><phrase role="special">()</phrase></computeroutput>.
3883 If the destructor body did not throw an exception:
3884 <orderedlist inheritnum="ignore" continuation="restarts">
3887 Check postconditions, by calling the nullay functor <literal moreinfo="none"><emphasis>s</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">()</phrase></computeroutput> passed to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">(</phrase></computeroutput><literal moreinfo="none"><emphasis>s</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">)</phrase></computeroutput>.
3895 Else (even if destructors should generally be programmed not to throw
3897 <orderedlist inheritnum="ignore" continuation="restarts">
3900 Check non-static class invariants, by calling <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">this</phrase><phrase role="special">-></phrase><phrase role="identifier">invariant</phrase><phrase role="special">()</phrase></computeroutput> (because the object was not successfully
3906 Check exception guarantees, by calling the nullary functor <literal moreinfo="none"><emphasis>e</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">()</phrase></computeroutput> passed to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">except</phrase><phrase role="special">(</phrase></computeroutput><literal moreinfo="none"><emphasis>e</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">)</phrase></computeroutput>.
3914 This together with C++ object destruction mechanism of base classes ensures
3915 that destructor contracts are correctly checked at run-time (see <link linkend="boost_contract.contract_programming_overview.destructor_calls">Destructor
3920 A destructor can avoid calling <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.destructor">boost::contract::destructor</link></computeroutput>
3921 for efficiency but only when it has no postconditions, no exception guarantees,
3922 and its class has no invariants (even if <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.destructor">boost::contract::destructor</link></computeroutput>
3923 is not used by a derived class, contracts of base class destructors will
3924 still be correctly checked by C++ object destruction mechanism).
3927 The default destructor automatically generated by C++ will not check contracts.
3928 Therefore, unless the destructor is not public or it has no postconditions,
3929 no exception guarantees, and its class has no invariants, programmers should
3930 manually define it using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.destructor">boost::contract::destructor</link></computeroutput>.
3933 <bridgehead renderas="sect4" id="boost_contract.tutorial.destructors.h0">
3934 <phrase id="boost_contract.tutorial.destructors.private_and_protected_destructors"/><link linkend="boost_contract.tutorial.destructors.private_and_protected_destructors">Private
3935 and Protected Destructors</link>
3938 Private and protected destructors can omit <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.destructor">boost::contract::destructor</link></computeroutput>
3939 (because they are not part of the public interface of the class so they are
3940 not required to check class invariants, see <link linkend="boost_contract.contract_programming_overview.destructor_calls">Destructor
3941 Calls</link>). They could use <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.function">boost::contract::function</link></computeroutput>
3942 (but not <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.destructor">boost::contract::destructor</link></computeroutput>)
3943 to only check postconditions and exception guarantees without checking class
3944 invariants and without calling <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">(...)</phrase></computeroutput>
3945 (see <link linkend="boost_contract.advanced.private_and_protected_functions">Private
3946 and Protected Functions</link>). For example:
3948 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">class</phrase> <phrase role="identifier">u</phrase> <phrase role="special">{</phrase>
3949 <phrase role="keyword">protected</phrase><phrase role="special">:</phrase>
3950 <phrase role="comment">// Contract for a protected destructor (same for private destructors).</phrase>
3951 <phrase role="keyword">virtual</phrase> <phrase role="special">~</phrase><phrase role="identifier">u</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
3952 <phrase role="comment">// Following will correctly not check class invariants.</phrase>
3953 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">function</phrase><phrase role="special">()</phrase>
3954 <phrase role="comment">// Do not use `.precondition(...)` here.</phrase>
3955 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
3956 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(...);</phrase>
3957 <phrase role="special">...</phrase>
3958 <phrase role="special">})</phrase>
3959 <phrase role="comment">// Could use `.except(...)` here in rare cases of destructors declared to throw.</phrase>
3960 <phrase role="special">;</phrase>
3962 <phrase role="special">...</phrase> <phrase role="comment">// Destructor body.</phrase>
3963 <phrase role="special">}</phrase>
3965 <phrase role="special">...</phrase>
3966 <phrase role="special">};</phrase>
3969 <section id="boost_contract.tutorial.public_functions">
3970 <title><link linkend="boost_contract.tutorial.public_functions">Public Functions</link></title>
3972 Contracts for public functions are programmed using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>.
3973 In this section, let's consider public functions that are not static, not
3974 virtual, and do not override any function from base classes. For example
3975 (see <ulink url="../../example/features/public.cpp"><literal moreinfo="none">public.cpp</literal></ulink>):
3978 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">class</phrase> <phrase role="identifier">unique_identifiers</phrase> <phrase role="special">:</phrase>
3979 <phrase role="keyword">private</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor_precondition</phrase><phrase role="special"><</phrase><phrase role="identifier">unique_identifiers</phrase><phrase role="special">></phrase>
3980 <phrase role="special">{</phrase>
3981 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
3982 <phrase role="keyword">void</phrase> <phrase role="identifier">invariant</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
3983 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">>=</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase>
3984 <phrase role="special">}</phrase>
3988 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">public</phrase><phrase role="special">:</phrase>
3989 <phrase role="comment">// Contract for a public function (but no static, virtual, or override).</phrase>
3990 <phrase role="keyword">bool</phrase> <phrase role="identifier">find</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">id</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
3991 <phrase role="keyword">bool</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
3992 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
3993 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
3994 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">id</phrase> <phrase role="special">>=</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase>
3995 <phrase role="special">})</phrase>
3996 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
3997 <phrase role="keyword">if</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(!</phrase><phrase role="identifier">result</phrase><phrase role="special">);</phrase>
3998 <phrase role="special">})</phrase>
3999 <phrase role="special">;</phrase>
4001 <phrase role="comment">// Function body.</phrase>
4002 <phrase role="keyword">return</phrase> <phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">find</phrase><phrase role="special">(</phrase><phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">begin</phrase><phrase role="special">(),</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">end</phrase><phrase role="special">(),</phrase> <phrase role="identifier">id</phrase><phrase role="special">)</phrase> <phrase role="special">!=</phrase>
4003 <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">end</phrase><phrase role="special">();</phrase>
4004 <phrase role="special">}</phrase>
4008 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="comment">/* ... */</phrase>
4009 <phrase role="special">};</phrase>
4013 It is possible to specify preconditions, postconditions, and exception guarantees
4014 for public functions (see <link linkend="boost_contract.tutorial.preconditions">Preconditions</link>,
4015 <link linkend="boost_contract.tutorial.postconditions">Postconditions</link>,
4016 and <link linkend="boost_contract.tutorial.exception_guarantees">Exception
4017 Guarantees</link>). When called from non-static public functions, the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>
4018 function takes <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">this</phrase></computeroutput> as a parameter
4019 (because public functions check class invariants, see <link linkend="boost_contract.tutorial.class_invariants">Class
4023 The <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>
4024 function returns an RAII object that must always be assigned to a local variable
4025 of type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.check">boost::contract::check</link></computeroutput>
4026 (otherwise this library will generate a run-time error, see <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394999694064">BOOST_CONTRACT_ON_MISSING_CHECK_DECL</link></computeroutput>).
4027 Furthermore, C++11 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">auto</phrase></computeroutput> declarations
4028 cannot be used here and the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.check">boost::contract::check</link></computeroutput>
4029 type must be explicitly specified (otherwise this library will generate a
4030 compile-time error prior C++17 and a run-time error post C++17). The public
4031 function body is programmed right after the declaration of this RAII object.
4034 At construction, the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.check">boost::contract::check</link></computeroutput>
4035 RAII object for public functions does the following (enclosing public function
4038 <orderedlist inheritnum="ignore" continuation="restarts">
4041 Check static and non-static class invariants, by calling <literal moreinfo="none"><emphasis>type-of</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">(*</phrase><phrase role="keyword">this</phrase><phrase role="special">)::</phrase><phrase role="identifier">static_invariant</phrase><phrase role="special">()</phrase></computeroutput> <link linkend="and_anchor"><literal moreinfo="none"><emphasis>AND</emphasis></literal></link>
4042 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">this</phrase><phrase role="special">-></phrase><phrase role="identifier">invariant</phrase><phrase role="special">()</phrase></computeroutput>.
4047 Check preconditions, by calling the nullary functor <literal moreinfo="none"><emphasis>r</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">()</phrase></computeroutput> passed to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">(</phrase></computeroutput><literal moreinfo="none"><emphasis>r</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">)</phrase></computeroutput>.
4052 At destruction instead (enclosing public function exit):
4054 <orderedlist inheritnum="ignore" continuation="restarts">
4057 Check static and non-static class invariants, by calling <literal moreinfo="none"><emphasis>type-of</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">(*</phrase><phrase role="keyword">this</phrase><phrase role="special">)::</phrase><phrase role="identifier">static_invariant</phrase><phrase role="special">()</phrase></computeroutput> <link linkend="and_anchor"><literal moreinfo="none"><emphasis>AND</emphasis></literal></link>
4058 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">this</phrase><phrase role="special">-></phrase><phrase role="identifier">invariant</phrase><phrase role="special">()</phrase></computeroutput>
4059 (even if the function body threw an exception).
4064 If the function body did not throw an exception:
4065 <orderedlist inheritnum="ignore" continuation="restarts">
4068 Check postconditions, by calling the nullary functor <literal moreinfo="none"><emphasis>s</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">()</phrase></computeroutput> passed to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">(</phrase></computeroutput><literal moreinfo="none"><emphasis>s</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">)</phrase></computeroutput>.
4077 <orderedlist inheritnum="ignore" continuation="restarts">
4080 Check exception guarantees, by calling the nullary functor <literal moreinfo="none"><emphasis>e</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">()</phrase></computeroutput> passed to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">except</phrase><phrase role="special">(</phrase></computeroutput><literal moreinfo="none"><emphasis>e</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">)</phrase></computeroutput>.
4088 This ensures that public function contracts are correctly checked at run-time
4089 (see <link linkend="boost_contract.contract_programming_overview.public_function_calls">Public
4090 Function Calls</link>).
4094 A public function can avoid calling <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>
4095 for efficiency but only when it has no preconditions, no postconditions,
4096 no exception guarantees, it is not virtual, it does not override any virtual
4097 function, and its class has no invariants.
4100 The default copy assignment operator automatically generated by C++ will
4101 not check contracts. Therefore, unless this operator is not public or it
4102 has no preconditions, no postconditions, no exception guarantees, and its
4103 class has no invariants, programmers should manually define it using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>.
4104 Similar considerations apply to all other operators automatically generated
4105 by C++ (e.g., the move operator).
4109 <section id="boost_contract.tutorial.virtual_public_functions">
4110 <title><link linkend="boost_contract.tutorial.virtual_public_functions">Virtual
4111 Public Functions</link></title>
4113 Contracts for public functions are programmed using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>.
4114 In this section, let's consider public functions that are virtual but that
4115 do not override any function from base classes. For example (see <ulink url="../../example/features/public.cpp"><literal moreinfo="none">public.cpp</literal></ulink>):
4118 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">class</phrase> <phrase role="identifier">unique_identifiers</phrase> <phrase role="special">:</phrase>
4119 <phrase role="keyword">private</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor_precondition</phrase><phrase role="special"><</phrase><phrase role="identifier">unique_identifiers</phrase><phrase role="special">></phrase>
4120 <phrase role="special">{</phrase>
4121 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
4122 <phrase role="keyword">void</phrase> <phrase role="identifier">invariant</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
4123 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">>=</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase>
4124 <phrase role="special">}</phrase>
4128 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">public</phrase><phrase role="special">:</phrase>
4129 <phrase role="comment">// Contract for a public virtual function (but no override).</phrase>
4130 <phrase role="keyword">virtual</phrase> <phrase role="keyword">int</phrase> <phrase role="identifier">push_back</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">id</phrase><phrase role="special">,</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Extra `v`.</phrase>
4131 <phrase role="keyword">int</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
4132 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">bool</phrase><phrase role="special">></phrase> <phrase role="identifier">old_find</phrase> <phrase role="special">=</phrase>
4133 <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">find</phrase><phrase role="special">(</phrase><phrase role="identifier">id</phrase><phrase role="special">));</phrase> <phrase role="comment">// Pass `v`.</phrase>
4134 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">></phrase> <phrase role="identifier">old_size</phrase> <phrase role="special">=</phrase>
4135 <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">size</phrase><phrase role="special">());</phrase> <phrase role="comment">// Pass `v`.</phrase>
4136 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase>
4137 <phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">result</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">)</phrase> <phrase role="comment">// Pass `v` and `result`.</phrase>
4138 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
4139 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">id</phrase> <phrase role="special">>=</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase>
4140 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(!</phrase><phrase role="identifier">find</phrase><phrase role="special">(</phrase><phrase role="identifier">id</phrase><phrase role="special">));</phrase> <phrase role="comment">// ID cannot be already present.</phrase>
4141 <phrase role="special">})</phrase>
4142 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">result</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
4143 <phrase role="keyword">if</phrase><phrase role="special">(!*</phrase><phrase role="identifier">old_find</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
4144 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">find</phrase><phrase role="special">(</phrase><phrase role="identifier">id</phrase><phrase role="special">));</phrase>
4145 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_size</phrase> <phrase role="special">+</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase>
4146 <phrase role="special">}</phrase>
4147 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">result</phrase> <phrase role="special">==</phrase> <phrase role="identifier">id</phrase><phrase role="special">);</phrase>
4148 <phrase role="special">})</phrase>
4149 <phrase role="special">;</phrase>
4151 <phrase role="comment">// Function body.</phrase>
4152 <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">push_back</phrase><phrase role="special">(</phrase><phrase role="identifier">id</phrase><phrase role="special">);</phrase>
4153 <phrase role="keyword">return</phrase> <phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="identifier">id</phrase><phrase role="special">;</phrase>
4154 <phrase role="special">}</phrase>
4158 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="comment">/* ... */</phrase>
4159 <phrase role="special">};</phrase>
4163 Virtual public functions must declare an extra trailing parameter of type
4164 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.virtual_">boost::contract::virtual_</link></computeroutput><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">*</phrase></computeroutput> with default value <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="number">0</phrase></computeroutput>
4165 (i.e., <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">nullptr</phrase></computeroutput>). <footnote id="boost_contract.tutorial.virtual_public_functions.f0">
4167 The name of this extra parameter is arbitrary, but <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">v</phrase></computeroutput>
4168 is often used in this documentation.
4170 </footnote> This extra parameter is the last parameter and it has a default
4171 value so it does not alter the calling interface of the virtual function
4172 (callers will rarely, if ever, have to explicitly deal with this extra parameter
4173 a part from when manipulating the virtual function type directly for function
4174 pointer type-casting, etc.). Programmers must pass the extra virtual parameter
4175 as the very first argument to all <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_OLDOF">BOOST_CONTRACT_OLDOF</link></computeroutput>
4176 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>
4177 calls in the virtual public function definition. <footnote id="boost_contract.tutorial.virtual_public_functions.f1">
4179 <emphasis role="bold">Rationale:</emphasis> The <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.virtual_">boost::contract::virtual_</link></computeroutput><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">*</phrase></computeroutput> parameter is used by this library to determine
4180 that a function is virtual (in C++ it is not possible to introspect if
4181 a function is declared <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">virtual</phrase></computeroutput>).
4182 Furthermore, this parameter is internally used by this library to implement
4183 subcontracting (specifically to pass result and old values that are evaluated
4184 by the overriding function to the contracts of overridden virtual functions
4185 in base classes, and also to check preconditions, postconditions, and exception
4186 guarantees of overridden virtual functions in <link linkend="or_anchor"><literal moreinfo="none"><emphasis>OR</emphasis></literal></link>
4187 and <link linkend="and_anchor"><literal moreinfo="none"><emphasis>AND</emphasis></literal></link>
4188 with contracts of the overriding virtual function).
4193 When called from virtual public functions, the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>
4194 function takes <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">this</phrase></computeroutput> as a parameter
4195 (because public functions check class invariants, see <link linkend="boost_contract.tutorial.class_invariants">Class
4196 Invariants</link>). For virtual public functions returning <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">void</phrase></computeroutput>:
4198 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">class</phrase> <phrase role="identifier">u</phrase> <phrase role="special">{</phrase>
4199 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
4200 <phrase role="comment">// A void virtual public function (that does not override).</phrase>
4201 <phrase role="keyword">virtual</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">f</phrase><phrase role="special">(</phrase><phrase role="identifier">t_1</phrase> <phrase role="identifier">a_1</phrase><phrase role="special">,</phrase> <phrase role="special">...,</phrase> <phrase role="identifier">t_n</phrase> <phrase role="identifier">a_n</phrase><phrase role="special">,</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
4202 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase>
4203 <phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">)</phrase> <phrase role="comment">// No result parameter...</phrase>
4204 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase> <phrase role="special">...</phrase> <phrase role="special">})</phrase>
4205 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase> <phrase role="special">...</phrase> <phrase role="special">})</phrase> <phrase role="comment">// ...so nullary functor.</phrase>
4206 <phrase role="special">.</phrase><phrase role="identifier">except</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase> <phrase role="special">...</phrase> <phrase role="special">})</phrase>
4207 <phrase role="special">;</phrase>
4209 <phrase role="special">...</phrase>
4210 <phrase role="special">}</phrase>
4212 <phrase role="special">...</phrase>
4213 <phrase role="special">}</phrase>
4216 For virtual public functions not returning <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">void</phrase></computeroutput>,
4217 programmers must also pass a reference to the function return value as the
4218 second argument to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>.
4219 In this case, the library will pass this return value reference to the postcondition
4220 functor that must therefore take one single argument matching the return
4221 type, otherwise this library will generate a compile-time error (the functor
4222 parameter can be a constant reference <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase><phrase role="special">&</phrase></computeroutput> to avoid extra copies of the return
4223 value): <footnote id="boost_contract.tutorial.virtual_public_functions.f2">
4225 <emphasis role="bold">Rationale:</emphasis> The extra function result parameter
4226 taken by the functor passed to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">(...)</phrase></computeroutput>
4227 is used by this library to pass the return value evaluated by the overriding
4228 function to all its overridden virtual functions to support subcontracting.
4232 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">class</phrase> <phrase role="identifier">u</phrase> <phrase role="special">{</phrase>
4233 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
4234 <phrase role="comment">// A void virtual public function (that does not override).</phrase>
4235 <phrase role="keyword">virtual</phrase> <phrase role="identifier">t</phrase> <phrase role="identifier">f</phrase><phrase role="special">(</phrase><phrase role="identifier">t_1</phrase> <phrase role="identifier">a_1</phrase><phrase role="special">,</phrase> <phrase role="special">...,</phrase> <phrase role="identifier">t_n</phrase> <phrase role="identifier">a_n</phrase><phrase role="special">,</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
4236 <phrase role="identifier">t</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
4237 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase>
4238 <phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">result</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">)</phrase> <phrase role="comment">// Result parameter...</phrase>
4239 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase> <phrase role="special">...</phrase> <phrase role="special">})</phrase>
4240 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">(</phrase><phrase role="identifier">t</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">result</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase> <phrase role="special">...</phrase> <phrase role="special">})</phrase> <phrase role="comment">// ...so unary functor.</phrase>
4241 <phrase role="special">.</phrase><phrase role="identifier">except</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase> <phrase role="special">...</phrase> <phrase role="special">})</phrase>
4242 <phrase role="special">;</phrase>
4244 <phrase role="special">...</phrase> <phrase role="comment">// Assign `result` at each return.</phrase>
4245 <phrase role="special">}</phrase>
4247 <phrase role="special">...</phrase>
4248 <phrase role="special">}</phrase>
4252 It is the responsibility of the programmers to pass the extra virtual parameter
4253 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">v</phrase></computeroutput> to all <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_OLDOF">BOOST_CONTRACT_OLDOF</link></computeroutput>
4254 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>
4255 calls within virtual public functions, and also to pass the return value
4256 reference after <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">v</phrase></computeroutput> to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>
4257 for non-void virtual public functions. This library cannot automatically
4258 generate compile-time errors if programmers fail to do so (but in general
4259 this will prevent the library from correctly checking contracts at run-time).
4260 <footnote id="boost_contract.tutorial.virtual_public_functions.f3">
4262 <emphasis role="bold">Rationale:</emphasis> This library does not require
4263 programmers to specify the function type when using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>
4264 for non-overriding virtual public functions. Therefore, this library
4265 does not know if the enclosing function has a non-void return type so
4266 it cannot check if the return value reference is passed as required for
4267 non-overriding virtual public functions. Instead the function type is
4268 passed to this library for virtual public function overrides and that
4269 also allows this library to give a compile-time error if the return value
4270 reference is missing in those cases.
4275 <emphasis role="bold">Mnemonics:</emphasis>
4279 When <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">v</phrase></computeroutput> is present, always
4280 pass it as the first argument to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>
4281 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_OLDOF">BOOST_CONTRACT_OLDOF</link></computeroutput>.
4286 Always pass <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">result</phrase></computeroutput> to
4287 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>
4288 right after <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">v</phrase></computeroutput> for non-void
4294 For the rest, considerations made in <link linkend="boost_contract.tutorial.public_functions">Public
4295 Functions</link> apply to virtual public functions as well.
4299 A virtual public function should always call <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>
4300 (even if it has no preconditions, no postconditions, no exception guarantees,
4301 and its class has no invariants), otherwise this library will not be able
4302 to correctly use it for subcontracting.
4306 <section id="boost_contract.tutorial.public_function_overrides__subcontracting_">
4307 <title><link linkend="boost_contract.tutorial.public_function_overrides__subcontracting_">Public
4308 Function Overrides (Subcontracting)</link></title>
4310 Contracts for public functions are programmed using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>.
4311 In this section, let's consider public functions (virtual or not) that override
4312 virtual public functions from one or more of their public base classes. For
4313 example (see <ulink url="../../example/features/public.cpp"><literal moreinfo="none">public.cpp</literal></ulink>):
4314 <footnote id="boost_contract.tutorial.public_function_overrides__subcontracting_.f0">
4316 In this documentation, function overrides are often marked with the code
4317 comment <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="comment">/* override */</phrase></computeroutput>. On
4318 compilers that support C++11 virtual specifiers, the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">override</phrase></computeroutput>
4319 identifier can be used instead (<computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">override</phrase></computeroutput>
4320 is not used in the documentation simply because virtual specifiers are
4321 not widely supported yet, even by compilers that support C++11 lambda functions).
4326 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">class</phrase> <phrase role="identifier">identifiers</phrase>
4327 <phrase role="preprocessor">#define</phrase> <phrase role="identifier">BASES</phrase> <phrase role="keyword">public</phrase> <phrase role="identifier">unique_identifiers</phrase>
4328 <phrase role="special">:</phrase> <phrase role="identifier">BASES</phrase>
4329 <phrase role="special">{</phrase>
4330 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
4331 <phrase role="keyword">typedef</phrase> <phrase role="identifier">BOOST_CONTRACT_BASE_TYPES</phrase><phrase role="special">(</phrase><phrase role="identifier">BASES</phrase><phrase role="special">)</phrase> <phrase role="identifier">base_types</phrase><phrase role="special">;</phrase> <phrase role="comment">// Bases typedef.</phrase>
4332 <phrase role="preprocessor">#undef</phrase> <phrase role="identifier">BASES</phrase>
4334 <phrase role="keyword">void</phrase> <phrase role="identifier">invariant</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Check in AND with bases.</phrase>
4335 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">empty</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">0</phrase><phrase role="special">));</phrase>
4336 <phrase role="special">}</phrase>
4340 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">public</phrase><phrase role="special">:</phrase>
4341 <phrase role="comment">// Contract for a public function override.</phrase>
4342 <phrase role="keyword">int</phrase> <phrase role="identifier">push_back</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">id</phrase><phrase role="special">,</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="comment">/* override */</phrase> <phrase role="special">{</phrase>
4343 <phrase role="keyword">int</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
4344 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">bool</phrase><phrase role="special">></phrase> <phrase role="identifier">old_find</phrase> <phrase role="special">=</phrase>
4345 <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">find</phrase><phrase role="special">(</phrase><phrase role="identifier">id</phrase><phrase role="special">));</phrase>
4346 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">></phrase> <phrase role="identifier">old_size</phrase> <phrase role="special">=</phrase>
4347 <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">size</phrase><phrase role="special">());</phrase>
4348 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special"><</phrase>
4349 <phrase role="identifier">override_push_back</phrase> <phrase role="comment">// Pass override type plus below function pointer...</phrase>
4350 <phrase role="special">>(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">result</phrase><phrase role="special">,</phrase> <phrase role="special">&</phrase><phrase role="identifier">identifiers</phrase><phrase role="special">::</phrase><phrase role="identifier">push_back</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">,</phrase> <phrase role="identifier">id</phrase><phrase role="special">)</phrase> <phrase role="comment">// ...and arguments.</phrase>
4351 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Check in OR with bases.</phrase>
4352 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">id</phrase> <phrase role="special">>=</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase>
4353 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">find</phrase><phrase role="special">(</phrase><phrase role="identifier">id</phrase><phrase role="special">));</phrase> <phrase role="comment">// ID can be already present.</phrase>
4354 <phrase role="special">})</phrase>
4355 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">result</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Check in AND with bases.</phrase>
4356 <phrase role="keyword">if</phrase><phrase role="special">(*</phrase><phrase role="identifier">old_find</phrase><phrase role="special">)</phrase> <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_size</phrase><phrase role="special">);</phrase>
4357 <phrase role="special">})</phrase>
4358 <phrase role="special">;</phrase>
4360 <phrase role="comment">// Function body.</phrase>
4361 <phrase role="keyword">if</phrase><phrase role="special">(!</phrase><phrase role="identifier">find</phrase><phrase role="special">(</phrase><phrase role="identifier">id</phrase><phrase role="special">))</phrase> <phrase role="identifier">unique_identifiers</phrase><phrase role="special">::</phrase><phrase role="identifier">push_back</phrase><phrase role="special">(</phrase><phrase role="identifier">id</phrase><phrase role="special">);</phrase> <phrase role="comment">// Else, do nothing.</phrase>
4362 <phrase role="keyword">return</phrase> <phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="identifier">id</phrase><phrase role="special">;</phrase>
4363 <phrase role="special">}</phrase>
4364 <phrase role="identifier">BOOST_CONTRACT_OVERRIDE</phrase><phrase role="special">(</phrase><phrase role="identifier">push_back</phrase><phrase role="special">)</phrase> <phrase role="comment">// Define `override_push_back`.</phrase>
4368 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="comment">/* ... */</phrase>
4369 <phrase role="special">};</phrase>
4373 The extra <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">typedef</phrase></computeroutput> declared using
4374 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_BASE_TYPES">BOOST_CONTRACT_BASE_TYPES</link></computeroutput>
4375 is required by this library for derived classes and it is internally used
4376 to detect base classes for subcontracting (see <link linkend="boost_contract.tutorial.base_classes__subcontracting_">Base
4377 Classes</link>). This library will generate a compile-time error if there
4378 is no suitable virtual function to override in any of the public base classes
4379 for subcontracting. <footnote id="boost_contract.tutorial.public_function_overrides__subcontracting_.f1">
4381 The compile-time error generated by the library in this case is similar
4382 in principle to the error generated by the C++11 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">override</phrase></computeroutput>
4383 specifier, but it is limited to functions with the extra <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.virtual_">boost::contract::virtual_</link></computeroutput><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">*</phrase></computeroutput> parameter and searched recursively only
4384 in <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">public</phrase></computeroutput> base classes passed
4385 to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_BASE_TYPES">BOOST_CONTRACT_BASE_TYPES</link></computeroutput>
4386 because only those are considered for subcontracting.
4391 When called from public function overrides, the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>
4392 function template takes an explicit template argument <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">override_</phrase></computeroutput><literal moreinfo="none"><emphasis>function-name</emphasis></literal>
4393 that must be defined using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_OVERRIDE">BOOST_CONTRACT_OVERRIDE</link></computeroutput>:
4395 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">BOOST_CONTRACT_OVERRIDE</phrase><phrase role="special">(</phrase><literal moreinfo="none"><emphasis>function-name</emphasis></literal><phrase role="special">)</phrase>
4398 This can be declared at any point in the public section of the enclosing
4399 class (see <link linkend="boost_contract.advanced.access_specifiers">Access
4400 Specifiers</link> to use <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_OVERRIDE">BOOST_CONTRACT_OVERRIDE</link></computeroutput>
4401 also in a non-public section of the class). <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_OVERRIDE">BOOST_CONTRACT_OVERRIDE</link></computeroutput>
4402 is used only once in a class for a given function name and overloaded functions
4403 can reuse the same <literal moreinfo="none">override_<emphasis>function-name</emphasis></literal>
4404 definition (see <link linkend="boost_contract.advanced.function_overloads">Function
4405 Overloads</link>). <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394998912688">BOOST_CONTRACT_NAMED_OVERRIDE</link></computeroutput>
4406 can be used to generate a name different than <literal moreinfo="none">override_<emphasis>function-name</emphasis></literal>
4407 (e.g., to avoid generating C++ reserved names containing double underscores
4408 "<computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">__</phrase></computeroutput>" for function
4409 names that already start with an underscore "<computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">_</phrase></computeroutput>",
4410 see <link linkend="boost_contract.advanced.named_overrides">Named Overrides</link>).
4411 For convenience <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_OVERRIDES">BOOST_CONTRACT_OVERRIDES</link></computeroutput>
4412 can be used with multiple function names instead of repeating <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_OVERRIDE">BOOST_CONTRACT_OVERRIDE</link></computeroutput> for each
4413 function name (on compilers that support variadic macros). For example, for
4414 three functions named <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">f</phrase></computeroutput>,
4415 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">g</phrase></computeroutput>, and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">h</phrase></computeroutput>
4416 (but same for any other number of functions), the following:
4418 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">BOOST_CONTRACT_OVERRIDES</phrase><phrase role="special">(</phrase><phrase role="identifier">f</phrase><phrase role="special">,</phrase> <phrase role="identifier">g</phrase><phrase role="special">,</phrase> <phrase role="identifier">h</phrase><phrase role="special">)</phrase>
4421 Is equivalent to: <footnote id="boost_contract.tutorial.public_function_overrides__subcontracting_.f2">
4423 There is no equivalent of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394998912688">BOOST_CONTRACT_NAMED_OVERRIDE</link></computeroutput>
4424 that operates on multiple function names at once (<computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394998912688">BOOST_CONTRACT_NAMED_OVERRIDE</link></computeroutput>
4425 is not expected to be used often so it can simply be repeated multiple
4430 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">BOOST_CONTRACT_OVERRIDE</phrase><phrase role="special">(</phrase><phrase role="identifier">f</phrase><phrase role="special">)</phrase>
4431 <phrase role="identifier">BOOST_CONTRACT_OVERRIDE</phrase><phrase role="special">(</phrase><phrase role="identifier">g</phrase><phrase role="special">)</phrase>
4432 <phrase role="identifier">BOOST_CONTRACT_OVERRIDE</phrase><phrase role="special">(</phrase><phrase role="identifier">h</phrase><phrase role="special">)</phrase>
4435 Public function overrides must always list the extra trailing parameter of
4436 type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.virtual_">boost::contract::virtual_</link></computeroutput><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">*</phrase></computeroutput> with default value <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="number">0</phrase></computeroutput>
4437 (i.e., <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">nullptr</phrase></computeroutput>), even when they
4438 are not declared <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">virtual</phrase></computeroutput>, if
4439 this parameter is present in the signature of the virtual function being
4440 overridden from base classes. Programmers must pass the extra virtual parameter
4441 as the very first argument to all <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_OLDOF">BOOST_CONTRACT_OLDOF</link></computeroutput>
4442 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>
4443 calls in the public function override definition (see <link linkend="boost_contract.tutorial.virtual_public_functions">Virtual
4444 Public Functions</link>).
4447 When called from public function overrides, the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>
4448 function takes a pointer to the enclosing function, the object <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">*</phrase><phrase role="keyword">this</phrase></computeroutput> (because
4449 public function overrides check class invariants, see <link linkend="boost_contract.tutorial.class_invariants">Class
4450 Invariants</link>), and references to each function argument in the order
4451 they appear in the function declaration. <footnote id="boost_contract.tutorial.public_function_overrides__subcontracting_.f3">
4453 <emphasis role="bold">Rationale:</emphasis> The object <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">this</phrase></computeroutput>
4454 is passed after the function pointer to follow <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">bind</phrase></computeroutput>'s
4455 syntax. The function pointer and references to all function arguments are
4456 needed for public function overrides because this library has to internally
4457 call overridden virtual public functions to check their contracts for subcontracting
4458 (even if this library will not actually execute the bodies of the overridden
4461 </footnote> For public function overrides returning <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">void</phrase></computeroutput>:
4463 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">class</phrase> <phrase role="identifier">u</phrase> <phrase role="special">{</phrase>
4464 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
4465 <phrase role="comment">// A void public function override.</phrase>
4466 <phrase role="keyword">void</phrase> <phrase role="identifier">f</phrase><phrase role="special">(</phrase><phrase role="identifier">t_1</phrase> <phrase role="identifier">a_1</phrase><phrase role="special">,</phrase> <phrase role="special">...,</phrase> <phrase role="identifier">t_n</phrase> <phrase role="identifier">a_n</phrase><phrase role="special">,</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="comment">/* override */</phrase> <phrase role="special">{</phrase>
4467 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special"><</phrase><phrase role="identifier">override_f</phrase><phrase role="special">>(</phrase>
4468 <phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="special">&</phrase><phrase role="identifier">u</phrase><phrase role="special">::</phrase><phrase role="identifier">f</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">,</phrase> <phrase role="identifier">a_1</phrase><phrase role="special">,</phrase> <phrase role="special">...,</phrase> <phrase role="identifier">a_n</phrase><phrase role="special">)</phrase> <phrase role="comment">// No result parameter...</phrase>
4469 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase> <phrase role="special">...</phrase> <phrase role="special">})</phrase>
4470 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase> <phrase role="special">...</phrase> <phrase role="special">})</phrase> <phrase role="comment">// ...so nullary functor.</phrase>
4471 <phrase role="special">.</phrase><phrase role="identifier">except</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase> <phrase role="special">...</phrase> <phrase role="special">})</phrase>
4472 <phrase role="special">;</phrase>
4474 <phrase role="special">...</phrase>
4475 <phrase role="special">}</phrase>
4476 <phrase role="identifier">BOOST_CONTRACT_OVERRIDE</phrase><phrase role="special">(</phrase><phrase role="identifier">f</phrase><phrase role="special">)</phrase>
4478 <phrase role="special">...</phrase>
4479 <phrase role="special">}</phrase>
4482 For public function overrides not returning <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">void</phrase></computeroutput>,
4483 programmers must also pass a reference to the function return value as the
4484 second argument to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>
4485 (this library will generate a compile-time error otherwise). <footnote id="boost_contract.tutorial.public_function_overrides__subcontracting_.f4">
4487 <emphasis role="bold">Rationale:</emphasis> As for non-overriding virtual
4488 public functions, also public function overrides use the extra return value
4489 parameter to pass it to the overridden functions when subcontracting. In
4490 the case of public function overrides, this library has the function pointer
4491 so it will generate a compile-time error if the function is non-void and
4492 programmers forget to specify the extra return value parameter (this extra
4493 error checking is not possible instead for non-overriding virtual public
4494 functions because their contracts do not take the function pointer as a
4495 parameter, see <link linkend="boost_contract.tutorial.virtual_public_functions">Virtual
4496 Public Functions</link>).
4498 </footnote> In this case, the library will pass this return value reference
4499 to the postcondition functor that must therefore take one single argument
4500 matching the return type, otherwise this library will generate a compile-time
4501 error (the functor parameter can be a constant reference <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase><phrase role="special">&</phrase></computeroutput> to avoid extra copies of the return
4502 value, similarly to non-overriding non-void <link linkend="boost_contract.tutorial.virtual_public_functions">Virtual
4503 Public Functions</link>):
4505 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">class</phrase> <phrase role="identifier">u</phrase> <phrase role="special">{</phrase>
4506 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
4507 <phrase role="comment">// A non-void public function override.</phrase>
4508 <phrase role="identifier">t</phrase> <phrase role="identifier">f</phrase><phrase role="special">(</phrase><phrase role="identifier">t_1</phrase> <phrase role="identifier">a_1</phrase><phrase role="special">,</phrase> <phrase role="special">...,</phrase> <phrase role="identifier">t_n</phrase> <phrase role="identifier">a_n</phrase><phrase role="special">,</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="comment">/* override */</phrase> <phrase role="special">{</phrase>
4509 <phrase role="identifier">t</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
4510 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special"><</phrase><phrase role="identifier">override_f</phrase><phrase role="special">>(</phrase>
4511 <phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">result</phrase><phrase role="special">,</phrase> <phrase role="special">&</phrase><phrase role="identifier">u</phrase><phrase role="special">::</phrase><phrase role="identifier">f</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">,</phrase> <phrase role="identifier">a_1</phrase><phrase role="special">,</phrase> <phrase role="special">...,</phrase> <phrase role="identifier">a_n</phrase><phrase role="special">)</phrase> <phrase role="comment">// Result parameter...</phrase>
4512 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase> <phrase role="special">...</phrase> <phrase role="special">})</phrase>
4513 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">(</phrase><phrase role="identifier">t</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">result</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase> <phrase role="special">...</phrase> <phrase role="special">})</phrase> <phrase role="comment">// ...so unary functor.</phrase>
4514 <phrase role="special">.</phrase><phrase role="identifier">except</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase> <phrase role="special">...</phrase> <phrase role="special">})</phrase>
4515 <phrase role="special">;</phrase>
4517 <phrase role="special">...</phrase> <phrase role="comment">// Assign `result` at each return.</phrase>
4518 <phrase role="special">}</phrase>
4519 <phrase role="identifier">BOOST_CONTRACT_OVERRIDE</phrase><phrase role="special">(</phrase><phrase role="identifier">f</phrase><phrase role="special">)</phrase>
4521 <phrase role="special">...</phrase>
4522 <phrase role="special">}</phrase>
4525 This library will throw <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.bad_virtual_result_cast">boost::contract::bad_virtual_result_cast</link></computeroutput>
4526 if programmers specify return values for public function overrides in derived
4527 classes that are not consistent with the return types of the virtual public
4528 functions being overridden in the base classes. <footnote id="boost_contract.tutorial.public_function_overrides__subcontracting_.f5">
4530 <emphasis role="bold">Rationale:</emphasis> The <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">bad_any_cast</phrase></computeroutput>
4531 exception was not used here because it does not print the from- and to-
4532 type names (so it is not descriptive enough).
4538 It is the responsibility of the programmers to pass the extra virtual parameter
4539 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">v</phrase></computeroutput> to all <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_OLDOF">BOOST_CONTRACT_OLDOF</link></computeroutput>
4540 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>
4541 calls within public function overrides, and also to pass the return value
4542 reference after <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">v</phrase></computeroutput> to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>
4543 for non-void public function overrides. This library cannot always generate
4544 compile-time errors if programmers fail to do so (but in general this will
4545 prevent the library from correctly checking contracts at run-time).
4548 <emphasis role="bold">Mnemonics:</emphasis>
4552 When <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">override_</phrase><phrase role="special">...</phrase></computeroutput>
4553 is present, always pass it as template parameter to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>.
4558 When <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">v</phrase></computeroutput> is present, always
4559 pass it as the first argument to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>
4560 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_OLDOF">BOOST_CONTRACT_OLDOF</link></computeroutput>.
4565 Always pass <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">result</phrase></computeroutput> to
4566 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>
4567 right after <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">v</phrase></computeroutput> for non-void
4573 At construction, the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.check">boost::contract::check</link></computeroutput>
4574 RAII object for public function overrides does the following (enclosing public
4575 function override entry):
4577 <orderedlist inheritnum="ignore" continuation="restarts">
4580 Check static and non-static class invariants for all overridden bases
4581 and for the derived class in <link linkend="and_anchor"><literal moreinfo="none"><emphasis>AND</emphasis></literal></link>
4582 with each other, by calling <literal moreinfo="none"><emphasis>type-of</emphasis>(<emphasis>overridden-base_1</emphasis>)</literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">::</phrase><phrase role="identifier">static_invariant</phrase><phrase role="special">()</phrase></computeroutput> <link linkend="and_anchor"><literal moreinfo="none"><emphasis>AND</emphasis></literal></link>
4583 <literal moreinfo="none"><emphasis>overridden-base_1</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">invariant</phrase><phrase role="special">()</phrase></computeroutput> <link linkend="and_anchor"><literal moreinfo="none"><emphasis>AND</emphasis></literal></link>...
4584 <literal moreinfo="none"><emphasis>type-of</emphasis>(<emphasis>overridden-base_n</emphasis>)</literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">::</phrase><phrase role="identifier">static_invariant</phrase><phrase role="special">()</phrase></computeroutput> <link linkend="and_anchor"><literal moreinfo="none"><emphasis>AND</emphasis></literal></link>
4585 <literal moreinfo="none"><emphasis>overridden-base_n</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">invariant</phrase><phrase role="special">()</phrase></computeroutput> <link linkend="and_anchor"><literal moreinfo="none"><emphasis>AND</emphasis></literal></link>
4586 <literal moreinfo="none"><emphasis>type-of</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">(*</phrase><phrase role="keyword">this</phrase><phrase role="special">)::</phrase><phrase role="identifier">static_invariant</phrase><phrase role="special">()</phrase></computeroutput>
4587 <link linkend="and_anchor"><literal moreinfo="none"><emphasis>AND</emphasis></literal></link>
4588 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">this</phrase><phrase role="special">-></phrase><phrase role="identifier">invariant</phrase><phrase role="special">()</phrase></computeroutput>.
4593 Check preconditions for all overridden base functions and for the overriding
4594 derived function in <link linkend="or_anchor"><literal moreinfo="none"><emphasis>OR</emphasis></literal></link>
4595 with each other, by calling the nullary functors <literal moreinfo="none"><emphasis>r_1</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">()</phrase></computeroutput> <link linkend="or_anchor"><literal moreinfo="none"><emphasis>OR</emphasis></literal></link>...
4596 <literal moreinfo="none"><emphasis>r_n</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">()</phrase></computeroutput>
4597 <link linkend="or_anchor"><literal moreinfo="none"><emphasis>OR</emphasis></literal></link>
4598 <literal moreinfo="none"><emphasis>r</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">()</phrase></computeroutput>
4599 passed to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">(</phrase></computeroutput><literal moreinfo="none"><emphasis>r_1</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">)</phrase></computeroutput>, ... <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">(</phrase></computeroutput><literal moreinfo="none"><emphasis>r_n</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">)</phrase></computeroutput>, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">(</phrase></computeroutput><literal moreinfo="none"><emphasis>r</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">)</phrase></computeroutput> for all of the overridden and overriding
4600 functions respectively.
4605 At destruction instead (enclosing public function override exit):
4607 <orderedlist inheritnum="ignore" continuation="restarts">
4610 Check static and non-static class invariants for all overridden bases
4611 and for the derived class in <link linkend="and_anchor"><literal moreinfo="none"><emphasis>AND</emphasis></literal></link>
4612 with each other, by calling <literal moreinfo="none"><emphasis>type-of</emphasis>(<emphasis>overridden-base_1</emphasis>)</literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">::</phrase><phrase role="identifier">static_invariant</phrase><phrase role="special">()</phrase></computeroutput> <link linkend="and_anchor"><literal moreinfo="none"><emphasis>AND</emphasis></literal></link>
4613 <literal moreinfo="none"><emphasis>overridden-base_1</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">invariant</phrase><phrase role="special">()</phrase></computeroutput> <link linkend="and_anchor"><literal moreinfo="none"><emphasis>AND</emphasis></literal></link>...
4614 <literal moreinfo="none"><emphasis>type-of</emphasis>(<emphasis>overridden-base_n</emphasis>)</literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">::</phrase><phrase role="identifier">static_invariant</phrase><phrase role="special">()</phrase></computeroutput> <link linkend="and_anchor"><literal moreinfo="none"><emphasis>AND</emphasis></literal></link>
4615 <literal moreinfo="none"><emphasis>overridden-base_n</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">invariant</phrase><phrase role="special">()</phrase></computeroutput> <link linkend="and_anchor"><literal moreinfo="none"><emphasis>AND</emphasis></literal></link>
4616 <literal moreinfo="none"><emphasis>type-of</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">(*</phrase><phrase role="keyword">this</phrase><phrase role="special">)::</phrase><phrase role="identifier">static_invariant</phrase><phrase role="special">()</phrase></computeroutput>
4617 <link linkend="and_anchor"><literal moreinfo="none"><emphasis>AND</emphasis></literal></link>
4618 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">this</phrase><phrase role="special">-></phrase><phrase role="identifier">invariant</phrase><phrase role="special">()</phrase></computeroutput>
4619 (even if the function body threw an exception).
4624 If the function body did not throw an exception:
4625 <orderedlist inheritnum="ignore" continuation="restarts">
4628 Check postconditions for all overridden base functions and for
4629 the overriding derived function in <link linkend="and_anchor"><literal moreinfo="none"><emphasis>AND</emphasis></literal></link>
4630 with each other, by calling the nullary functors <literal moreinfo="none"><emphasis>s_1</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">()</phrase></computeroutput> <link linkend="and_anchor"><literal moreinfo="none"><emphasis>AND</emphasis></literal></link>...
4631 <literal moreinfo="none"><emphasis>s_n</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">()</phrase></computeroutput>
4632 <link linkend="and_anchor"><literal moreinfo="none"><emphasis>AND</emphasis></literal></link>
4633 <literal moreinfo="none"><emphasis>s</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">()</phrase></computeroutput>
4634 passed to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">(</phrase></computeroutput><literal moreinfo="none"><emphasis>s_1</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">)</phrase></computeroutput>, ... <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">(</phrase></computeroutput><literal moreinfo="none"><emphasis>s_n</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">)</phrase></computeroutput>, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">(</phrase></computeroutput><literal moreinfo="none"><emphasis>s</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">)</phrase></computeroutput> for all of the overridden and
4635 overriding functions respectively (or the unary functors <literal moreinfo="none"><emphasis>s_1</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">(</phrase></computeroutput><literal moreinfo="none"><emphasis>result</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">)</phrase></computeroutput> <link linkend="and_anchor"><literal moreinfo="none"><emphasis>AND</emphasis></literal></link>...
4636 <literal moreinfo="none"><emphasis>s_n</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">(</phrase></computeroutput><literal moreinfo="none"><emphasis>result</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">)</phrase></computeroutput> <link linkend="and_anchor"><literal moreinfo="none"><emphasis>AND</emphasis></literal></link>
4637 <literal moreinfo="none"><emphasis>s</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">(</phrase></computeroutput><literal moreinfo="none"><emphasis>result</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">)</phrase></computeroutput> for non-void public function overrides).
4646 <orderedlist inheritnum="ignore" continuation="restarts">
4649 Check exception guarantees for all overridden base functions and
4650 for the overriding derived function in <link linkend="and_anchor"><literal moreinfo="none"><emphasis>AND</emphasis></literal></link>
4651 with each other, by calling the nullary functors <literal moreinfo="none"><emphasis>e_1</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">()</phrase></computeroutput> <link linkend="and_anchor"><literal moreinfo="none"><emphasis>AND</emphasis></literal></link>...
4652 <literal moreinfo="none"><emphasis>e_n</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">()</phrase></computeroutput>
4653 <link linkend="and_anchor"><literal moreinfo="none"><emphasis>AND</emphasis></literal></link>
4654 <literal moreinfo="none"><emphasis>e</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">()</phrase></computeroutput>
4655 passed to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">except</phrase><phrase role="special">(</phrase></computeroutput><literal moreinfo="none"><emphasis>e_1</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">)</phrase></computeroutput>, ... <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">except</phrase><phrase role="special">(</phrase></computeroutput><literal moreinfo="none"><emphasis>e_n</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">)</phrase></computeroutput>, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">except</phrase><phrase role="special">(</phrase></computeroutput><literal moreinfo="none"><emphasis>e</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">)</phrase></computeroutput> for all of the overridden and
4656 overriding functions respectively.
4664 This ensures that contracts and subcontracts of public function overrides
4665 are correctly checked at run-time in accordance with the <ulink url="http://en.wikipedia.org/wiki/Liskov_substitution_principle">substitution
4666 principle</ulink> (see <link linkend="boost_contract.contract_programming_overview.public_function_calls">Public
4667 Function Calls</link>).
4670 For the rest, considerations made in <link linkend="boost_contract.tutorial.virtual_public_functions">Virtual
4671 Public Functions</link> apply to public function overrides as well.
4675 A public function override should always call <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>
4676 (even if it has no preconditions, no postconditions, no exception guarantees,
4677 and its class has no invariants), otherwise this library will not be able
4678 to correctly use it for subcontracting.
4682 <section id="boost_contract.tutorial.base_classes__subcontracting_">
4683 <title><link linkend="boost_contract.tutorial.base_classes__subcontracting_">Base
4684 Classes (Subcontracting)</link></title>
4686 In order for this library to support subcontracting, programmers must specify
4687 the bases of a derived class declaring a public member type named <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">base_types</phrase></computeroutput> via a <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">typedef</phrase></computeroutput>
4688 using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_BASE_TYPES">BOOST_CONTRACT_BASE_TYPES</link></computeroutput>.
4689 For example (see <ulink url="../../example/features/base_types.cpp"><literal moreinfo="none">base_types.cpp</literal></ulink>):
4692 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">class</phrase> <phrase role="identifier">chars</phrase>
4693 <phrase role="preprocessor">#define</phrase> <phrase role="identifier">BASES</phrase> <phrase role="comment">/* local macro (for convenience) */</phrase> <phrase role="special">\</phrase>
4694 <phrase role="keyword">private</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor_precondition</phrase><phrase role="special"><</phrase><phrase role="identifier">chars</phrase><phrase role="special">>,</phrase> <phrase role="special">\</phrase>
4695 <phrase role="keyword">public</phrase> <phrase role="identifier">unique_chars</phrase><phrase role="special">,</phrase> <phrase role="special">\</phrase>
4696 <phrase role="keyword">public</phrase> <phrase role="keyword">virtual</phrase> <phrase role="identifier">pushable</phrase><phrase role="special"><</phrase><phrase role="keyword">char</phrase><phrase role="special">>,</phrase> <phrase role="special">\</phrase>
4697 <phrase role="keyword">virtual</phrase> <phrase role="keyword">protected</phrase> <phrase role="identifier">has_size</phrase><phrase role="special">,</phrase> <phrase role="special">\</phrase>
4698 <phrase role="keyword">private</phrase> <phrase role="identifier">has_empty</phrase>
4699 <phrase role="special">:</phrase> <phrase role="identifier">BASES</phrase> <phrase role="comment">// Bases of this class.</phrase>
4700 <phrase role="special">{</phrase>
4701 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
4702 <phrase role="keyword">typedef</phrase> <phrase role="identifier">BOOST_CONTRACT_BASE_TYPES</phrase><phrase role="special">(</phrase><phrase role="identifier">BASES</phrase><phrase role="special">)</phrase> <phrase role="identifier">base_types</phrase><phrase role="special">;</phrase> <phrase role="comment">// Bases typedef.</phrase>
4703 <phrase role="preprocessor">#undef</phrase> <phrase role="identifier">BASES</phrase> <phrase role="comment">// Undefine local macro.</phrase>
4705 <phrase role="comment">/* ... */</phrase>
4709 For convenience, a <emphasis>local macro</emphasis> named <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">BASES</phrase></computeroutput>
4710 can be used to avoid repeating the base list twice (first in the derived
4711 class declaration <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">class</phrase> </computeroutput><literal moreinfo="none"><emphasis>class-name</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude">
4712 <phrase role="special">:</phrase> </computeroutput><literal moreinfo="none"><emphasis>base-list</emphasis></literal>
4713 and then again when invoking <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">BOOST_CONTRACT_BASE_TYPES</phrase><phrase role="special">(</phrase></computeroutput><literal moreinfo="none"><emphasis>base-list</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">)</phrase></computeroutput>). Being a local macro, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">BASES</phrase></computeroutput>
4714 must be undefined using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#undef</phrase>
4715 <phrase role="identifier">BASES</phrase></computeroutput> after it is used to declare
4716 the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">base_types</phrase></computeroutput> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">typedef</phrase></computeroutput> (to avoid name clashes and macro redefinition
4717 errors). <footnote id="boost_contract.tutorial.base_classes__subcontracting_.f0">
4719 The name of this local macro is arbitrary, but <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">BASES</phrase></computeroutput>
4720 is often used in this documentation.
4725 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_BASE_TYPES">BOOST_CONTRACT_BASE_TYPES</link></computeroutput>
4726 is a variadic macro and accepts a list of bases separated by commas (see
4727 <link linkend="boost_contract.extras.no_macros__and_no_variadic_macros_">No
4728 Macros</link> to program <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">base_types</phrase></computeroutput>
4729 without using macros). As already noted in <link linkend="boost_contract.tutorial.constructors">Constructors</link>,
4730 when the extra base <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.constructor_precondition">boost::contract::constructor_precondition</link></computeroutput>
4731 is used to program constructor preconditions, its inheritance access level
4732 must always be <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">private</phrase></computeroutput> and it
4733 must be specified as the very first base.
4737 Each base passed to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_BASE_TYPES">BOOST_CONTRACT_BASE_TYPES</link></computeroutput>
4738 must <emphasis>explicitly</emphasis> specify its inheritance access level
4739 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">public</phrase></computeroutput>, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">protected</phrase></computeroutput>,
4740 or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">private</phrase></computeroutput> (but <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">virtual</phrase></computeroutput> is optional and can be specified
4741 either before or after the access level as usual in C++). This library
4742 will generate a compile-time error if the first base is missing its inheritance
4743 access level, but this library will not be able to always generate an error
4744 if the access level is missing for bases after the first one. <footnote id="boost_contract.tutorial.base_classes__subcontracting_.f1">
4746 <emphasis role="bold">Rationale:</emphasis> This library explicitly requires
4747 the inheritance access level because derived classes must subcontract
4748 only from public bases, but not from protected or private bases (see
4749 <link linkend="boost_contract.contract_programming_overview.public_function_calls">Public
4750 Function Calls</link>). <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_BASE_TYPES">BOOST_CONTRACT_BASE_TYPES</link></computeroutput>
4751 inspects each inheritance access level using preprocessor meta-programming
4752 and removes non-public bases from the list of bases internally used for
4753 subcontracting. However, this library cannot always detect when programmers
4754 forget to specify the inheritance access level because, when commas are
4755 used to separate template parameters passed to base classes, the preprocessor
4756 will not be able to correctly use commas to identify the next base class
4757 token in the inheritance list (the preprocessor cannot distinguish between
4758 commas that are not protected by round parenthesis, like the ones used
4759 in templates). Therefore, this library uses the inheritance access level
4760 keyword <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">public</phrase></computeroutput>, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">protected</phrase></computeroutput>, or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">private</phrase></computeroutput>
4761 instead of commas <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">,</phrase></computeroutput> for
4762 the preprocessor to correctly find the next base class token in the inheritance
4763 list (thus inheritance access levels must always be explicit specified
4764 by programmers for each base).
4766 </footnote> It is the responsibility of the programmers to make sure that
4767 all bases passed to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_BASE_TYPES">BOOST_CONTRACT_BASE_TYPES</link></computeroutput>
4768 explicitly specify their inheritance access level (inheritance access levels
4769 are instead optional in C++ because <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">private</phrase></computeroutput>
4770 is implicitly assumed for <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">class</phrase></computeroutput>
4771 types and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">public</phrase></computeroutput> for <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">struct</phrase></computeroutput> types).
4774 <emphasis role="bold">Mnemonics:</emphasis>
4778 Always explicitly specify the inheritance access level <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">public</phrase></computeroutput>, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">protected</phrase></computeroutput>,
4779 or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">private</phrase></computeroutput> for base classes
4780 passed to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_BASE_TYPES">BOOST_CONTRACT_BASE_TYPES</link></computeroutput>.
4785 See <link linkend="boost_contract.advanced.access_specifiers">Access Specifiers</link>
4786 to avoid making the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">base_types</phrase></computeroutput>
4787 member type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">public</phrase></computeroutput>. <footnote id="boost_contract.tutorial.base_classes__subcontracting_.f2">
4789 In this documentation the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">base_type</phrase></computeroutput>
4790 member type is often declared <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">public</phrase></computeroutput>
4791 for simplicity. However, in production code it might not be acceptable
4792 to augment the public members of a class adding the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">base_types</phrase></computeroutput>
4793 type (and that can be avoided using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.access">boost::contract::access</link></computeroutput>
4794 as explained in <link linkend="boost_contract.advanced.access_specifiers">Access
4797 </footnote> See <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394999732400">BOOST_CONTRACT_BASES_TYPEDEF</link></computeroutput>
4798 to use a name different from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">base_types</phrase></computeroutput>
4799 (e.g., because <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">base_types</phrase></computeroutput>
4800 clashes with other names in user-defined classes).
4803 <section id="boost_contract.tutorial.static_public_functions">
4804 <title><link linkend="boost_contract.tutorial.static_public_functions">Static
4805 Public Functions</link></title>
4807 Contracts for public functions are programmed using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>.
4808 In this section, let's consider static public functions. For example (see
4809 <ulink url="../../example/features/static_public.cpp"><literal moreinfo="none">static_public.cpp</literal></ulink>):
4812 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">C</phrase><phrase role="special">></phrase>
4813 <phrase role="keyword">class</phrase> <phrase role="identifier">make</phrase> <phrase role="special">{</phrase>
4814 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
4815 <phrase role="keyword">static</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">static_invariant</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Static class invariants.</phrase>
4816 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">instances</phrase><phrase role="special">()</phrase> <phrase role="special">>=</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase>
4817 <phrase role="special">}</phrase>
4819 <phrase role="comment">// Contract for a static public function.</phrase>
4820 <phrase role="keyword">static</phrase> <phrase role="keyword">int</phrase> <phrase role="identifier">instances</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
4821 <phrase role="comment">// Explicit template parameter `make` (check static invariants).</phrase>
4822 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special"><</phrase><phrase role="identifier">make</phrase><phrase role="special">>();</phrase>
4824 <phrase role="keyword">return</phrase> <phrase role="identifier">instances_</phrase><phrase role="special">;</phrase> <phrase role="comment">// Function body.</phrase>
4825 <phrase role="special">}</phrase>
4827 <phrase role="comment">/* ... */</phrase>
4831 It is possible to specify preconditions, postconditions, and exception guarantees
4832 for static public functions (see <link linkend="boost_contract.tutorial.preconditions">Preconditions</link>,
4833 <link linkend="boost_contract.tutorial.postconditions">Postconditions</link>,
4834 and <link linkend="boost_contract.tutorial.exception_guarantees">Exception
4835 Guarantees</link>). When called from static public functions, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>
4836 cannot take the object <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">this</phrase></computeroutput>
4837 as a parameter (because there is no object <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">this</phrase></computeroutput>
4838 in static member functions) so the enclosing class type is specified via
4839 an explicit template parameter as in <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput><literal moreinfo="none"><<emphasis>class-type</emphasis>></literal>
4840 (the class type is required to check static class invariants, see <link linkend="boost_contract.tutorial.class_invariants">Class
4843 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">class</phrase> <phrase role="identifier">u</phrase> <phrase role="special">{</phrase>
4844 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
4845 <phrase role="comment">// A static public function.</phrase>
4846 <phrase role="keyword">static</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">f</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
4847 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special"><</phrase><phrase role="identifier">u</phrase><phrase role="special">>()</phrase> <phrase role="comment">// Class type `u` as explicit template parameter.</phrase>
4848 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase> <phrase role="special">...</phrase> <phrase role="special">})</phrase>
4849 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase> <phrase role="special">...</phrase> <phrase role="special">})</phrase>
4850 <phrase role="special">.</phrase><phrase role="identifier">except</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase> <phrase role="special">...</phrase> <phrase role="special">})</phrase>
4851 <phrase role="special">;</phrase>
4853 <phrase role="special">...</phrase>
4854 <phrase role="special">}</phrase>
4856 <phrase role="special">...</phrase>
4857 <phrase role="special">};</phrase>
4860 The <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>
4861 function returns an RAII object that must be assigned to a local variable
4862 of type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.check">boost::contract::check</link></computeroutput>
4863 (otherwise this library will generate a run-time error, see <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394999694064">BOOST_CONTRACT_ON_MISSING_CHECK_DECL</link></computeroutput>).
4864 Furthermore, C++11 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">auto</phrase></computeroutput> declarations
4865 cannot be used here and the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.check">boost::contract::check</link></computeroutput>
4866 type must be explicitly specified (otherwise this library will generate a
4867 compile-time error prior C++17 and a run-time error post C++17). The static
4868 public functions body is programmed right after the declaration of this RAII
4872 At construction, the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.check">boost::contract::check</link></computeroutput>
4873 RAII object for static public functions does the following (enclosing static
4874 public function entry):
4876 <orderedlist inheritnum="ignore" continuation="restarts">
4879 Check static class invariants, by calling <literal moreinfo="none"><emphasis>class-type</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">::</phrase><phrase role="identifier">static_invariant</phrase><phrase role="special">()</phrase></computeroutput> (but never non-static class invariants).
4884 Check preconditions, by calling the nullary functor <literal moreinfo="none"><emphasis>r</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">()</phrase></computeroutput> passed to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">(</phrase></computeroutput><literal moreinfo="none"><emphasis>r</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">)</phrase></computeroutput>.
4889 At destruction instead (enclosing static public function exit):
4891 <orderedlist inheritnum="ignore" continuation="restarts">
4894 Check static class invariants, by calling <literal moreinfo="none"><emphasis>class-type</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">::</phrase><phrase role="identifier">static_invariant</phrase><phrase role="special">()</phrase></computeroutput> (even if the function body threw an
4895 exception, but never non-static class invariants).
4900 If the function body did not throw an exception:
4901 <orderedlist inheritnum="ignore" continuation="restarts">
4904 Check postconditions, by calling the nullary functor <literal moreinfo="none"><emphasis>s</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">()</phrase></computeroutput> passed to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">(</phrase></computeroutput><literal moreinfo="none"><emphasis>s</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">)</phrase></computeroutput>.
4913 <orderedlist inheritnum="ignore" continuation="restarts">
4916 Check exception guarantees, by calling the nullary functor <literal moreinfo="none"><emphasis>e</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">()</phrase></computeroutput> passed to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">except</phrase><phrase role="special">(</phrase></computeroutput><literal moreinfo="none"><emphasis>e</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">)</phrase></computeroutput>.
4924 This ensures that static public function contracts are correctly checked
4925 at run-time (static public functions do not subcontract because they have
4926 no object <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">this</phrase></computeroutput> and therefore
4927 there is no inheritance, see <link linkend="boost_contract.contract_programming_overview.public_function_calls">Public
4928 Function Calls</link>).
4932 A static public function can avoid calling <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>
4933 for efficiency but only when it has no preconditions, no postconditions,
4934 no exception guarantees, and its class has no static invariants (the class
4935 can still have non-static invariants or base classes instead).
4940 <section id="boost_contract.advanced">
4941 <title><link linkend="boost_contract.advanced">Advanced</link></title>
4943 This section is a guide to advanced usage of this library.
4945 <section id="boost_contract.advanced.pure_virtual_public_functions">
4946 <title><link linkend="boost_contract.advanced.pure_virtual_public_functions">Pure
4947 Virtual Public Functions</link></title>
4949 In C++, pure virtual functions are allowed to have a <ulink url="http://en.cppreference.com/w/cpp/language/abstract_class">default
4950 implementation</ulink> as long as such implementation is programmed out-of-line
4951 so defined outside the class declaring the pure virtual function <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">virtual</phrase> <phrase role="special">...</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase></computeroutput>.
4954 Contracts for pure virtual public functions are programmed using the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>
4955 function like for (non-pure) virtual public functions (all consideration
4956 made in <link linkend="boost_contract.tutorial.virtual_public_functions">Virtual
4957 Public Functions</link> apply). However, contracts have to be programmed
4958 out-of-line, in the default implementation of the pure virtual function.
4959 For example (see <ulink url="../../example/features/pure_virtual_public.cpp"><literal moreinfo="none">pure_virtual_public.cpp</literal></ulink>):
4962 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">Iterator</phrase><phrase role="special">></phrase>
4963 <phrase role="keyword">class</phrase> <phrase role="identifier">range</phrase> <phrase role="special">{</phrase>
4964 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
4965 <phrase role="comment">// Pure virtual function declaration (contract in definition below).</phrase>
4966 <phrase role="keyword">virtual</phrase> <phrase role="identifier">Iterator</phrase> <phrase role="identifier">begin</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase>
4970 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="comment">/* ... */</phrase>
4971 <phrase role="special">};</phrase>
4975 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="comment">// Pure virtual function default implementation (out-of-line in C++).</phrase>
4976 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">Iterator</phrase><phrase role="special">></phrase>
4977 <phrase role="identifier">Iterator</phrase> <phrase role="identifier">range</phrase><phrase role="special"><</phrase><phrase role="identifier">Iterator</phrase><phrase role="special">>::</phrase><phrase role="identifier">begin</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
4978 <phrase role="identifier">Iterator</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase> <phrase role="comment">// As usual, virtual pass `result` right after `v`...</phrase>
4979 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">result</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">)</phrase>
4980 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">(</phrase><phrase role="identifier">Iterator</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">result</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
4981 <phrase role="keyword">if</phrase><phrase role="special">(</phrase><phrase role="identifier">empty</phrase><phrase role="special">())</phrase> <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">result</phrase> <phrase role="special">==</phrase> <phrase role="identifier">end</phrase><phrase role="special">());</phrase>
4982 <phrase role="special">})</phrase>
4983 <phrase role="special">;</phrase>
4985 <phrase role="comment">// Pure function body (never executed by this library).</phrase>
4986 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="keyword">false</phrase><phrase role="special">);</phrase>
4987 <phrase role="keyword">return</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
4988 <phrase role="special">}</phrase>
4992 This library will never actually execute the pure virtual function body while
4993 it is calling the pure virtual function default implementation to check contracts
4994 for subcontracting. Therefore, programmers can safely <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="keyword">false</phrase><phrase role="special">)</phrase></computeroutput>
4995 at the beginning of the body if they intend for that body to never be executed
4996 (or they can program a working body in case they need to use pure virtual
4997 function default implementations as usual in C++).
4999 <bridgehead renderas="sect4" id="boost_contract.advanced.pure_virtual_public_functions.h0">
5000 <phrase id="boost_contract.advanced.pure_virtual_public_functions.subcontracting_preconditions_always_true_or_false"/><link linkend="boost_contract.advanced.pure_virtual_public_functions.subcontracting_preconditions_always_true_or_false">Subcontracting
5001 Preconditions Always True or False</link>
5004 As seen in <link linkend="boost_contract.tutorial.public_function_overrides__subcontracting_">Public
5005 Function Overrides</link>, preconditions of overriding public functions are
5006 checked in <link linkend="or_anchor"><literal moreinfo="none"><emphasis>OR</emphasis></literal></link>
5007 with preconditions of overridden virtual public functions. Therefore, if
5008 a virtual public function in a base class specifies no precondition then
5009 preconditions specified by all its overriding functions in derived classes
5010 will have no effect (because when checked in <link linkend="or_anchor"><literal moreinfo="none"><emphasis>OR</emphasis></literal></link>
5011 with the overridden function from the base class that has no preconditions,
5012 they will always pass):
5014 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">class</phrase> <phrase role="identifier">u</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Some base class.</phrase>
5015 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
5016 <phrase role="keyword">virtual</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">f</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
5017 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">)</phrase>
5018 <phrase role="comment">// No preconditions, same as `ASSERT(true)`.</phrase>
5019 <phrase role="special">...</phrase>
5020 <phrase role="special">;</phrase>
5022 <phrase role="special">...</phrase>
5023 <phrase role="special">}</phrase>
5025 <phrase role="special">...</phrase>
5026 <phrase role="special">};</phrase>
5029 This correctly reflects the fact that the overridden function in the base
5030 class can be called from any context (because it has no precondition) and
5031 so must all its overriding functions in all derived classes in accordance
5032 to the <ulink url="http://en.wikipedia.org/wiki/Liskov_substitution_principle">substitution
5033 principle</ulink>. <footnote id="boost_contract.advanced.pure_virtual_public_functions.f0">
5035 This consequence of the <ulink url="http://en.wikipedia.org/wiki/Liskov_substitution_principle">substitution
5036 principle</ulink> <quote>that if any function in an inheritance hierarchy
5037 has no preconditions, then preconditions on functions overriding it have
5038 no useful effect</quote> is also explicitly mentioned in the contract documentation
5039 of the D Programming Language (see <link linkend="Bright04_anchor">[Bright04]</link>).
5041 </footnote> In other words, the code above has the same effect as declaring
5042 the virtual public function in the base class with a single precondition
5043 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="keyword">true</phrase><phrase role="special">)</phrase></computeroutput> that
5044 will always trivially pass:
5046 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">class</phrase> <phrase role="identifier">u</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Some base class.</phrase>
5047 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
5048 <phrase role="keyword">virtual</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">f</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
5049 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">)</phrase>
5050 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([]</phrase> <phrase role="special">{</phrase>
5051 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="keyword">true</phrase><phrase role="special">);</phrase> <phrase role="comment">// Same as no preconditions.</phrase>
5052 <phrase role="special">})</phrase>
5053 <phrase role="special">...</phrase>
5054 <phrase role="special">;</phrase>
5056 <phrase role="special">...</phrase>
5057 <phrase role="special">}</phrase>
5059 <phrase role="special">...</phrase>
5060 <phrase role="special">};</phrase>
5063 On the flip side, programmers might sometimes consider to declare a pure
5064 virtual public function in a base class with a single precondition <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="keyword">false</phrase><phrase role="special">)</phrase></computeroutput> that
5065 will always fail. This indicates that the pure virtual public function can
5066 never be called unless it is redefined by a derived class (which is already
5067 the case with C++ pure virtual functions) and also that the base class designers
5068 have intentionally left it up to derived classes to specify preconditions
5069 for the pure virtual function in question. This technique might make sense
5070 only for preconditions of pure virtual public functions (otherwise <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="keyword">false</phrase><phrase role="special">)</phrase></computeroutput> will
5071 prevent calling virtual public functions in concrete bases). For example
5072 (see <ulink url="../../example/features/named_override.cpp"><literal moreinfo="none">named_override.cpp</literal></ulink>):
5075 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">></phrase>
5076 <phrase role="keyword">class</phrase> <phrase role="identifier">generic_unary_pack</phrase> <phrase role="special">{</phrase>
5077 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
5078 <phrase role="keyword">virtual</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">_1</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">value</phrase><phrase role="special">,</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase>
5079 <phrase role="keyword">virtual</phrase> <phrase role="identifier">T</phrase> <phrase role="identifier">_1</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase>
5080 <phrase role="special">};</phrase>
5082 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">></phrase>
5083 <phrase role="keyword">void</phrase> <phrase role="identifier">generic_unary_pack</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">>::</phrase><phrase role="identifier">_1</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">value</phrase><phrase role="special">,</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
5084 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">)</phrase>
5085 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
5086 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="keyword">false</phrase><phrase role="special">);</phrase> <phrase role="comment">// Defer preconditions to overrides.</phrase>
5087 <phrase role="special">})</phrase>
5088 <phrase role="special">;</phrase>
5089 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="keyword">false</phrase><phrase role="special">);</phrase>
5090 <phrase role="special">}</phrase>
5092 <phrase role="comment">/* ... */</phrase>
5096 That said, the need to declare such a precondition <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="keyword">false</phrase><phrase role="special">)</phrase></computeroutput>
5097 that will always fail might also be an indication that the base class interface
5098 is not correctly designed. In general, the base class interface should still
5099 contain all functions (eventually as pure virtual) that are necessary to
5100 program its contracts.
5103 <section id="boost_contract.advanced.optional_return_values">
5104 <title><link linkend="boost_contract.advanced.optional_return_values">Optional
5105 Return Values</link></title>
5107 It is possible to use <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">optional</phrase></computeroutput>
5108 to handle return values when programmers cannot construct the result variable
5109 at its point of declaration before the contract (e.g., because an appropriate
5110 constructor for the return type is not available at that point, or just because
5111 it would be too expensive to execute an extra initialization of the return
5112 value at run-time). <footnote id="boost_contract.advanced.optional_return_values.f0">
5114 <emphasis role="bold">Rationale:</emphasis> This library uses <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">optional</phrase></computeroutput> instead of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">optional</phrase></computeroutput>
5115 to support a larger number of compilers and their versions (because <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">optional</phrase></computeroutput> was not available before C++17).
5117 </footnote> For example (see <ulink url="../../example/features/optional_result.cpp"><literal moreinfo="none">optional_result.cpp</literal></ulink>):
5120 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">unsigned</phrase> <phrase role="identifier">Index</phrase><phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">></phrase>
5121 <phrase role="identifier">T</phrase><phrase role="special">&</phrase> <phrase role="identifier">get</phrase><phrase role="special">(</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">>&</phrase> <phrase role="identifier">vect</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
5122 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">optional</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">&></phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase> <phrase role="comment">// Result not initialized here...</phrase>
5123 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">function</phrase><phrase role="special">()</phrase>
5124 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
5125 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">Index</phrase> <phrase role="special"><</phrase> <phrase role="identifier">vect</phrase><phrase role="special">.</phrase><phrase role="identifier">size</phrase><phrase role="special">());</phrase>
5126 <phrase role="special">})</phrase>
5127 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
5128 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(*</phrase><phrase role="identifier">result</phrase> <phrase role="special">==</phrase> <phrase role="identifier">vect</phrase><phrase role="special">[</phrase><phrase role="identifier">Index</phrase><phrase role="special">]);</phrase>
5129 <phrase role="special">})</phrase>
5130 <phrase role="special">;</phrase>
5132 <phrase role="comment">// Function body (executed after preconditions checked).</phrase>
5133 <phrase role="keyword">return</phrase> <phrase role="special">*(</phrase><phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="identifier">vect</phrase><phrase role="special">[</phrase><phrase role="identifier">Index</phrase><phrase role="special">]);</phrase> <phrase role="comment">// ...result initialized here instead.</phrase>
5134 <phrase role="special">}</phrase>
5138 In this example the return type is a reference so it does not have default
5139 constructor that can be used to initialize <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">result</phrase></computeroutput>
5140 when it is declared before the contract declaration. In addition, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Index</phrase></computeroutput> needs to be validated to be smaller
5141 than <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">size</phrase><phrase role="special">()</phrase></computeroutput>
5142 by the precondition before it can be used to retrieve the reference to assign
5143 to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">result</phrase></computeroutput> so <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">vect</phrase><phrase role="special">[</phrase><phrase role="identifier">Index</phrase><phrase role="special">]</phrase></computeroutput> cannot be used to initialize <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">result</phrase></computeroutput> when it is declared before the contract
5144 declaration. Therefore, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">optional</phrase></computeroutput>
5145 is used to defer <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">result</phrase></computeroutput> real
5146 initialization until the execution of the function body, after the contract
5147 declaration, where <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Index</phrase></computeroutput>
5148 has been validated by the precondition and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">vect</phrase><phrase role="special">[</phrase><phrase role="identifier">Index</phrase><phrase role="special">]</phrase></computeroutput> can be safely evaluated to initialize <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">result</phrase></computeroutput>.
5151 As seen in <link linkend="boost_contract.tutorial.return_values">Return Values</link>,
5152 it is the responsibility of the programmers to ensure that <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">result</phrase></computeroutput> is always set to the return value
5153 (when the function exits without trowing an exception). This also ensures
5154 that <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">result</phrase></computeroutput> is always set
5155 before the postconditions are checked so programmers can always dereference
5156 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">result</phrase></computeroutput> in postconditions
5157 to access the return value (using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">operator</phrase><phrase role="special">*</phrase></computeroutput> and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">operator</phrase><phrase role="special">-></phrase></computeroutput> as usual with <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">optional</phrase></computeroutput>,
5158 and without having to explicitly check if <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">result</phrase></computeroutput>
5159 is an empty <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">optional</phrase></computeroutput> object or not). This can be done
5160 ensuring that <emphasis>all</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">return</phrase></computeroutput>
5161 statements in the function are of the form:
5163 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">optional</phrase><phrase role="special"><</phrase><literal moreinfo="none"><emphasis>return-type</emphasis></literal><phrase role="special">></phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
5164 <phrase role="special">...</phrase>
5165 <phrase role="keyword">return</phrase> <phrase role="special">*(</phrase><phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <literal moreinfo="none"><emphasis>return-expression</emphasis></literal><phrase role="special">);</phrase> <phrase role="comment">// Assign `result` at each return.</phrase>
5167 <bridgehead renderas="sect4" id="boost_contract.advanced.optional_return_values.h0">
5168 <phrase id="boost_contract.advanced.optional_return_values.optional_results_in_virtual_public_functions"/><link linkend="boost_contract.advanced.optional_return_values.optional_results_in_virtual_public_functions">Optional
5169 Results in Virtual Public Functions</link>
5172 Similarly, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">optional</phrase></computeroutput> can be used to handle the return
5173 value passed to contracts of virtual public functions (pure or not) and of
5174 public function overrides. As seen in <link linkend="boost_contract.advanced.pure_virtual_public_functions">Pure
5175 Virtual Public Functions</link>, <link linkend="boost_contract.tutorial.virtual_public_functions">Virtual
5176 Public Functions</link>, and <link linkend="boost_contract.tutorial.public_function_overrides__subcontracting_">Public
5177 Function Overrides</link>, in these cases the return value <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">result</phrase></computeroutput> must be passed as a parameter to
5178 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>
5179 right after the parameter <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">v</phrase></computeroutput>
5180 of type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.virtual_">boost::contract::virtual_</link></computeroutput><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">*</phrase></computeroutput>. Then the functor passed to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">(...)</phrase></computeroutput> takes one single parameter of type
5181 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">optional</phrase><phrase role="special"><</phrase></computeroutput><literal moreinfo="none"><emphasis>return-type</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude">
5182 <phrase role="keyword">const</phrase><phrase role="special">&></phrase>
5183 <phrase role="keyword">const</phrase><phrase role="special">&</phrase></computeroutput>.
5184 For example (see <ulink url="../../example/features/optional_result_virtual.cpp"><literal moreinfo="none">optional_result_virtual.cpp</literal></ulink>):
5187 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">></phrase>
5188 <phrase role="identifier">T</phrase><phrase role="special">&</phrase> <phrase role="identifier">accessible</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">>::</phrase><phrase role="identifier">at</phrase><phrase role="special">(</phrase><phrase role="keyword">unsigned</phrase> <phrase role="identifier">index</phrase><phrase role="special">,</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
5189 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">optional</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">&></phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
5190 <phrase role="comment">// Pass `result` right after `v`...</phrase>
5191 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">result</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">)</phrase>
5192 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
5193 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">index</phrase> <phrase role="special"><</phrase> <phrase role="identifier">size</phrase><phrase role="special">());</phrase>
5194 <phrase role="special">})</phrase>
5195 <phrase role="comment">// ...plus postconditions take `result` as a parameter (not capture).</phrase>
5196 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">optional</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&></phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">result</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
5197 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(*</phrase><phrase role="identifier">result</phrase> <phrase role="special">==</phrase> <phrase role="keyword">operator</phrase><phrase role="special">[](</phrase><phrase role="identifier">index</phrase><phrase role="special">));</phrase>
5198 <phrase role="special">})</phrase>
5199 <phrase role="special">;</phrase>
5201 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="keyword">false</phrase><phrase role="special">);</phrase>
5202 <phrase role="keyword">return</phrase> <phrase role="special">*</phrase><phrase role="identifier">result</phrase><phrase role="special">;</phrase>
5203 <phrase role="special">}</phrase>
5207 The inner <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase><phrase role="special">&</phrase></computeroutput>
5208 in the postcondition functor parameter type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">optional</phrase><phrase role="special"><...</phrase> <phrase role="keyword">const</phrase><phrase role="special">&></phrase> <phrase role="special">...</phrase></computeroutput>
5209 is mandatory (while the outer <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase><phrase role="special">&</phrase></computeroutput> in the postcondition functor parameter
5210 type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">optional</phrase><phrase role="special"><...></phrase>
5211 <phrase role="keyword">const</phrase><phrase role="special">&</phrase></computeroutput>
5212 is not). <footnote id="boost_contract.advanced.optional_return_values.f1">
5214 <emphasis role="bold">Rationale:</emphasis> This library requires the postcondition
5215 functor parameter to be of type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">optional</phrase><phrase role="special"><...</phrase> <phrase role="keyword">const</phrase><phrase role="special">&></phrase></computeroutput> so the return value does not have
5216 to be copied (because of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">&</phrase></computeroutput>)
5217 while postconditions are still not allowed to change its value (because
5218 of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase></computeroutput>, see <link linkend="boost_contract.contract_programming_overview.constant_correctness">Constant-Correctness</link>).
5219 In addition, programmers are encouraged to declare the postcondition functor
5220 to take its argument also as a constant reference <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">optional</phrase><phrase role="special"><...</phrase> <phrase role="keyword">const</phrase><phrase role="special">&></phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase></computeroutput> to avoid possibly expensive copies
5221 of the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">optional</phrase></computeroutput> type itself.
5226 <section id="boost_contract.advanced.private_and_protected_functions">
5227 <title><link linkend="boost_contract.advanced.private_and_protected_functions">Private
5228 and Protected Functions</link></title>
5230 Private and protected functions do not check class invariants (because they
5231 are not part of the public class interface) and they do not subcontract (because
5232 they are not accessible at the calling site where the <ulink url="http://en.wikipedia.org/wiki/Liskov_substitution_principle">substitution
5233 principle</ulink> applies, see <link linkend="boost_contract.contract_programming_overview.function_calls">Function
5234 Calls</link>). However, programmers may still want to specify preconditions
5235 and postconditions for private and protected functions when they want to
5236 check correctness of their implementation and use (from within the class,
5237 base classes, friend classes or functions, etc.). When programmers decide
5238 to specify contracts for private and protected functions, they can use <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.function">boost::contract::function</link></computeroutput>
5239 (because, like for non-member functions, this does not check class invariants
5240 and does not subcontract). For example (see <ulink url="../../example/features/private_protected.cpp"><literal moreinfo="none">private_protected.cpp</literal></ulink>):
5243 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">class</phrase> <phrase role="identifier">counter</phrase> <phrase role="special">{</phrase>
5244 <phrase role="keyword">protected</phrase><phrase role="special">:</phrase> <phrase role="comment">// Protected functions use `function()` (like non-members).</phrase>
5245 <phrase role="keyword">void</phrase> <phrase role="identifier">set</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">n</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
5246 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">function</phrase><phrase role="special">()</phrase>
5247 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
5248 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">n</phrase> <phrase role="special"><=</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase>
5249 <phrase role="special">})</phrase>
5250 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
5251 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">get</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">n</phrase><phrase role="special">);</phrase>
5252 <phrase role="special">})</phrase>
5253 <phrase role="special">;</phrase>
5255 <phrase role="identifier">n_</phrase> <phrase role="special">=</phrase> <phrase role="identifier">n</phrase><phrase role="special">;</phrase>
5256 <phrase role="special">}</phrase>
5258 <phrase role="keyword">private</phrase><phrase role="special">:</phrase> <phrase role="comment">// Private functions use `function()` (like non-members).</phrase>
5259 <phrase role="keyword">void</phrase> <phrase role="identifier">dec</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
5260 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">></phrase> <phrase role="identifier">old_get</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">get</phrase><phrase role="special">());</phrase>
5261 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">function</phrase><phrase role="special">()</phrase>
5262 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
5263 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase>
5264 <phrase role="identifier">get</phrase><phrase role="special">()</phrase> <phrase role="special">+</phrase> <phrase role="number">1</phrase> <phrase role="special">>=</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">numeric_limits</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">>::</phrase><phrase role="identifier">min</phrase><phrase role="special">());</phrase>
5265 <phrase role="special">})</phrase>
5266 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
5267 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">get</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_get</phrase> <phrase role="special">-</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase>
5268 <phrase role="special">})</phrase>
5269 <phrase role="special">;</phrase>
5271 <phrase role="identifier">set</phrase><phrase role="special">(</phrase><phrase role="identifier">get</phrase><phrase role="special">()</phrase> <phrase role="special">-</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase>
5272 <phrase role="special">}</phrase>
5274 <phrase role="keyword">int</phrase> <phrase role="identifier">n_</phrase><phrase role="special">;</phrase>
5276 <phrase role="comment">/* ... */</phrase>
5280 Considerations made in <link linkend="boost_contract.tutorial.non_member_functions">Non-Member
5281 Functions</link> apply to private and protected functions as well. See <link linkend="boost_contract.tutorial.constructors">Constructors</link> and <link linkend="boost_contract.tutorial.destructors">Destructors</link> on how to
5282 program contracts for private and protected constructors and destructors
5285 <bridgehead renderas="sect4" id="boost_contract.advanced.private_and_protected_functions.h0">
5286 <phrase id="boost_contract.advanced.private_and_protected_functions.virtual_private_and_protected_functions"/><link linkend="boost_contract.advanced.private_and_protected_functions.virtual_private_and_protected_functions">Virtual
5287 Private and Protected Functions</link>
5290 When private and protected functions are virtual they should still declare
5291 the extra virtual parameter of type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.virtual_">boost::contract::virtual_</link></computeroutput><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">*</phrase></computeroutput> with default value <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="number">0</phrase></computeroutput>
5292 (see <link linkend="boost_contract.tutorial.virtual_public_functions">Virtual
5293 Public Functions</link>) even if that parameter does not have to be passed
5294 to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_OLDOF">BOOST_CONTRACT_OLDOF</link></computeroutput>
5295 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.function">boost::contract::function</link></computeroutput>
5296 takes no such an argument (so the extra virtual parameter will remain unused
5297 and it does not need a name). <footnote id="boost_contract.advanced.private_and_protected_functions.f0">
5299 Technically, the extra virtual parameter can still be passed to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_OLDOF">BOOST_CONTRACT_OLDOF</link></computeroutput> but that is
5300 not necessary and it has no effect so it is not done in this documentation.
5302 </footnote> That is necessary otherwise the private and protected virtual
5303 functions cannot be overridden by public functions in derived classes that
5304 specify contracts (because the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase></computeroutput>
5305 parameter has to be part of signatures for public function overrides). For
5306 example (see <ulink url="../../example/features/private_protected_virtual.cpp"><literal moreinfo="none">private_protected_virtual.cpp</literal></ulink>):
5309 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">class</phrase> <phrase role="identifier">counter</phrase> <phrase role="special">{</phrase>
5310 <phrase role="comment">// Virtual private and protected functions still declare extra</phrase>
5311 <phrase role="comment">// `virtual_* = 0` parameter (otherwise they cannot be overridden), but...</phrase>
5312 <phrase role="keyword">protected</phrase><phrase role="special">:</phrase>
5313 <phrase role="keyword">virtual</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">set</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">n</phrase><phrase role="special">,</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
5314 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">function</phrase><phrase role="special">()</phrase> <phrase role="comment">// ...no `v`.</phrase>
5315 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
5316 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">n</phrase> <phrase role="special"><=</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase>
5317 <phrase role="special">})</phrase>
5318 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
5319 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">get</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">n</phrase><phrase role="special">);</phrase>
5320 <phrase role="special">})</phrase>
5321 <phrase role="special">;</phrase>
5323 <phrase role="identifier">n_</phrase> <phrase role="special">=</phrase> <phrase role="identifier">n</phrase><phrase role="special">;</phrase>
5324 <phrase role="special">}</phrase>
5326 <phrase role="keyword">private</phrase><phrase role="special">:</phrase>
5327 <phrase role="keyword">virtual</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">dec</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
5328 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">></phrase> <phrase role="identifier">old_get</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">get</phrase><phrase role="special">());</phrase> <phrase role="comment">// ...no `v`.</phrase>
5329 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">function</phrase><phrase role="special">()</phrase> <phrase role="comment">// ...no `v`.</phrase>
5330 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
5331 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase>
5332 <phrase role="identifier">get</phrase><phrase role="special">()</phrase> <phrase role="special">+</phrase> <phrase role="number">1</phrase> <phrase role="special">>=</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">numeric_limits</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">>::</phrase><phrase role="identifier">min</phrase><phrase role="special">());</phrase>
5333 <phrase role="special">})</phrase>
5334 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
5335 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">get</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_get</phrase> <phrase role="special">-</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase>
5336 <phrase role="special">})</phrase>
5337 <phrase role="special">;</phrase>
5339 <phrase role="identifier">set</phrase><phrase role="special">(</phrase><phrase role="identifier">get</phrase><phrase role="special">()</phrase> <phrase role="special">-</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase>
5340 <phrase role="special">}</phrase>
5342 <phrase role="keyword">int</phrase> <phrase role="identifier">n_</phrase><phrase role="special">;</phrase>
5344 <phrase role="comment">/* ... */</phrase>
5348 However, public functions in derived classes overriding private or protected
5349 virtual functions from base classes shall not specify the extra <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">override_</phrase><phrase role="special">...</phrase></computeroutput>
5350 template parameter to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>
5351 because the overridden functions are private or protected and, not being
5352 public, they do not participate to subcontracting (this library will generate
5353 a compile-time error if <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">override_</phrase><phrase role="special">...</phrase></computeroutput> is specified because there will be no
5354 virtual <emphasis>public</emphasis> function to override from the base class).
5355 For example (see <ulink url="../../example/features/private_protected_virtual.cpp"><literal moreinfo="none">private_protected_virtual.cpp</literal></ulink>):
5358 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">class</phrase> <phrase role="identifier">counter10</phrase>
5359 <phrase role="preprocessor">#define</phrase> <phrase role="identifier">BASES</phrase> <phrase role="keyword">public</phrase> <phrase role="identifier">counter</phrase>
5360 <phrase role="special">:</phrase> <phrase role="identifier">BASES</phrase>
5361 <phrase role="special">{</phrase>
5362 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
5363 <phrase role="keyword">typedef</phrase> <phrase role="identifier">BOOST_CONTRACT_BASE_TYPES</phrase><phrase role="special">(</phrase><phrase role="identifier">BASES</phrase><phrase role="special">)</phrase> <phrase role="identifier">base_types</phrase><phrase role="special">;</phrase>
5364 <phrase role="preprocessor">#undef</phrase> <phrase role="identifier">BASES</phrase>
5366 <phrase role="comment">// Overriding from non-public members so no subcontracting, no override_...</phrase>
5368 <phrase role="keyword">virtual</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">set</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">n</phrase><phrase role="special">,</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="comment">/* override */</phrase> <phrase role="special">{</phrase>
5369 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">)</phrase>
5370 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
5371 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">n</phrase> <phrase role="special">%</phrase> <phrase role="number">10</phrase> <phrase role="special">==</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase>
5372 <phrase role="special">})</phrase>
5373 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
5374 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">get</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">n</phrase><phrase role="special">);</phrase>
5375 <phrase role="special">})</phrase>
5376 <phrase role="special">;</phrase>
5378 <phrase role="identifier">counter</phrase><phrase role="special">::</phrase><phrase role="identifier">set</phrase><phrase role="special">(</phrase><phrase role="identifier">n</phrase><phrase role="special">);</phrase>
5379 <phrase role="special">}</phrase>
5381 <phrase role="keyword">virtual</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">dec</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="comment">/* override */</phrase> <phrase role="special">{</phrase>
5382 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">></phrase> <phrase role="identifier">old_get</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">get</phrase><phrase role="special">());</phrase>
5383 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">)</phrase>
5384 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
5385 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase>
5386 <phrase role="identifier">get</phrase><phrase role="special">()</phrase> <phrase role="special">+</phrase> <phrase role="number">10</phrase> <phrase role="special">>=</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">numeric_limits</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">>::</phrase><phrase role="identifier">min</phrase><phrase role="special">());</phrase>
5387 <phrase role="special">})</phrase>
5388 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
5389 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">get</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_get</phrase> <phrase role="special">-</phrase> <phrase role="number">10</phrase><phrase role="special">);</phrase>
5390 <phrase role="special">})</phrase>
5391 <phrase role="special">;</phrase>
5393 <phrase role="identifier">set</phrase><phrase role="special">(</phrase><phrase role="identifier">get</phrase><phrase role="special">()</phrase> <phrase role="special">-</phrase> <phrase role="number">10</phrase><phrase role="special">);</phrase>
5394 <phrase role="special">}</phrase>
5396 <phrase role="comment">/* ... */</phrase>
5400 Furthermore, using multiple inheritance it is possible to override functions
5401 that are private or protected from one base but public from another base.
5402 In this case, public function overrides in derived classes will specify the
5403 extra <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">override_</phrase><phrase role="special">...</phrase></computeroutput>
5404 template parameter to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>
5405 (because the overridden functions are private or protected in one base and
5406 those do not participate to subcontracting, but public in another base and
5407 these participate to subcontracting instead). For example (see <ulink url="../../example/features/private_protected_virtual_multi.cpp"><literal moreinfo="none">private_protected_virtual_multi.cpp</literal></ulink>):
5410 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">class</phrase> <phrase role="identifier">countable</phrase> <phrase role="special">{</phrase>
5411 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
5412 <phrase role="keyword">void</phrase> <phrase role="identifier">invariant</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
5413 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">get</phrase><phrase role="special">()</phrase> <phrase role="special"><=</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase>
5414 <phrase role="special">}</phrase>
5416 <phrase role="keyword">virtual</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">dec</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase>
5417 <phrase role="keyword">virtual</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">set</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">n</phrase><phrase role="special">,</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase>
5418 <phrase role="keyword">virtual</phrase> <phrase role="keyword">int</phrase> <phrase role="identifier">get</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase>
5419 <phrase role="special">};</phrase>
5421 <phrase role="comment">/* ... */</phrase>
5425 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">class</phrase> <phrase role="identifier">counter10</phrase>
5426 <phrase role="preprocessor">#define</phrase> <phrase role="identifier">BASES</phrase> <phrase role="keyword">public</phrase> <phrase role="identifier">countable</phrase><phrase role="special">,</phrase> <phrase role="keyword">public</phrase> <phrase role="identifier">counter</phrase> <phrase role="comment">// Multiple inheritance.</phrase>
5427 <phrase role="special">:</phrase> <phrase role="identifier">BASES</phrase>
5428 <phrase role="special">{</phrase>
5429 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
5430 <phrase role="keyword">typedef</phrase> <phrase role="identifier">BOOST_CONTRACT_BASE_TYPES</phrase><phrase role="special">(</phrase><phrase role="identifier">BASES</phrase><phrase role="special">)</phrase> <phrase role="identifier">base_types</phrase><phrase role="special">;</phrase>
5431 <phrase role="preprocessor">#undef</phrase> <phrase role="identifier">BASES</phrase>
5433 <phrase role="comment">// Overriding from public members from `countable` so use `override_...`.</phrase>
5435 <phrase role="keyword">virtual</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">set</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">n</phrase><phrase role="special">,</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="comment">/* override */</phrase> <phrase role="special">{</phrase>
5436 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special"><</phrase>
5437 <phrase role="identifier">override_set</phrase><phrase role="special">>(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="special">&</phrase><phrase role="identifier">counter10</phrase><phrase role="special">::</phrase><phrase role="identifier">set</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">,</phrase> <phrase role="identifier">n</phrase><phrase role="special">)</phrase>
5438 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
5439 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">n</phrase> <phrase role="special">%</phrase> <phrase role="number">10</phrase> <phrase role="special">==</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase>
5440 <phrase role="special">})</phrase>
5441 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
5442 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">get</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">n</phrase><phrase role="special">);</phrase>
5443 <phrase role="special">})</phrase>
5444 <phrase role="special">;</phrase>
5446 <phrase role="identifier">counter</phrase><phrase role="special">::</phrase><phrase role="identifier">set</phrase><phrase role="special">(</phrase><phrase role="identifier">n</phrase><phrase role="special">);</phrase>
5447 <phrase role="special">}</phrase>
5449 <phrase role="keyword">virtual</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">dec</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="comment">/* override */</phrase> <phrase role="special">{</phrase>
5450 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">></phrase> <phrase role="identifier">old_get</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">get</phrase><phrase role="special">());</phrase>
5451 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special"><</phrase>
5452 <phrase role="identifier">override_dec</phrase><phrase role="special">>(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="special">&</phrase><phrase role="identifier">counter10</phrase><phrase role="special">::</phrase><phrase role="identifier">dec</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">)</phrase>
5453 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
5454 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase>
5455 <phrase role="identifier">get</phrase><phrase role="special">()</phrase> <phrase role="special">+</phrase> <phrase role="number">10</phrase> <phrase role="special">>=</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">numeric_limits</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">>::</phrase><phrase role="identifier">min</phrase><phrase role="special">());</phrase>
5456 <phrase role="special">})</phrase>
5457 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
5458 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">get</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_get</phrase> <phrase role="special">-</phrase> <phrase role="number">10</phrase><phrase role="special">);</phrase>
5459 <phrase role="special">})</phrase>
5460 <phrase role="special">;</phrase>
5462 <phrase role="identifier">set</phrase><phrase role="special">(</phrase><phrase role="identifier">get</phrase><phrase role="special">()</phrase> <phrase role="special">-</phrase> <phrase role="number">10</phrase><phrase role="special">);</phrase>
5463 <phrase role="special">}</phrase>
5465 <phrase role="identifier">BOOST_CONTRACT_OVERRIDES</phrase><phrase role="special">(</phrase><phrase role="identifier">set</phrase><phrase role="special">,</phrase> <phrase role="identifier">dec</phrase><phrase role="special">)</phrase>
5467 <phrase role="comment">/* ... */</phrase>
5472 Unfortunately, the code above does not compile on MSVC (at least up to
5473 Visual Studio 2015) because MSVC incorrectly gives a compile-time error
5474 when SFINAE fails due to private or protected access levels. Instead, GCC
5475 and Clang correctly implement SFINAE failures due to private and protected
5476 functions so the code above correctly complies on GCC and Clang. Therefore,
5477 currently it is not possible to override a function that is public in one
5478 base but private or protected in other base using this library on MSVC
5479 (at least up to Visual Studio 2015), but that can correctly be done on
5480 GCC or Clang instead.
5484 <section id="boost_contract.advanced.friend_functions">
5485 <title><link linkend="boost_contract.advanced.friend_functions">Friend Functions</link></title>
5487 In general, friend functions are not member functions so <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.function">boost::contract::function</link></computeroutput>
5488 is used to program their contracts and all considerations made in <link linkend="boost_contract.tutorial.non_member_functions">Non-Member
5489 Functions</link> apply. For example (see <ulink url="../../example/features/friend.cpp"><literal moreinfo="none">friend.cpp</literal></ulink>):
5492 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">class</phrase> <phrase role="identifier">buffer</phrase><phrase role="special">;</phrase>
5494 <phrase role="keyword">class</phrase> <phrase role="identifier">byte</phrase> <phrase role="special">{</phrase>
5495 <phrase role="keyword">friend</phrase> <phrase role="keyword">bool</phrase> <phrase role="keyword">operator</phrase><phrase role="special">==(</phrase><phrase role="identifier">buffer</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">left</phrase><phrase role="special">,</phrase> <phrase role="identifier">byte</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">right</phrase><phrase role="special">);</phrase>
5497 <phrase role="keyword">private</phrase><phrase role="special">:</phrase>
5498 <phrase role="keyword">char</phrase> <phrase role="identifier">value_</phrase><phrase role="special">;</phrase>
5500 <phrase role="comment">/* ... */</phrase>
5504 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">class</phrase> <phrase role="identifier">buffer</phrase> <phrase role="special">{</phrase>
5505 <phrase role="comment">// Friend functions are not member functions...</phrase>
5506 <phrase role="keyword">friend</phrase> <phrase role="keyword">bool</phrase> <phrase role="keyword">operator</phrase><phrase role="special">==(</phrase><phrase role="identifier">buffer</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">left</phrase><phrase role="special">,</phrase> <phrase role="identifier">byte</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">right</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
5507 <phrase role="comment">// ...so check contracts via `function` (which won't check invariants).</phrase>
5508 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">function</phrase><phrase role="special">()</phrase>
5509 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
5510 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(!</phrase><phrase role="identifier">left</phrase><phrase role="special">.</phrase><phrase role="identifier">empty</phrase><phrase role="special">());</phrase>
5511 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(!</phrase><phrase role="identifier">right</phrase><phrase role="special">.</phrase><phrase role="identifier">empty</phrase><phrase role="special">());</phrase>
5512 <phrase role="special">})</phrase>
5513 <phrase role="special">;</phrase>
5515 <phrase role="keyword">for</phrase><phrase role="special">(</phrase><phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase><phrase role="special">*</phrase> <phrase role="identifier">x</phrase> <phrase role="special">=</phrase> <phrase role="identifier">left</phrase><phrase role="special">.</phrase><phrase role="identifier">values_</phrase><phrase role="special">.</phrase><phrase role="identifier">c_str</phrase><phrase role="special">();</phrase> <phrase role="special">*</phrase><phrase role="identifier">x</phrase> <phrase role="special">!=</phrase> <phrase role="char">'\0'</phrase><phrase role="special">;</phrase> <phrase role="special">++</phrase><phrase role="identifier">x</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
5516 <phrase role="keyword">if</phrase><phrase role="special">(*</phrase><phrase role="identifier">x</phrase> <phrase role="special">!=</phrase> <phrase role="identifier">right</phrase><phrase role="special">.</phrase><phrase role="identifier">value_</phrase><phrase role="special">)</phrase> <phrase role="keyword">return</phrase> <phrase role="keyword">false</phrase><phrase role="special">;</phrase>
5517 <phrase role="special">}</phrase>
5518 <phrase role="keyword">return</phrase> <phrase role="keyword">true</phrase><phrase role="special">;</phrase>
5519 <phrase role="special">}</phrase>
5521 <phrase role="keyword">private</phrase><phrase role="special">:</phrase>
5522 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">string</phrase> <phrase role="identifier">values_</phrase><phrase role="special">;</phrase>
5524 <phrase role="comment">/* ... */</phrase>
5528 However, in some cases a friend function might take an object as parameter
5529 and it can be logically considered an extension of that object's public interface
5530 (essentially at the same level as the object's public functions). In these
5531 cases, programmers might chose to program the friend function contracts using
5532 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>
5533 (instead of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.function">boost::contract::function</link></computeroutput>)
5534 so to also check the class invariants of the object passed as parameter (and
5535 not just pre- and postconditions). For example (see <ulink url="../../example/features/friend_invariant.cpp"><literal moreinfo="none">friend_invariant.cpp</literal></ulink>):
5536 <footnote id="boost_contract.advanced.friend_functions.f0">
5538 <emphasis role="bold">Rationale:</emphasis> Contract programming proposals
5539 for C++ like <link linkend="N1962_anchor">[N1962]</link> do not provide
5540 a mechanism for friend functions to check class invariants of objects passed
5541 as parameters. In other words, these proposals do not enable contracts
5542 to recognize that in C++ some friend functions logically act as if they
5543 were part of the public interface of the objects they take as parameters.
5544 This is reasonable for proposals that add contracts to the core language
5545 because friend functions are not always meant to extend an object public
5546 interface and C++ does not provide a mechanism to programmatically specify
5547 when they do and when they do not. However, this library provides the flexibility
5548 to let programmers manually specify when friend functions should also check
5549 class invariants of the objects they take as parameters (using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>)
5550 and when they should not (using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.function">boost::contract::function</link></computeroutput>
5556 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">></phrase>
5557 <phrase role="keyword">class</phrase> <phrase role="identifier">positive</phrase> <phrase role="special">{</phrase>
5558 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
5559 <phrase role="keyword">void</phrase> <phrase role="identifier">invariant</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
5560 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">value</phrase><phrase role="special">()</phrase> <phrase role="special">></phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase>
5561 <phrase role="special">}</phrase>
5563 <phrase role="comment">// Can be considered an extension of enclosing class' public interface...</phrase>
5564 <phrase role="keyword">friend</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">swap</phrase><phrase role="special">(</phrase><phrase role="identifier">positive</phrase><phrase role="special">&</phrase> <phrase role="identifier">object</phrase><phrase role="special">,</phrase> <phrase role="identifier">T</phrase><phrase role="special">&</phrase> <phrase role="identifier">value</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
5565 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase> <phrase role="identifier">old_object_value</phrase> <phrase role="special">=</phrase>
5566 <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">object</phrase><phrase role="special">.</phrase><phrase role="identifier">value</phrase><phrase role="special">());</phrase>
5567 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase> <phrase role="identifier">old_value</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">value</phrase><phrase role="special">);</phrase>
5568 <phrase role="comment">// ...so it can be made to check invariants via `public_function`.</phrase>
5569 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(&</phrase><phrase role="identifier">object</phrase><phrase role="special">)</phrase>
5570 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
5571 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">value</phrase> <phrase role="special">></phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase>
5572 <phrase role="special">})</phrase>
5573 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
5574 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">object</phrase><phrase role="special">.</phrase><phrase role="identifier">value</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_value</phrase><phrase role="special">);</phrase>
5575 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">value</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_object_value</phrase><phrase role="special">);</phrase>
5576 <phrase role="special">})</phrase>
5577 <phrase role="special">;</phrase>
5579 <phrase role="identifier">T</phrase> <phrase role="identifier">saved</phrase> <phrase role="special">=</phrase> <phrase role="identifier">object</phrase><phrase role="special">.</phrase><phrase role="identifier">value_</phrase><phrase role="special">;</phrase>
5580 <phrase role="identifier">object</phrase><phrase role="special">.</phrase><phrase role="identifier">value_</phrase> <phrase role="special">=</phrase> <phrase role="identifier">value</phrase><phrase role="special">;</phrase>
5581 <phrase role="identifier">value</phrase> <phrase role="special">=</phrase> <phrase role="identifier">saved</phrase><phrase role="special">;</phrase>
5582 <phrase role="special">}</phrase>
5584 <phrase role="keyword">private</phrase><phrase role="special">:</phrase>
5585 <phrase role="identifier">T</phrase> <phrase role="identifier">value_</phrase><phrase role="special">;</phrase>
5587 <phrase role="comment">/* ... */</phrase>
5591 This technique can also be extended to friend functions that take multiple
5592 objects as parameters and can be logically considered extensions to the public
5593 interfaces of each of these objects. For example:
5595 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="comment">// Can be considered an extension of multiple objects' public interfaces.</phrase>
5596 <phrase role="keyword">friend</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">f</phrase><phrase role="special">(</phrase><phrase role="identifier">class1</phrase><phrase role="special">&</phrase> <phrase role="identifier">object1</phrase><phrase role="special">,</phrase> <phrase role="identifier">class2</phrase><phrase role="special">*</phrase> <phrase role="identifier">object2</phrase><phrase role="special">,</phrase> <phrase role="identifier">type3</phrase><phrase role="special">&</phrase> <phrase role="identifier">value3</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
5597 <phrase role="comment">// Check preconditions.</phrase>
5598 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">pre</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">function</phrase><phrase role="special">()</phrase>
5599 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
5600 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">object2</phrase> <phrase role="special">!=</phrase> <phrase role="keyword">nullptr</phrase><phrase role="special">);</phrase>
5601 <phrase role="special">...</phrase>
5602 <phrase role="special">})</phrase>
5603 <phrase role="special">;</phrase>
5604 <phrase role="comment">// Check class invariants for each object (programmers chose the order).</phrase>
5605 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">inv1</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(&</phrase><phrase role="identifier">object1</phrase><phrase role="special">);</phrase>
5606 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">inv2</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="identifier">object2</phrase><phrase role="special">);</phrase>
5607 <phrase role="comment">// Check postconditions and exception guarantees.</phrase>
5608 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">postex</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">function</phrase><phrase role="special">()</phrase>
5609 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">(...)</phrase>
5610 <phrase role="special">.</phrase><phrase role="identifier">except</phrase><phrase role="special">(...)</phrase>
5611 <phrase role="special">;</phrase>
5613 <phrase role="special">...</phrase> <phrase role="comment">// Function body.</phrase>
5614 <phrase role="special">}</phrase>
5617 Changing the order of the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.check">boost::contract::check</link></computeroutput>
5618 declarations above, programmers can chose the order for checking class invariants
5619 among the different objects passed to the friend function and also whether
5620 to check these invariants before or after preconditions, postconditions,
5621 and exception guarantees of the friend function (see <link linkend="boost_contract.tutorial.non_member_functions">Non-Member
5622 Functions</link> and <link linkend="boost_contract.tutorial.public_functions">Public
5623 Functions</link> for information on how the RAII objects returned by <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.function">boost::contract::function</link></computeroutput>
5624 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>
5625 check contract conditions). The example above is programmed to check <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">class1</phrase></computeroutput> invariants before <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">class2</phrase></computeroutput> invariants (but that order could
5626 have been inverted if programmers so chose).
5630 In the example above, preconditions are intentionally programmed to be
5631 checked before class invariants so the objects passed to the friend function
5632 can be validated by the preconditions before they are passed as pointers
5633 to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>
5634 (e.g., check <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">object2</phrase></computeroutput> is
5635 not null). (Within member functions instead, the object pointer <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">this</phrase></computeroutput> is always well-formed, its validation
5636 is never needed, and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>
5637 checks class invariants before checking preconditions so programming preconditions
5638 can be simplified assuming the class invariants are satisfied already,
5639 see <link linkend="boost_contract.contract_programming_overview.public_function_calls">Public
5640 Function Calls</link>.)
5644 <section id="boost_contract.advanced.function_overloads">
5645 <title><link linkend="boost_contract.advanced.function_overloads">Function
5646 Overloads</link></title>
5648 No special attention is required when using this library with overloaded
5649 functions or constructors. The only exception is for the function pointer
5650 passed to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>
5651 from public function overrides (see <link linkend="boost_contract.tutorial.public_function_overrides__subcontracting_">Public
5652 Function Overrides</link>). When the name of public function override are
5653 also overloaded, the related function pointer cannot be automatically deduced
5654 by the compiler so programmers have to use <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">static_cast</phrase></computeroutput>
5655 to resolve ambiguities (as usual with pointers to overloaded functions in
5656 C++). <footnote id="boost_contract.advanced.function_overloads.f0">
5658 <emphasis role="bold">Rationale:</emphasis> In order to avoid copies, this
5659 library takes all function arguments and the return value passed to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>
5660 as references when used within public function overrides. Therefore, the
5661 library cannot differentiate when the actual function argument and return
5662 types are passed by reference and when they are not. As a result, the library
5663 cannot automatically reconstruct the type of the enclosing public function
5664 so this type must be deduced from the function pointer passed by programmers
5665 to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>.
5666 When this automatic deduction is not possible due to overloaded function
5667 names, programmers must explicitly use <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">static_cast</phrase></computeroutput>
5668 to resolve ambiguities as usual in C++ with pointers to overloaded functions.
5670 </footnote> For example, note how <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">static_cast</phrase></computeroutput>
5671 is used in the following calls to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>
5672 (see <ulink url="../../example/features/overload.cpp"><literal moreinfo="none">overload.cpp</literal></ulink>):
5675 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">class</phrase> <phrase role="identifier">string_lines</phrase>
5676 <phrase role="preprocessor">#define</phrase> <phrase role="identifier">BASES</phrase> <phrase role="keyword">public</phrase> <phrase role="identifier">lines</phrase>
5677 <phrase role="special">:</phrase> <phrase role="identifier">BASES</phrase>
5678 <phrase role="special">{</phrase>
5679 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
5680 <phrase role="keyword">typedef</phrase> <phrase role="identifier">BOOST_CONTRACT_BASE_TYPES</phrase><phrase role="special">(</phrase><phrase role="identifier">BASES</phrase><phrase role="special">)</phrase> <phrase role="identifier">base_types</phrase><phrase role="special">;</phrase>
5681 <phrase role="preprocessor">#undef</phrase> <phrase role="identifier">BASES</phrase>
5683 <phrase role="identifier">BOOST_CONTRACT_OVERRIDES</phrase><phrase role="special">(</phrase><phrase role="identifier">str</phrase><phrase role="special">)</phrase> <phrase role="comment">// Invoked only once for all `str` overloads.</phrase>
5685 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">string</phrase> <phrase role="identifier">str</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase> <phrase role="comment">/* override */</phrase> <phrase role="special">{</phrase>
5686 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">string</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
5687 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special"><</phrase>
5688 <phrase role="identifier">override_str</phrase><phrase role="special">>(</phrase>
5689 <phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">result</phrase><phrase role="special">,</phrase>
5690 <phrase role="comment">// `static_cast` resolves overloaded function pointer ambiguities.</phrase>
5691 <phrase role="keyword">static_cast</phrase><phrase role="special"><</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">string</phrase> <phrase role="special">(</phrase><phrase role="identifier">string_lines</phrase><phrase role="special">::*)(</phrase>
5692 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*)</phrase> <phrase role="keyword">const</phrase><phrase role="special">>(&</phrase><phrase role="identifier">string_lines</phrase><phrase role="special">::</phrase><phrase role="identifier">str</phrase><phrase role="special">),</phrase>
5693 <phrase role="keyword">this</phrase>
5694 <phrase role="special">);</phrase>
5696 <phrase role="keyword">return</phrase> <phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="identifier">str_</phrase><phrase role="special">;</phrase>
5697 <phrase role="special">}</phrase>
5699 <phrase role="comment">// Overload on (absence of) `const` qualifier.</phrase>
5700 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">string</phrase><phrase role="special">&</phrase> <phrase role="identifier">str</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="comment">/* override */</phrase> <phrase role="special">{</phrase>
5701 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special"><</phrase>
5702 <phrase role="identifier">override_str</phrase><phrase role="special">>(</phrase>
5703 <phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">str_</phrase><phrase role="special">,</phrase>
5704 <phrase role="comment">// `static_cast` resolves overloaded function pointer ambiguities.</phrase>
5705 <phrase role="keyword">static_cast</phrase><phrase role="special"><</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">string</phrase><phrase role="special">&</phrase> <phrase role="special">(</phrase><phrase role="identifier">string_lines</phrase><phrase role="special">::*)(</phrase>
5706 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*)>(&</phrase><phrase role="identifier">string_lines</phrase><phrase role="special">::</phrase><phrase role="identifier">str</phrase><phrase role="special">),</phrase>
5707 <phrase role="keyword">this</phrase>
5708 <phrase role="special">);</phrase>
5710 <phrase role="keyword">return</phrase> <phrase role="identifier">str_</phrase><phrase role="special">;</phrase>
5711 <phrase role="special">}</phrase>
5713 <phrase role="identifier">BOOST_CONTRACT_OVERRIDES</phrase><phrase role="special">(</phrase><phrase role="identifier">put</phrase><phrase role="special">)</phrase> <phrase role="comment">// Invoked only once for all `put` overloads.</phrase>
5715 <phrase role="keyword">void</phrase> <phrase role="identifier">put</phrase><phrase role="special">(</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">string</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">x</phrase><phrase role="special">,</phrase>
5716 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="comment">/* override */</phrase> <phrase role="special">{</phrase>
5717 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">string</phrase><phrase role="special">></phrase> <phrase role="identifier">old_str</phrase> <phrase role="special">=</phrase>
5718 <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">str</phrase><phrase role="special">());</phrase>
5719 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special"><</phrase>
5720 <phrase role="identifier">override_put</phrase><phrase role="special">>(</phrase>
5721 <phrase role="identifier">v</phrase><phrase role="special">,</phrase>
5722 <phrase role="comment">// `static_cast` resolves overloaded function pointer ambiguities.</phrase>
5723 <phrase role="keyword">static_cast</phrase><phrase role="special"><</phrase><phrase role="keyword">void</phrase> <phrase role="special">(</phrase><phrase role="identifier">string_lines</phrase><phrase role="special">::*)(</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">string</phrase> <phrase role="keyword">const</phrase><phrase role="special">&,</phrase>
5724 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*)>(&</phrase><phrase role="identifier">string_lines</phrase><phrase role="special">::</phrase><phrase role="identifier">put</phrase><phrase role="special">),</phrase>
5725 <phrase role="keyword">this</phrase><phrase role="special">,</phrase> <phrase role="identifier">x</phrase>
5726 <phrase role="special">)</phrase>
5727 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
5728 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">str</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_str</phrase> <phrase role="special">+</phrase> <phrase role="identifier">x</phrase> <phrase role="special">+</phrase> <phrase role="char">'\n'</phrase><phrase role="special">);</phrase>
5729 <phrase role="special">})</phrase>
5730 <phrase role="special">;</phrase>
5732 <phrase role="identifier">str_</phrase> <phrase role="special">=</phrase> <phrase role="identifier">str_</phrase> <phrase role="special">+</phrase> <phrase role="identifier">x</phrase> <phrase role="special">+</phrase> <phrase role="char">'\n'</phrase><phrase role="special">;</phrase>
5733 <phrase role="special">}</phrase>
5735 <phrase role="comment">// Overload on argument type.</phrase>
5736 <phrase role="keyword">void</phrase> <phrase role="identifier">put</phrase><phrase role="special">(</phrase><phrase role="keyword">char</phrase> <phrase role="identifier">x</phrase><phrase role="special">,</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="comment">/* override */</phrase> <phrase role="special">{</phrase>
5737 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">string</phrase><phrase role="special">></phrase> <phrase role="identifier">old_str</phrase> <phrase role="special">=</phrase>
5738 <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">str</phrase><phrase role="special">());</phrase>
5739 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special"><</phrase>
5740 <phrase role="identifier">override_put</phrase><phrase role="special">>(</phrase>
5741 <phrase role="identifier">v</phrase><phrase role="special">,</phrase>
5742 <phrase role="comment">// `static_cast` resolves overloaded function pointer ambiguities.</phrase>
5743 <phrase role="keyword">static_cast</phrase><phrase role="special"><</phrase><phrase role="keyword">void</phrase> <phrase role="special">(</phrase><phrase role="identifier">string_lines</phrase><phrase role="special">::*)(</phrase><phrase role="keyword">char</phrase><phrase role="special">,</phrase>
5744 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*)>(&</phrase><phrase role="identifier">string_lines</phrase><phrase role="special">::</phrase><phrase role="identifier">put</phrase><phrase role="special">),</phrase>
5745 <phrase role="keyword">this</phrase><phrase role="special">,</phrase> <phrase role="identifier">x</phrase>
5746 <phrase role="special">)</phrase>
5747 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
5748 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">str</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_str</phrase> <phrase role="special">+</phrase> <phrase role="identifier">x</phrase> <phrase role="special">+</phrase> <phrase role="char">'\n'</phrase><phrase role="special">);</phrase>
5749 <phrase role="special">})</phrase>
5750 <phrase role="special">;</phrase>
5752 <phrase role="identifier">str_</phrase> <phrase role="special">=</phrase> <phrase role="identifier">str_</phrase> <phrase role="special">+</phrase> <phrase role="identifier">x</phrase> <phrase role="special">+</phrase> <phrase role="char">'\n'</phrase><phrase role="special">;</phrase>
5753 <phrase role="special">}</phrase>
5755 <phrase role="comment">// Overload on argument type and arity (also with default parameter).</phrase>
5756 <phrase role="keyword">void</phrase> <phrase role="identifier">put</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">x</phrase><phrase role="special">,</phrase> <phrase role="keyword">bool</phrase> <phrase role="identifier">tab</phrase> <phrase role="special">=</phrase> <phrase role="keyword">false</phrase><phrase role="special">,</phrase>
5757 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="comment">/* override */</phrase> <phrase role="special">{</phrase>
5758 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">string</phrase><phrase role="special">></phrase> <phrase role="identifier">old_str</phrase> <phrase role="special">=</phrase>
5759 <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">str</phrase><phrase role="special">());</phrase>
5760 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special"><</phrase>
5761 <phrase role="identifier">override_put</phrase><phrase role="special">>(</phrase>
5762 <phrase role="identifier">v</phrase><phrase role="special">,</phrase>
5763 <phrase role="comment">// `static_cast` resolves overloaded function pointer ambiguities.</phrase>
5764 <phrase role="keyword">static_cast</phrase><phrase role="special"><</phrase><phrase role="keyword">void</phrase> <phrase role="special">(</phrase><phrase role="identifier">string_lines</phrase><phrase role="special">::*)(</phrase><phrase role="keyword">int</phrase><phrase role="special">,</phrase> <phrase role="keyword">bool</phrase><phrase role="special">,</phrase>
5765 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*)>(&</phrase><phrase role="identifier">string_lines</phrase><phrase role="special">::</phrase><phrase role="identifier">put</phrase><phrase role="special">),</phrase>
5766 <phrase role="keyword">this</phrase><phrase role="special">,</phrase> <phrase role="identifier">x</phrase><phrase role="special">,</phrase> <phrase role="identifier">tab</phrase>
5767 <phrase role="special">)</phrase>
5768 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
5769 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">ostringstream</phrase> <phrase role="identifier">s</phrase><phrase role="special">;</phrase>
5770 <phrase role="identifier">s</phrase> <phrase role="special"><<</phrase> <phrase role="identifier">x</phrase><phrase role="special">;</phrase>
5771 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase>
5772 <phrase role="identifier">str</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_str</phrase> <phrase role="special">+</phrase> <phrase role="special">(</phrase><phrase role="identifier">tab</phrase> <phrase role="special">?</phrase> <phrase role="string">"\t"</phrase> <phrase role="special">:</phrase> <phrase role="string">""</phrase><phrase role="special">)</phrase> <phrase role="special">+</phrase> <phrase role="identifier">s</phrase><phrase role="special">.</phrase><phrase role="identifier">str</phrase><phrase role="special">()</phrase> <phrase role="special">+</phrase> <phrase role="char">'\n'</phrase><phrase role="special">);</phrase>
5773 <phrase role="special">})</phrase>
5774 <phrase role="special">;</phrase>
5776 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">ostringstream</phrase> <phrase role="identifier">s</phrase><phrase role="special">;</phrase>
5777 <phrase role="identifier">s</phrase> <phrase role="special"><<</phrase> <phrase role="identifier">str_</phrase> <phrase role="special"><<</phrase> <phrase role="special">(</phrase><phrase role="identifier">tab</phrase> <phrase role="special">?</phrase> <phrase role="string">"\t"</phrase> <phrase role="special">:</phrase> <phrase role="string">""</phrase><phrase role="special">)</phrase> <phrase role="special"><<</phrase> <phrase role="identifier">x</phrase> <phrase role="special"><<</phrase> <phrase role="char">'\n'</phrase><phrase role="special">;</phrase>
5778 <phrase role="identifier">str_</phrase> <phrase role="special">=</phrase> <phrase role="identifier">s</phrase><phrase role="special">.</phrase><phrase role="identifier">str</phrase><phrase role="special">();</phrase>
5779 <phrase role="special">}</phrase>
5781 <phrase role="keyword">private</phrase><phrase role="special">:</phrase>
5782 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">string</phrase> <phrase role="identifier">str_</phrase><phrase role="special">;</phrase>
5783 <phrase role="special">};</phrase>
5787 Overloaded functions have the same function name so the same <literal moreinfo="none">override_<emphasis>function-name</emphasis></literal>
5788 type can be reused as template parameter for all <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>
5789 calls in a given class. Therefore, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_OVERRIDE">BOOST_CONTRACT_OVERRIDE</link></computeroutput>
5790 only needs to be invoked once for a function name in a given class, even
5791 when that function name is overloaded.
5794 <section id="boost_contract.advanced.lambdas__loops__code_blocks__and__constexpr__">
5795 <title><link linkend="boost_contract.advanced.lambdas__loops__code_blocks__and__constexpr__">Lambdas,
5796 Loops, Code Blocks (and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">constexpr</phrase></computeroutput>)</link></title>
5798 While contracts are usually most useful to program specifications of functions
5799 and class interfaces, this library also allows to check contract conditions
5800 for implementation code (lambda functions, loops, code blocks, etc.).
5803 Lambda functions are not member functions, they are not part of class public
5804 interfaces so they do not check class invariants and they do not subcontract.
5805 They can use <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.function">boost::contract::function</link></computeroutput>
5806 to specify preconditions, postconditions, and exception guarantees (considerations
5807 made in <link linkend="boost_contract.tutorial.non_member_functions">Non-Member
5808 Functions</link> apply). For example (see <ulink url="../../example/features/lambda.cpp"><literal moreinfo="none">lambda.cpp</literal></ulink>):
5811 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="identifier">total</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase>
5812 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">for_each</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">.</phrase><phrase role="identifier">cbegin</phrase><phrase role="special">(),</phrase> <phrase role="identifier">v</phrase><phrase role="special">.</phrase><phrase role="identifier">cend</phrase><phrase role="special">(),</phrase>
5813 <phrase role="comment">// Contract for a lambda function.</phrase>
5814 <phrase role="special">[&</phrase><phrase role="identifier">total</phrase><phrase role="special">]</phrase> <phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">x</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
5815 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">></phrase> <phrase role="identifier">old_total</phrase> <phrase role="special">=</phrase>
5816 <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">total</phrase><phrase role="special">);</phrase>
5817 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">function</phrase><phrase role="special">()</phrase>
5818 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
5819 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase>
5820 <phrase role="identifier">total</phrase> <phrase role="special"><</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">numeric_limits</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">>::</phrase><phrase role="identifier">max</phrase><phrase role="special">()</phrase> <phrase role="special">-</phrase> <phrase role="identifier">x</phrase><phrase role="special">);</phrase>
5821 <phrase role="special">})</phrase>
5822 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
5823 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">total</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_total</phrase> <phrase role="special">+</phrase> <phrase role="identifier">x</phrase><phrase role="special">);</phrase>
5824 <phrase role="special">})</phrase>
5825 <phrase role="special">;</phrase>
5827 <phrase role="identifier">total</phrase> <phrase role="special">+=</phrase> <phrase role="identifier">x</phrase><phrase role="special">;</phrase> <phrase role="comment">// Lambda function body.</phrase>
5828 <phrase role="special">}</phrase>
5829 <phrase role="special">);</phrase>
5833 Similarly, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.function">boost::contract::function</link></computeroutput>
5834 can be used to program preconditions, postconditions, and exception guarantees
5835 for loops. For example, for a for-loop but same for while- and all other
5836 loops (see <ulink url="../../example/features/loop.cpp"><literal moreinfo="none">loop.cpp</literal></ulink>):
5839 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="identifier">total</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase>
5840 <phrase role="comment">// Contract for a for-loop (same for while- and all other loops).</phrase>
5841 <phrase role="keyword">for</phrase><phrase role="special">(</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">>::</phrase><phrase role="identifier">const_iterator</phrase> <phrase role="identifier">i</phrase> <phrase role="special">=</phrase> <phrase role="identifier">v</phrase><phrase role="special">.</phrase><phrase role="identifier">begin</phrase><phrase role="special">();</phrase> <phrase role="identifier">i</phrase> <phrase role="special">!=</phrase> <phrase role="identifier">v</phrase><phrase role="special">.</phrase><phrase role="identifier">end</phrase><phrase role="special">();</phrase> <phrase role="special">++</phrase><phrase role="identifier">i</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
5842 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">></phrase> <phrase role="identifier">old_total</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">total</phrase><phrase role="special">);</phrase>
5843 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">function</phrase><phrase role="special">()</phrase>
5844 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
5845 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase>
5846 <phrase role="identifier">total</phrase> <phrase role="special"><</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">numeric_limits</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">>::</phrase><phrase role="identifier">max</phrase><phrase role="special">()</phrase> <phrase role="special">-</phrase> <phrase role="special">*</phrase><phrase role="identifier">i</phrase><phrase role="special">);</phrase>
5847 <phrase role="special">})</phrase>
5848 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
5849 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">total</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_total</phrase> <phrase role="special">+</phrase> <phrase role="special">*</phrase><phrase role="identifier">i</phrase><phrase role="special">);</phrase>
5850 <phrase role="special">})</phrase>
5851 <phrase role="special">;</phrase>
5853 <phrase role="identifier">total</phrase> <phrase role="special">+=</phrase> <phrase role="special">*</phrase><phrase role="identifier">i</phrase><phrase role="special">;</phrase> <phrase role="comment">// For-loop body.</phrase>
5854 <phrase role="special">}</phrase>
5858 More in general, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.function">boost::contract::function</link></computeroutput>
5859 can be used to program preconditions, postconditions, and exception guarantees
5860 of any block of code in a given function. For example (see <ulink url="../../example/features/code_block.cpp"><literal moreinfo="none">code_block.cpp</literal></ulink>):
5863 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="comment">/* ... */</phrase>
5865 <phrase role="comment">// Contract for a code block.</phrase>
5866 <phrase role="special">{</phrase> <phrase role="comment">// Code block entry (check preconditions).</phrase>
5867 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">></phrase> <phrase role="identifier">old_total</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">total</phrase><phrase role="special">);</phrase>
5868 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">function</phrase><phrase role="special">()</phrase>
5869 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
5870 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">.</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">3</phrase><phrase role="special">);</phrase>
5871 <phrase role="special">})</phrase>
5872 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
5873 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">total</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_total</phrase> <phrase role="special">+</phrase> <phrase role="identifier">v</phrase><phrase role="special">[</phrase><phrase role="number">0</phrase><phrase role="special">]</phrase> <phrase role="special">+</phrase> <phrase role="identifier">v</phrase><phrase role="special">[</phrase><phrase role="number">1</phrase><phrase role="special">]</phrase> <phrase role="special">+</phrase> <phrase role="identifier">v</phrase><phrase role="special">[</phrase><phrase role="number">2</phrase><phrase role="special">]);</phrase>
5874 <phrase role="special">})</phrase>
5875 <phrase role="special">;</phrase>
5877 <phrase role="identifier">total</phrase> <phrase role="special">+=</phrase> <phrase role="identifier">v</phrase><phrase role="special">[</phrase><phrase role="number">0</phrase><phrase role="special">]</phrase> <phrase role="special">+</phrase> <phrase role="identifier">v</phrase><phrase role="special">[</phrase><phrase role="number">1</phrase><phrase role="special">]</phrase> <phrase role="special">+</phrase> <phrase role="identifier">v</phrase><phrase role="special">[</phrase><phrase role="number">2</phrase><phrase role="special">];</phrase> <phrase role="comment">// Code block body.</phrase>
5878 <phrase role="special">}</phrase> <phrase role="comment">// Code block exit (check postconditions and exceptions guarantees).</phrase>
5880 <phrase role="comment">/* ... */</phrase>
5884 The library does not support contracts for functions and classes declared
5885 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">constexpr</phrase></computeroutput>. <footnote id="boost_contract.advanced.lambdas__loops__code_blocks__and__constexpr__.f0">
5887 <emphasis role="bold">Rationale:</emphasis> In general, it might be useful
5888 to specify contracts for <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">constexpr</phrase></computeroutput>
5889 functions and literal classes. However, the current implementation of this
5890 library cannot support contracts for <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">constexpr</phrase></computeroutput>
5891 functions and classes because C++ does not currently allow <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">constexpr</phrase></computeroutput> functions to do the following:
5892 Declare local variables of (literal) types with non-trivial <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">constexpr</phrase></computeroutput> destructors (this RAII technique
5893 is used by this library to check invariants, postconditions, and exceptions
5894 guarantees at exit); Call other <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">constexpr</phrase></computeroutput>
5895 functions using try-catch statements (used by this library to report contract
5896 assertion failures and catch any other exception that might be thrown when
5897 evaluating the asserted conditions); Use lambda functions (used by this
5898 library for convenience to program functors that that check preconditions,
5899 postconditions, and exception guarantees). Also note that even if supported,
5900 contracts for <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">constexpr</phrase></computeroutput> functions
5901 probably would not use old values (because <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">constexpr</phrase></computeroutput>
5902 prevents functions from having any side effect visible to the caller and
5903 variables recording such side-effects are usually the candidates for old
5904 value copies) and subcontracting (because <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">constexpr</phrase></computeroutput>
5905 functions cannot be virtual).
5910 <section id="boost_contract.advanced.implementation_checks">
5911 <title><link linkend="boost_contract.advanced.implementation_checks">Implementation
5912 Checks</link></title>
5914 This library provides also a mechanism to check assertions within implementation
5915 code (differently from preconditions, postconditions, exceptions guarantees,
5916 and class invariants that are instead checked before or after code that implements
5917 a function body). These <emphasis>implementation checks</emphasis> are programmed
5918 using a nullary functor that is directly assigned to a <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.check">boost::contract::check</link></computeroutput>
5919 object declaration right at the place within the code where the checks need
5920 to be performed (without calling <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.function">boost::contract::function</link></computeroutput>,
5921 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>,
5922 etc. in this case). For example (see <ulink url="../../example/features/check.cpp"><literal moreinfo="none">check.cpp</literal></ulink>):
5925 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="identifier">main</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
5926 <phrase role="comment">// Implementation checks (via nullary functor).</phrase>
5927 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="special">[]</phrase> <phrase role="special">{</phrase>
5928 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">gcd</phrase><phrase role="special">(</phrase><phrase role="number">12</phrase><phrase role="special">,</phrase> <phrase role="number">28</phrase><phrase role="special">)</phrase> <phrase role="special">==</phrase> <phrase role="number">4</phrase><phrase role="special">);</phrase>
5929 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">gcd</phrase><phrase role="special">(</phrase><phrase role="number">4</phrase><phrase role="special">,</phrase> <phrase role="number">14</phrase><phrase role="special">)</phrase> <phrase role="special">==</phrase> <phrase role="number">2</phrase><phrase role="special">);</phrase>
5930 <phrase role="special">};</phrase>
5932 <phrase role="keyword">return</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase>
5933 <phrase role="special">}</phrase>
5937 The implementation check functor should capture all the variables that it
5938 needs for its assertions. These variables can be captured by value when the
5939 overhead of copying such variables is acceptable. In any case, programmers
5940 should not write implementation checks that modify the value of the captured
5941 variables, even when those are captured by reference (see <link linkend="boost_contract.contract_programming_overview.constant_correctness">Constant-Correctness</link>).
5944 Any code can be programmed in the implementation check functor, but it is
5945 recommended to keep this code simple using mainly assertions and if-statements
5946 (to avoid programming complex checks that might be buggy and also slow to
5947 check at run-time). It is also recommended to use <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_ASSERT">BOOST_CONTRACT_ASSERT</link></computeroutput>
5948 to program the assertions because that enables this library to print informative
5949 error messages when the asserted conditions are evaluated to be false (note
5950 that this is not a variadic macro, see <link linkend="boost_contract.extras.no_macros__and_no_variadic_macros_">No
5953 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><literal moreinfo="none"><emphasis>boolean-condition</emphasis></literal><phrase role="special">)</phrase>
5954 <phrase role="comment">// Or, if `boolean-condition` contains commas `,` not already within parenthesis `()`...</phrase>
5955 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">((</phrase><literal moreinfo="none"><emphasis>boolean-condition</emphasis></literal><phrase role="special">))</phrase> <phrase role="comment">// ...use extra parenthesis (not a variadic macro).</phrase>
5958 This library will automatically call the failure handler <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.check_failure">boost::contract::check_failure</link></computeroutput>
5959 if any of the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_ASSERT">BOOST_CONTRACT_ASSERT</link></computeroutput>
5960 conditions are false or, more in general, if calling the implementation check
5961 functor throws any exception. By default, this failure handler prints an
5962 error message to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">cerr</phrase></computeroutput> and terminates the program calling
5963 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">terminate</phrase></computeroutput> (see <link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__">Throw
5964 on Failures</link> to change the failure handler to throw exceptions, exit
5965 the program with an error code, etc.).
5968 Similarly to the C-style <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">assert</phrase></computeroutput>
5969 macro that is disabled when <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">NDEBUG</phrase></computeroutput>
5970 is defined, implementation checks are disabled when <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_NO_CHECKS">BOOST_CONTRACT_NO_CHECKS</link></computeroutput>
5971 is defined (see <link linkend="boost_contract.extras.disable_contract_checking">Disable
5972 Contract Checking</link>). That will skip all implementation checks at run-time
5973 but it will not eliminate some of the overhead of executing and compiling
5974 the related <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.check">boost::contract::check</link></computeroutput>
5975 declarations. Alternatively, this library provides the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_CHECK">BOOST_CONTRACT_CHECK</link></computeroutput>
5976 macro that allows to completely remove run- and compile-time overheads of
5977 implementation checks when <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_NO_CHECKS">BOOST_CONTRACT_NO_CHECKS</link></computeroutput>
5978 is defined (note that this is not a variadic macro):
5980 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">BOOST_CONTRACT_CHECK</phrase><phrase role="special">(</phrase><literal moreinfo="none"><emphasis>boolean-condition</emphasis></literal><phrase role="special">)</phrase>
5981 <phrase role="comment">// Or, if `boolean-condition` contains commas `,` not already within parenthesis `()`...</phrase>
5982 <phrase role="identifier">BOOST_CONTRACT_CHECK</phrase><phrase role="special">((</phrase><literal moreinfo="none"><emphasis>boolean-condition</emphasis></literal><phrase role="special">))</phrase> <phrase role="comment">// ...use extra parenthesis (not a variadic macro).</phrase>
5985 For example (see <ulink url="../../example/features/check_macro.cpp"><literal moreinfo="none">check_macro.cpp</literal></ulink>):
5988 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="identifier">main</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
5989 <phrase role="comment">// Implementation checks (via macro, disable run-/compile-time overhead).</phrase>
5990 <phrase role="identifier">BOOST_CONTRACT_CHECK</phrase><phrase role="special">(</phrase><phrase role="identifier">gcd</phrase><phrase role="special">(</phrase><phrase role="number">12</phrase><phrase role="special">,</phrase> <phrase role="number">28</phrase><phrase role="special">)</phrase> <phrase role="special">==</phrase> <phrase role="number">4</phrase><phrase role="special">);</phrase>
5991 <phrase role="identifier">BOOST_CONTRACT_CHECK</phrase><phrase role="special">(</phrase><phrase role="identifier">gcd</phrase><phrase role="special">(</phrase><phrase role="number">4</phrase><phrase role="special">,</phrase> <phrase role="number">14</phrase><phrase role="special">)</phrase> <phrase role="special">==</phrase> <phrase role="number">2</phrase><phrase role="special">);</phrase>
5993 <phrase role="keyword">return</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase>
5994 <phrase role="special">}</phrase>
5998 The <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_CHECK">BOOST_CONTRACT_CHECK</link></computeroutput>
5999 macro is similar to the C-style assert macro as it accepts a boolean condition
6000 (instead of a nullary functor like <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.check">boost::contract::check</link></computeroutput>
6001 does). <footnote id="boost_contract.advanced.implementation_checks.f0">
6003 Of course, nothing prevents programmers from calling functors within <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_CHECK">BOOST_CONTRACT_CHECK</link></computeroutput> to specify
6004 boolean conditions when if-guards and other statements are required to
6005 assert the implementation checks. For example, programmers can use C++11
6006 lambda functions to define and call such functors in place where the implementation
6007 checks are specified:
6008 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">BOOST_CONTRACT_CHECK</phrase><phrase role="special">([&]</phrase> <phrase role="special">-></phrase> <phrase role="keyword">bool</phrase> <phrase role="special">{</phrase>
6009 <phrase role="keyword">if</phrase><phrase role="special">(</phrase><phrase role="identifier">even_numbers</phrase><phrase role="special">)</phrase> <phrase role="keyword">return</phrase> <phrase role="identifier">gcd</phrase><phrase role="special">(</phrase><phrase role="identifier">x</phrase><phrase role="special">,</phrase> <phrase role="identifier">y</phrase><phrase role="special">)</phrase> <phrase role="special">==</phrase> <phrase role="number">2</phrase><phrase role="special">;</phrase>
6010 <phrase role="keyword">else</phrase> <phrase role="keyword">return</phrase> <phrase role="identifier">gcd</phrase><phrase role="special">(</phrase><phrase role="identifier">x</phrase><phrase role="special">,</phrase> <phrase role="identifier">y</phrase><phrase role="special">)</phrase> <phrase role="special">==</phrase> <phrase role="number">3</phrase><phrase role="special">;</phrase>
6011 <phrase role="special">}</phrase> <phrase role="special">());</phrase>
6014 </footnote> Using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_CHECK">BOOST_CONTRACT_CHECK</link></computeroutput>
6015 is essentially equivalent to using the C-style <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">assert</phrase></computeroutput>
6016 macro a part from the following:
6021 Implementation checks are disabled defining <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_NO_CHECKS">BOOST_CONTRACT_NO_CHECKS</link></computeroutput>
6022 (instead of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">NDEBUG</phrase></computeroutput> for
6023 disabling <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">assert</phrase></computeroutput>).
6028 If the asserted boolean condition is either false or it throws an exception
6029 then this library will call <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.check_failure">boost::contract::check_failure</link></computeroutput>
6030 (instead <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">assert</phrase></computeroutput> calls
6031 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">abort</phrase></computeroutput> if the asserted condition is
6032 false and it unwinds the stack if evaluating the condition throws an
6038 Implementation checks are automatically disabled when other contract
6039 conditions specified using this library are already being checked (to
6040 avoid infinite recursion, see <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394999679376">BOOST_CONTRACT_ALL_DISABLE_NO_ASSERTION</link></computeroutput>).
6045 <section id="boost_contract.advanced.old_values_copied_at_body">
6046 <title><link linkend="boost_contract.advanced.old_values_copied_at_body">Old
6047 Values Copied at Body</link></title>
6049 In the examples seen so far, old value variables of type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.old_ptr">boost::contract::old_ptr</link></computeroutput>
6050 are initialized to a copy of the expression passed to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_OLDOF">BOOST_CONTRACT_OLDOF</link></computeroutput>
6051 as soon as they are declared. That correctly happens before the function
6052 body is executed but also before the contract is declared, therefore even
6053 before class invariants (for public functions) and preconditions are checked
6054 at function entry. This might work well in most practical cases however,
6055 technically speaking, old values should be copied before executing the function
6056 body but <emphasis>after</emphasis> checking class invariants and preconditions
6057 at function entry (see <link linkend="boost_contract.contract_programming_overview.assertions">Assertions</link>).
6058 Specifically, there could be cases in which it makes sense to evaluate the
6059 expressions passed to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_OLDOF">BOOST_CONTRACT_OLDOF</link></computeroutput>
6060 only under the assumption that assertions programmed in class invariants
6061 and preconditions are true.
6064 This library allows to construct <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.old_ptr">boost::contract::old_ptr</link></computeroutput>
6065 variables using their default constructor (equivalent to a null pointer)
6066 and then to later assign them to a copy of the expression specified by <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_OLDOF">BOOST_CONTRACT_OLDOF</link></computeroutput> in a nullary
6067 functor <literal moreinfo="none"><emphasis>d</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">()</phrase></computeroutput>
6068 passed to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">old</phrase><phrase role="special">(</phrase></computeroutput><literal moreinfo="none"><emphasis>d</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">)</phrase></computeroutput>. The functor <literal moreinfo="none"><emphasis>d</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">()</phrase></computeroutput> is called by this library before the function
6069 body is executed but only after class invariants and preconditions are checked.
6070 Old value assignments via <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">old</phrase><phrase role="special">(...)</phrase></computeroutput>
6071 must appear after preconditions but before postconditions and exception guarantees
6072 wen these are all present (see <link linkend="boost_contract.tutorial.preconditions">Preconditions</link>,
6073 <link linkend="boost_contract.tutorial.postconditions">Postconditions</link>,
6074 and <link linkend="boost_contract.tutorial.exception_guarantees">Exception
6075 Guarantees</link>). <footnote id="boost_contract.advanced.old_values_copied_at_body.f0">
6077 <emphasis role="bold">Rationale:</emphasis> Functors for preconditions,
6078 old value assignments, postconditions, and exception guarantees are all
6079 optional but when specified, they must be specified in that order. Such
6080 order is enforced by the fact that <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.specify__idm45394999179040">boost::contract::specify_precondition_old_postcondition_except</link></computeroutput>,
6081 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.specify__idm45394999245856">boost::contract::specify_old_postcondition_except</link></computeroutput>,
6082 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.specify__idm45394999207792">boost::contract::specify_postcondition_except</link></computeroutput>,
6083 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.specify_except">boost::contract::specify_except</link></computeroutput>,
6084 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.specify_nothing">boost::contract::specify_nothing</link></computeroutput>
6085 provide a progressively smaller subset of their <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">(...)</phrase></computeroutput>,
6086 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">old</phrase><phrase role="special">(...)</phrase></computeroutput>, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">(...)</phrase></computeroutput>,
6087 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">except</phrase><phrase role="special">(...)</phrase></computeroutput> member functions. The enforced order
6088 for specifying preconditions, old value assignments, postconditions, and
6089 exception guarantees makes logical sense because it follows the order at
6090 which these are executed at run-time. Other contract programming frameworks
6091 allow to mix this order, that could have been implemented for this library
6092 as well but it would have complicated somewhat the library implementation
6093 while adding no real value (arguably creating confusion in user code by
6094 not enforcing a consistent order for specifying contract conditions).
6099 For example, the following old value expression <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">s</phrase><phrase role="special">[</phrase><phrase role="identifier">index</phrase><phrase role="special">]</phrase></computeroutput> passed to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_OLDOF">BOOST_CONTRACT_OLDOF</link></computeroutput>
6100 is valid only after the precondition has checked that <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">index</phrase></computeroutput>
6101 is within the valid range <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">index</phrase>
6102 <phrase role="special"><</phrase> <phrase role="identifier">s</phrase><phrase role="special">.</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase></computeroutput>.
6103 Therefore, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">old_char</phrase></computeroutput> is first
6104 declared using its default constructor (i.e., initialized to a null pointer)
6105 and later assigned to a copy of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">s</phrase><phrase role="special">[</phrase><phrase role="identifier">index</phrase><phrase role="special">]</phrase></computeroutput> in <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">old</phrase><phrase role="special">(...)</phrase></computeroutput>
6106 after the precondition has checked <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">index</phrase></computeroutput>
6107 (see <ulink url="../../example/features/old.cpp"><literal moreinfo="none">old.cpp</literal></ulink>):
6110 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">char</phrase> <phrase role="identifier">replace</phrase><phrase role="special">(</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">string</phrase><phrase role="special">&</phrase> <phrase role="identifier">s</phrase><phrase role="special">,</phrase> <phrase role="keyword">unsigned</phrase> <phrase role="identifier">index</phrase><phrase role="special">,</phrase> <phrase role="keyword">char</phrase> <phrase role="identifier">x</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
6111 <phrase role="keyword">char</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
6112 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">char</phrase><phrase role="special">></phrase> <phrase role="identifier">old_char</phrase><phrase role="special">;</phrase> <phrase role="comment">// Null, old value copied later...</phrase>
6113 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">function</phrase><phrase role="special">()</phrase>
6114 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
6115 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">index</phrase> <phrase role="special"><</phrase> <phrase role="identifier">s</phrase><phrase role="special">.</phrase><phrase role="identifier">size</phrase><phrase role="special">());</phrase>
6116 <phrase role="special">})</phrase>
6117 <phrase role="special">.</phrase><phrase role="identifier">old</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// ...after preconditions (and invariants) checked.</phrase>
6118 <phrase role="identifier">old_char</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">s</phrase><phrase role="special">[</phrase><phrase role="identifier">index</phrase><phrase role="special">]);</phrase>
6119 <phrase role="special">})</phrase>
6120 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
6121 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">s</phrase><phrase role="special">[</phrase><phrase role="identifier">index</phrase><phrase role="special">]</phrase> <phrase role="special">==</phrase> <phrase role="identifier">x</phrase><phrase role="special">);</phrase>
6122 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">result</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_char</phrase><phrase role="special">);</phrase>
6123 <phrase role="special">})</phrase>
6124 <phrase role="special">;</phrase>
6126 <phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="identifier">s</phrase><phrase role="special">[</phrase><phrase role="identifier">index</phrase><phrase role="special">];</phrase>
6127 <phrase role="identifier">s</phrase><phrase role="special">[</phrase><phrase role="identifier">index</phrase><phrase role="special">]</phrase> <phrase role="special">=</phrase> <phrase role="identifier">x</phrase><phrase role="special">;</phrase>
6128 <phrase role="keyword">return</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
6129 <phrase role="special">}</phrase>
6133 The functor passed to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">old</phrase><phrase role="special">(...)</phrase></computeroutput> should capture all the variables that
6134 it needs to evaluate the old value expressions passed to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_OLDOF">BOOST_CONTRACT_OLDOF</link></computeroutput>.
6135 In general, these variables should be captured by reference and not by value
6136 (because old values need to copy the values the captured variables will have
6137 just before executing the function body, and not the values these variables
6138 had when the functor passed to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">old</phrase><phrase role="special">(...)</phrase></computeroutput>
6139 was first declared). In any case, programmers should write the functor passed
6140 to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">old</phrase><phrase role="special">(...)</phrase></computeroutput> so that it modifies only old values
6141 and not the values of other captured variables, even when those are captured
6142 by reference (see <link linkend="boost_contract.contract_programming_overview.constant_correctness">Constant-Correctness</link>).
6145 This library will automatically call the failure handler <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.old_failure">boost::contract::old_failure</link></computeroutput>
6146 if calling the functor specified via <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">old</phrase><phrase role="special">(...)</phrase></computeroutput>
6147 throws an exception (by default, this handler prints an error message to
6148 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">cerr</phrase></computeroutput> and terminates the program calling
6149 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">terminate</phrase></computeroutput>, but see <link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__">Throw
6150 on Failures</link> to throw exceptions, exit the program with an error code,
6155 If old value pointers are initialized at the point of their construction
6156 instead of using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">old</phrase><phrase role="special">(...)</phrase></computeroutput> then an exception thrown by the old
6157 value expression passed to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_OLDOF">BOOST_CONTRACT_OLDOF</link></computeroutput>,
6158 or more in general any exception thrown by the old value pointer initialization,
6159 will result in that exception being thrown up the stack by the enclosing
6160 function. This is arguably less correct than calling <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.old_failure">boost::contract::old_failure</link></computeroutput>
6161 because an exception thrown by an old value copy causes the program to
6162 fail to check its postconditions and exception guarantees but should not
6163 automatically causes the enclosing function to thrown an exception (this
6164 might not be a significant difference in practice, but it could be an additional
6165 reason to use <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">old</phrase><phrase role="special">(...)</phrase></computeroutput> instead of assigning old values when
6166 they are declared before the contract). <footnote id="boost_contract.advanced.old_values_copied_at_body.f1">
6168 <emphasis role="bold">Rationale:</emphasis> It would be possible for
6169 this library to internally wrap all old value operations (<computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.old_ptr">boost::contract::old_ptr</link></computeroutput> copy
6170 constructor, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.make_old_idm45394998968720">boost::contract::make_old</link></computeroutput>,
6171 etc.) with try-catch statements so to call <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.old_failure">boost::contract::old_failure</link></computeroutput>
6172 also when old values are copied when they are constructed outside <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">old</phrase><phrase role="special">(...)</phrase></computeroutput>. However, that will prevent this
6173 library from knowing the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.from">boost::contract::from</link></computeroutput>
6174 parameter and that would be problematic (specifically because destructors
6175 can have postconditions so that parameter is necessary to make sure user-defined
6176 failure handlers can be programmed to never throw from destructors as
6177 C++ usually requires).
6183 <section id="boost_contract.advanced.named_overrides">
6184 <title><link linkend="boost_contract.advanced.named_overrides">Named Overrides</link></title>
6186 As seen in <link linkend="boost_contract.tutorial.public_function_overrides__subcontracting_">Public
6187 Function Overrides</link>, the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_OVERRIDE">BOOST_CONTRACT_OVERRIDE</link></computeroutput>
6188 macro has to be used to declare the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">override_</phrase><phrase role="special">...</phrase></computeroutput> that is passed as an explicit template
6189 parameter to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>
6190 for public function overrides. The function names passed to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_OVERRIDE">BOOST_CONTRACT_OVERRIDE</link></computeroutput>
6191 (and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_OVERRIDES">BOOST_CONTRACT_OVERRIDES</link></computeroutput>)
6192 should never start with an underscore to avoid generating names containing
6193 double underscores <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">override__</phrase><phrase role="special">...</phrase></computeroutput> (because all symbols containing double
6194 underscores <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">...</phrase><phrase role="identifier">__</phrase><phrase role="special">...</phrase></computeroutput> are reserved symbols in the C++ standard).
6195 There is a separate macro <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394998912688">BOOST_CONTRACT_NAMED_OVERRIDE</link></computeroutput>
6196 that can be used to explicitly specify the name of the type being declared:
6197 <footnote id="boost_contract.advanced.named_overrides.f0">
6199 <emphasis role="bold">Rationale:</emphasis> A different macro <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394998912688">BOOST_CONTRACT_NAMED_OVERRIDE</link></computeroutput>
6200 is used instead of overloading <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_OVERRIDE">BOOST_CONTRACT_OVERRIDE</link></computeroutput>
6201 using variadic macros because the override macro cannot be programmed manually
6202 by users so making it a variadic would prevent to use this library on compilers
6203 that do not support variadic macros (see <link linkend="boost_contract.extras.no_macros__and_no_variadic_macros_">No
6208 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">BOOST_CONTRACT_OVERRIDE</phrase><phrase role="special">(</phrase><literal moreinfo="none"><emphasis>function-name</emphasis></literal><phrase role="special">)</phrase> <phrase role="comment">// Generate `override_...`.</phrase>
6209 <phrase role="identifier">BOOST_CONTRACT_NAMED_OVERRIDE</phrase><phrase role="special">(</phrase><literal moreinfo="none"><emphasis>type-name</emphasis></literal><phrase role="special">,</phrase> <literal moreinfo="none"><emphasis>function-name</emphasis></literal><phrase role="special">)</phrase> <phrase role="comment">// Generate `type-name`.</phrase>
6212 For example, the following public function override is named <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">_1</phrase></computeroutput> so <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">BOOST_CONTRACT_OVERRIDE</phrase><phrase role="special">(</phrase><phrase role="identifier">_1</phrase><phrase role="special">)</phrase></computeroutput>
6213 would declare a type named <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">override__1</phrase></computeroutput>
6214 (which is reserved symbol in C++ because it contains a double underscore
6215 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">__</phrase></computeroutput>), thus <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">BOOST_CONTRACT_NAMED_OVERRIDE</phrase><phrase role="special">(</phrase><phrase role="identifier">override1</phrase><phrase role="special">,</phrase> <phrase role="identifier">_1</phrase><phrase role="special">)</phrase></computeroutput>
6216 is used to name the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">override1</phrase></computeroutput>
6217 instead (see <ulink url="../../example/features/named_override.cpp"><literal moreinfo="none">named_override.cpp</literal></ulink>):
6220 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">></phrase>
6221 <phrase role="keyword">class</phrase> <phrase role="identifier">positive_unary_pack</phrase>
6222 <phrase role="preprocessor">#define</phrase> <phrase role="identifier">BASES</phrase> <phrase role="keyword">public</phrase> <phrase role="identifier">generic_unary_pack</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase>
6223 <phrase role="special">:</phrase> <phrase role="identifier">BASES</phrase>
6224 <phrase role="special">{</phrase>
6225 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
6226 <phrase role="keyword">typedef</phrase> <phrase role="identifier">BOOST_CONTRACT_BASE_TYPES</phrase><phrase role="special">(</phrase><phrase role="identifier">BASES</phrase><phrase role="special">)</phrase> <phrase role="identifier">base_types</phrase><phrase role="special">;</phrase>
6227 <phrase role="preprocessor">#undef</phrase> <phrase role="identifier">BASES</phrase>
6229 <phrase role="comment">// BOOST_CONTRACT_OVERRIDE(_1) would generate reserved name `override__1`.</phrase>
6230 <phrase role="identifier">BOOST_CONTRACT_NAMED_OVERRIDE</phrase><phrase role="special">(</phrase><phrase role="identifier">override1</phrase><phrase role="special">,</phrase> <phrase role="identifier">_1</phrase><phrase role="special">)</phrase> <phrase role="comment">// Generate `override1`.</phrase>
6232 <phrase role="keyword">virtual</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">_1</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">value</phrase><phrase role="special">,</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase>
6233 <phrase role="comment">/* override */</phrase> <phrase role="special">{</phrase>
6234 <phrase role="comment">// Use `override1` generated by BOOST_CONTRACT_NAMED_OVERRIDE above.</phrase>
6235 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special"><</phrase><phrase role="identifier">override1</phrase><phrase role="special">>(</phrase>
6236 <phrase role="identifier">v</phrase><phrase role="special">,</phrase>
6237 <phrase role="keyword">static_cast</phrase><phrase role="special"><</phrase><phrase role="keyword">void</phrase> <phrase role="special">(</phrase><phrase role="identifier">positive_unary_pack</phrase><phrase role="special">::*)(</phrase><phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&,</phrase>
6238 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*)>(&</phrase><phrase role="identifier">positive_unary_pack</phrase><phrase role="special">::</phrase><phrase role="identifier">_1</phrase><phrase role="special">),</phrase>
6239 <phrase role="keyword">this</phrase><phrase role="special">,</phrase>
6240 <phrase role="identifier">value</phrase>
6241 <phrase role="special">)</phrase>
6242 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
6243 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">value</phrase> <phrase role="special">></phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase>
6244 <phrase role="special">})</phrase>
6245 <phrase role="special">;</phrase>
6246 <phrase role="identifier">value1_</phrase> <phrase role="special">=</phrase> <phrase role="identifier">value</phrase><phrase role="special">;</phrase>
6247 <phrase role="special">}</phrase>
6249 <phrase role="comment">/* ... */</phrase>
6253 The <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394998912688">BOOST_CONTRACT_NAMED_OVERRIDE</link></computeroutput>
6254 macro can also be used when the name <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">override_</phrase><phrase role="special">...</phrase></computeroutput> generated by <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_OVERRIDE">BOOST_CONTRACT_OVERRIDE</link></computeroutput>
6255 would clash with other names in user code, to generate names in CamelCase
6256 or in any other preferred style, and in any other case when programmers need
6257 or prefer to generate names different from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">override_</phrase><phrase role="special">...</phrase></computeroutput>.
6260 Note that there is not a <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">BOOST_CONTRACT_NAMED_OVERRIDES</phrase></computeroutput>
6261 macro so <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394998912688">BOOST_CONTRACT_NAMED_OVERRIDE</link></computeroutput>
6262 needs to be invoked separately on each function name (there is instead a
6263 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_OVERRIDES">BOOST_CONTRACT_OVERRIDES</link></computeroutput>
6264 macro as seen in <link linkend="boost_contract.tutorial.public_function_overrides__subcontracting_">Public
6265 Function Overrides</link>). <footnote id="boost_contract.advanced.named_overrides.f1">
6267 <emphasis role="bold">Rationale:</emphasis> The syntax for invoking a possible
6268 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">BOOST_CONTRACT_NAMED_OVERRIDES</phrase></computeroutput>
6269 macro would need to be something like <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">BOOST_CONTRACT_NAMED_OVERRIDES</phrase><phrase role="special">(</phrase><phrase role="identifier">type_name1</phrase><phrase role="special">,</phrase> <phrase role="identifier">func_name1</phrase><phrase role="special">,</phrase> <phrase role="identifier">type_name2</phrase><phrase role="special">,</phrase> <phrase role="identifier">func_name2</phrase><phrase role="special">,</phrase> <phrase role="special">...)</phrase></computeroutput>.
6270 The authors found such a syntax less readable than repeating single <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394998912688">BOOST_CONTRACT_NAMED_OVERRIDE</link></computeroutput>
6271 invocations as in <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">BOOST_CONTRACT_NAMED_OVERRIDE</phrase><phrase role="special">(</phrase><phrase role="identifier">type_name1</phrase><phrase role="special">,</phrase> <phrase role="identifier">func_name1</phrase><phrase role="special">)</phrase> <phrase role="identifier">BOOST_CONTRACT_NAMED_OVERRIDE</phrase><phrase role="special">(</phrase><phrase role="identifier">type_name2</phrase><phrase role="special">,</phrase> <phrase role="identifier">func_name2</phrase><phrase role="special">)</phrase> <phrase role="special">...</phrase></computeroutput> so
6272 decided not to provide the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">BOOST_CONTRACT_NAMED_OVERRIDES</phrase></computeroutput>
6278 <section id="boost_contract.advanced.access_specifiers">
6279 <title><link linkend="boost_contract.advanced.access_specifiers">Access Specifiers</link></title>
6281 As seen thus far, this library requires programmers to decorate their classes
6282 declaring the following extra members:
6287 The <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">invariant</phrase></computeroutput> and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">static_invariant</phrase></computeroutput> member functions (used
6288 to check class invariants, see <link linkend="boost_contract.tutorial.class_invariants">Class
6294 The <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">base_types</phrase></computeroutput> member
6295 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">typedef</phrase></computeroutput> declared via <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_BASE_TYPES">BOOST_CONTRACT_BASE_TYPES</link></computeroutput>
6296 (used to implement subcontracting, see <link linkend="boost_contract.tutorial.public_function_overrides__subcontracting_">Public
6297 Function Overrides</link>).
6302 The <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">override_</phrase><phrase role="special">...</phrase></computeroutput>
6303 member types declared via <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_OVERRIDE">BOOST_CONTRACT_OVERRIDE</link></computeroutput>,
6304 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394998912688">BOOST_CONTRACT_NAMED_OVERRIDE</link></computeroutput>,
6305 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_OVERRIDES">BOOST_CONTRACT_OVERRIDES</link></computeroutput>
6306 (used to implement subcontracting for overriding functions, see <link linkend="boost_contract.tutorial.public_function_overrides__subcontracting_">Public
6307 Function Overrides</link>). <footnote id="boost_contract.advanced.access_specifiers.f0">
6309 <emphasis role="bold">Rationale:</emphasis> Note that the internals
6310 of the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">override_</phrase><phrase role="special">...</phrase></computeroutput>
6311 type generated by <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_OVERRIDE">BOOST_CONTRACT_OVERRIDE</link></computeroutput>
6312 use names reserved by this library so programmers should not actually
6313 use such a type even when it is declared <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">public</phrase></computeroutput>.
6320 In general, these members must be declared <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">public</phrase></computeroutput>
6321 in the user class in order for this library to be able to access them. <footnote id="boost_contract.advanced.access_specifiers.f1">
6323 There is some variability among compiler implementations: The <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">base_types</phrase></computeroutput> member type needs to be declared
6324 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">public</phrase></computeroutput> on MSVC, GCC, and Clang;
6325 The <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">invariant</phrase></computeroutput> and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">static_invariant</phrase></computeroutput> member functions need
6326 to be declared <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">public</phrase></computeroutput> on MSVC,
6327 but not on GCC and Clang; The <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">override_</phrase><phrase role="special">...</phrase></computeroutput> member types do not have to be declared
6328 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">public</phrase></computeroutput> on any compiler. In
6329 any case, declaring these extra members all <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">public</phrase></computeroutput>
6330 or all <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">private</phrase></computeroutput> when the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.access">boost::contract::access</link></computeroutput> class
6331 is also declared <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">friend</phrase></computeroutput> always
6332 works on all compilers.
6334 </footnote> However, programmers might need to more precisely control the
6335 public members of their classes to prevent incorrect access of encapsulated
6336 members. All these members can be declared <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">private</phrase></computeroutput>
6337 as long as the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.access">boost::contract::access</link></computeroutput>
6338 class is declared as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">friend</phrase></computeroutput>
6339 of the user class. For example (see <ulink url="../../example/features/access.cpp"><literal moreinfo="none">access.cpp</literal></ulink>):
6342 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">></phrase>
6343 <phrase role="keyword">class</phrase> <phrase role="identifier">vector</phrase>
6344 <phrase role="preprocessor">#define</phrase> <phrase role="identifier">BASES</phrase> <phrase role="keyword">public</phrase> <phrase role="identifier">pushable</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase>
6345 <phrase role="special">:</phrase> <phrase role="identifier">BASES</phrase>
6346 <phrase role="special">{</phrase> <phrase role="comment">// Private section of the class.</phrase>
6347 <phrase role="keyword">friend</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">access</phrase><phrase role="special">;</phrase> <phrase role="comment">// Friend `access` class so...</phrase>
6349 <phrase role="keyword">typedef</phrase> <phrase role="identifier">BOOST_CONTRACT_BASE_TYPES</phrase><phrase role="special">(</phrase><phrase role="identifier">BASES</phrase><phrase role="special">)</phrase> <phrase role="identifier">base_types</phrase><phrase role="special">;</phrase> <phrase role="comment">// ...private bases.</phrase>
6350 <phrase role="preprocessor">#undef</phrase> <phrase role="identifier">BASES</phrase>
6352 <phrase role="keyword">void</phrase> <phrase role="identifier">invariant</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase> <phrase role="comment">// ...private invariants.</phrase>
6353 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special"><=</phrase> <phrase role="identifier">capacity</phrase><phrase role="special">());</phrase>
6354 <phrase role="special">}</phrase>
6356 <phrase role="identifier">BOOST_CONTRACT_OVERRIDE</phrase><phrase role="special">(</phrase><phrase role="identifier">push_back</phrase><phrase role="special">)</phrase> <phrase role="comment">// ...private overrides.</phrase>
6358 <phrase role="keyword">public</phrase><phrase role="special">:</phrase> <phrase role="comment">// Public section of the class.</phrase>
6359 <phrase role="keyword">void</phrase> <phrase role="identifier">push_back</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">value</phrase><phrase role="special">,</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase>
6360 <phrase role="comment">/* override */</phrase> <phrase role="special">{</phrase>
6361 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">unsigned</phrase><phrase role="special">></phrase> <phrase role="identifier">old_size</phrase> <phrase role="special">=</phrase>
6362 <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">size</phrase><phrase role="special">());</phrase>
6363 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special"><</phrase>
6364 <phrase role="identifier">override_push_back</phrase><phrase role="special">>(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="special">&</phrase><phrase role="identifier">vector</phrase><phrase role="special">::</phrase><phrase role="identifier">push_back</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">,</phrase> <phrase role="identifier">value</phrase><phrase role="special">)</phrase>
6365 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
6366 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special"><</phrase> <phrase role="identifier">max_size</phrase><phrase role="special">());</phrase>
6367 <phrase role="special">})</phrase>
6368 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
6369 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_size</phrase> <phrase role="special">+</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase>
6370 <phrase role="special">})</phrase>
6371 <phrase role="special">;</phrase>
6373 <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">push_back</phrase><phrase role="special">(</phrase><phrase role="identifier">value</phrase><phrase role="special">);</phrase>
6374 <phrase role="special">}</phrase>
6376 <phrase role="comment">/* ... */</phrase>
6380 This technique is not used in most examples of this documentation only for
6381 brevity. Programmers are encouraged to use <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.access">boost::contract::access</link></computeroutput>
6382 in real production code freely as they see fit.
6386 Not declaring <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.access">boost::contract::access</link></computeroutput>
6387 friend of user classes might cause compiler errors on some compilers (e.g.,
6388 MSVC) because the private members needed to check the contracts will not
6389 be accessible. On other compilers (e.g., GCC and Clang), the private access
6390 level will instead fail SFINAE and no compiler error will be reported while
6391 invariants and subcontracting will be silently skipped at run-time. Therefore,
6392 programmers should always make sure to either declare invariant functions
6393 and base types <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">typedef</phrase></computeroutput> as
6394 public members or to declare <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.access">boost::contract::access</link></computeroutput>
6399 <section id="boost_contract.advanced.throw_on_failures__and__noexcept__">
6400 <title><link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__">Throw
6401 on Failures (and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">noexcept</phrase></computeroutput>)</link></title>
6403 If a condition checked using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_ASSERT">BOOST_CONTRACT_ASSERT</link></computeroutput>
6404 is evaluated to be false or, more in general, if any of the specified contract
6405 code throws an exception (<computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_ASSERT">BOOST_CONTRACT_ASSERT</link></computeroutput>
6406 simply expands to code that throws a <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.assertion_failure">boost::contract::assertion_failure</link></computeroutput>
6407 exception, see <link linkend="boost_contract.extras.no_macros__and_no_variadic_macros_">No
6408 Macros</link>), this library will call an appropriate <emphasis>contract
6409 failure handler</emphasis> function as follow:
6414 Preconditions: False <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_ASSERT">BOOST_CONTRACT_ASSERT</link></computeroutput>
6415 assertions and exceptions thrown from within <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">(...)</phrase></computeroutput>
6416 call <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.precondition_failure">boost::contract::precondition_failure</link></computeroutput>.
6421 Postconditions: False <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_ASSERT">BOOST_CONTRACT_ASSERT</link></computeroutput>
6422 assertions and exceptions thrown from within <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">(...)</phrase></computeroutput>
6423 call <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.postcondition_failure">boost::contract::postcondition_failure</link></computeroutput>.
6428 Exceptions guarantees: False <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_ASSERT">BOOST_CONTRACT_ASSERT</link></computeroutput>
6429 assertions and exceptions thrown from within <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">except</phrase><phrase role="special">(...)</phrase></computeroutput>
6430 call <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.except_failure">boost::contract::except_failure</link></computeroutput>.
6435 Class invariants: False <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_ASSERT">BOOST_CONTRACT_ASSERT</link></computeroutput>
6436 assertions and exceptions thrown from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">invariant</phrase><phrase role="special">()</phrase></computeroutput> and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">static_invariant</phrase><phrase role="special">()</phrase></computeroutput> call <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.entry_invariant_failure">boost::contract::entry_invariant_failure</link></computeroutput>
6437 when checked at function entry and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.exit_invariant_failure">boost::contract::exit_invariant_failure</link></computeroutput>
6438 when checked at function exit.
6443 Old values copied at body: Exceptions thrown from old values copied at
6444 body within <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">old</phrase><phrase role="special">(...)</phrase></computeroutput> call <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.old_failure">boost::contract::old_failure</link></computeroutput>.
6449 Implementation checks: False <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_ASSERT">BOOST_CONTRACT_ASSERT</link></computeroutput>
6450 assertions and exceptions thrown from implementation checks <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase>
6451 <phrase role="special">=</phrase> </computeroutput><literal moreinfo="none"><emphasis>nullary-functor</emphasis></literal>
6452 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">BOOST_CONTRACT_CHECK</phrase><phrase role="special">(...)</phrase></computeroutput> call <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.check_failure">boost::contract::check_failure</link></computeroutput>.
6457 By default, these contract failure handlers print a message to the standard
6458 error <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">cerr</phrase></computeroutput> and then terminate the program calling
6459 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">terminate</phrase></computeroutput>. <footnote id="boost_contract.advanced.throw_on_failures__and__noexcept__.f0">
6461 <emphasis role="bold">Rationale:</emphasis> In general, when a contract
6462 fails the only safe thing to do is to terminate program execution (because
6463 the contract failure indicates a bug in the program, and in general a buggy
6464 program will be in a state for which no operation can be successfully and
6465 safely performed, so the program should be stopped as soon as possible).
6466 Therefore, this library terminates the program by default. However, for
6467 specific applications, programmers could implement some fail-safe mechanism
6468 for which some mission-critical operations could always be performed upon
6469 handling failures so this library allows programmers to override the default
6470 contract failure handlers to fully customize how to handle contract failures.
6472 </footnote> However, programmers can override the default contract failure
6473 handlers to perform any custom action on contract failure using the following
6474 functions respectively:
6479 Preconditions: <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.set_precondition_failure">boost::contract::set_precondition_failure</link></computeroutput>.
6484 Postconditions: <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.set_postcondition_failure">boost::contract::set_postcondition_failure</link></computeroutput>.
6489 Exception guarantees: <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.set_except_failure">boost::contract::set_except_failure</link></computeroutput>.
6494 Class invariants: <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.set_entr_idm45394999333872">boost::contract::set_entry_invariant_failure</link></computeroutput>
6495 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.set_exit_invariant_failure">boost::contract::set_exit_invariant_failure</link></computeroutput>,
6496 or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.set_invariant_failure">boost::contract::set_invariant_failure</link></computeroutput>
6497 (to set both entry and exit invariant failure handlers at once for convenience).
6502 Old values copied at body: <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.set_old_failure">boost::contract::set_old_failure</link></computeroutput>.
6507 Implementation checks: <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.set_check_failure">boost::contract::set_check_failure</link></computeroutput>.
6512 These <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">set_</phrase><phrase role="special">...</phrase><phrase role="identifier">_failure</phrase><phrase role="special">(</phrase></computeroutput><literal moreinfo="none"><emphasis>f</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">)</phrase></computeroutput> function calls return a reference to the
6513 contract failure handler functor <literal moreinfo="none"><emphasis>f</emphasis></literal>
6514 that they take as input parameter (so they can be concatenated). <footnote id="boost_contract.advanced.throw_on_failures__and__noexcept__.f1">
6516 <emphasis role="bold">Rationale:</emphasis> The <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">set_</phrase><phrase role="special">...</phrase><phrase role="identifier">_failure</phrase></computeroutput>
6517 functions take a functor as parameter (to accept not just function pointers
6518 but also lambdas, binds, etc.) and they return this same functor as result
6519 so they can be concatenated (this interface is a bit different from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">set_terminate</phrase></computeroutput>). The related <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">get_</phrase><phrase role="special">...</phrase><phrase role="identifier">_failure</phrase></computeroutput> functions can be used to query
6520 the functors currently set as failure handlers (this interface is similar
6521 to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">get_terminate</phrase></computeroutput>).
6523 </footnote> For example (see <ulink url="../../example/features/throw_on_failure.cpp"><literal moreinfo="none">throw_on_failure.cpp</literal></ulink>):
6526 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="identifier">main</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
6527 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">set_precondition_failure</phrase><phrase role="special">(</phrase>
6528 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">set_postcondition_failure</phrase><phrase role="special">(</phrase>
6529 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">set_invariant_failure</phrase><phrase role="special">(</phrase>
6530 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">set_old_failure</phrase><phrase role="special">(</phrase>
6531 <phrase role="special">[]</phrase> <phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">from</phrase> <phrase role="identifier">where</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
6532 <phrase role="keyword">if</phrase><phrase role="special">(</phrase><phrase role="identifier">where</phrase> <phrase role="special">==</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">from_destructor</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
6533 <phrase role="comment">// Shall not throw from C++ destructors.</phrase>
6534 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">clog</phrase> <phrase role="special"><<</phrase> <phrase role="string">"ignored destructor contract failure"</phrase> <phrase role="special"><<</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">endl</phrase><phrase role="special">;</phrase>
6535 <phrase role="special">}</phrase> <phrase role="keyword">else</phrase> <phrase role="keyword">throw</phrase><phrase role="special">;</phrase> <phrase role="comment">// Re-throw (assertion_failure, user-defined, etc.).</phrase>
6536 <phrase role="special">}</phrase>
6537 <phrase role="special">))));</phrase>
6538 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">set_except_failure</phrase><phrase role="special">(</phrase>
6539 <phrase role="special">[]</phrase> <phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">from</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
6540 <phrase role="comment">// Already an active exception so shall not throw another...</phrase>
6541 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">clog</phrase> <phrase role="special"><<</phrase> <phrase role="string">"ignored exception guarantee failure"</phrase> <phrase role="special"><<</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">endl</phrase><phrase role="special">;</phrase>
6542 <phrase role="special">}</phrase>
6543 <phrase role="special">);</phrase>
6544 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">set_check_failure</phrase><phrase role="special">(</phrase>
6545 <phrase role="special">[]</phrase> <phrase role="special">{</phrase>
6546 <phrase role="comment">// But now CHECK shall not be used in destructor implementations.</phrase>
6547 <phrase role="keyword">throw</phrase><phrase role="special">;</phrase> <phrase role="comment">// Re-throw (assertion_failure, user-defined, etc.).</phrase>
6548 <phrase role="special">}</phrase>
6549 <phrase role="special">);</phrase>
6551 <phrase role="comment">/* ... */</phrase>
6555 When programming custom failure handlers that trow exceptions instead of
6556 terminating the program, programmers should be wary of the following:
6561 In order to comply with C++ and STL exception safety, destructors should
6562 never throw (in fact destructors are implicitly declared <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">noexcept</phrase></computeroutput> since C++11). This library passes
6563 a <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.from">boost::contract::from</link></computeroutput>
6564 parameter to the contract failure handlers for preconditions, postconditions,
6565 class invariants, and old values copied at body (see <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.precondition_failure">boost::contract::precondition_failure</link></computeroutput>,
6566 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.postcondition_failure">boost::contract::postcondition_failure</link></computeroutput>,
6567 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.entry_invariant_failure">boost::contract::entry_invariant_failure</link></computeroutput>,
6568 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.exit_invariant_failure">boost::contract::exit_invariant_failure</link></computeroutput>,
6569 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.old_failure">boost::contract::old_failure</link></computeroutput>
6570 respectively). This <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.from">boost::contract::from</link></computeroutput>
6571 parameter indicates if the contract failure occurred in a destructor,
6572 constructor, or function call so programmers can use it to code custom
6573 contract failure hander functions that never throw from destructors.
6574 (In the example above, contract failures from destructors are simply
6575 ignored even if that is probably never a safe thing to do in real production
6581 C++ stack-unwinding will execute base class destructors even when the
6582 derived class destructor trows an exception. Therefore, the contracts
6583 of base class destructors will continue to be checked when contract failure
6584 handlers are programmed to throw exceptions on contract failures from
6585 destructors (yet another reason not to throw exceptions from destructors,
6586 not even because of contract failures).
6591 The contract failure handler for exception guarantees <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.except_failure">boost::contract::except_failure</link></computeroutput>
6592 should never throw (regardless of the value of its <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.from">boost::contract::from</link></computeroutput>
6593 parameter) because when <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.except_failure">boost::contract::except_failure</link></computeroutput>
6594 is called there is already an active exception on the stack, the exception
6595 that triggered the exception guarantees to be checked in the first place
6596 (throwing an exception while there is already an active exception will
6597 force program termination or lead to undefined behaviour in C++).
6602 Implementation checks can appear in any code, including destructor implementation
6603 code, so <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.check_failure">boost::contract::check_failure</link></computeroutput>
6604 should also never throw, or implementation checks should never be used
6605 in destructors otherwise these destructors will throw (note that <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.check_failure">boost::contract::check_failure</link></computeroutput>
6606 does not provide the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.from">boost::contract::from</link></computeroutput>
6607 parameter so it is not possible to differentiate from implementation
6608 checks failing from destructors instead than from other parts of the
6615 Programmers need to decide how to handle contract failures from destructors
6616 when they write custom contract failure handlers that throw exceptions
6617 instead of terminating the program (given that C++ and STL exception safety
6618 rules requires destructors to never throw). This is not a simple dilemma
6619 and it might be a good reason to terminate the program instead of throwing
6620 exceptions when assertions fail in C++ (as this library and also C-style
6621 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">assert</phrase></computeroutput> do by default).
6624 <bridgehead renderas="sect4" id="boost_contract.advanced.throw_on_failures__and__noexcept__.h0">
6625 <phrase id="boost_contract.advanced.throw_on_failures__and__noexcept__.throw_user_defined_exceptions"/><link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__.throw_user_defined_exceptions">Throw
6626 User-Defined Exceptions</link>
6629 Contract assertions can be programmed to throw <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.assertion_failure">boost::contract::assertion_failure</link></computeroutput>
6630 using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase></computeroutput><literal moreinfo="none"><emphasis>condition</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">)</phrase></computeroutput> as we have seen so far (see <link linkend="boost_contract.extras.no_macros__and_no_variadic_macros_">No
6631 Macros</link>). Alternatively, contract assertions can be programmed to throw
6632 any other exception (including user-defined exceptions) using code similar
6635 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">if</phrase><phrase role="special">(!</phrase><literal moreinfo="none"><emphasis>condition</emphasis></literal><phrase role="special">)</phrase> <phrase role="keyword">throw</phrase> <literal moreinfo="none"><emphasis>exception-object</emphasis></literal><phrase role="special">;</phrase>
6638 For example, the following precondition functor throws <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.assertion_failure">boost::contract::assertion_failure</link></computeroutput>
6639 (via <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_ASSERT">BOOST_CONTRACT_ASSERT</link></computeroutput>)
6640 on its first assertion and the user-defined exception <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">too_large_error</phrase></computeroutput>
6641 on its second assertion (both exceptions will cause this library to call
6642 the customized <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.precondition_failure">boost::contract::precondition_failure</link></computeroutput>
6643 listed above which will in turn re-throw the exceptions up the stack, see
6644 <ulink url="../../example/features/throw_on_failure.cpp"><literal moreinfo="none">throw_on_failure.cpp</literal></ulink>):
6647 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">struct</phrase> <phrase role="identifier">too_large_error</phrase> <phrase role="special">{};</phrase>
6649 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">unsigned</phrase> <phrase role="identifier">MaxSize</phrase><phrase role="special">></phrase>
6650 <phrase role="keyword">class</phrase> <phrase role="identifier">cstring</phrase>
6651 <phrase role="preprocessor">#define</phrase> <phrase role="identifier">BASES</phrase> <phrase role="keyword">private</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor_precondition</phrase><phrase role="special"><</phrase><phrase role="identifier">cstring</phrase><phrase role="special"><</phrase> <phrase role="special">\</phrase>
6652 <phrase role="identifier">MaxSize</phrase><phrase role="special">></phrase> <phrase role="special">></phrase>
6653 <phrase role="special">:</phrase> <phrase role="identifier">BASES</phrase>
6654 <phrase role="special">{</phrase>
6658 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">public</phrase><phrase role="special">:</phrase>
6659 <phrase role="comment">/* implicit */</phrase> <phrase role="identifier">cstring</phrase><phrase role="special">(</phrase><phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase><phrase role="special">*</phrase> <phrase role="identifier">chars</phrase><phrase role="special">)</phrase> <phrase role="special">:</phrase>
6660 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor_precondition</phrase><phrase role="special"><</phrase><phrase role="identifier">cstring</phrase><phrase role="special">>([&]</phrase> <phrase role="special">{</phrase>
6661 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">chars</phrase><phrase role="special">);</phrase> <phrase role="comment">// Throw `assertion_failure`.</phrase>
6662 <phrase role="comment">// Or, throw user-defined exception.</phrase>
6663 <phrase role="keyword">if</phrase><phrase role="special">(</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">strlen</phrase><phrase role="special">(</phrase><phrase role="identifier">chars</phrase><phrase role="special">)</phrase> <phrase role="special">></phrase> <phrase role="identifier">MaxSize</phrase><phrase role="special">)</phrase> <phrase role="keyword">throw</phrase> <phrase role="identifier">too_large_error</phrase><phrase role="special">();</phrase>
6664 <phrase role="special">})</phrase>
6665 <phrase role="special">{</phrase>
6669 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="comment">/* ... */</phrase>
6670 <phrase role="special">};</phrase>
6673 <bridgehead renderas="sect4" id="boost_contract.advanced.throw_on_failures__and__noexcept__.h1">
6674 <phrase id="boost_contract.advanced.throw_on_failures__and__noexcept__.exception_specifiers___code__phrase_role__keyword__noexcept__phrase___code__and__code__phrase_role__keyword__throw__phrase___code___"/><link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__.exception_specifiers___code__phrase_role__keyword__noexcept__phrase___code__and__code__phrase_role__keyword__throw__phrase___code___">Exception
6675 Specifiers (<computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">noexcept</phrase></computeroutput> and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">throw</phrase></computeroutput>`)</link>
6678 Exception specifiers <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">noexcept</phrase></computeroutput>
6679 (since C++11) and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">throw</phrase></computeroutput> (deprecated
6680 in C++11) of the enclosing function, constructor, or destructor declaring
6681 the contract correctly apply to the contract code as well. Therefore, even
6682 if the contract failure handlers are reprogrammed to throw exceptions in
6683 case of contract failures, those exceptions will never be thrown outside
6684 the context of the enclosing operation if that is not in accordance with
6685 the exception specifiers of that operation (specifically, note that all destructors
6686 are implicitly declared <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">noexcept</phrase></computeroutput>
6690 For example, the following code will correctly never throw from the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">noexcept</phrase></computeroutput> destructor, not even if the class
6691 invariants checked at destructor entry throw <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">too_large_error</phrase></computeroutput>
6692 and the contract failure handlers for invariants are programmed to throw
6693 from destructors (the program will always terminate in this case instead,
6694 see <ulink url="../../example/features/throw_on_failure.cpp"><literal moreinfo="none">throw_on_failure.cpp</literal></ulink>):
6697 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">struct</phrase> <phrase role="identifier">too_large_error</phrase> <phrase role="special">{};</phrase>
6699 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">unsigned</phrase> <phrase role="identifier">MaxSize</phrase><phrase role="special">></phrase>
6700 <phrase role="keyword">class</phrase> <phrase role="identifier">cstring</phrase>
6701 <phrase role="preprocessor">#define</phrase> <phrase role="identifier">BASES</phrase> <phrase role="keyword">private</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor_precondition</phrase><phrase role="special"><</phrase><phrase role="identifier">cstring</phrase><phrase role="special"><</phrase> <phrase role="special">\</phrase>
6702 <phrase role="identifier">MaxSize</phrase><phrase role="special">></phrase> <phrase role="special">></phrase>
6703 <phrase role="special">:</phrase> <phrase role="identifier">BASES</phrase>
6704 <phrase role="special">{</phrase>
6708 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">public</phrase><phrase role="special">:</phrase>
6709 <phrase role="keyword">void</phrase> <phrase role="identifier">invariant</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
6710 <phrase role="keyword">if</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">></phrase> <phrase role="identifier">MaxSize</phrase><phrase role="special">)</phrase> <phrase role="keyword">throw</phrase> <phrase role="identifier">too_large_error</phrase><phrase role="special">();</phrase> <phrase role="comment">// Throw user-defined ex.</phrase>
6711 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">chars_</phrase><phrase role="special">);</phrase> <phrase role="comment">// Or, throw `assertion_failure`.</phrase>
6712 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">chars_</phrase><phrase role="special">[</phrase><phrase role="identifier">size</phrase><phrase role="special">()]</phrase> <phrase role="special">==</phrase> <phrase role="char">'\0'</phrase><phrase role="special">);</phrase>
6713 <phrase role="special">}</phrase>
6715 <phrase role="special">~</phrase><phrase role="identifier">cstring</phrase><phrase role="special">()</phrase> <phrase role="keyword">noexcept</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Exception specifiers apply to contract code.</phrase>
6716 <phrase role="comment">// Check invariants.</phrase>
6717 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">destructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
6718 <phrase role="special">}</phrase>
6722 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="comment">/* ... */</phrase>
6723 <phrase role="special">};</phrase>
6727 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="comment">/* ... */</phrase>
6729 <phrase role="comment">// Warning... might cause destructors to throw (unless declared noexcept).</phrase>
6730 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">set_invariant_failure</phrase><phrase role="special">(</phrase>
6731 <phrase role="special">[]</phrase> <phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">from</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
6732 <phrase role="keyword">throw</phrase><phrase role="special">;</phrase> <phrase role="comment">// Throw no matter if from destructor, etc.</phrase>
6733 <phrase role="special">}</phrase>
6734 <phrase role="special">);</phrase>
6736 <phrase role="comment">/* ... */</phrase>
6741 <section id="boost_contract.extras">
6742 <title><link linkend="boost_contract.extras">Extras</link></title>
6744 This section can be consulted selectively for specific topics of interest.
6746 <section id="boost_contract.extras.old_value_requirements__templates_">
6747 <title><link linkend="boost_contract.extras.old_value_requirements__templates_">Old
6748 Value Requirements (Templates)</link></title>
6750 Old values require to copy the expression passed to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_OLDOF">BOOST_CONTRACT_OLDOF</link></computeroutput>
6751 thus the type of that expression needs to be copyable. More precisely, dereferencing
6752 an old value pointer of type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.old_ptr">boost::contract::old_ptr</link></computeroutput><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase></computeroutput>
6753 requires <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.is_old_value_copyable">boost::contract::is_old_value_copyable</link></computeroutput><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">>::</phrase><phrase role="identifier">value</phrase></computeroutput> to be <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">true</phrase></computeroutput>,
6754 otherwise this library will generate a compile-time error.
6757 In some cases it might be acceptable, or even desirable, to cause a compile-time
6758 error when a program uses old value types that are not copyable (because
6759 it is not possible to fully check the correctness of the program as stated
6760 by the contract assertions that use these old values). In these cases, programmers
6761 can declare old values using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.old_ptr">boost::contract::old_ptr</link></computeroutput>
6765 However, in some other cases it might be desirable to simply skip assertions
6766 that use old values when the respective old value types are not copyable,
6767 without causing compile-time errors. Programmers can do this using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.old_ptr_if_copyable">boost::contract::old_ptr_if_copyable</link></computeroutput>
6768 instead of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.old_ptr">boost::contract::old_ptr</link></computeroutput>
6769 and checking if the old value pointer is not null before dereferencing it
6770 in postconditions. For example, consider the following function template
6771 that could in general be instantiated for types <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
6772 that are not copy constructible (that is for which <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.is_old_value_copyable">boost::contract::is_old_value_copyable</link></computeroutput><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">>::</phrase><phrase role="identifier">value</phrase></computeroutput> is <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">false</phrase></computeroutput>,
6773 see <ulink url="../../example/features/old_if_copyable.cpp"><literal moreinfo="none">old_if_copyable.cpp</literal></ulink>):
6774 <footnote id="boost_contract.extras.old_value_requirements__templates_.f0">
6776 <emphasis role="bold">Rationale:</emphasis> <link linkend="N1962_anchor">[N1962]</link>
6777 and other proposals to add contracts to C++ do not provide a mechanism
6778 to selectively disable copies only for old value types that are not copy
6779 constructible. However, this library provides such a mechanism to allow
6780 to program contracts for template code without necessarily adding extra
6781 copy constructible type requirements that would not be present if it were
6782 not for copying old values (so compiling the code with and without contracts
6783 will not necessarily alter the type requirements of the program). Something
6784 similar could be achieved combing C++17 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">if</phrase>
6785 <phrase role="keyword">constexpr</phrase></computeroutput> with <link linkend="N1962_anchor">[N1962]</link>
6786 or <link linkend="P0380_anchor">[P0380]</link> so that old value expressions
6787 within template code can be guarded by <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">if</phrase>
6788 <phrase role="keyword">constexpr</phrase></computeroutput> statements checking if
6789 the old value types are copyable or not. For example, assuming old values
6790 are added to <link linkend="P0380_anchor">[P0380]</link> (using some kind
6791 of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">oldof</phrase><phrase role="special">(...)</phrase></computeroutput>
6792 syntax) and that C++17 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">if</phrase> <phrase role="keyword">constexpr</phrase></computeroutput> can be used within <link linkend="P0380_anchor">[P0380]</link>
6794 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">></phrase>
6795 <phrase role="keyword">void</phrase> <phrase role="identifier">offset</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">&</phrase> <phrase role="identifier">x</phrase><phrase role="special">,</phrase> <phrase role="keyword">int</phrase> <phrase role="identifier">count</phrase><phrase role="special">)</phrase>
6796 <phrase role="special">[[</phrase><phrase role="identifier">ensures</phrase><phrase role="special">:</phrase> <phrase role="keyword">if</phrase> <phrase role="keyword">constexpr</phrase><phrase role="special">(</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">is_copy_constructible</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">>::</phrase><phrase role="identifier">value</phrase><phrase role="special">)</phrase> <phrase role="identifier">x</phrase> <phrase role="special">==</phrase> <phrase role="identifier">oldof</phrase><phrase role="special">(</phrase><phrase role="identifier">x</phrase><phrase role="special">)</phrase> <phrase role="special">+</phrase> <phrase role="identifier">count</phrase><phrase role="special">]]</phrase>
6797 <phrase role="special">...</phrase>
6803 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">></phrase> <phrase role="comment">// T might or might not be copyable.</phrase>
6804 <phrase role="keyword">void</phrase> <phrase role="identifier">offset</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">&</phrase> <phrase role="identifier">x</phrase><phrase role="special">,</phrase> <phrase role="keyword">int</phrase> <phrase role="identifier">count</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
6805 <phrase role="comment">// No compiler error if T has no copy constructor...</phrase>
6806 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr_if_copyable</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase> <phrase role="identifier">old_x</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">x</phrase><phrase role="special">);</phrase>
6807 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">function</phrase><phrase role="special">()</phrase>
6808 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
6809 <phrase role="comment">// ...but old value null if T has no copy constructor.</phrase>
6810 <phrase role="keyword">if</phrase><phrase role="special">(</phrase><phrase role="identifier">old_x</phrase><phrase role="special">)</phrase> <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">x</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_x</phrase> <phrase role="special">+</phrase> <phrase role="identifier">count</phrase><phrase role="special">);</phrase>
6811 <phrase role="special">})</phrase>
6812 <phrase role="special">;</phrase>
6814 <phrase role="identifier">x</phrase> <phrase role="special">+=</phrase> <phrase role="identifier">count</phrase><phrase role="special">;</phrase>
6815 <phrase role="special">}</phrase>
6819 The old value pointer <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">old_x</phrase></computeroutput>
6820 is programmed using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.old_ptr_if_copyable">boost::contract::old_ptr_if_copyable</link></computeroutput>.
6821 When <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> is copyable, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.old_ptr_if_copyable">boost::contract::old_ptr_if_copyable</link></computeroutput><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase></computeroutput>
6822 behaves like <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.old_ptr">boost::contract::old_ptr</link></computeroutput><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase></computeroutput>.
6823 When <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> is not copyable instead,
6824 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.old_ptr_if_copyable">boost::contract::old_ptr_if_copyable</link></computeroutput><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase></computeroutput>
6825 will simply not copy <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">x</phrase></computeroutput> at
6826 run-time and leave <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">old_x</phrase></computeroutput>
6827 initialized to a null pointer. Therefore, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.old_ptr_if_copyable">boost::contract::old_ptr_if_copyable</link></computeroutput>
6828 objects like <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">old_x</phrase></computeroutput> must be
6829 checked to be not null as in <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">if</phrase><phrase role="special">(</phrase><phrase role="identifier">old_x</phrase><phrase role="special">)</phrase> <phrase role="special">...</phrase></computeroutput> before
6830 they are dereferenced in postconditions and exception guarantees (to avoid
6831 run-time errors of dereferencing null pointers).
6834 If the above example used <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.old_ptr">boost::contract::old_ptr</link></computeroutput>
6835 instead then this library would have generated a compile-time error when
6836 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">offset</phrase></computeroutput> is instantiated with
6837 types <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> that are not copy
6838 constructible (but only if <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">old_x</phrase></computeroutput>
6839 is actually dereferenced somewhere, for example in the contract assertions
6840 using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">*</phrase><phrase role="identifier">old_x</phrase>
6841 <phrase role="special">...</phrase></computeroutput> or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">old_x</phrase><phrase role="special">->...</phrase></computeroutput>). <footnote id="boost_contract.extras.old_value_requirements__templates_.f1">
6843 Technically, on C++17 it is possible to use <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.old_ptr">boost::contract::old_ptr</link></computeroutput>
6844 together with <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">if</phrase> <phrase role="keyword">constexpr</phrase></computeroutput>
6845 instead of using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.old_ptr_if_copyable">boost::contract::old_ptr_if_copyable</link></computeroutput>,
6847 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">></phrase>
6848 <phrase role="keyword">void</phrase> <phrase role="identifier">offset</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">&</phrase> <phrase role="identifier">x</phrase><phrase role="special">,</phrase> <phrase role="keyword">int</phrase> <phrase role="identifier">count</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
6849 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase> <phrase role="identifier">old_x</phrase><phrase role="special">;</phrase>
6850 <phrase role="keyword">if</phrase> <phrase role="keyword">constexpr</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">is_old_value_copyable</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">>::</phrase><phrase role="identifier">value</phrase><phrase role="special">)</phrase> <phrase role="identifier">old_x</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">x</phrase><phrase role="special">);</phrase>
6851 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">function</phrase><phrase role="special">()</phrase>
6852 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
6853 <phrase role="keyword">if</phrase> <phrase role="keyword">constexpr</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">is_old_value_copyable</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">>::</phrase><phrase role="identifier">value</phrase><phrase role="special">)</phrase> <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">x</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_x</phrase> <phrase role="special">+</phrase> <phrase role="identifier">count</phrase><phrase role="special">);</phrase>
6854 <phrase role="special">})</phrase>
6855 <phrase role="special">;</phrase>
6857 <phrase role="identifier">x</phrase> <phrase role="special">+=</phrase> <phrase role="identifier">count</phrase><phrase role="special">;</phrase>
6858 <phrase role="special">}</phrase>
6860 However, the authors find this code less readable and more verbose than
6861 its equivalent that uses <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.old_ptr_if_copyable">boost::contract::old_ptr_if_copyable</link></computeroutput>.
6862 Guarding old value copies and related assertions with <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">if</phrase>
6863 <phrase role="keyword">constexpr</phrase></computeroutput> is useful instead when
6864 the guard condition checks type requirements more complex than just <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.is_old_value_copyable">boost::contract::is_old_value_copyable</link></computeroutput>
6865 (as shown later in this documentation).
6870 When C++11 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">auto</phrase></computeroutput> declarations
6871 are used with <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_OLDOF">BOOST_CONTRACT_OLDOF</link></computeroutput>,
6872 this library always defaults to using the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.old_ptr">boost::contract::old_ptr</link></computeroutput>
6873 type (because its type requirements are more stringent than <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.old_ptr_if_copyable">boost::contract::old_ptr_if_copyable</link></computeroutput>).
6874 For example, the following statements are equivalent:
6876 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">auto</phrase> <phrase role="identifier">old_x</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">x</phrase><phrase role="special">);</phrase> <phrase role="comment">// C++11 auto declarations always use `old_ptr` (never `old_ptr_if_copyable`).</phrase>
6877 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">decltype</phrase><phrase role="special">(</phrase><phrase role="identifier">x</phrase><phrase role="special">)></phrase> <phrase role="identifier">old_x</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">x</phrase><phrase role="special">);</phrase>
6880 If programmers want to relax the copyable type requirement, they must do
6881 so explicitly by using the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.old_ptr_if_copyable">boost::contract::old_ptr_if_copyable</link></computeroutput>
6882 type instead of using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">auto</phrase></computeroutput> declarations.
6884 <bridgehead renderas="sect4" id="boost_contract.extras.old_value_requirements__templates_.h0">
6885 <phrase id="boost_contract.extras.old_value_requirements__templates_.old_value_type_traits"/><link linkend="boost_contract.extras.old_value_requirements__templates_.old_value_type_traits">Old
6886 Value Type Traits</link>
6889 This library uses <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.is_old_value_copyable">boost::contract::is_old_value_copyable</link></computeroutput>
6890 to determine if an old value type is copyable or not, and then <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.old_value_copy">boost::contract::old_value_copy</link></computeroutput>
6891 to actually copy the old value.
6894 By default, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.is_old_value_copyable">boost::contract::is_old_value_copyable</link></computeroutput><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase></computeroutput>
6895 is equivalent to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">is_copy_constructible</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase></computeroutput> and
6896 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.old_value_copy">boost::contract::old_value_copy</link></computeroutput><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase></computeroutput>
6897 is implemented using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>'s
6898 copy constructor. However, these type traits can be specialized by programmers
6899 for example to avoid making old value copies of types even when they have
6900 a copy constructor (maybe because these copy constructors are too expensive),
6901 or to make old value copies for types that do not have a copy constructor,
6902 or for any other specific need programmers might have for the types in question.
6905 For example, the following specialization of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.is_old_value_copyable">boost::contract::is_old_value_copyable</link></computeroutput>
6906 intentionally avoids making old value copies for all expressions of type
6907 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">w</phrase></computeroutput> even if that type has a
6908 copy constructor (see <ulink url="../../example/features/old_if_copyable.cpp"><literal moreinfo="none">old_if_copyable.cpp</literal></ulink>):
6911 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="comment">// Copyable type but...</phrase>
6912 <phrase role="keyword">class</phrase> <phrase role="identifier">w</phrase> <phrase role="special">{</phrase>
6913 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
6914 <phrase role="identifier">w</phrase><phrase role="special">(</phrase><phrase role="identifier">w</phrase> <phrase role="keyword">const</phrase><phrase role="special">&)</phrase> <phrase role="special">{</phrase> <phrase role="comment">/* Some very expensive copy operation here... */</phrase> <phrase role="special">}</phrase>
6916 <phrase role="comment">/* ... */</phrase>
6920 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="comment">// ...never copy old values for type `w` (because its copy is too expensive).</phrase>
6921 <phrase role="keyword">namespace</phrase> <phrase role="identifier">boost</phrase> <phrase role="special">{</phrase> <phrase role="keyword">namespace</phrase> <phrase role="identifier">contract</phrase> <phrase role="special">{</phrase>
6922 <phrase role="keyword">template</phrase><phrase role="special"><></phrase>
6923 <phrase role="keyword">struct</phrase> <phrase role="identifier">is_old_value_copyable</phrase><phrase role="special"><</phrase><phrase role="identifier">w</phrase><phrase role="special">></phrase> <phrase role="special">:</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">false_type</phrase> <phrase role="special">{};</phrase>
6924 <phrase role="special">}</phrase> <phrase role="special">}</phrase>
6928 On the flip side, the following specializations of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.is_old_value_copyable">boost::contract::is_old_value_copyable</link></computeroutput>
6929 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.old_value_copy">boost::contract::old_value_copy</link></computeroutput>
6930 make old value copies of expressions of type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">p</phrase></computeroutput>
6931 even if that type does not actually have a copy constructor (see <ulink url="../../example/features/old_if_copyable.cpp"><literal moreinfo="none">old_if_copyable.cpp</literal></ulink>):
6934 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="comment">// Non-copyable type but...</phrase>
6935 <phrase role="keyword">class</phrase> <phrase role="identifier">p</phrase> <phrase role="special">:</phrase> <phrase role="keyword">private</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">noncopyable</phrase> <phrase role="special">{</phrase>
6936 <phrase role="keyword">int</phrase><phrase role="special">*</phrase> <phrase role="identifier">num_</phrase><phrase role="special">;</phrase>
6938 <phrase role="keyword">friend</phrase> <phrase role="keyword">struct</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_value_copy</phrase><phrase role="special"><</phrase><phrase role="identifier">p</phrase><phrase role="special">>;</phrase>
6940 <phrase role="comment">/* ... */</phrase>
6944 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="comment">// ...still copy old values for type `p` (using a deep copy).</phrase>
6945 <phrase role="keyword">namespace</phrase> <phrase role="identifier">boost</phrase> <phrase role="special">{</phrase> <phrase role="keyword">namespace</phrase> <phrase role="identifier">contract</phrase> <phrase role="special">{</phrase>
6946 <phrase role="keyword">template</phrase><phrase role="special"><></phrase>
6947 <phrase role="keyword">struct</phrase> <phrase role="identifier">old_value_copy</phrase><phrase role="special"><</phrase><phrase role="identifier">p</phrase><phrase role="special">></phrase> <phrase role="special">{</phrase>
6948 <phrase role="keyword">explicit</phrase> <phrase role="identifier">old_value_copy</phrase><phrase role="special">(</phrase><phrase role="identifier">p</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">old</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
6949 <phrase role="special">*</phrase><phrase role="identifier">old_</phrase><phrase role="special">.</phrase><phrase role="identifier">num_</phrase> <phrase role="special">=</phrase> <phrase role="special">*</phrase><phrase role="identifier">old</phrase><phrase role="special">.</phrase><phrase role="identifier">num_</phrase><phrase role="special">;</phrase> <phrase role="comment">// Deep copy pointed value.</phrase>
6950 <phrase role="special">}</phrase>
6952 <phrase role="identifier">p</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">old</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase> <phrase role="keyword">return</phrase> <phrase role="identifier">old_</phrase><phrase role="special">;</phrase> <phrase role="special">}</phrase>
6954 <phrase role="keyword">private</phrase><phrase role="special">:</phrase>
6955 <phrase role="identifier">p</phrase> <phrase role="identifier">old_</phrase><phrase role="special">;</phrase>
6956 <phrase role="special">};</phrase>
6958 <phrase role="keyword">template</phrase><phrase role="special"><></phrase>
6959 <phrase role="keyword">struct</phrase> <phrase role="identifier">is_old_value_copyable</phrase><phrase role="special"><</phrase><phrase role="identifier">p</phrase><phrase role="special">></phrase> <phrase role="special">:</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">true_type</phrase> <phrase role="special">{};</phrase>
6960 <phrase role="special">}</phrase> <phrase role="special">}</phrase>
6964 In general, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">is_copy_constructible</phrase></computeroutput> and therefore <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.is_old_value_copyable">boost::contract::is_old_value_copyable</link></computeroutput>
6965 require C++11 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">decltype</phrase></computeroutput> and SFINAE
6966 to automatically detect if a given type is copyable or not. On non-C++11
6967 compilers, it is possible to inherit the old value type from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">noncopyable</phrase></computeroutput>, or use <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">BOOST_MOVABLE_BUT_NOT_COPYABLE</phrase></computeroutput>,
6968 or specialize <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">is_copy_constructible</phrase></computeroutput> (see <ulink url="http://www.boost.org/doc/libs/release/libs/type_traits/doc/html/boost_typetraits/reference/is_copy_constructible.html"><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">is_copy_constructible</phrase></computeroutput></ulink> documentation
6969 for more information), or just specialize <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.is_old_value_copyable">boost::contract::is_old_value_copyable</link></computeroutput>.
6970 For example, for a non-copyable type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">n</phrase></computeroutput>
6971 the following code will work also on non-C++11 compilers (see <ulink url="../../example/features/old_if_copyable.cpp"><literal moreinfo="none">old_if_copyable.cpp</literal></ulink>):
6974 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">class</phrase> <phrase role="identifier">n</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Do not want to use boost::noncopyable but...</phrase>
6975 <phrase role="keyword">int</phrase> <phrase role="identifier">num_</phrase><phrase role="special">;</phrase>
6977 <phrase role="keyword">private</phrase><phrase role="special">:</phrase>
6978 <phrase role="identifier">n</phrase><phrase role="special">(</phrase><phrase role="identifier">n</phrase> <phrase role="keyword">const</phrase><phrase role="special">&);</phrase> <phrase role="comment">// ...unimplemented private copy constructor (so non-copyable).</phrase>
6980 <phrase role="comment">/* ... */</phrase>
6984 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="comment">// Specialize `boost::is_copy_constructible` (no need for this on C++11).</phrase>
6985 <phrase role="keyword">namespace</phrase> <phrase role="identifier">boost</phrase> <phrase role="special">{</phrase> <phrase role="keyword">namespace</phrase> <phrase role="identifier">contract</phrase> <phrase role="special">{</phrase>
6986 <phrase role="keyword">template</phrase><phrase role="special"><></phrase>
6987 <phrase role="keyword">struct</phrase> <phrase role="identifier">is_old_value_copyable</phrase><phrase role="special"><</phrase><phrase role="identifier">n</phrase><phrase role="special">></phrase> <phrase role="special">:</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">false_type</phrase> <phrase role="special">{};</phrase>
6988 <phrase role="special">}</phrase> <phrase role="special">}</phrase>
6992 <section id="boost_contract.extras.assertion_requirements__templates_">
6993 <title><link linkend="boost_contract.extras.assertion_requirements__templates_">Assertion
6994 Requirements (Templates)</link></title>
6996 In general, assertions can introduce a new set of requirements on the types
6997 used by the program. Some of these type requirements might be necessary only
6998 to check the assertions and they would not be required by the program otherwise.
7001 In some cases it might be acceptable, or even desirable, to cause a compile-time
7002 error when a program uses types that do not provide all the operations needed
7003 to check contract assertions (because it is not possible to fully check the
7004 correctness of the program as specified by its contracts). In these cases,
7005 programmers can specify contract assertions as we have seen so far, compilation
7006 will fail if user types do not provide all operations necessary to check
7010 However, in some other cases it might be desirable to not augment the type
7011 requirements of a program just because of contract assertions and to simply
7012 skip assertions when user types do not provide all the operations necessary
7013 to check them, without causing compile-time errors. Programmers can do this
7014 using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">if</phrase> <phrase role="keyword">constexpr</phrase></computeroutput>
7015 on C++17 compilers, and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.condition_if">boost::contract::condition_if</link></computeroutput>
7016 (or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.condition_if_c">boost::contract::condition_if_c</link></computeroutput>)
7017 on non-C++17 compilers.
7020 For example, let's consider the following <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase></computeroutput>
7021 class template equivalent to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase></computeroutput>.
7022 C++ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase></computeroutput> does
7023 not require that its value type parameter <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
7024 has an equality operator <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">==</phrase></computeroutput>
7025 (it only requires <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> to be
7026 copy constructible, see <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase></computeroutput>
7027 documentation). However, the contracts for the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">>::</phrase><phrase role="identifier">push_back</phrase><phrase role="special">(</phrase><phrase role="identifier">value</phrase><phrase role="special">)</phrase></computeroutput>
7028 public function include a postcondition <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">back</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">value</phrase></computeroutput>
7029 that introduces the new requirement that <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
7030 must also have an equality operator <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">==</phrase></computeroutput>.
7031 Programmers can specify this postcondition as usual with <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">back</phrase><phrase role="special">()</phrase>
7032 <phrase role="special">==</phrase> <phrase role="identifier">value</phrase><phrase role="special">)</phrase></computeroutput> an let the program fail to compile when
7033 users instantiate <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase></computeroutput>
7034 with a type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> that does not
7035 provide an equality operator <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">==</phrase></computeroutput>.
7036 Otherwise, programmers can guard this postcondition using C++17 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">if</phrase> <phrase role="keyword">constexpr</phrase></computeroutput>
7037 to evaluate the asserted condition only for types <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
7038 that have an equality operator <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">==</phrase></computeroutput>
7039 and skip it otherwise. <footnote id="boost_contract.extras.assertion_requirements__templates_.f0">
7041 <emphasis role="bold">Rationale:</emphasis> <link linkend="N1962_anchor">[N1962]</link>
7042 and other proposals to add contracts to C++ do not provide a mechanism
7043 to selectively disable assertions based on their type requirements. However,
7044 this library provides such a mechanism to allow to program contracts for
7045 template code without necessarily adding extra type requirements that would
7046 not be present if it was not for the contracts (so compiling the code with
7047 and without contracts will not alter the type requirements of the program).
7048 Something similar could be achieved combing C++17 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">if</phrase>
7049 <phrase role="keyword">constexpr</phrase></computeroutput> with <link linkend="N1962_anchor">[N1962]</link>
7050 or <link linkend="P0380_anchor">[P0380]</link> so that contract assertions
7051 within template code could be guarded by <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">if</phrase>
7052 <phrase role="keyword">constexpr</phrase></computeroutput> statements checking the
7053 related type requirements (<link linkend="N1962_anchor">[N1962]</link>
7054 already allows of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">if</phrase></computeroutput> statements
7055 in contracts under the name of <emphasis>select assertions</emphasis>,
7056 <link linkend="P0380_anchor">[P0380]</link> does not so probably <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">if</phrase></computeroutput> statements should be added to <link linkend="P0380_anchor">[P0380]</link>
7057 as well). For example, assuming C++17 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">if</phrase>
7058 <phrase role="keyword">constexpr</phrase></computeroutput> can be used within <link linkend="P0380_anchor">[P0380]</link> contracts:
7059 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">></phrase>
7060 <phrase role="keyword">class</phrase> <phrase role="identifier">vector</phrase> <phrase role="special">{</phrase>
7061 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
7062 <phrase role="keyword">void</phrase> <phrase role="identifier">push_back</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">value</phrase><phrase role="special">)</phrase>
7063 <phrase role="special">[[</phrase><phrase role="identifier">ensures</phrase><phrase role="special">:</phrase> <phrase role="keyword">if</phrase> <phrase role="keyword">constexpr</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">has_equal_to</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">>::</phrase><phrase role="identifier">value</phrase><phrase role="special">)</phrase> <phrase role="identifier">back</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">value</phrase><phrase role="special">]]</phrase>
7064 <phrase role="special">...</phrase>
7065 <phrase role="special">};</phrase>
7068 </footnote> For example:
7070 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">></phrase>
7071 <phrase role="keyword">class</phrase> <phrase role="identifier">vector</phrase> <phrase role="special">{</phrase>
7072 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
7073 <phrase role="keyword">void</phrase> <phrase role="identifier">push_back</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">value</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
7074 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boot</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
7075 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
7076 <phrase role="comment">// Guard with `if constexpr` for T without `==`.</phrase>
7077 <phrase role="keyword">if</phrase> <phrase role="keyword">constexpr</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">has_equal_to</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">>::</phrase><phrase role="identifier">value</phrase><phrase role="special">)</phrase>
7078 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">back</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">value</phrase><phrase role="special">);</phrase>
7079 <phrase role="special">})</phrase>
7080 <phrase role="special">;</phrase>
7082 <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">push_back</phrase><phrase role="special">(</phrase><phrase role="identifier">value</phrase><phrase role="special">);</phrase>
7083 <phrase role="special">}</phrase>
7085 <phrase role="comment">/* ... */</phrase>
7088 More in general, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">if</phrase> <phrase role="keyword">constexpr</phrase></computeroutput>
7089 can be used to guard a mix of both old value copies and contract assertions
7090 that introduce specific extra type requirements. For example, the following
7091 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">swap</phrase></computeroutput> function can be called
7092 on any type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> that is movable
7093 but its old value copies and postcondition assertions are evaluated only
7094 for types <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> that are also
7095 copyable and have an equality operator <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">==</phrase></computeroutput>
7096 (see <ulink url="../../example/features/if_constexpr.cpp"><literal moreinfo="none">if_constexpr.cpp</literal></ulink>):
7099 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">></phrase>
7100 <phrase role="keyword">void</phrase> <phrase role="identifier">swap</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">&</phrase> <phrase role="identifier">x</phrase><phrase role="special">,</phrase> <phrase role="identifier">T</phrase><phrase role="special">&</phrase> <phrase role="identifier">y</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
7101 <phrase role="keyword">constexpr</phrase> <phrase role="keyword">bool</phrase> <phrase role="identifier">b</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">is_old_value_copyable</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">>::</phrase><phrase role="identifier">value</phrase> <phrase role="special">&&</phrase>
7102 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">has_equal_to</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">>::</phrase><phrase role="identifier">value</phrase><phrase role="special">;</phrase>
7103 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase> <phrase role="identifier">old_x</phrase><phrase role="special">,</phrase> <phrase role="identifier">old_y</phrase><phrase role="special">;</phrase>
7104 <phrase role="keyword">if</phrase> <phrase role="keyword">constexpr</phrase><phrase role="special">(</phrase><phrase role="identifier">b</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Contract requires copyable T...</phrase>
7105 <phrase role="identifier">old_x</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">x</phrase><phrase role="special">);</phrase>
7106 <phrase role="identifier">old_y</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">y</phrase><phrase role="special">);</phrase>
7107 <phrase role="special">}</phrase>
7108 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">function</phrase><phrase role="special">()</phrase>
7109 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
7110 <phrase role="keyword">if</phrase> <phrase role="keyword">constexpr</phrase><phrase role="special">(</phrase><phrase role="identifier">b</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase> <phrase role="comment">// ... and T with `==`...</phrase>
7111 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">x</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_y</phrase><phrase role="special">);</phrase>
7112 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">y</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_x</phrase><phrase role="special">);</phrase>
7113 <phrase role="special">}</phrase>
7114 <phrase role="special">})</phrase>
7115 <phrase role="special">;</phrase>
7117 <phrase role="identifier">T</phrase> <phrase role="identifier">t</phrase> <phrase role="special">=</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">move</phrase><phrase role="special">(</phrase><phrase role="identifier">x</phrase><phrase role="special">);</phrase> <phrase role="comment">// ...but body only requires movable T.</phrase>
7118 <phrase role="identifier">x</phrase> <phrase role="special">=</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">move</phrase><phrase role="special">(</phrase><phrase role="identifier">y</phrase><phrase role="special">);</phrase>
7119 <phrase role="identifier">y</phrase> <phrase role="special">=</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">move</phrase><phrase role="special">(</phrase><phrase role="identifier">t</phrase><phrase role="special">);</phrase>
7120 <phrase role="special">}</phrase>
7123 <bridgehead renderas="sect4" id="boost_contract.extras.assertion_requirements__templates_.h0">
7124 <phrase id="boost_contract.extras.assertion_requirements__templates_.no__code__phrase_role__keyword__if__phrase___phrase_role__keyword__constexpr__phrase___code___no_c__17_"/><link linkend="boost_contract.extras.assertion_requirements__templates_.no__code__phrase_role__keyword__if__phrase___phrase_role__keyword__constexpr__phrase___code___no_c__17_">No
7125 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">if</phrase> <phrase role="keyword">constexpr</phrase></computeroutput>
7129 On non-C++17 compilers where <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">if</phrase> <phrase role="keyword">constexpr</phrase></computeroutput> is not available, it is possible
7130 to use <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.condition_if">boost::contract::condition_if</link></computeroutput>
7131 to skip assertions based on type requirements (even if this code is less
7132 readable and more verbose than using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">if</phrase>
7133 <phrase role="keyword">constexpr</phrase></computeroutput>). For example (see <ulink url="../../example/features/condition_if.cpp"><literal moreinfo="none">condition_if.cpp</literal></ulink>):
7136 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">></phrase>
7137 <phrase role="keyword">class</phrase> <phrase role="identifier">vector</phrase> <phrase role="special">{</phrase>
7138 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
7139 <phrase role="keyword">void</phrase> <phrase role="identifier">push_back</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">value</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
7140 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
7141 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
7142 <phrase role="comment">// Instead of `ASSERT(back() == value)` for T without `==`.</phrase>
7143 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase>
7144 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">condition_if</phrase><phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">has_equal_to</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase> <phrase role="special">>(</phrase>
7145 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">bind</phrase><phrase role="special">(</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">equal_to</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">>(),</phrase>
7146 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">cref</phrase><phrase role="special">(</phrase><phrase role="identifier">back</phrase><phrase role="special">()),</phrase>
7147 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">cref</phrase><phrase role="special">(</phrase><phrase role="identifier">value</phrase><phrase role="special">)</phrase>
7148 <phrase role="special">)</phrase>
7149 <phrase role="special">)</phrase>
7150 <phrase role="special">);</phrase>
7151 <phrase role="special">})</phrase>
7152 <phrase role="special">;</phrase>
7154 <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">push_back</phrase><phrase role="special">(</phrase><phrase role="identifier">value</phrase><phrase role="special">);</phrase>
7155 <phrase role="special">}</phrase>
7157 <phrase role="comment">/* ... */</phrase>
7161 More in general, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.condition_if">boost::contract::condition_if</link></computeroutput>
7164 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">condition_if</phrase><phrase role="special"><</phrase><phrase role="identifier">Pred</phrase><phrase role="special">>(</phrase>
7165 <phrase role="identifier">cond</phrase>
7166 <phrase role="special">)</phrase>
7169 Where <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Pred</phrase></computeroutput> is a nullary boolean
7170 meta-function and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">cond</phrase></computeroutput> is
7171 a nullary boolean functor. If <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Pred</phrase><phrase role="special">::</phrase><phrase role="identifier">value</phrase></computeroutput>
7172 is statically evaluated to be <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">true</phrase></computeroutput>
7173 at compile-time then <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">cond</phrase><phrase role="special">()</phrase></computeroutput> is called at run-time and its boolean result
7174 is returned by the enclosing <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.condition_if">boost::contract::condition_if</link></computeroutput>
7175 call. Otherwise, if <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Pred</phrase><phrase role="special">::</phrase><phrase role="identifier">value</phrase></computeroutput>
7176 is statically evaluated to be <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">false</phrase></computeroutput>
7177 at compile-time then <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.condition_if">boost::contract::condition_if</link></computeroutput>
7178 trivially returns <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">true</phrase></computeroutput>. Therefore,
7179 if <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">cond</phrase></computeroutput> is a functor template
7180 instantiation (not just a functor) then its call that contains the assertion
7181 operations with the extra type requirements (e.g., the equality operator
7182 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">==</phrase></computeroutput>) will not be actually instantiated
7183 and compiled unless the compiler determines at compile-time that <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Pred</phrase><phrase role="special">::</phrase><phrase role="identifier">value</phrase></computeroutput> is <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">true</phrase></computeroutput>
7184 (when used this way, functor templates like <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">equal_to</phrase></computeroutput>
7185 and C++14 generic lambdas can be used to program <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">cond</phrase></computeroutput>,
7186 but C++11 lambdas cannot).
7189 The <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.condition_if">boost::contract::condition_if</link></computeroutput>
7190 function template is a special case of the more general <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.call_if">boost::contract::call_if</link></computeroutput>,
7191 specifically <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.condition_if">boost::contract::condition_if</link></computeroutput><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special"><</phrase><phrase role="identifier">Pred</phrase><phrase role="special">>(</phrase><phrase role="identifier">cond</phrase><phrase role="special">)</phrase></computeroutput> is logically equivalent to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.call_if">boost::contract::call_if</link></computeroutput><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special"><</phrase><phrase role="identifier">Pred</phrase><phrase role="special">>(</phrase><phrase role="identifier">cond</phrase><phrase role="special">).</phrase><phrase role="identifier">else_</phrase><phrase role="special">([]</phrase> <phrase role="special">{</phrase> <phrase role="keyword">return</phrase>
7192 <phrase role="keyword">true</phrase><phrase role="special">;</phrase> <phrase role="special">})</phrase></computeroutput>. <footnote id="boost_contract.extras.assertion_requirements__templates_.f1">
7194 The internal implementation of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.condition_if">boost::contract::condition_if</link></computeroutput>
7195 is optimized and it does not actually use <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.call_if">boost::contract::call_if</link></computeroutput>.
7197 </footnote> The <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.call_if">boost::contract::call_if</link></computeroutput>
7198 function template also accepts a number of optional <emphasis>else-if</emphasis>
7199 statements and one optional <emphasis>else</emphasis> statement:
7201 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">call_if</phrase><phrase role="special"><</phrase><phrase role="identifier">Pred1</phrase><phrase role="special">>(</phrase>
7202 <phrase role="identifier">t1</phrase>
7203 <phrase role="special">).</phrase><phrase role="keyword">template</phrase> <phrase role="identifier">else_if</phrase><phrase role="special"><</phrase><phrase role="identifier">Pred2</phrase><phrase role="special">>(</phrase> <phrase role="comment">// Optional.</phrase>
7204 <phrase role="identifier">t2</phrase>
7205 <phrase role="special">)</phrase>
7206 <phrase role="special">...</phrase> <phrase role="comment">// Optionally, other `else_if` statements.</phrase>
7207 <phrase role="special">.</phrase><phrase role="identifier">else_</phrase><phrase role="special">(</phrase> <phrase role="comment">// Optional for `void` functors, otherwise required.</phrase>
7208 <phrase role="identifier">e</phrase>
7209 <phrase role="special">)</phrase>
7212 Where <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Pred1</phrase></computeroutput>, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Pred2</phrase></computeroutput>, ... are nullary boolean meta-functions
7213 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">t1</phrase></computeroutput>, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">t2</phrase></computeroutput>,
7214 ..., <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">e</phrase></computeroutput> are nullary functors.
7215 The return types of the functor calls <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">t1</phrase><phrase role="special">()</phrase></computeroutput>, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">t2</phrase><phrase role="special">()</phrase></computeroutput>, ..., <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">e</phrase><phrase role="special">()</phrase></computeroutput> must either be all the same (including
7216 possibly all <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">void</phrase></computeroutput>) or be of
7217 types implicitly convertible into one another. At run-time <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.call_if">boost::contract::call_if</link></computeroutput> will
7218 call the functor <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">t1</phrase><phrase role="special">()</phrase></computeroutput>,
7219 or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">t2</phrase><phrase role="special">()</phrase></computeroutput>,
7220 ..., or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">e</phrase><phrase role="special">()</phrase></computeroutput>
7221 depending on which meta-function <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Pred1</phrase><phrase role="special">::</phrase><phrase role="identifier">value</phrase></computeroutput>,
7222 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Pred2</phrase><phrase role="special">::</phrase><phrase role="identifier">value</phrase></computeroutput>, ... is statically evaluated to be
7223 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">true</phrase></computeroutput> or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">false</phrase></computeroutput>
7224 at compile-time, and it will return the value returned by the functor being
7225 called. If <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">t1</phrase></computeroutput>, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">t2</phrase></computeroutput>, ..., <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">e</phrase></computeroutput>
7226 are functor template instantiations (not just functors) then their code will
7227 only be compiled if the compiler determines they need to be actually called
7228 at run-time (so only if the related <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Pred1</phrase><phrase role="special">::</phrase><phrase role="identifier">value</phrase></computeroutput>,
7229 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Pred2</phrase><phrase role="special">::</phrase><phrase role="identifier">value</phrase></computeroutput>, ... are respectively evaluated to
7230 be <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">true</phrase></computeroutput> or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">false</phrase></computeroutput>
7231 at compile-time). All the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">else_if</phrase><phrase role="special"><...>(...)</phrase></computeroutput> statements are optional.
7232 The <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">else_</phrase><phrase role="special">(...)</phrase></computeroutput>
7233 statement is optional if the functor calls return <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">void</phrase></computeroutput>,
7234 otherwise it is required.
7237 In general, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.call_if">boost::contract::call_if</link></computeroutput>
7238 can be used to program contract assertions that compile and check different
7239 functor templates depending on related predicates being statically evaluated
7240 to be <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">true</phrase></computeroutput> or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">false</phrase></computeroutput> at compile-time (but in most cases
7241 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.condition_if">boost::contract::condition_if</link></computeroutput>
7242 should be sufficient and less verbose to use). The <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.condition_if_c">boost::contract::condition_if_c</link></computeroutput>,
7243 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.call_if_c">boost::contract::call_if_c</link></computeroutput>,
7244 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">else_if_c</phrase></computeroutput>
7245 function templates work similarly to their counterparts without the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">...</phrase><phrase role="identifier">_c</phrase></computeroutput> postfix
7246 seen so far, but they take their predicate template parameters as static
7247 boolean values instead of nullary boolean meta-functions.
7250 On compilers that support C++17 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">if</phrase>
7251 <phrase role="keyword">constexpr</phrase></computeroutput> there should be no need
7252 to use <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.condition_if">boost::contract::condition_if</link></computeroutput>
7253 or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.call_if">boost::contract::call_if</link></computeroutput>
7254 because <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">if</phrase> <phrase role="keyword">constexpr</phrase></computeroutput>
7255 can be used instead (making the code more readable and easier to program).
7256 <footnote id="boost_contract.extras.assertion_requirements__templates_.f2">
7259 A part from its use within contracts, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.call_if">boost::contract::call_if</link></computeroutput>
7260 can be used together with C++14 generic lambdas to emulate C++17 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">if</phrase> <phrase role="keyword">constexpr</phrase></computeroutput>
7261 (<computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">hana</phrase><phrase role="special">::</phrase><phrase role="identifier">if_</phrase></computeroutput> and probably other approaches can
7262 also be used together with generic lambdas to emulate C++17 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">if</phrase> <phrase role="keyword">constexpr</phrase></computeroutput>
7263 on C++14 compilers). For example, the following implementation of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">myadvance</phrase></computeroutput> will compile since C++14
7264 and it is more concise, easier to read and maintain than the usual implementation
7265 of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">advance</phrase></computeroutput> that uses tag dispatching (see
7266 <ulink url="../../example/features/call_if_cxx14.cpp"><literal moreinfo="none">call_if_cxx14.cpp</literal></ulink>):
7269 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">Iter</phrase><phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">Dist</phrase><phrase role="special">></phrase>
7270 <phrase role="keyword">void</phrase> <phrase role="identifier">myadvance</phrase><phrase role="special">(</phrase><phrase role="identifier">Iter</phrase><phrase role="special">&</phrase> <phrase role="identifier">i</phrase><phrase role="special">,</phrase> <phrase role="identifier">Dist</phrase> <phrase role="identifier">n</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
7271 <phrase role="identifier">Iter</phrase><phrase role="special">*</phrase> <phrase role="identifier">p</phrase> <phrase role="special">=</phrase> <phrase role="special">&</phrase><phrase role="identifier">i</phrase><phrase role="special">;</phrase> <phrase role="comment">// So captures change actual pointed iterator value.</phrase>
7272 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">call_if</phrase><phrase role="special"><</phrase><phrase role="identifier">is_random_access_iterator</phrase><phrase role="special"><</phrase><phrase role="identifier">Iter</phrase><phrase role="special">></phrase> <phrase role="special">>(</phrase>
7273 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">bind</phrase><phrase role="special">([]</phrase> <phrase role="special">(</phrase><phrase role="keyword">auto</phrase> <phrase role="identifier">p</phrase><phrase role="special">,</phrase> <phrase role="keyword">auto</phrase> <phrase role="identifier">n</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase> <phrase role="comment">// C++14 generic lambda.</phrase>
7274 <phrase role="special">*</phrase><phrase role="identifier">p</phrase> <phrase role="special">+=</phrase> <phrase role="identifier">n</phrase><phrase role="special">;</phrase>
7275 <phrase role="special">},</phrase> <phrase role="identifier">p</phrase><phrase role="special">,</phrase> <phrase role="identifier">n</phrase><phrase role="special">)</phrase>
7276 <phrase role="special">).</phrase><phrase role="keyword">template</phrase> <phrase role="identifier">else_if</phrase><phrase role="special"><</phrase><phrase role="identifier">is_bidirectional_iterator</phrase><phrase role="special"><</phrase><phrase role="identifier">Iter</phrase><phrase role="special">></phrase> <phrase role="special">>(</phrase>
7277 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">bind</phrase><phrase role="special">([]</phrase> <phrase role="special">(</phrase><phrase role="keyword">auto</phrase> <phrase role="identifier">p</phrase><phrase role="special">,</phrase> <phrase role="keyword">auto</phrase> <phrase role="identifier">n</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
7278 <phrase role="keyword">if</phrase><phrase role="special">(</phrase><phrase role="identifier">n</phrase> <phrase role="special">>=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="keyword">while</phrase><phrase role="special">(</phrase><phrase role="identifier">n</phrase><phrase role="special">--)</phrase> <phrase role="special">++*</phrase><phrase role="identifier">p</phrase><phrase role="special">;</phrase>
7279 <phrase role="keyword">else</phrase> <phrase role="keyword">while</phrase><phrase role="special">(</phrase><phrase role="identifier">n</phrase><phrase role="special">++)</phrase> <phrase role="special">--*</phrase><phrase role="identifier">p</phrase><phrase role="special">;</phrase>
7280 <phrase role="special">},</phrase> <phrase role="identifier">p</phrase><phrase role="special">,</phrase> <phrase role="identifier">n</phrase><phrase role="special">)</phrase>
7281 <phrase role="special">).</phrase><phrase role="keyword">template</phrase> <phrase role="identifier">else_if</phrase><phrase role="special"><</phrase><phrase role="identifier">is_input_iterator</phrase><phrase role="special"><</phrase><phrase role="identifier">Iter</phrase><phrase role="special">></phrase> <phrase role="special">>(</phrase>
7282 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">bind</phrase><phrase role="special">([]</phrase> <phrase role="special">(</phrase><phrase role="keyword">auto</phrase> <phrase role="identifier">p</phrase><phrase role="special">,</phrase> <phrase role="keyword">auto</phrase> <phrase role="identifier">n</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
7283 <phrase role="keyword">while</phrase><phrase role="special">(</phrase><phrase role="identifier">n</phrase><phrase role="special">--)</phrase> <phrase role="special">++*</phrase><phrase role="identifier">p</phrase><phrase role="special">;</phrase>
7284 <phrase role="special">},</phrase> <phrase role="identifier">p</phrase><phrase role="special">,</phrase> <phrase role="identifier">n</phrase><phrase role="special">)</phrase>
7285 <phrase role="special">).</phrase><phrase role="identifier">else_</phrase><phrase role="special">(</phrase>
7286 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">bind</phrase><phrase role="special">([]</phrase> <phrase role="special">(</phrase><phrase role="keyword">auto</phrase> <phrase role="identifier">false_</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
7287 <phrase role="keyword">static_assert</phrase><phrase role="special">(</phrase><phrase role="identifier">false_</phrase><phrase role="special">,</phrase> <phrase role="string">"requires at least input iterator"</phrase><phrase role="special">);</phrase>
7288 <phrase role="special">},</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">false_type</phrase><phrase role="special">())</phrase> <phrase role="comment">// Use constexpr value.</phrase>
7289 <phrase role="special">);</phrase>
7290 <phrase role="special">}</phrase>
7294 Of course, since C++17 the implementation that uses <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">if</phrase>
7295 <phrase role="keyword">constexpr</phrase></computeroutput> is even more readable
7297 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">Iter</phrase><phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">Dist</phrase><phrase role="special">></phrase>
7298 <phrase role="keyword">void</phrase> <phrase role="identifier">myadvance</phrase><phrase role="special">(</phrase><phrase role="identifier">Iter</phrase><phrase role="special">&</phrase> <phrase role="identifier">i</phrase><phrase role="special">,</phrase> <phrase role="identifier">Dist</phrase> <phrase role="identifier">n</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
7299 <phrase role="keyword">if</phrase> <phrase role="keyword">constexpr</phrase><phrase role="special">(</phrase><phrase role="identifier">is_random_access_iterator</phrase><phrase role="special"><</phrase><phrase role="identifier">Iter</phrase><phrase role="special">>::</phrase><phrase role="identifier">value</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
7300 <phrase role="identifier">i</phrase> <phrase role="special">+=</phrase> <phrase role="identifier">n</phrase><phrase role="special">;</phrase>
7301 <phrase role="special">}</phrase> <phrase role="keyword">else</phrase> <phrase role="keyword">if</phrase> <phrase role="keyword">constexpr</phrase><phrase role="special">(</phrase><phrase role="identifier">is_bidirectional_iterator</phrase><phrase role="special"><</phrase><phrase role="identifier">Iter</phrase><phrase role="special">>::</phrase><phrase role="identifier">value</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
7302 <phrase role="keyword">if</phrase><phrase role="special">(</phrase><phrase role="identifier">n</phrase> <phrase role="special">>=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="keyword">while</phrase><phrase role="special">(</phrase><phrase role="identifier">n</phrase><phrase role="special">--)</phrase> <phrase role="special">++</phrase><phrase role="identifier">i</phrase><phrase role="special">;</phrase>
7303 <phrase role="keyword">else</phrase> <phrase role="keyword">while</phrase><phrase role="special">(</phrase><phrase role="identifier">n</phrase><phrase role="special">++)</phrase> <phrase role="special">--</phrase><phrase role="identifier">i</phrase><phrase role="special">;</phrase>
7304 <phrase role="special">}</phrase> <phrase role="keyword">else</phrase> <phrase role="keyword">if</phrase> <phrase role="keyword">constexpr</phrase><phrase role="special">(</phrase><phrase role="identifier">is_input_iterator</phrase><phrase role="special"><</phrase><phrase role="identifier">Iter</phrase><phrase role="special">>::</phrase><phrase role="identifier">value</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
7305 <phrase role="keyword">while</phrase><phrase role="special">(</phrase><phrase role="identifier">n</phrase><phrase role="special">--)</phrase> <phrase role="special">++</phrase><phrase role="identifier">i</phrase><phrase role="special">;</phrase>
7306 <phrase role="special">}</phrase> <phrase role="keyword">else</phrase> <phrase role="special">{</phrase>
7307 <phrase role="keyword">static_assert</phrase><phrase role="special">(</phrase><phrase role="keyword">false</phrase><phrase role="special">,</phrase> <phrase role="string">"requires at least input iterator"</phrase><phrase role="special">);</phrase>
7308 <phrase role="special">}</phrase>
7309 <phrase role="special">}</phrase>
7316 <section id="boost_contract.extras.volatile_public_functions">
7317 <title><link linkend="boost_contract.extras.volatile_public_functions">Volatile
7318 Public Functions</link></title>
7320 This library allows to specify a different set of class invariants to check
7321 for volatile public functions. These <emphasis>volatile class invariants</emphasis>
7322 are programmed in a public <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase></computeroutput> function, named <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">invariant</phrase></computeroutput>,
7323 taking no argument, and returning <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">void</phrase></computeroutput>
7324 (see <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394999724496">BOOST_CONTRACT_INVARIANT_FUNC</link></computeroutput>
7325 to name the invariant function differently from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">invariant</phrase></computeroutput>
7326 and <link linkend="boost_contract.advanced.access_specifiers">Access Specifiers</link>
7327 to not have to declare it <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">public</phrase></computeroutput>).
7328 Classes that do no have invariants for their volatile public functions, simply
7329 do not declare the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">void</phrase> <phrase role="identifier">invariant</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase></computeroutput> function.
7332 In general, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase></computeroutput>
7333 invariants work the same as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase></computeroutput>
7334 invariants (see <link linkend="boost_contract.tutorial.class_invariants">Class
7335 Invariants</link>) with the only difference that <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">volatile</phrase></computeroutput>
7336 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase></computeroutput>
7337 functions check <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase></computeroutput>
7338 invariants while non-<computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase></computeroutput> (i.e.,
7339 neither <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase></computeroutput> nor <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">volatile</phrase></computeroutput>) and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase></computeroutput>
7340 functions check <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase></computeroutput> invariants.
7341 A given class can specify any combination of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">static</phrase></computeroutput>,
7342 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase></computeroutput>,
7343 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase></computeroutput> invariant functions
7344 (see <link linkend="boost_contract.tutorial.class_invariants">Class Invariants</link>):
7345 <footnote id="boost_contract.extras.volatile_public_functions.f0">
7347 <emphasis role="bold">Rationale:</emphasis> Constructors and destructors
7348 check <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase></computeroutput>
7349 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase></computeroutput> invariants in that
7350 order because the qualifier that can be applied to more calls is checked
7351 first (note that <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase></computeroutput>
7352 calls can be made on any object while <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase></computeroutput>
7353 calls cannot be made on <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">volatile</phrase></computeroutput>
7354 objects, in that sense the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase>
7355 <phrase role="keyword">volatile</phrase></computeroutput> qualifier can be applied
7356 to more calls than <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase></computeroutput> alone
7357 can). This is consistent with <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">static</phrase></computeroutput>
7358 class invariants that are checked even before <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase>
7359 <phrase role="keyword">volatile</phrase></computeroutput> invariants (the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">static</phrase></computeroutput> classifier can be applied to even
7360 more calls than <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase></computeroutput>,
7361 in fact an object is not even needed to make static calls).
7368 Constructors check <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">static</phrase></computeroutput>
7369 invariants at entry and exit (even if an exception is thrown), plus
7370 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase></computeroutput>
7371 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase></computeroutput> invariants in
7372 that order at exit but only if no exception is thrown.
7377 Destructors check <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">static</phrase></computeroutput>
7378 invariants at entry and exit (even if an exception is thrown), plus
7379 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase></computeroutput>
7380 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase></computeroutput> invariants in
7381 that order at entry (and at exit but only if an exception is thrown,
7382 even is destructors should in general never throw in C++).
7387 Both non-<computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase></computeroutput> and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase></computeroutput> public functions check <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">static</phrase></computeroutput> and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase></computeroutput>
7388 invariants at entry and at exit (even if an exception is thrown).
7393 Both <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">volatile</phrase></computeroutput> and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase></computeroutput>
7394 public functions check <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">static</phrase></computeroutput>
7395 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase></computeroutput>
7396 invariants at entry and at exit (even if an exception is thrown).
7401 These rules ensure that volatile class invariants are correctly checked (see
7402 <link linkend="boost_contract.contract_programming_overview.constructor_calls">Constructor
7403 Calls</link>, <link linkend="boost_contract.contract_programming_overview.destructor_calls">Destructor
7404 Calls</link>, and <link linkend="boost_contract.contract_programming_overview.public_function_calls">Public
7405 Function Calls</link>). For example (see <ulink url="../../example/features/volatile.cpp"><literal moreinfo="none">volatile.cpp</literal></ulink>):
7408 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">class</phrase> <phrase role="identifier">u</phrase> <phrase role="special">{</phrase>
7409 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
7410 <phrase role="keyword">static</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">static_invariant</phrase><phrase role="special">();</phrase> <phrase role="comment">// Static invariants.</phrase>
7411 <phrase role="keyword">void</phrase> <phrase role="identifier">invariant</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">;</phrase> <phrase role="comment">// Volatile invariants.</phrase>
7412 <phrase role="keyword">void</phrase> <phrase role="identifier">invariant</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase><phrase role="special">;</phrase> <phrase role="comment">// Const invariants.</phrase>
7414 <phrase role="identifier">u</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Check static, volatile, and const invariants.</phrase>
7415 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase><phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
7416 <phrase role="special">}</phrase>
7418 <phrase role="special">~</phrase><phrase role="identifier">u</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Check static, volatile, and const invariants.</phrase>
7419 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">destructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
7420 <phrase role="special">}</phrase>
7422 <phrase role="keyword">void</phrase> <phrase role="identifier">nc</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Check static and const invariants.</phrase>
7423 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
7424 <phrase role="special">}</phrase>
7426 <phrase role="keyword">void</phrase> <phrase role="identifier">c</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Check static and const invariants.</phrase>
7427 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
7428 <phrase role="special">}</phrase>
7430 <phrase role="keyword">void</phrase> <phrase role="identifier">v</phrase><phrase role="special">()</phrase> <phrase role="keyword">volatile</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Check static and volatile invariants.</phrase>
7431 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
7432 <phrase role="special">}</phrase>
7434 <phrase role="keyword">void</phrase> <phrase role="identifier">cv</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Check static and volatile invariants.</phrase>
7435 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
7436 <phrase role="special">}</phrase>
7438 <phrase role="keyword">static</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">s</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Check static invariants only.</phrase>
7439 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special"><</phrase><phrase role="identifier">u</phrase><phrase role="special">>();</phrase>
7440 <phrase role="special">}</phrase>
7441 <phrase role="special">};</phrase>
7445 This library does not automatically check <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase>
7446 <phrase role="keyword">volatile</phrase></computeroutput> invariants for non-<computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">volatile</phrase></computeroutput> functions. However, if the contract
7447 specifications require it, programmers can explicitly call the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase></computeroutput>
7448 invariant function from the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase></computeroutput>
7449 invariant function (preferably in that order to be consistent with the order
7450 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase></computeroutput>
7451 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase></computeroutput> invariants are checked
7452 for constructors and destructors). That way all public functions, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">volatile</phrase></computeroutput> or not, will check <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase></computeroutput>
7453 invariants (while only <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase></computeroutput>
7454 and non-<computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase></computeroutput> public functions
7455 will check only <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase></computeroutput> invariants,
7456 correctly so because the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">volatile</phrase></computeroutput>
7457 qualifier shall not be stripped away): <footnote id="boost_contract.extras.volatile_public_functions.f1">
7459 <emphasis role="bold">Rationale:</emphasis> Note that while all public
7460 functions can be made to check <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase>
7461 <phrase role="keyword">volatile</phrase></computeroutput> invariants, it is never
7462 possible to make volatile public functions check <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase></computeroutput>
7463 non-volatile invariants. That is because both <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase></computeroutput>
7464 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">volatile</phrase></computeroutput> can always be
7465 added but never stripped in C++ (a part from forcefully via <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const_cast</phrase></computeroutput>) but <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase></computeroutput>
7466 is always automatically added by this library in order to enforce contract
7467 constant-correctness (see <link linkend="boost_contract.contract_programming_overview.constant_correctness">Constant-Correctness</link>).
7468 That said, it would be too stringent for this library to also automatically
7469 add <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">volatile</phrase></computeroutput> and require all
7470 functions to check <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase></computeroutput> (not just <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase></computeroutput>)
7471 invariants because only <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">volatile</phrase></computeroutput>
7472 members can be accessed from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase>
7473 <phrase role="keyword">volatile</phrase></computeroutput> invariants so there could
7474 be many <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase></computeroutput> (but not <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase></computeroutput>)
7475 members that are accessible from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase></computeroutput>
7476 invariants but not from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase></computeroutput> invariants. To avoid this confusion,
7477 this library has chosen to draw a clear dichotomy between <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase></computeroutput> and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase>
7478 <phrase role="keyword">volatile</phrase></computeroutput> invariants so that only
7479 volatile public functions check <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase>
7480 <phrase role="keyword">volatile</phrase></computeroutput> invariants and only non-volatile
7481 public functions check <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase></computeroutput>
7482 (but not <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase></computeroutput>)
7483 invariants. This is a clear distinction and it should serve most cases.
7484 If programmers need non-volatile public functions to also check <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase></computeroutput>
7485 invariants, they can explicitly do so by calling the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase>
7486 <phrase role="keyword">volatile</phrase></computeroutput> invariant function from
7487 the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase></computeroutput> invariant function
7488 as shown in this documentation.
7492 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">class</phrase> <phrase role="identifier">u</phrase> <phrase role="special">{</phrase>
7493 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
7494 <phrase role="keyword">void</phrase> <phrase role="identifier">invariant</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase> <phrase role="special">{</phrase> <phrase role="special">...</phrase> <phrase role="special">}</phrase> <phrase role="comment">// Volatile invariants.</phrase>
7496 <phrase role="keyword">void</phrase> <phrase role="identifier">invariant</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
7497 <phrase role="keyword">auto</phrase> <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">*</phrase> <phrase role="identifier">cv</phrase> <phrase role="special">=</phrase> <phrase role="keyword">this</phrase><phrase role="special">;</phrase> <phrase role="identifier">cv</phrase><phrase role="special">-></phrase><phrase role="identifier">invariant</phrase><phrase role="special">();</phrase> <phrase role="comment">// Call `const volatile` invariant function above.</phrase>
7498 <phrase role="special">...</phrase> <phrase role="comment">// Other non-volatile invariants.</phrase>
7499 <phrase role="special">}</phrase>
7501 <phrase role="special">...</phrase>
7502 <phrase role="special">};</phrase>
7505 (As usual, private and protected functions do not check any invariant, not
7506 even when they are <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">volatile</phrase></computeroutput>
7507 or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase></computeroutput>,
7508 see <link linkend="boost_contract.advanced.private_and_protected_functions">Private
7509 and Protected Functions</link>).
7512 <section id="boost_contract.extras.move_operations">
7513 <title><link linkend="boost_contract.extras.move_operations">Move Operations</link></title>
7515 As with all public operations of a class, also public move operations should
7516 maintain class invariants (see <link linkend="Stroustrup13_anchor">[Stroustrup13]</link>,
7517 p. 520). Specifically, at a minimum C++ requires the following:
7522 The moved-from object can be copy assigned.
7527 The moved-from object can be move assigned.
7532 The moved-from object can be destroyed (if not for any other reason,
7533 this requires that class invariants are maintained by move operations
7534 because the destructor of the moved-from object requires class invariants
7535 to be satisfied at its entry, as always with destructors see <link linkend="boost_contract.contract_programming_overview.destructor_calls">Destructor
7541 Therefore, both the move constructor and the move assignment operator need
7542 to maintain the class invariants of the moved-from object so their contracts
7543 can be programmed using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.constructor">boost::contract::constructor</link></computeroutput>
7544 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>
7545 as usual. For example (see <ulink url="../../example/features/move.cpp"><literal moreinfo="none">move.cpp</literal></ulink>):
7548 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">class</phrase> <phrase role="identifier">circular_buffer</phrase> <phrase role="special">:</phrase>
7549 <phrase role="keyword">private</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor_precondition</phrase><phrase role="special"><</phrase><phrase role="identifier">circular_buffer</phrase><phrase role="special">></phrase> <phrase role="special">{</phrase>
7550 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
7551 <phrase role="keyword">void</phrase> <phrase role="identifier">invariant</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
7552 <phrase role="keyword">if</phrase><phrase role="special">(!</phrase><phrase role="identifier">moved</phrase><phrase role="special">())</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Do not check (some) invariants for moved-from objects.</phrase>
7553 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">index</phrase><phrase role="special">()</phrase> <phrase role="special"><</phrase> <phrase role="identifier">size</phrase><phrase role="special">());</phrase>
7554 <phrase role="special">}</phrase>
7555 <phrase role="comment">// More invariants here that hold also for moved-from objects (e.g.,</phrase>
7556 <phrase role="comment">// all assertions necessary to successfully destroy moved-from objects).</phrase>
7557 <phrase role="special">}</phrase>
7559 <phrase role="comment">// Move constructor.</phrase>
7560 <phrase role="identifier">circular_buffer</phrase><phrase role="special">(</phrase><phrase role="identifier">circular_buffer</phrase><phrase role="special">&&</phrase> <phrase role="identifier">other</phrase><phrase role="special">)</phrase> <phrase role="special">:</phrase>
7561 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor_precondition</phrase><phrase role="special"><</phrase><phrase role="identifier">circular_buffer</phrase><phrase role="special">>([&]</phrase> <phrase role="special">{</phrase>
7562 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(!</phrase><phrase role="identifier">other</phrase><phrase role="special">.</phrase><phrase role="identifier">moved</phrase><phrase role="special">());</phrase>
7563 <phrase role="special">})</phrase>
7564 <phrase role="special">{</phrase>
7565 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
7566 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
7567 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(!</phrase><phrase role="identifier">moved</phrase><phrase role="special">());</phrase>
7568 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">other</phrase><phrase role="special">.</phrase><phrase role="identifier">moved</phrase><phrase role="special">());</phrase>
7569 <phrase role="special">})</phrase>
7570 <phrase role="special">;</phrase>
7572 <phrase role="identifier">move</phrase><phrase role="special">(</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">forward</phrase><phrase role="special"><</phrase><phrase role="identifier">circular_buffer</phrase><phrase role="special">>(</phrase><phrase role="identifier">other</phrase><phrase role="special">));</phrase>
7573 <phrase role="special">}</phrase>
7575 <phrase role="comment">// Move assignment.</phrase>
7576 <phrase role="identifier">circular_buffer</phrase><phrase role="special">&</phrase> <phrase role="keyword">operator</phrase><phrase role="special">=(</phrase><phrase role="identifier">circular_buffer</phrase><phrase role="special">&&</phrase> <phrase role="identifier">other</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
7577 <phrase role="comment">// Moved-from can be (move) assigned (so no pre `!moved()` here).</phrase>
7578 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
7579 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
7580 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(!</phrase><phrase role="identifier">other</phrase><phrase role="special">.</phrase><phrase role="identifier">moved</phrase><phrase role="special">());</phrase>
7581 <phrase role="special">})</phrase>
7582 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
7583 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(!</phrase><phrase role="identifier">moved</phrase><phrase role="special">());</phrase>
7584 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">other</phrase><phrase role="special">.</phrase><phrase role="identifier">moved</phrase><phrase role="special">());</phrase>
7585 <phrase role="special">})</phrase>
7586 <phrase role="special">;</phrase>
7588 <phrase role="keyword">return</phrase> <phrase role="identifier">move</phrase><phrase role="special">(</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">forward</phrase><phrase role="special"><</phrase><phrase role="identifier">circular_buffer</phrase><phrase role="special">>(</phrase><phrase role="identifier">other</phrase><phrase role="special">));</phrase>
7589 <phrase role="special">}</phrase>
7591 <phrase role="special">~</phrase><phrase role="identifier">circular_buffer</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
7592 <phrase role="comment">// Moved-from can always be destroyed (in fact no preconditions).</phrase>
7593 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">destructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
7594 <phrase role="special">}</phrase>
7596 <phrase role="keyword">bool</phrase> <phrase role="identifier">moved</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
7597 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
7598 <phrase role="keyword">return</phrase> <phrase role="identifier">moved_</phrase><phrase role="special">;</phrase>
7599 <phrase role="special">}</phrase>
7601 <phrase role="keyword">private</phrase><phrase role="special">:</phrase>
7602 <phrase role="keyword">bool</phrase> <phrase role="identifier">moved_</phrase><phrase role="special">;</phrase>
7604 <phrase role="comment">/* ... */</phrase>
7608 This example assumes that it is possible to call the public function <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">moved</phrase><phrase role="special">()</phrase></computeroutput>
7609 on the moved-from object. <footnote id="boost_contract.extras.move_operations.f0">
7611 In this example, the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">moved</phrase><phrase role="special">()</phrase></computeroutput> function is simple enough that programmers
7612 could decide to not even call <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>
7613 from it for optimization reasons. However, calling <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>
7614 from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">moved</phrase><phrase role="special">()</phrase></computeroutput>
7615 has no negative impact, a part from run-time overhead, because this library
7616 automatically disables contract checking while checking other contracts
7617 (so this call will not cause infinite recursion).
7623 The default move constructor and move assignment operator generated by
7624 C++ will not automatically check contracts. Therefore, unless the move
7625 operations are not public or they have no preconditions, no postconditions,
7626 and their class has no invariants, programmers should manually define them
7627 using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.constructor">boost::contract::constructor</link></computeroutput>,
7628 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.constructor_precondition">boost::contract::constructor_precondition</link></computeroutput>,
7629 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>
7630 instead of relying on their default implementations generated by C++. (Same
7631 as for all other operations automatically implemented by C++.)
7635 As always, programmers can decide to not program contracts for a given type.
7636 Specifically, they might decide to not program contracts for a class that
7637 needs to be moved in order to avoid the run-time overhead of checking contract
7638 assertions and to maximize performance (see <link linkend="boost_contract.contract_programming_overview.benefits_and_costs">Benefits
7642 <section id="boost_contract.extras.unions">
7643 <title><link linkend="boost_contract.extras.unions">Unions</link></title>
7645 A C++ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">union</phrase></computeroutput> cannot have virtual
7646 functions, base classes, and cannot be used as a base class thus subcontracting
7647 (<computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.virtual_">boost::contract::virtual_</link></computeroutput>,
7648 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_OVERRIDE">BOOST_CONTRACT_OVERRIDE</link></computeroutput>,
7649 etc.) do not apply to unions. Also a <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">union</phrase></computeroutput>
7650 cannot inherit from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.constructor_precondition">boost::contract::constructor_precondition</link></computeroutput>
7651 (because it cannot have base classes), instead <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.constructor_precondition">boost::contract::constructor_precondition</link></computeroutput>
7652 is used to declare a local object that checks constructor preconditions (at
7653 the very beginning of the constructor before old value copies and other contracts,
7654 see declaration of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">pre</phrase></computeroutput> in
7655 the example below). A part from that, this library is used as usual to program
7656 contracts for unions. For example (see <ulink url="../../example/features/union.cpp"><literal moreinfo="none">union.cpp</literal></ulink>):
7659 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">union</phrase> <phrase role="identifier">positive</phrase> <phrase role="special">{</phrase>
7660 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
7661 <phrase role="keyword">static</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">static_invariant</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Static class invariants (as usual).</phrase>
7662 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">instances</phrase><phrase role="special">()</phrase> <phrase role="special">>=</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase>
7663 <phrase role="special">}</phrase>
7665 <phrase role="keyword">void</phrase> <phrase role="identifier">invariant</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Class invariants (as usual).</phrase>
7666 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">i_</phrase> <phrase role="special">></phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase>
7667 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">d_</phrase> <phrase role="special">></phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase>
7668 <phrase role="special">}</phrase>
7670 <phrase role="comment">// Contracts for constructor, as usual but...</phrase>
7671 <phrase role="keyword">explicit</phrase> <phrase role="identifier">positive</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">x</phrase><phrase role="special">)</phrase> <phrase role="special">:</phrase> <phrase role="identifier">d_</phrase><phrase role="special">(</phrase><phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
7672 <phrase role="comment">// ...unions cannot have bases so constructor preconditions here.</phrase>
7673 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor_precondition</phrase><phrase role="special"><</phrase><phrase role="identifier">positive</phrase><phrase role="special">></phrase> <phrase role="identifier">pre</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
7674 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">x</phrase> <phrase role="special">></phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase>
7675 <phrase role="special">});</phrase>
7676 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">></phrase> <phrase role="identifier">old_instances</phrase> <phrase role="special">=</phrase>
7677 <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">instances</phrase><phrase role="special">());</phrase>
7678 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
7679 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
7680 <phrase role="special">{</phrase> <phrase role="keyword">int</phrase> <phrase role="identifier">y</phrase><phrase role="special">;</phrase> <phrase role="identifier">get</phrase><phrase role="special">(</phrase><phrase role="identifier">y</phrase><phrase role="special">);</phrase> <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">y</phrase> <phrase role="special">==</phrase> <phrase role="identifier">x</phrase><phrase role="special">);</phrase> <phrase role="special">}</phrase>
7681 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">instances</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_instances</phrase> <phrase role="special">+</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase>
7682 <phrase role="special">})</phrase>
7683 <phrase role="special">;</phrase>
7685 <phrase role="identifier">i_</phrase> <phrase role="special">=</phrase> <phrase role="identifier">x</phrase><phrase role="special">;</phrase>
7686 <phrase role="special">++</phrase><phrase role="identifier">instances_</phrase><phrase role="special">;</phrase>
7687 <phrase role="special">}</phrase>
7689 <phrase role="comment">// Contracts for destructor (as usual).</phrase>
7690 <phrase role="special">~</phrase><phrase role="identifier">positive</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
7691 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">></phrase> <phrase role="identifier">old_instances</phrase> <phrase role="special">=</phrase>
7692 <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">instances</phrase><phrase role="special">());</phrase>
7693 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">destructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
7694 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
7695 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">instances</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_instances</phrase> <phrase role="special">-</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase>
7696 <phrase role="special">})</phrase>
7697 <phrase role="special">;</phrase>
7699 <phrase role="special">--</phrase><phrase role="identifier">instances_</phrase><phrase role="special">;</phrase>
7700 <phrase role="special">}</phrase>
7702 <phrase role="comment">// Contracts for public function (as usual, but no virtual or override).</phrase>
7703 <phrase role="keyword">void</phrase> <phrase role="identifier">get</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase><phrase role="special">&</phrase> <phrase role="identifier">x</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
7704 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
7705 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
7706 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">x</phrase> <phrase role="special">></phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase>
7707 <phrase role="special">})</phrase>
7708 <phrase role="special">;</phrase>
7710 <phrase role="identifier">x</phrase> <phrase role="special">=</phrase> <phrase role="identifier">i_</phrase><phrase role="special">;</phrase>
7711 <phrase role="special">}</phrase>
7713 <phrase role="comment">// Contracts for static public function (as usual).</phrase>
7714 <phrase role="keyword">static</phrase> <phrase role="keyword">int</phrase> <phrase role="identifier">instances</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
7715 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special"><</phrase><phrase role="identifier">positive</phrase><phrase role="special">>();</phrase>
7716 <phrase role="keyword">return</phrase> <phrase role="identifier">instances_</phrase><phrase role="special">;</phrase>
7717 <phrase role="special">}</phrase>
7719 <phrase role="keyword">private</phrase><phrase role="special">:</phrase>
7720 <phrase role="keyword">int</phrase> <phrase role="identifier">i_</phrase><phrase role="special">;</phrase>
7721 <phrase role="keyword">double</phrase> <phrase role="identifier">d_</phrase><phrase role="special">;</phrase>
7723 <phrase role="comment">/* ... */</phrase>
7727 <section id="boost_contract.extras.assertion_levels">
7728 <title><link linkend="boost_contract.extras.assertion_levels">Assertion Levels</link></title>
7730 This library provides three predefined <emphasis>assertion levels</emphasis>
7731 that can be used to selectively disable assertions depending on their computational
7732 complexity: <footnote id="boost_contract.extras.assertion_levels.f0">
7734 The assertion levels predefined by this library are similar to the default,
7735 audit, and axiom levels from <link linkend="P0380_anchor">[P0380]</link>.
7742 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_ASSERT">BOOST_CONTRACT_ASSERT</link></computeroutput>
7743 is used to assert conditions that are not computationally expensive,
7744 at least compared to the cost of executing the function body. These assertions
7745 are the ones we have seen so far, they are always checked at run-time
7746 and they cannot be disabled.
7751 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45395000817520">BOOST_CONTRACT_ASSERT_AUDIT</link></computeroutput>
7752 is used to assert conditions that are computationally expensive compared
7753 to the cost of executing the function body. These assertions are not
7754 checked at run-time unless programmers explicitly define <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_AUDITS">BOOST_CONTRACT_AUDITS</link></computeroutput>
7755 (undefined by default), but the asserted conditions are always compiled
7756 and therefore validated syntactically (even when they are not actually
7757 evaluated and checked at run-time).
7762 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45395027441616">BOOST_CONTRACT_ASSERT_AXIOM</link></computeroutput>
7763 is used to assert conditions that are computationally prohibitive, at
7764 least compared to the cost of executing the function body. These assertions
7765 are never evaluated or checked at run-time, but the asserted conditions
7766 are always compiled and therefore validated syntactically (so these assertions
7767 can serve as formal comments to the code).
7772 In addition, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_CHECK_AUDIT">BOOST_CONTRACT_CHECK_AUDIT</link></computeroutput>
7773 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_CHECK_AXIOM">BOOST_CONTRACT_CHECK_AXIOM</link></computeroutput>
7774 are similar to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45395000817520">BOOST_CONTRACT_ASSERT_AUDIT</link></computeroutput>
7775 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45395027441616">BOOST_CONTRACT_ASSERT_AXIOM</link></computeroutput>
7776 but they are used to program audit and axiom levels for implementation checks
7777 instead of assertions (see <link linkend="boost_contract.advanced.implementation_checks">Implementation
7781 For example, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45395000817520">BOOST_CONTRACT_ASSERT_AUDIT</link></computeroutput>
7782 can be used to program computationally expensive assertions (see <ulink url="../../example/features/assertion_level.cpp"><literal moreinfo="none">assertion_level.cpp</literal></ulink>):
7785 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">RandomIter</phrase><phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">></phrase>
7786 <phrase role="identifier">RandomIter</phrase> <phrase role="identifier">random_binary_search</phrase><phrase role="special">(</phrase><phrase role="identifier">RandomIter</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">RandomIter</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase>
7787 <phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">value</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
7788 <phrase role="identifier">RandomIter</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
7789 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">function</phrase><phrase role="special">()</phrase>
7790 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
7791 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase> <phrase role="special"><=</phrase> <phrase role="identifier">last</phrase><phrase role="special">);</phrase> <phrase role="comment">// Default, not expensive.</phrase>
7792 <phrase role="comment">// Expensive O(n) assertion (use AXIOM if prohibitive instead).</phrase>
7793 <phrase role="identifier">BOOST_CONTRACT_ASSERT_AUDIT</phrase><phrase role="special">(</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">is_sorted</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">last</phrase><phrase role="special">));</phrase>
7794 <phrase role="special">})</phrase>
7795 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
7796 <phrase role="keyword">if</phrase><phrase role="special">(</phrase><phrase role="identifier">result</phrase> <phrase role="special">!=</phrase> <phrase role="identifier">last</phrase><phrase role="special">)</phrase> <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(*</phrase><phrase role="identifier">result</phrase> <phrase role="special">==</phrase> <phrase role="identifier">value</phrase><phrase role="special">);</phrase>
7797 <phrase role="special">})</phrase>
7798 <phrase role="special">;</phrase>
7800 <phrase role="comment">/* ... */</phrase>
7804 Similarly, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_AUDITS">BOOST_CONTRACT_AUDITS</link></computeroutput>
7805 can be used to disable expensive old value copies and related assertions
7806 that use them (see <ulink url="../../example/features/assertion_level.cpp"><literal moreinfo="none">assertion_level.cpp</literal></ulink>):
7809 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">></phrase>
7810 <phrase role="keyword">class</phrase> <phrase role="identifier">vector</phrase> <phrase role="special">{</phrase>
7814 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">public</phrase><phrase role="special">:</phrase>
7815 <phrase role="keyword">void</phrase> <phrase role="identifier">swap</phrase><phrase role="special">(</phrase><phrase role="identifier">vector</phrase><phrase role="special">&</phrase> <phrase role="identifier">other</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
7816 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="identifier">vector</phrase><phrase role="special">></phrase> <phrase role="identifier">old_me</phrase><phrase role="special">,</phrase> <phrase role="identifier">old_other</phrase><phrase role="special">;</phrase>
7817 <phrase role="preprocessor">#ifdef</phrase> <phrase role="identifier">BOOST_CONTRACT_AUDITS</phrase>
7818 <phrase role="identifier">old_me</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(*</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
7819 <phrase role="identifier">old_other</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">other</phrase><phrase role="special">);</phrase>
7820 <phrase role="preprocessor">#endif</phrase> <phrase role="comment">// Else, skip old value copies...</phrase>
7821 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
7822 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
7823 <phrase role="comment">// ...and also skip related assertions.</phrase>
7824 <phrase role="identifier">BOOST_CONTRACT_ASSERT_AUDIT</phrase><phrase role="special">(*</phrase><phrase role="keyword">this</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_other</phrase><phrase role="special">);</phrase>
7825 <phrase role="identifier">BOOST_CONTRACT_ASSERT_AUDIT</phrase><phrase role="special">(</phrase><phrase role="identifier">other</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_me</phrase><phrase role="special">);</phrase>
7826 <phrase role="special">})</phrase>
7827 <phrase role="special">;</phrase>
7829 <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">swap</phrase><phrase role="special">(</phrase><phrase role="identifier">other</phrase><phrase role="special">.</phrase><phrase role="identifier">vect_</phrase><phrase role="special">);</phrase>
7830 <phrase role="special">}</phrase>
7834 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="comment">/* ... */</phrase>
7836 <phrase role="keyword">private</phrase><phrase role="special">:</phrase>
7837 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase> <phrase role="identifier">vect_</phrase><phrase role="special">;</phrase>
7838 <phrase role="special">};</phrase>
7842 The condition passed to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45395027441616">BOOST_CONTRACT_ASSERT_AXIOM</link></computeroutput>
7843 is compiled but not actually evaluated at run-time so this macro can be used
7844 to program computationally prohibitive assertions but also assertions that
7845 cannot actually be programmed in C++ using functions that are declared but
7846 left undefined. For example, (see <ulink url="../../example/features/assertion_level.cpp"><literal moreinfo="none">assertion_level.cpp</literal></ulink>):
7849 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="comment">// If valid iterator range (cannot implement in C++ but OK to use in AXIOM).</phrase>
7850 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">Iter</phrase><phrase role="special">></phrase>
7851 <phrase role="keyword">bool</phrase> <phrase role="identifier">valid</phrase><phrase role="special">(</phrase><phrase role="identifier">Iter</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">Iter</phrase> <phrase role="identifier">last</phrase><phrase role="special">);</phrase> <phrase role="comment">// Only declared, not actually defined.</phrase>
7855 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">></phrase>
7856 <phrase role="keyword">class</phrase> <phrase role="identifier">vector</phrase> <phrase role="special">{</phrase>
7860 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">public</phrase><phrase role="special">:</phrase>
7861 <phrase role="identifier">iterator</phrase> <phrase role="identifier">insert</phrase><phrase role="special">(</phrase><phrase role="identifier">iterator</phrase> <phrase role="identifier">where</phrase><phrase role="special">,</phrase> <phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">value</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
7862 <phrase role="identifier">iterator</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
7863 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">unsigned</phrase><phrase role="special">></phrase> <phrase role="identifier">old_capacity</phrase> <phrase role="special">=</phrase>
7864 <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">capacity</phrase><phrase role="special">());</phrase>
7865 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
7866 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
7867 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">capacity</phrase><phrase role="special">()</phrase> <phrase role="special">>=</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_capacity</phrase><phrase role="special">);</phrase>
7868 <phrase role="keyword">if</phrase><phrase role="special">(</phrase><phrase role="identifier">capacity</phrase><phrase role="special">()</phrase> <phrase role="special">></phrase> <phrase role="special">*</phrase><phrase role="identifier">old_capacity</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
7869 <phrase role="identifier">BOOST_CONTRACT_ASSERT_AXIOM</phrase><phrase role="special">(!</phrase><phrase role="identifier">valid</phrase><phrase role="special">(</phrase><phrase role="identifier">begin</phrase><phrase role="special">(),</phrase> <phrase role="identifier">end</phrase><phrase role="special">()));</phrase>
7870 <phrase role="special">}</phrase> <phrase role="keyword">else</phrase> <phrase role="special">{</phrase>
7871 <phrase role="identifier">BOOST_CONTRACT_ASSERT_AXIOM</phrase><phrase role="special">(!</phrase><phrase role="identifier">valid</phrase><phrase role="special">(</phrase><phrase role="identifier">where</phrase><phrase role="special">,</phrase> <phrase role="identifier">end</phrase><phrase role="special">()));</phrase>
7872 <phrase role="special">}</phrase>
7873 <phrase role="special">})</phrase>
7874 <phrase role="special">;</phrase>
7876 <phrase role="keyword">return</phrase> <phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">insert</phrase><phrase role="special">(</phrase><phrase role="identifier">where</phrase><phrase role="special">,</phrase> <phrase role="identifier">value</phrase><phrase role="special">);</phrase>
7877 <phrase role="special">}</phrase>
7881 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="comment">/* ... */</phrase>
7883 <phrase role="keyword">private</phrase><phrase role="special">:</phrase>
7884 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase> <phrase role="identifier">vect_</phrase><phrase role="special">;</phrase>
7885 <phrase role="special">};</phrase>
7889 In addition to these assertion levels that are predefined by this library,
7890 programmers are free to define their own. For example, the following macro
7891 could be used to program and selectively disable assertions that have exponential
7892 computational complexity <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">O</phrase><phrase role="special">(</phrase><phrase role="identifier">e</phrase><phrase role="special">^</phrase><phrase role="identifier">n</phrase><phrase role="special">)</phrase></computeroutput>:
7894 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#ifdef</phrase> <phrase role="identifier">EXPONENTIALLY_COMPLEX_ASSERTIONS</phrase>
7895 <phrase role="comment">// Following will compile and also evaluate `cond`.</phrase>
7896 <phrase role="preprocessor">#define</phrase> <phrase role="identifier">ASSERT_EXP</phrase><phrase role="special">(</phrase><phrase role="identifier">cond</phrase><phrase role="special">)</phrase> <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">cond</phrase><phrase role="special">)</phrase>
7897 <phrase role="preprocessor">#else</phrase>
7898 <phrase role="comment">// Following will compile but never actually evaluate `cond`.</phrase>
7899 <phrase role="preprocessor">#define</phrase> <phrase role="identifier">ASSERT_EXP</phrase><phrase role="special">(</phrase><phrase role="identifier">cond</phrase><phrase role="special">)</phrase> <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="keyword">true</phrase> <phrase role="special">||</phrase> <phrase role="special">(</phrase><phrase role="identifier">cond</phrase><phrase role="special">))</phrase>
7900 <phrase role="preprocessor">#endif</phrase>
7902 <phrase role="special">...</phrase>
7904 <phrase role="identifier">ASSERT_EXP</phrase><phrase role="special">(</phrase><literal moreinfo="none"><emphasis>some-exponentially-complex-boolean-condition</emphasis></literal><phrase role="special">);</phrase>
7907 <section id="boost_contract.extras.disable_contract_checking">
7908 <title><link linkend="boost_contract.extras.disable_contract_checking">Disable
7909 Contract Checking</link></title>
7911 Checking contracts adds run-time overhead and can slow down program execution
7912 (see <link linkend="boost_contract.contract_programming_overview.benefits_and_costs">Benefits
7913 and Costs</link>). Therefore, programmers can define any combination of the
7914 following macros (<computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">-</phrase><phrase role="identifier">D</phrase></computeroutput>
7915 option in Clang and GCC, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">/</phrase><phrase role="identifier">D</phrase></computeroutput>
7916 option in MSVC, etc.) to instruct this library to not check specific groups
7917 of contract conditions at run-time:
7922 Define <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394999662416">BOOST_CONTRACT_NO_PRECONDITIONS</link></computeroutput>
7923 to not check preconditions.
7928 Define <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394999656032">BOOST_CONTRACT_NO_POSTCONDITIONS</link></computeroutput>
7929 to not check postconditions.
7934 Define <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_NO_EXCEPTS">BOOST_CONTRACT_NO_EXCEPTS</link></computeroutput>
7935 to not check exception guarantees.
7940 Define <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394999637264">BOOST_CONTRACT_NO_ENTRY_INVARIANTS</link></computeroutput>
7941 to not check class invariants at call entry.
7946 Define <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394999629648">BOOST_CONTRACT_NO_EXIT_INVARIANTS</link></computeroutput>
7947 to not check class invariants at call exit.
7952 Or, define <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394999622032">BOOST_CONTRACT_NO_INVARIANTS</link></computeroutput>
7953 to not check class invariants at both call entry and exit. (This is provided
7954 for convenience, it is equivalent to defining both <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394999637264">BOOST_CONTRACT_NO_ENTRY_INVARIANTS</link></computeroutput>
7955 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394999629648">BOOST_CONTRACT_NO_EXIT_INVARIANTS</link></computeroutput>.)
7960 Define <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_NO_CHECKS">BOOST_CONTRACT_NO_CHECKS</link></computeroutput>
7961 to not evaluate implementation checks.
7967 Old values can be used by both postconditions and exception guarantees
7968 so it is necessary to define both <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394999656032">BOOST_CONTRACT_NO_POSTCONDITIONS</link></computeroutput>
7969 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_NO_EXCEPTS">BOOST_CONTRACT_NO_EXCEPTS</link></computeroutput>
7970 to disable old value copies.
7974 By default, none of these macros are defined so this library checks all contracts.
7975 When these macros are defined by the user, the implementation code of this
7976 library is internally optimized to minimize as much as possible any run-time
7977 and compile-time overhead associated with checking and compiling contracts
7978 (see <link linkend="boost_contract.extras.disable_contract_compilation__macro_interface_">Disable
7979 Contract Compilation</link> for techniques to completely remove any run-time
7980 and compile-time overheads associated with contract code).
7983 For example, programmers could decide to check all contracts during early
7984 development builds, but later check only preconditions and maybe entry invariants
7985 for release builds by defining <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394999656032">BOOST_CONTRACT_NO_POSTCONDITIONS</link></computeroutput>,
7986 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_NO_EXCEPTS">BOOST_CONTRACT_NO_EXCEPTS</link></computeroutput>,
7987 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394999629648">BOOST_CONTRACT_NO_EXIT_INVARIANTS</link></computeroutput>,
7988 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_NO_CHECKS">BOOST_CONTRACT_NO_CHECKS</link></computeroutput>.
7991 <section id="boost_contract.extras.disable_contract_compilation__macro_interface_">
7992 <title><link linkend="boost_contract.extras.disable_contract_compilation__macro_interface_">Disable
7993 Contract Compilation (Macro Interface)</link></title>
7995 This library provides macros that can be used to completely disable compile-time
7996 and run-time overhead introduced by contracts but at the cost of manually
7997 programming <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_</phrase><phrase role="special">...</phrase></computeroutput> statements around contract code:
8002 This library defines <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394999605408">BOOST_CONTRACT_NO_CONSTRUCTORS</link></computeroutput>
8003 when contract checking is disabled for constructors.
8008 This library defines <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394999594544">BOOST_CONTRACT_NO_DESTRUCTORS</link></computeroutput>
8009 when contract checking is disabled for destructors.
8014 This library defines <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394999586272">BOOST_CONTRACT_NO_PUBLIC_FUNCTIONS</link></computeroutput>
8015 when contract checking is disabled for public functions.
8020 This library defines <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394999577072">BOOST_CONTRACT_NO_FUNCTIONS</link></computeroutput>
8021 when contract checking is disabled for (non-public and non-member) functions.
8026 This library defines <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_NO_OLDS">BOOST_CONTRACT_NO_OLDS</link></computeroutput>
8027 when old value copies are disabled.
8032 This library defines <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_NO_ALL">BOOST_CONTRACT_NO_ALL</link></computeroutput>
8033 when all contracts above and also implementation checks (see <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_NO_CHECKS">BOOST_CONTRACT_NO_CHECKS</link></computeroutput>)
8039 These macros are not configuration macros and they should not be defined
8040 directly by programmers (otherwise this library will generate compile-time
8041 errors). Instead, these macros are automatically defined by this library
8042 when programmers define <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394999662416">BOOST_CONTRACT_NO_PRECONDITIONS</link></computeroutput>,
8043 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394999656032">BOOST_CONTRACT_NO_POSTCONDITIONS</link></computeroutput>,
8044 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_NO_EXCEPTS">BOOST_CONTRACT_NO_EXCEPTS</link></computeroutput>,
8045 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394999622032">BOOST_CONTRACT_NO_INVARIANTS</link></computeroutput>
8046 (or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394999637264">BOOST_CONTRACT_NO_ENTRY_INVARIANTS</link></computeroutput>
8047 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394999629648">BOOST_CONTRACT_NO_EXIT_INVARIANTS</link></computeroutput>),
8048 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_NO_CHECKS">BOOST_CONTRACT_NO_CHECKS</link></computeroutput>
8049 (see <link linkend="boost_contract.extras.disable_contract_checking">Disable
8050 Contract Checking</link>).
8053 Alternatively, this library provides a macro-based interface defined in
8054 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="header.boost.contract_macro_hpp">boost/contract_macro.hpp</link></computeroutput>
8055 that can also be used to completely disable compile-time and run-time overheads
8056 introduced by contracts but without the burden of manually writing the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_</phrase><phrase role="special">...</phrase></computeroutput> statements. For example, the following
8057 code shows how to use both the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="header.boost.contract_macro_hpp">boost/contract_macro.hpp</link></computeroutput>
8058 macro interface and the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#ifndef</phrase>
8059 <phrase role="identifier">BOOST_CONTRACT_NO_</phrase><phrase role="special">...</phrase></computeroutput>
8060 statements to completely disable compile-time and run-time overheads for
8061 non-member function contracts (see <ulink url="../../example/features/ifdef_macro.cpp"><literal moreinfo="none">ifdef_macro.cpp</literal></ulink>
8062 and <ulink url="../../example/features/ifdef.cpp"><literal moreinfo="none">ifdef.cpp</literal></ulink>):
8064 <informaltable frame="all">
8075 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_</phrase><phrase role="special">...</phrase></computeroutput> Statements
8084 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="comment">// Use macro interface to completely disable contract code compilation.</phrase>
8085 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">contract_macro</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">></phrase>
8087 <phrase role="keyword">int</phrase> <phrase role="identifier">inc</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase><phrase role="special">&</phrase> <phrase role="identifier">x</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
8088 <phrase role="keyword">int</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
8089 <phrase role="identifier">BOOST_CONTRACT_OLD_PTR</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase><phrase role="special">)(</phrase><phrase role="identifier">old_x</phrase><phrase role="special">,</phrase> <phrase role="identifier">x</phrase><phrase role="special">);</phrase>
8090 <phrase role="identifier">BOOST_CONTRACT_FUNCTION</phrase><phrase role="special">()</phrase>
8091 <phrase role="identifier">BOOST_CONTRACT_PRECONDITION</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
8092 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">x</phrase> <phrase role="special"><</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">numeric_limits</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">>::</phrase><phrase role="identifier">max</phrase><phrase role="special">());</phrase>
8093 <phrase role="special">})</phrase>
8094 <phrase role="identifier">BOOST_CONTRACT_POSTCONDITION</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
8095 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">x</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_x</phrase> <phrase role="special">+</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase>
8096 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">result</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_x</phrase><phrase role="special">);</phrase>
8097 <phrase role="special">})</phrase>
8098 <phrase role="special">;</phrase>
8100 <phrase role="keyword">return</phrase> <phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="identifier">x</phrase><phrase role="special">++;</phrase>
8101 <phrase role="special">}</phrase>
8107 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="comment">// Use #ifdef to completely disable contract code compilation.</phrase>
8108 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">contract</phrase><phrase role="special">/</phrase><phrase role="identifier">core</phrase><phrase role="special">/</phrase><phrase role="identifier">config</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">></phrase>
8109 <phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_ALL</phrase>
8110 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">contract</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">></phrase>
8111 <phrase role="preprocessor">#endif</phrase>
8113 <phrase role="keyword">int</phrase> <phrase role="identifier">inc</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase><phrase role="special">&</phrase> <phrase role="identifier">x</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
8114 <phrase role="keyword">int</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
8115 <phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_OLDS</phrase>
8116 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">></phrase> <phrase role="identifier">old_x</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">x</phrase><phrase role="special">);</phrase>
8117 <phrase role="preprocessor">#endif</phrase>
8118 <phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_FUNCTIONS</phrase>
8119 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">function</phrase><phrase role="special">()</phrase>
8120 <phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_PRECONDITIONS</phrase>
8121 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
8122 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">x</phrase> <phrase role="special"><</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">numeric_limits</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">>::</phrase><phrase role="identifier">max</phrase><phrase role="special">());</phrase>
8123 <phrase role="special">})</phrase>
8124 <phrase role="preprocessor">#endif</phrase>
8125 <phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_POSTCONDITIONS</phrase>
8126 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
8127 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">x</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_x</phrase> <phrase role="special">+</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase>
8128 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">result</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_x</phrase><phrase role="special">);</phrase>
8129 <phrase role="special">})</phrase>
8130 <phrase role="preprocessor">#endif</phrase>
8131 <phrase role="special">;</phrase>
8132 <phrase role="preprocessor">#endif</phrase>
8134 <phrase role="keyword">return</phrase> <phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="identifier">x</phrase><phrase role="special">++;</phrase>
8135 <phrase role="special">}</phrase>
8144 The same can be done to disable contract code complication for private and
8145 protected functions. The <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394998674080">BOOST_CONTRACT_OLD_PTR_IF_COPYABLE</link></computeroutput>
8146 macro is provided to handle non-copyable old value types (similar to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.old_ptr_if_copyable">boost::contract::old_ptr_if_copyable</link></computeroutput>).
8149 For constructors, destructors, and public functions the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="header.boost.contract_macro_hpp">boost/contract_macro.hpp</link></computeroutput>
8150 macro interface and the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#ifndef</phrase>
8151 <phrase role="identifier">BOOST_CONTRACT_NO_</phrase><phrase role="special">...</phrase></computeroutput>
8152 statements can be used as follow (see <ulink url="../../example/features/ifdef_macro.cpp"><literal moreinfo="none">ifdef_macro.cpp</literal></ulink>
8153 and <ulink url="../../example/features/ifdef.cpp"><literal moreinfo="none">ifdef.cpp</literal></ulink>):
8155 <informaltable frame="all">
8166 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_</phrase><phrase role="special">...</phrase></computeroutput> Statements
8175 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">class</phrase> <phrase role="identifier">integers</phrase>
8176 <phrase role="preprocessor">#define</phrase> <phrase role="identifier">BASES</phrase> <phrase role="keyword">public</phrase> <phrase role="identifier">pushable</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">></phrase>
8177 <phrase role="special">:</phrase>
8178 <phrase role="comment">// Left in code (almost no overhead).</phrase>
8179 <phrase role="keyword">private</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor_precondition</phrase><phrase role="special"><</phrase><phrase role="identifier">integers</phrase><phrase role="special">>,</phrase>
8180 <phrase role="identifier">BASES</phrase>
8181 <phrase role="special">{</phrase>
8182 <phrase role="comment">// Followings left in code (almost no overhead).</phrase>
8183 <phrase role="keyword">friend</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">access</phrase><phrase role="special">;</phrase>
8185 <phrase role="keyword">typedef</phrase> <phrase role="identifier">BOOST_CONTRACT_BASE_TYPES</phrase><phrase role="special">(</phrase><phrase role="identifier">BASES</phrase><phrase role="special">)</phrase> <phrase role="identifier">base_types</phrase><phrase role="special">;</phrase>
8186 <phrase role="preprocessor">#undef</phrase> <phrase role="identifier">BASES</phrase>
8188 <phrase role="identifier">BOOST_CONTRACT_INVARIANT</phrase><phrase role="special">({</phrase>
8189 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special"><=</phrase> <phrase role="identifier">capacity</phrase><phrase role="special">());</phrase>
8190 <phrase role="special">})</phrase>
8192 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
8193 <phrase role="identifier">integers</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">from</phrase><phrase role="special">,</phrase> <phrase role="keyword">int</phrase> <phrase role="identifier">to</phrase><phrase role="special">)</phrase> <phrase role="special">:</phrase>
8194 <phrase role="identifier">BOOST_CONTRACT_CONSTRUCTOR_PRECONDITION</phrase><phrase role="special">(</phrase><phrase role="identifier">integers</phrase><phrase role="special">)([&]</phrase> <phrase role="special">{</phrase>
8195 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">from</phrase> <phrase role="special"><=</phrase> <phrase role="identifier">to</phrase><phrase role="special">);</phrase>
8196 <phrase role="special">}),</phrase>
8197 <phrase role="identifier">vect_</phrase><phrase role="special">(</phrase><phrase role="identifier">to</phrase> <phrase role="special">-</phrase> <phrase role="identifier">from</phrase> <phrase role="special">+</phrase> <phrase role="number">1</phrase><phrase role="special">)</phrase>
8198 <phrase role="special">{</phrase>
8199 <phrase role="identifier">BOOST_CONTRACT_CONSTRUCTOR</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
8200 <phrase role="identifier">BOOST_CONTRACT_POSTCONDITION</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
8201 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">())</phrase> <phrase role="special">==</phrase> <phrase role="special">(</phrase><phrase role="identifier">to</phrase> <phrase role="special">-</phrase> <phrase role="identifier">from</phrase> <phrase role="special">+</phrase> <phrase role="number">1</phrase><phrase role="special">));</phrase>
8202 <phrase role="special">})</phrase>
8203 <phrase role="special">;</phrase>
8205 <phrase role="keyword">for</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">x</phrase> <phrase role="special">=</phrase> <phrase role="identifier">from</phrase><phrase role="special">;</phrase> <phrase role="identifier">x</phrase> <phrase role="special"><=</phrase> <phrase role="identifier">to</phrase><phrase role="special">;</phrase> <phrase role="special">++</phrase><phrase role="identifier">x</phrase><phrase role="special">)</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">at</phrase><phrase role="special">(</phrase><phrase role="identifier">x</phrase> <phrase role="special">-</phrase> <phrase role="identifier">from</phrase><phrase role="special">)</phrase> <phrase role="special">=</phrase> <phrase role="identifier">x</phrase><phrase role="special">;</phrase>
8206 <phrase role="special">}</phrase>
8208 <phrase role="keyword">virtual</phrase> <phrase role="special">~</phrase><phrase role="identifier">integers</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
8209 <phrase role="identifier">BOOST_CONTRACT_DESTRUCTOR</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase> <phrase role="comment">// Check invariants.</phrase>
8210 <phrase role="special">}</phrase>
8212 <phrase role="keyword">virtual</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">push_back</phrase><phrase role="special">(</phrase>
8213 <phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">x</phrase><phrase role="special">,</phrase>
8214 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase> <phrase role="comment">// Left in code (almost no overhead).</phrase>
8215 <phrase role="special">)</phrase> <phrase role="comment">/* override */</phrase> <phrase role="special">{</phrase>
8216 <phrase role="identifier">BOOST_CONTRACT_OLD_PTR</phrase><phrase role="special">(</phrase><phrase role="keyword">unsigned</phrase><phrase role="special">)(</phrase><phrase role="identifier">old_size</phrase><phrase role="special">);</phrase>
8217 <phrase role="identifier">BOOST_CONTRACT_PUBLIC_FUNCTION_OVERRIDE</phrase><phrase role="special">(</phrase><phrase role="identifier">override_push_back</phrase><phrase role="special">)(</phrase>
8218 <phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="special">&</phrase><phrase role="identifier">integers</phrase><phrase role="special">::</phrase><phrase role="identifier">push_back</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">,</phrase> <phrase role="identifier">x</phrase><phrase role="special">)</phrase>
8219 <phrase role="identifier">BOOST_CONTRACT_PRECONDITION</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
8220 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special"><</phrase> <phrase role="identifier">max_size</phrase><phrase role="special">());</phrase>
8221 <phrase role="special">})</phrase>
8222 <phrase role="identifier">BOOST_CONTRACT_OLD</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
8223 <phrase role="identifier">old_size</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">size</phrase><phrase role="special">());</phrase>
8224 <phrase role="special">})</phrase>
8225 <phrase role="identifier">BOOST_CONTRACT_POSTCONDITION</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
8226 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_size</phrase> <phrase role="special">+</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase>
8227 <phrase role="special">})</phrase>
8228 <phrase role="identifier">BOOST_CONTRACT_EXCEPT</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
8229 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_size</phrase><phrase role="special">);</phrase>
8230 <phrase role="special">})</phrase>
8231 <phrase role="special">;</phrase>
8233 <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">push_back</phrase><phrase role="special">(</phrase><phrase role="identifier">x</phrase><phrase role="special">);</phrase>
8234 <phrase role="special">}</phrase>
8236 <phrase role="keyword">private</phrase><phrase role="special">:</phrase>
8237 <phrase role="identifier">BOOST_CONTRACT_OVERRIDE</phrase><phrase role="special">(</phrase><phrase role="identifier">push_back</phrase><phrase role="special">)</phrase> <phrase role="comment">// Left in code (almost no overhead).</phrase>
8239 <phrase role="comment">/* ... */</phrase>
8245 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">class</phrase> <phrase role="identifier">integers</phrase>
8246 <phrase role="preprocessor">#define</phrase> <phrase role="identifier">BASES</phrase> <phrase role="keyword">public</phrase> <phrase role="identifier">pushable</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">></phrase>
8247 <phrase role="special">:</phrase>
8248 <phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_PRECONDITIONS</phrase>
8249 <phrase role="keyword">private</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor_precondition</phrase><phrase role="special"><</phrase><phrase role="identifier">integers</phrase><phrase role="special">>,</phrase> <phrase role="identifier">BASES</phrase>
8250 <phrase role="preprocessor">#else</phrase>
8251 <phrase role="identifier">BASES</phrase>
8252 <phrase role="preprocessor">#endif</phrase>
8253 <phrase role="special">{</phrase>
8254 <phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_ALL</phrase>
8255 <phrase role="keyword">friend</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">access</phrase><phrase role="special">;</phrase>
8256 <phrase role="preprocessor">#endif</phrase>
8258 <phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_PUBLIC_FUNCTIONS</phrase>
8259 <phrase role="keyword">typedef</phrase> <phrase role="identifier">BOOST_CONTRACT_BASE_TYPES</phrase><phrase role="special">(</phrase><phrase role="identifier">BASES</phrase><phrase role="special">)</phrase> <phrase role="identifier">base_types</phrase><phrase role="special">;</phrase>
8260 <phrase role="preprocessor">#endif</phrase>
8261 <phrase role="preprocessor">#undef</phrase> <phrase role="identifier">BASES</phrase>
8263 <phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_INVARIANTS</phrase>
8264 <phrase role="keyword">void</phrase> <phrase role="identifier">invariant</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
8265 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special"><=</phrase> <phrase role="identifier">capacity</phrase><phrase role="special">());</phrase>
8266 <phrase role="special">}</phrase>
8267 <phrase role="preprocessor">#endif</phrase>
8269 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
8270 <phrase role="identifier">integers</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">from</phrase><phrase role="special">,</phrase> <phrase role="keyword">int</phrase> <phrase role="identifier">to</phrase><phrase role="special">)</phrase> <phrase role="special">:</phrase>
8271 <phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_PRECONDITIONS</phrase>
8272 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor_precondition</phrase><phrase role="special"><</phrase><phrase role="identifier">integers</phrase><phrase role="special">>([&]</phrase> <phrase role="special">{</phrase>
8273 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">from</phrase> <phrase role="special"><=</phrase> <phrase role="identifier">to</phrase><phrase role="special">);</phrase>
8274 <phrase role="special">}),</phrase>
8275 <phrase role="preprocessor">#endif</phrase>
8276 <phrase role="identifier">vect_</phrase><phrase role="special">(</phrase><phrase role="identifier">to</phrase> <phrase role="special">-</phrase> <phrase role="identifier">from</phrase> <phrase role="special">+</phrase> <phrase role="number">1</phrase><phrase role="special">)</phrase>
8277 <phrase role="special">{</phrase>
8278 <phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_CONSTRUCTORS</phrase>
8279 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
8280 <phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_POSTCONDITIONS</phrase>
8281 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
8282 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">())</phrase> <phrase role="special">==</phrase> <phrase role="special">(</phrase><phrase role="identifier">to</phrase> <phrase role="special">-</phrase> <phrase role="identifier">from</phrase> <phrase role="special">+</phrase> <phrase role="number">1</phrase><phrase role="special">));</phrase>
8283 <phrase role="special">})</phrase>
8284 <phrase role="preprocessor">#endif</phrase>
8285 <phrase role="special">;</phrase>
8286 <phrase role="preprocessor">#endif</phrase>
8288 <phrase role="keyword">for</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">x</phrase> <phrase role="special">=</phrase> <phrase role="identifier">from</phrase><phrase role="special">;</phrase> <phrase role="identifier">x</phrase> <phrase role="special"><=</phrase> <phrase role="identifier">to</phrase><phrase role="special">;</phrase> <phrase role="special">++</phrase><phrase role="identifier">x</phrase><phrase role="special">)</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">at</phrase><phrase role="special">(</phrase><phrase role="identifier">x</phrase> <phrase role="special">-</phrase> <phrase role="identifier">from</phrase><phrase role="special">)</phrase> <phrase role="special">=</phrase> <phrase role="identifier">x</phrase><phrase role="special">;</phrase>
8289 <phrase role="special">}</phrase>
8291 <phrase role="keyword">virtual</phrase> <phrase role="special">~</phrase><phrase role="identifier">integers</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
8292 <phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_DESTRUCTORS</phrase>
8293 <phrase role="comment">// Check invariants.</phrase>
8294 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">destructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
8295 <phrase role="preprocessor">#endif</phrase>
8296 <phrase role="special">}</phrase>
8298 <phrase role="keyword">virtual</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">push_back</phrase><phrase role="special">(</phrase>
8299 <phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">x</phrase>
8300 <phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_PUBLIC_FUNCTIONS</phrase>
8301 <phrase role="special">,</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase>
8302 <phrase role="preprocessor">#endif</phrase>
8303 <phrase role="special">)</phrase> <phrase role="comment">/* override */</phrase> <phrase role="special">{</phrase>
8304 <phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_OLDS</phrase>
8305 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">unsigned</phrase><phrase role="special">></phrase> <phrase role="identifier">old_size</phrase><phrase role="special">;</phrase>
8306 <phrase role="preprocessor">#endif</phrase>
8307 <phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_PUBLIC_FUNCTIONS</phrase>
8308 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special"><</phrase>
8309 <phrase role="identifier">override_push_back</phrase><phrase role="special">>(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="special">&</phrase><phrase role="identifier">integers</phrase><phrase role="special">::</phrase><phrase role="identifier">push_back</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">,</phrase> <phrase role="identifier">x</phrase><phrase role="special">)</phrase>
8310 <phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_PRECONDITIONS</phrase>
8311 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
8312 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special"><</phrase> <phrase role="identifier">max_size</phrase><phrase role="special">());</phrase>
8313 <phrase role="special">})</phrase>
8314 <phrase role="preprocessor">#endif</phrase>
8315 <phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_OLDS</phrase>
8316 <phrase role="special">.</phrase><phrase role="identifier">old</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
8317 <phrase role="identifier">old_size</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">size</phrase><phrase role="special">());</phrase>
8318 <phrase role="special">})</phrase>
8319 <phrase role="preprocessor">#endif</phrase>
8320 <phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_POSTCONDITIONS</phrase>
8321 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
8322 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_size</phrase> <phrase role="special">+</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase>
8323 <phrase role="special">})</phrase>
8324 <phrase role="preprocessor">#endif</phrase>
8325 <phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_EXCEPTS</phrase>
8326 <phrase role="special">.</phrase><phrase role="identifier">except</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
8327 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_size</phrase><phrase role="special">);</phrase>
8328 <phrase role="special">})</phrase>
8329 <phrase role="preprocessor">#endif</phrase>
8330 <phrase role="special">;</phrase>
8331 <phrase role="preprocessor">#endif</phrase>
8333 <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">push_back</phrase><phrase role="special">(</phrase><phrase role="identifier">x</phrase><phrase role="special">);</phrase>
8334 <phrase role="special">}</phrase>
8336 <phrase role="keyword">private</phrase><phrase role="special">:</phrase>
8337 <phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_PUBLIC_FUNCTIONS</phrase>
8338 <phrase role="identifier">BOOST_CONTRACT_OVERRIDE</phrase><phrase role="special">(</phrase><phrase role="identifier">push_back</phrase><phrase role="special">)</phrase>
8339 <phrase role="preprocessor">#endif</phrase>
8341 <phrase role="comment">/* ... */</phrase>
8350 Static and volatile class invariants can be programmed using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394998621472">BOOST_CONTRACT_STATIC_INVARIANT</link></computeroutput>
8351 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394998635328">BOOST_CONTRACT_INVARIANT_VOLATILE</link></computeroutput>
8352 respectively (these macros expand code equivalent to the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">static</phrase>
8353 <phrase role="keyword">void</phrase> <phrase role="identifier">BOOST_CONTRACT_STATIC_INVARIANT_FUNC</phrase><phrase role="special">()</phrase></computeroutput> and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">void</phrase>
8354 <phrase role="identifier">BOOST_CONTRACT_INVARIANT_FUNC</phrase><phrase role="special">()</phrase>
8355 <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase></computeroutput>
8359 The <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="header.boost.contract_macro_hpp">boost/contract_macro.hpp</link></computeroutput>
8360 macro interface is usually preferred because more concise and easier to use
8361 than programming <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_</phrase><phrase role="special">...</phrase></computeroutput>
8362 statements by hand. However, C++ macros expand on a single line of code and
8363 that can make compiler errors less useful when using this macro interface
8364 plus all contract assertions within a given set of preconditions, postconditions,
8365 exception guarantees, and class invariants will list the same line number
8366 in error messages when assertions fail at run-time (but error messages still
8367 list the assertion code and that should still allow programmers to identify
8368 the specific assertion that failed). Finally, the macro interface leaves
8369 a bit of contract decorations in the code but that should add no measurable
8370 compile-time or run-time overhead (specifically, extra <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.virtual_">boost::contract::virtual_</link></computeroutput><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">*</phrase></computeroutput> parameters, calls to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.constructor_precondition">boost::contract::constructor_precondition</link></computeroutput>
8371 default constructor which does nothing, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_BASE_TYPES">BOOST_CONTRACT_BASE_TYPES</link></computeroutput>
8372 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">typedef</phrase></computeroutput>s, and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.access">boost::contract::access</link></computeroutput>
8373 friendships are left in user code even when contracts are disabled unless
8374 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_</phrase><phrase role="special">...</phrase></computeroutput> statements are used).
8377 Disabling contract as shown in <link linkend="boost_contract.extras.disable_contract_checking">Disable
8378 Contract Checking</link> leaves the overhead of compiling contract code plus
8379 some small run-time overhead due to the initialization of old value pointers
8380 (even if those will be all null and no old value will be actually copied),
8381 the calls to the contract functions used to initialize <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.check">boost::contract::check</link></computeroutput>
8382 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.constructor_precondition">boost::contract::constructor_precondition</link></computeroutput>
8383 (even if those calls will be internally optimized by this library to essentially
8384 do nothing), etc. For truly performance critical code for which even such
8385 small run-time overhead might not be acceptable, the macro interface (or
8386 the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_</phrase><phrase role="special">...</phrase></computeroutput> statements) can be used to completely
8387 disable compile-time and run-time overheads of contracts. However, for such
8388 performance critical code even the overhead of checking simple preconditions
8389 might be too much so it might be best to not program contracts at all.
8392 Usually, if the overhead of checking preconditions and other assertions is
8393 already considered acceptable for an application then the compile-time overhead
8394 of contracts should not represent an issue and it should be sufficient to
8395 disable contract checking at run-time as indicated in <link linkend="boost_contract.extras.disable_contract_checking">Disable
8396 Contract Checking</link> (without a real need to use the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="header.boost.contract_macro_hpp">boost/contract_macro.hpp</link></computeroutput>
8397 macro interface or the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#ifndef</phrase>
8398 <phrase role="identifier">BOOST_CONTRACT_NO_</phrase><phrase role="special">...</phrase></computeroutput>
8399 statements in most cases).
8402 <section id="boost_contract.extras.separate_body_implementation">
8403 <title><link linkend="boost_contract.extras.separate_body_implementation">Separate
8404 Body Implementation</link></title>
8406 Contracts are part of the program specifications and not of its implementation
8407 (see <link linkend="boost_contract.contract_programming_overview.specifications_vs__implementation">Specifications
8408 vs. Implementation</link>). However, this library uses function definitions
8409 to program contracts so contract code appears together with the function
8410 implementation code. This is not ideal (even if contracts programmed using
8411 this library will always appear at the very beginning of the function definition
8412 so programmers will easily be able to distinguish contract code from the
8413 rest of the function implementation code so this might not be real limitation
8417 In some cases, it might be desirable to completely separate the contract
8418 code from the function implementation code. For example, this could be necessary
8419 for software that ships only header files and compiled object files to its
8420 users. If contracts are programmed in function definitions that are compiled
8421 in the object files, users will not be able to see the contract code to understand
8422 semantics and usage of the functions (again, this might not be a real problem
8423 in practice for example if contracts are already somehow extracted from the
8424 source code by some tool and presented as part of the documentation of the
8428 In any case, when it is truly important to separate contracts from function
8429 implementation code, function implementations can be programmed in extra
8430 <emphasis>body functions</emphasis> (here named <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">...</phrase><phrase role="identifier">_body</phrase></computeroutput>, but any other naming scheme could
8431 be used) that are compiled in object files. Function definitions that remain
8432 in header files instead will contain just contract code followed by calls
8433 to the extra body functions. This technique allows to keep the contract code
8434 in header files while separating the implementation code to source and object
8435 files. However, this adds the overhead of manually programming an extra function
8436 declaration for each body function (plus the limitation that constructor
8437 member initialization lists must be programmed in header files because that
8438 is where constructors need to be defined to list constructor contract code).
8439 <footnote id="boost_contract.extras.separate_body_implementation.f0">
8441 When used as default parameter values, lambda functions allow to program
8442 code statements within function declarations. However, these lambadas cannot
8443 be effectively used to program contracts in function declarations instead
8444 of definitions. That is because the C++11 standard does not allow lambdas
8445 in function declarations to capture any variable (for the good reason that
8446 it is not at all obvious how to correctly define the semantics of such
8447 captures). For example, the following code is not valid C++ and it does
8449 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="comment">// Specifications (in declaration).</phrase>
8450 <phrase role="keyword">int</phrase> <phrase role="identifier">inc</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase><phrase role="special">&</phrase> <phrase role="identifier">x</phrase><phrase role="special">,</phrase>
8451 <phrase role="comment">// Error: Lambdas in default parameters cannot capture `this`, `x`, or any other variable.</phrase>
8452 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">function</phrase><phrase role="special"><</phrase><phrase role="keyword">void</phrase> <phrase role="special">()></phrase> <phrase role="identifier">pre</phrase> <phrase role="special">=</phrase> <phrase role="special">[&]</phrase> <phrase role="special">{</phrase>
8453 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">x</phrase> <phrase role="special"><</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">numeric_limits</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">>::</phrase><phrase role="identifier">max</phrase><phrase role="special">());</phrase>
8454 <phrase role="special">},</phrase>
8455 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">function</phrase><phrase role="special"><</phrase><phrase role="keyword">void</phrase> <phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&,</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">></phrase> <phrase role="keyword">const</phrase><phrase role="special">&)></phrase> <phrase role="identifier">post</phrase>
8456 <phrase role="special">=</phrase> <phrase role="special">[&]</phrase> <phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">result</phrase><phrase role="special">,</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">></phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">old_x</phrase><phrase role="special">)</phrase>
8457 <phrase role="special">{</phrase>
8458 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">x</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_x</phrase> <phrase role="special">+</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase>
8459 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">result</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_x</phrase><phrase role="special">);</phrase>
8460 <phrase role="special">}</phrase>
8461 <phrase role="special">);</phrase>
8463 <phrase role="comment">// Implementation (in definition).</phrase>
8464 <phrase role="keyword">int</phrase> <phrase role="identifier">inc</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase><phrase role="special">&</phrase> <phrase role="identifier">x</phrase><phrase role="special">,</phrase>
8465 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">function</phrase><phrase role="special"><</phrase><phrase role="keyword">void</phrase> <phrase role="special">()></phrase> <phrase role="identifier">pre</phrase><phrase role="special">,</phrase>
8466 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">function</phrase><phrase role="special"><</phrase><phrase role="keyword">void</phrase> <phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&,</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">></phrase> <phrase role="keyword">const</phrase><phrase role="special">&)></phrase> <phrase role="identifier">post</phrase>
8467 <phrase role="special">)</phrase> <phrase role="special">{</phrase>
8468 <phrase role="keyword">int</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
8469 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">></phrase> <phrase role="identifier">old_x</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">x</phrase><phrase role="special">);</phrase>
8470 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">function</phrase><phrase role="special">()</phrase>
8471 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">(</phrase><phrase role="identifier">pre</phrase><phrase role="special">)</phrase>
8472 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">(</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">bind</phrase><phrase role="special">(</phrase><phrase role="identifier">post</phrase><phrase role="special">,</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">cref</phrase><phrase role="special">(</phrase><phrase role="identifier">result</phrase><phrase role="special">),</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">cref</phrase><phrase role="special">(</phrase><phrase role="identifier">old_x</phrase><phrase role="special">)))</phrase>
8473 <phrase role="special">;</phrase>
8475 <phrase role="keyword">return</phrase> <phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="identifier">x</phrase><phrase role="special">++;</phrase> <phrase role="comment">// Function body.</phrase>
8476 <phrase role="special">}</phrase>
8478 In any case, even if the above code compiled, it would require significant
8479 boiler-plate code to bind return and old values.
8484 For example, the following header file only contains function declarations,
8485 contract code, and constructor member initializations, but it does not contain
8486 the code implementing the function bodies (see <ulink url="../../example/features/separate_body.hpp"><literal moreinfo="none">separate_body.hpp</literal></ulink>):
8489 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">class</phrase> <phrase role="identifier">iarray</phrase> <phrase role="special">:</phrase>
8490 <phrase role="keyword">private</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor_precondition</phrase><phrase role="special"><</phrase><phrase role="identifier">iarray</phrase><phrase role="special">></phrase> <phrase role="special">{</phrase>
8491 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
8492 <phrase role="keyword">void</phrase> <phrase role="identifier">invariant</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
8493 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special"><=</phrase> <phrase role="identifier">capacity</phrase><phrase role="special">());</phrase>
8494 <phrase role="special">}</phrase>
8496 <phrase role="keyword">explicit</phrase> <phrase role="identifier">iarray</phrase><phrase role="special">(</phrase><phrase role="keyword">unsigned</phrase> <phrase role="identifier">max</phrase><phrase role="special">,</phrase> <phrase role="keyword">unsigned</phrase> <phrase role="identifier">count</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="special">:</phrase>
8497 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor_precondition</phrase><phrase role="special"><</phrase><phrase role="identifier">iarray</phrase><phrase role="special">>([&]</phrase> <phrase role="special">{</phrase>
8498 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase> <phrase role="special"><=</phrase> <phrase role="identifier">max</phrase><phrase role="special">);</phrase>
8499 <phrase role="special">}),</phrase>
8500 <phrase role="comment">// Still, member initializations must be here.</phrase>
8501 <phrase role="identifier">values_</phrase><phrase role="special">(</phrase><phrase role="keyword">new</phrase> <phrase role="keyword">int</phrase><phrase role="special">[</phrase><phrase role="identifier">max</phrase><phrase role="special">]),</phrase>
8502 <phrase role="identifier">capacity_</phrase><phrase role="special">(</phrase><phrase role="identifier">max</phrase><phrase role="special">)</phrase>
8503 <phrase role="special">{</phrase>
8504 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
8505 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
8506 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">capacity</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">max</phrase><phrase role="special">);</phrase>
8507 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">count</phrase><phrase role="special">);</phrase>
8508 <phrase role="special">})</phrase>
8509 <phrase role="special">;</phrase>
8510 <phrase role="identifier">constructor_body</phrase><phrase role="special">(</phrase><phrase role="identifier">max</phrase><phrase role="special">,</phrase> <phrase role="identifier">count</phrase><phrase role="special">);</phrase> <phrase role="comment">// Separate constructor body impl.</phrase>
8511 <phrase role="special">}</phrase>
8513 <phrase role="keyword">virtual</phrase> <phrase role="special">~</phrase><phrase role="identifier">iarray</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
8514 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">destructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase> <phrase role="comment">// Inv.</phrase>
8515 <phrase role="identifier">destructor_body</phrase><phrase role="special">();</phrase> <phrase role="comment">// Separate destructor body implementation.</phrase>
8516 <phrase role="special">}</phrase>
8518 <phrase role="keyword">virtual</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">push_back</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">value</phrase><phrase role="special">,</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
8519 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">unsigned</phrase><phrase role="special">></phrase> <phrase role="identifier">old_size</phrase> <phrase role="special">=</phrase>
8520 <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">size</phrase><phrase role="special">());</phrase>
8521 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">)</phrase>
8522 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
8523 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special"><</phrase> <phrase role="identifier">capacity</phrase><phrase role="special">());</phrase>
8524 <phrase role="special">})</phrase>
8525 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
8526 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_size</phrase> <phrase role="special">+</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase>
8527 <phrase role="special">})</phrase>
8528 <phrase role="special">;</phrase>
8529 <phrase role="identifier">push_back_body</phrase><phrase role="special">(</phrase><phrase role="identifier">value</phrase><phrase role="special">);</phrase> <phrase role="comment">// Separate member function body implementation.</phrase>
8530 <phrase role="special">}</phrase>
8532 <phrase role="keyword">private</phrase><phrase role="special">:</phrase>
8533 <phrase role="comment">// Contracts in class declaration (above), but body implementations are not.</phrase>
8534 <phrase role="keyword">void</phrase> <phrase role="identifier">constructor_body</phrase><phrase role="special">(</phrase><phrase role="keyword">unsigned</phrase> <phrase role="identifier">max</phrase><phrase role="special">,</phrase> <phrase role="keyword">unsigned</phrase> <phrase role="identifier">count</phrase><phrase role="special">);</phrase>
8535 <phrase role="keyword">void</phrase> <phrase role="identifier">destructor_body</phrase><phrase role="special">();</phrase>
8536 <phrase role="keyword">void</phrase> <phrase role="identifier">push_back_body</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">value</phrase><phrase role="special">);</phrase>
8538 <phrase role="comment">/* ... */</phrase>
8542 Instead, the function bodies are implemented in a separate source file (see
8543 <ulink url="../../example/features/separate_body.cpp"><literal moreinfo="none">separate_body.cpp</literal></ulink>):
8546 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">void</phrase> <phrase role="identifier">iarray</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor_body</phrase><phrase role="special">(</phrase><phrase role="keyword">unsigned</phrase> <phrase role="identifier">max</phrase><phrase role="special">,</phrase> <phrase role="keyword">unsigned</phrase> <phrase role="identifier">count</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
8547 <phrase role="keyword">for</phrase><phrase role="special">(</phrase><phrase role="keyword">unsigned</phrase> <phrase role="identifier">i</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase> <phrase role="identifier">i</phrase> <phrase role="special"><</phrase> <phrase role="identifier">count</phrase><phrase role="special">;</phrase> <phrase role="special">++</phrase><phrase role="identifier">i</phrase><phrase role="special">)</phrase> <phrase role="identifier">values_</phrase><phrase role="special">[</phrase><phrase role="identifier">i</phrase><phrase role="special">]</phrase> <phrase role="special">=</phrase> <phrase role="keyword">int</phrase><phrase role="special">();</phrase>
8548 <phrase role="identifier">size_</phrase> <phrase role="special">=</phrase> <phrase role="identifier">count</phrase><phrase role="special">;</phrase>
8549 <phrase role="special">}</phrase>
8551 <phrase role="keyword">void</phrase> <phrase role="identifier">iarray</phrase><phrase role="special">::</phrase><phrase role="identifier">destructor_body</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase> <phrase role="keyword">delete</phrase><phrase role="special">[]</phrase> <phrase role="identifier">values_</phrase><phrase role="special">;</phrase> <phrase role="special">}</phrase>
8553 <phrase role="keyword">void</phrase> <phrase role="identifier">iarray</phrase><phrase role="special">::</phrase><phrase role="identifier">push_back_body</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">value</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase> <phrase role="identifier">values_</phrase><phrase role="special">[</phrase><phrase role="identifier">size_</phrase><phrase role="special">++]</phrase> <phrase role="special">=</phrase> <phrase role="identifier">value</phrase><phrase role="special">;</phrase> <phrase role="special">}</phrase>
8555 <phrase role="comment">/* ... */</phrase>
8559 The same technique can be used for non-member, private, and protected functions,
8564 When contracts are programmed only in <literal moreinfo="none">.cpp</literal> files and
8565 also all this library headers are <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#include</phrase></computeroutput>d
8566 only from <literal moreinfo="none">.cpp</literal> files, then these <literal moreinfo="none">.cpp</literal>
8567 files can be compiled disabling specific contract checking (for example,
8568 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394999656032">BOOST_CONTRACT_NO_POSTCONDITIONS</link></computeroutput>,
8569 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_NO_EXCEPTS">BOOST_CONTRACT_NO_EXCEPTS</link></computeroutput>,
8570 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394999629648">BOOST_CONTRACT_NO_EXIT_INVARIANTS</link></computeroutput>,
8571 see <link linkend="boost_contract.extras.disable_contract_checking">Disable
8572 Contract Checking</link>). Then the code in these <literal moreinfo="none">.cpp</literal>
8573 files will always have such contract checking disabled even when linked
8574 to some other user code that might have been compiled with a different
8575 set of contracts disabled (i.e., a different set of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">BOOST_CONTRACT_NO_</phrase><phrase role="special">...</phrase></computeroutput> macros defined). This technique might
8576 be useful to ship compiled object files (e.g., for a library) that will
8577 never check some contracts (e.g., postconditions, exception guarantees,
8578 and exit invariants) regardless of the definition of the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">BOOST_CONTRACT_NO_</phrase><phrase role="special">...</phrase></computeroutput>
8579 macros used to compile code that links against the shipped object files.
8582 On the flip side, if contracts are programmed only in header files (e.g.,
8583 using extra <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">...</phrase><phrase role="identifier">_body</phrase></computeroutput>
8584 functions as shown in this section) and this library headers are <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#include</phrase></computeroutput>d only in these header files
8585 that are being shipped, then end users can enable or disables contract
8586 checking of the shipped code by defining the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">BOOST_CONTRACT_NO_</phrase><phrase role="special">...</phrase></computeroutput> macros when they compile the shipped
8587 header files as part of their code. This technique might be useful in other
8588 situations when programmers that ship code want to leave it up the their
8589 end users to decide which contracts of the shipped code should be checked
8594 <section id="boost_contract.extras.no_lambda_functions__no_c__11_">
8595 <title><link linkend="boost_contract.extras.no_lambda_functions__no_c__11_">No
8596 Lambda Functions (No C++11)</link></title>
8598 This section shows how to use this library without C++11 lambda functions.
8599 This has some advantages:
8604 It allows to use this library on compilers that do not support C++11
8605 lambda functions (essentially most C++03 compilers with adequate support
8606 for SFINAE can be used in that case, see <link linkend="boost_contract.extras.no_macros__and_no_variadic_macros_">No
8607 Macros</link> to also avoid using variadic macros). <footnote id="boost_contract.extras.no_lambda_functions__no_c__11_.f0">
8609 Alternatively, on compilers that do not support C++11 lambda functions,
8610 <ulink url="http://www.boost.org/doc/libs/release/libs/local_function/doc/html/index.html">Boost.LocalFunction</ulink>
8611 could be used to program the contract functors still within the function
8612 definitions (for example, see <ulink url="../../example/features/no_lambdas_local_func.cpp"><literal moreinfo="none">no_lambda_local_func.cpp</literal></ulink>).
8613 In general, such a code is less verbose than the example shown in this
8614 section that uses contract functions programmed outside of the original
8615 function definitions (about 30% less lines of code) but the contract
8616 code is hard to read. Other libraries could also be used to program
8617 the contract functors without C++11 lambda functions (Boost.Lambda,
8618 Boost.Fusion, etc.) but again all these techniques will result in contract
8619 code either more verbose, or harder to read and maintain than the code
8620 that uses C++11 lambda functions.
8627 Contract functions (i.e., the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">...</phrase><phrase role="identifier">_precondition</phrase></computeroutput>, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">...</phrase><phrase role="identifier">_old</phrase></computeroutput>, and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">...</phrase><phrase role="identifier">_postcondition</phrase></computeroutput> functions in the example
8628 below) can be programmed to fully enforce constant-correctness and other
8629 contract requirements at compile-time (see <link linkend="boost_contract.contract_programming_overview.constant_correctness">Constant-Correctness</link>).
8630 <footnote id="boost_contract.extras.no_lambda_functions__no_c__11_.f1">
8632 If C++ allowed lambda functions to capture variables by constant reference
8633 (for example allowing a syntax like this <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">[</phrase><phrase role="keyword">const</phrase><phrase role="special">&]</phrase>
8634 <phrase role="special">{</phrase> <phrase role="special">...</phrase>
8635 <phrase role="special">}</phrase></computeroutput> and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">[</phrase><phrase role="keyword">const</phrase><phrase role="special">&</phrase>
8636 </computeroutput><literal moreinfo="none"><emphasis>variable-name</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="special">...</phrase> <phrase role="special">}</phrase></computeroutput>,
8637 see <ulink url="https://groups.google.com/a/isocpp.org/forum/#!topic/std-proposals/0UKQw9eo3N0">https://groups.google.com/a/isocpp.org/forum/#!topic/std-proposals/0UKQw9eo3N0</ulink>)
8638 also lambdas could be used to program contract functors that fully
8639 enforce <link linkend="boost_contract.contract_programming_overview.constant_correctness">Constant-Correctness</link>
8640 at compile-time. Note that C++11 lambdas allow to capture variables
8641 by value (using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">[=]</phrase> <phrase role="special">{</phrase>
8642 <phrase role="special">...</phrase> <phrase role="special">}</phrase></computeroutput>
8643 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">[</phrase></computeroutput><literal moreinfo="none"><emphasis>variable-name</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="special">...</phrase> <phrase role="special">}</phrase></computeroutput>)
8644 and these value captures are <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase></computeroutput>
8645 (unless the lambda is explicitly declared <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">mutable</phrase></computeroutput>)
8646 but they are not suitable to program postconditions and exception guarantees
8647 using this library (because those require capturing by reference, see
8648 <link linkend="boost_contract.tutorial.postconditions">Postconditions</link>
8649 and <link linkend="boost_contract.tutorial.exception_guarantees">Exception
8650 Guarantees</link>), plus they introduce a copy of the captured value
8651 that might be too expensive in general and therefore not suitable for
8652 preconditions either.
8659 Code of the contract functions is separated from function body implementations
8660 (see <link linkend="boost_contract.extras.separate_body_implementation">Separate
8661 Body Implementation</link>).
8666 However, not using C++11 lambda functions comes at the significant cost of
8667 having to manually program the extra contract functions and related boiler-plate
8668 code. For example, the header file (see <ulink url="../../example/features/no_lambdas.hpp"><literal moreinfo="none">no_lambdas.hpp</literal></ulink>):
8671 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">class</phrase> <phrase role="identifier">iarray</phrase> <phrase role="special">:</phrase>
8672 <phrase role="keyword">private</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor_precondition</phrase><phrase role="special"><</phrase><phrase role="identifier">iarray</phrase><phrase role="special">></phrase> <phrase role="special">{</phrase>
8673 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
8674 <phrase role="keyword">static</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">static_invariant</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
8675 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">instances</phrase><phrase role="special">()</phrase> <phrase role="special">>=</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase>
8676 <phrase role="special">}</phrase>
8678 <phrase role="keyword">void</phrase> <phrase role="identifier">invariant</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
8679 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special"><=</phrase> <phrase role="identifier">capacity</phrase><phrase role="special">());</phrase>
8680 <phrase role="special">}</phrase>
8682 <phrase role="keyword">explicit</phrase> <phrase role="identifier">iarray</phrase><phrase role="special">(</phrase><phrase role="keyword">unsigned</phrase> <phrase role="identifier">max</phrase><phrase role="special">,</phrase> <phrase role="keyword">unsigned</phrase> <phrase role="identifier">count</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase>
8683 <phrase role="keyword">static</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">constructor_precondition</phrase><phrase role="special">(</phrase><phrase role="keyword">unsigned</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">max</phrase><phrase role="special">,</phrase>
8684 <phrase role="keyword">unsigned</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">count</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
8685 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase> <phrase role="special"><=</phrase> <phrase role="identifier">max</phrase><phrase role="special">);</phrase>
8686 <phrase role="special">}</phrase>
8687 <phrase role="keyword">static</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">constructor_old</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">>&</phrase>
8688 <phrase role="identifier">old_instances</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
8689 <phrase role="identifier">old_instances</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">instances</phrase><phrase role="special">());</phrase>
8690 <phrase role="special">}</phrase>
8691 <phrase role="keyword">void</phrase> <phrase role="identifier">constructor_postcondition</phrase><phrase role="special">(</phrase><phrase role="keyword">unsigned</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">max</phrase><phrase role="special">,</phrase> <phrase role="keyword">unsigned</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">count</phrase><phrase role="special">,</phrase>
8692 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">></phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">old_instances</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
8693 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">capacity</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">max</phrase><phrase role="special">);</phrase>
8694 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">count</phrase><phrase role="special">);</phrase>
8695 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">instances</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_instances</phrase> <phrase role="special">+</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase>
8696 <phrase role="special">}</phrase>
8698 <phrase role="keyword">virtual</phrase> <phrase role="special">~</phrase><phrase role="identifier">iarray</phrase><phrase role="special">();</phrase>
8699 <phrase role="keyword">void</phrase> <phrase role="identifier">destructor_old</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">>&</phrase> <phrase role="identifier">old_instances</phrase><phrase role="special">)</phrase>
8700 <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
8701 <phrase role="identifier">old_instances</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">instances</phrase><phrase role="special">());</phrase>
8702 <phrase role="special">}</phrase>
8703 <phrase role="keyword">static</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">destructor_postcondition</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">></phrase> <phrase role="keyword">const</phrase>
8704 <phrase role="identifier">old_instances</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
8705 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">instances</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_instances</phrase> <phrase role="special">-</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase>
8706 <phrase role="special">}</phrase>
8708 <phrase role="keyword">virtual</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">push_back</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">value</phrase><phrase role="special">,</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase>
8709 <phrase role="keyword">void</phrase> <phrase role="identifier">push_back_precondition</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
8710 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special"><</phrase> <phrase role="identifier">capacity</phrase><phrase role="special">());</phrase>
8711 <phrase role="special">}</phrase>
8712 <phrase role="keyword">void</phrase> <phrase role="identifier">push_back_old</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase><phrase role="special">,</phrase>
8713 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">unsigned</phrase><phrase role="special">>&</phrase> <phrase role="identifier">old_size</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
8714 <phrase role="identifier">old_size</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">size</phrase><phrase role="special">());</phrase>
8715 <phrase role="special">}</phrase>
8716 <phrase role="keyword">void</phrase> <phrase role="identifier">push_back_postcondition</phrase><phrase role="special">(</phrase>
8717 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">unsigned</phrase><phrase role="special">></phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">old_size</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
8718 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_size</phrase> <phrase role="special">+</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase>
8719 <phrase role="special">}</phrase>
8721 <phrase role="keyword">unsigned</phrase> <phrase role="identifier">capacity</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase><phrase role="special">;</phrase>
8722 <phrase role="keyword">unsigned</phrase> <phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase><phrase role="special">;</phrase>
8724 <phrase role="keyword">static</phrase> <phrase role="keyword">int</phrase> <phrase role="identifier">instances</phrase><phrase role="special">();</phrase>
8726 <phrase role="keyword">private</phrase><phrase role="special">:</phrase>
8727 <phrase role="keyword">int</phrase><phrase role="special">*</phrase> <phrase role="identifier">values_</phrase><phrase role="special">;</phrase>
8728 <phrase role="keyword">unsigned</phrase> <phrase role="identifier">capacity_</phrase><phrase role="special">;</phrase>
8729 <phrase role="keyword">unsigned</phrase> <phrase role="identifier">size_</phrase><phrase role="special">;</phrase>
8730 <phrase role="keyword">static</phrase> <phrase role="keyword">int</phrase> <phrase role="identifier">instances_</phrase><phrase role="special">;</phrase>
8731 <phrase role="special">};</phrase>
8735 And, the source file (see <ulink url="../../example/features/no_lambdas.cpp"><literal moreinfo="none">no_lambdas.cpp</literal></ulink>):
8738 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">iarray</phrase><phrase role="special">::</phrase><phrase role="identifier">iarray</phrase><phrase role="special">(</phrase><phrase role="keyword">unsigned</phrase> <phrase role="identifier">max</phrase><phrase role="special">,</phrase> <phrase role="keyword">unsigned</phrase> <phrase role="identifier">count</phrase><phrase role="special">)</phrase> <phrase role="special">:</phrase>
8739 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor_precondition</phrase><phrase role="special"><</phrase><phrase role="identifier">iarray</phrase><phrase role="special">>(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">bind</phrase><phrase role="special">(</phrase>
8740 <phrase role="special">&</phrase><phrase role="identifier">iarray</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor_precondition</phrase><phrase role="special">,</phrase> <phrase role="identifier">max</phrase><phrase role="special">,</phrase> <phrase role="identifier">count</phrase><phrase role="special">)),</phrase>
8741 <phrase role="identifier">values_</phrase><phrase role="special">(</phrase><phrase role="keyword">new</phrase> <phrase role="keyword">int</phrase><phrase role="special">[</phrase><phrase role="identifier">max</phrase><phrase role="special">]),</phrase> <phrase role="comment">// Member initializations can be here.</phrase>
8742 <phrase role="identifier">capacity_</phrase><phrase role="special">(</phrase><phrase role="identifier">max</phrase><phrase role="special">)</phrase>
8743 <phrase role="special">{</phrase>
8744 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">></phrase> <phrase role="identifier">old_instances</phrase><phrase role="special">;</phrase>
8745 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
8746 <phrase role="special">.</phrase><phrase role="identifier">old</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">bind</phrase><phrase role="special">(&</phrase><phrase role="identifier">iarray</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor_old</phrase><phrase role="special">,</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">ref</phrase><phrase role="special">(</phrase><phrase role="identifier">old_instances</phrase><phrase role="special">)))</phrase>
8747 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">bind</phrase><phrase role="special">(</phrase>
8748 <phrase role="special">&</phrase><phrase role="identifier">iarray</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor_postcondition</phrase><phrase role="special">,</phrase>
8749 <phrase role="keyword">this</phrase><phrase role="special">,</phrase>
8750 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">cref</phrase><phrase role="special">(</phrase><phrase role="identifier">max</phrase><phrase role="special">),</phrase>
8751 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">cref</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">),</phrase>
8752 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">cref</phrase><phrase role="special">(</phrase><phrase role="identifier">old_instances</phrase><phrase role="special">)</phrase>
8753 <phrase role="special">))</phrase>
8754 <phrase role="special">;</phrase>
8756 <phrase role="keyword">for</phrase><phrase role="special">(</phrase><phrase role="keyword">unsigned</phrase> <phrase role="identifier">i</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase> <phrase role="identifier">i</phrase> <phrase role="special"><</phrase> <phrase role="identifier">count</phrase><phrase role="special">;</phrase> <phrase role="special">++</phrase><phrase role="identifier">i</phrase><phrase role="special">)</phrase> <phrase role="identifier">values_</phrase><phrase role="special">[</phrase><phrase role="identifier">i</phrase><phrase role="special">]</phrase> <phrase role="special">=</phrase> <phrase role="keyword">int</phrase><phrase role="special">();</phrase>
8757 <phrase role="identifier">size_</phrase> <phrase role="special">=</phrase> <phrase role="identifier">count</phrase><phrase role="special">;</phrase>
8758 <phrase role="special">++</phrase><phrase role="identifier">instances_</phrase><phrase role="special">;</phrase>
8759 <phrase role="special">}</phrase>
8761 <phrase role="identifier">iarray</phrase><phrase role="special">::~</phrase><phrase role="identifier">iarray</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
8762 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">></phrase> <phrase role="identifier">old_instances</phrase><phrase role="special">;</phrase>
8763 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">destructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
8764 <phrase role="special">.</phrase><phrase role="identifier">old</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">bind</phrase><phrase role="special">(&</phrase><phrase role="identifier">iarray</phrase><phrase role="special">::</phrase><phrase role="identifier">destructor_old</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">,</phrase>
8765 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">ref</phrase><phrase role="special">(</phrase><phrase role="identifier">old_instances</phrase><phrase role="special">)))</phrase>
8766 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">bind</phrase><phrase role="special">(&</phrase><phrase role="identifier">iarray</phrase><phrase role="special">::</phrase><phrase role="identifier">destructor_postcondition</phrase><phrase role="special">,</phrase>
8767 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">cref</phrase><phrase role="special">(</phrase><phrase role="identifier">old_instances</phrase><phrase role="special">)))</phrase>
8768 <phrase role="special">;</phrase>
8770 <phrase role="keyword">delete</phrase><phrase role="special">[]</phrase> <phrase role="identifier">values_</phrase><phrase role="special">;</phrase>
8771 <phrase role="special">--</phrase><phrase role="identifier">instances_</phrase><phrase role="special">;</phrase>
8772 <phrase role="special">}</phrase>
8774 <phrase role="keyword">void</phrase> <phrase role="identifier">iarray</phrase><phrase role="special">::</phrase><phrase role="identifier">push_back</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">value</phrase><phrase role="special">,</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
8775 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">unsigned</phrase><phrase role="special">></phrase> <phrase role="identifier">old_size</phrase><phrase role="special">;</phrase>
8776 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">)</phrase>
8777 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">bind</phrase><phrase role="special">(&</phrase><phrase role="identifier">iarray</phrase><phrase role="special">::</phrase><phrase role="identifier">push_back_precondition</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">))</phrase>
8778 <phrase role="special">.</phrase><phrase role="identifier">old</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">bind</phrase><phrase role="special">(&</phrase><phrase role="identifier">iarray</phrase><phrase role="special">::</phrase><phrase role="identifier">push_back_old</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">,</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">cref</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">),</phrase>
8779 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">ref</phrase><phrase role="special">(</phrase><phrase role="identifier">old_size</phrase><phrase role="special">)))</phrase>
8780 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">bind</phrase><phrase role="special">(&</phrase><phrase role="identifier">iarray</phrase><phrase role="special">::</phrase><phrase role="identifier">push_back_postcondition</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">,</phrase>
8781 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">cref</phrase><phrase role="special">(</phrase><phrase role="identifier">old_size</phrase><phrase role="special">)))</phrase>
8782 <phrase role="special">;</phrase>
8784 <phrase role="identifier">values_</phrase><phrase role="special">[</phrase><phrase role="identifier">size_</phrase><phrase role="special">++]</phrase> <phrase role="special">=</phrase> <phrase role="identifier">value</phrase><phrase role="special">;</phrase>
8785 <phrase role="special">}</phrase>
8787 <phrase role="keyword">unsigned</phrase> <phrase role="identifier">iarray</phrase><phrase role="special">::</phrase><phrase role="identifier">capacity</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
8788 <phrase role="comment">// Check invariants.</phrase>
8789 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
8790 <phrase role="keyword">return</phrase> <phrase role="identifier">capacity_</phrase><phrase role="special">;</phrase>
8791 <phrase role="special">}</phrase>
8793 <phrase role="keyword">unsigned</phrase> <phrase role="identifier">iarray</phrase><phrase role="special">::</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
8794 <phrase role="comment">// Check invariants.</phrase>
8795 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
8796 <phrase role="keyword">return</phrase> <phrase role="identifier">size_</phrase><phrase role="special">;</phrase>
8797 <phrase role="special">}</phrase>
8799 <phrase role="keyword">int</phrase> <phrase role="identifier">iarray</phrase><phrase role="special">::</phrase><phrase role="identifier">instances</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
8800 <phrase role="comment">// Check static invariants.</phrase>
8801 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special"><</phrase><phrase role="identifier">iarray</phrase><phrase role="special">>();</phrase>
8802 <phrase role="keyword">return</phrase> <phrase role="identifier">instances_</phrase><phrase role="special">;</phrase>
8803 <phrase role="special">}</phrase>
8805 <phrase role="keyword">int</phrase> <phrase role="identifier">iarray</phrase><phrase role="special">::</phrase><phrase role="identifier">instances_</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase>
8809 If programmers also want to fully enforce all contract programming constant-correctness
8810 requirements at compile-time, they should follow these rules when programming
8811 the contract functions (see <link linkend="boost_contract.contract_programming_overview.constant_correctness">Constant-Correctness</link>):
8816 Precondition functions (i.e., the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">...</phrase><phrase role="identifier">_precondition</phrase></computeroutput> functions in the example
8817 above) can take their arguments either by <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase></computeroutput>
8818 value or by <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase><phrase role="special">&</phrase></computeroutput>,
8819 and when they are member functions they should be either <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">static</phrase></computeroutput> or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase></computeroutput>
8825 Postcondition functions (i.e., the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">...</phrase><phrase role="identifier">_postcondition</phrase></computeroutput> functions in the example
8826 above) should take their arguments by <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase><phrase role="special">&</phrase></computeroutput>, and when they are member functions
8827 they should be either <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">static</phrase></computeroutput>
8828 or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase></computeroutput> functions.
8833 Similarly, exception guarantee functions (not shown in the example above)
8834 should take their arguments by <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase><phrase role="special">&</phrase></computeroutput>, and when they are member functions
8835 they should be either <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">static</phrase></computeroutput>
8836 or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase></computeroutput> functions.
8841 Old value functions (i.e., the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">...</phrase><phrase role="identifier">_old</phrase></computeroutput> functions in the example above)
8842 should take their arguments by <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase><phrase role="special">&</phrase></computeroutput> a part from old value pointers that
8843 should be taken by <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">&</phrase></computeroutput>
8844 (so only old value pointers can be modified), and when they are member
8845 functions they should be either <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">static</phrase></computeroutput>
8846 or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase></computeroutput> functions.
8851 For constructors: Precondition, old value, and exception guarantee functions
8852 should be <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">static</phrase></computeroutput> (because
8853 there is no valid object <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">this</phrase></computeroutput>
8854 if the constructor body does not run successfully, see <link linkend="boost_contract.contract_programming_overview.constructor_calls">Constructor
8860 For destructors: Postcondition functions should be <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">static</phrase></computeroutput>
8861 (because there is no valid object <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">this</phrase></computeroutput>
8862 after the destructor body runs successfully, but exception guarantee
8863 functions do not have to be <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">static</phrase></computeroutput>
8864 since the object <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">this</phrase></computeroutput> is
8865 still valid because the destructor body did not run successfully, see
8866 <link linkend="boost_contract.contract_programming_overview.destructor_calls">Destructor
8872 Note that the extra contract functions also allow to keep the contract code
8873 in the header file while all function bodies are implemented in a separate
8874 source file (including the constructor member initialization list, that could
8875 not be done with the techniques shown in <link linkend="boost_contract.extras.separate_body_implementation">Separate
8876 Body Implementation</link>). <footnote id="boost_contract.extras.no_lambda_functions__no_c__11_.f2">
8878 In this example, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">bind</phrase></computeroutput> was
8879 used to generate nullary functors from the contract functions. As always
8880 with <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">bind</phrase></computeroutput>, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">cref</phrase></computeroutput> and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">ref</phrase></computeroutput>
8881 must be used to bind arguments by <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase><phrase role="special">&</phrase></computeroutput> and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">&</phrase></computeroutput>
8882 respectively, plus it might be necessary to explicitly <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">static_cast</phrase></computeroutput>
8883 the function pointer passed to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">bind</phrase></computeroutput>
8884 for overloaded functions.
8886 </footnote> Also note that the contract functions can always be declared
8887 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">private</phrase></computeroutput> if programmers need
8888 to exactly control the public members of the class (this was not done in
8889 this example only for brevity).
8892 The authors think this library is most useful when used together with C++11
8893 lambda functions (because of the large amount of boiler-plate code required
8894 when C++11 lambdas are not used as also shown by the example above).
8897 <section id="boost_contract.extras.no_macros__and_no_variadic_macros_">
8898 <title><link linkend="boost_contract.extras.no_macros__and_no_variadic_macros_">No
8899 Macros (and No Variadic Macros)</link></title>
8901 It is possible to specify contracts without using most of the macros provided
8902 by this library and programming the related code manually instead (the only
8903 macros that cannot be programmed manually are <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_OVERRIDE">BOOST_CONTRACT_OVERRIDE</link></computeroutput>,
8904 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_OVERRIDES">BOOST_CONTRACT_OVERRIDES</link></computeroutput>,
8905 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394998912688">BOOST_CONTRACT_NAMED_OVERRIDE</link></computeroutput>).
8909 Some of this library macros are variadic macros, others are not (see below).
8910 Variadic macros were officially added to the language in C++11 but most
8911 compilers have been supporting them as an extension for a long time, plus
8912 all compilers that support C++11 lambda functions should also support C++11
8913 variadic macros (and this library might rarely be used without the convenience
8914 of C++11 lambda functions, see <link linkend="boost_contract.extras.no_lambda_functions__no_c__11_">No
8915 Lambda Functions</link>). <footnote id="boost_contract.extras.no_macros__and_no_variadic_macros_.f0">
8917 Compilation times of this library were measured to be comparable between
8918 compilers that support variadic macros and compilers that do not.
8920 </footnote> Therefore, the rest of this section can be considered mainly
8921 a curiosity because programmers should seldom, if ever, need to use this
8922 library without using its macros.
8925 <bridgehead renderas="sect4" id="boost_contract.extras.no_macros__and_no_variadic_macros_.h0">
8926 <phrase id="boost_contract.extras.no_macros__and_no_variadic_macros_.overrides"/><link linkend="boost_contract.extras.no_macros__and_no_variadic_macros_.overrides">Overrides</link>
8929 As shown in <link linkend="boost_contract.tutorial.public_function_overrides__subcontracting_">Public
8930 Function Overrides</link> and <link linkend="boost_contract.advanced.named_overrides">Named
8931 Overrides</link>, this library provides the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_OVERRIDE">BOOST_CONTRACT_OVERRIDE</link></computeroutput>
8932 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45394998912688">BOOST_CONTRACT_NAMED_OVERRIDE</link></computeroutput>
8933 macros to program contracts for overriding public functions (see <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_MAX_ARGS">BOOST_CONTRACT_MAX_ARGS</link></computeroutput> for compilers
8934 that do not support variadic templates). <footnote id="boost_contract.extras.no_macros__and_no_variadic_macros_.f1">
8936 <emphasis role="bold">Rationale:</emphasis> The <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_MAX_ARGS">BOOST_CONTRACT_MAX_ARGS</link></computeroutput>
8937 macro is named after <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">BOOST_FUNCTION_MAX_ARGS</phrase></computeroutput>.
8939 </footnote> These macro cannot be programmed manually but they are not variadic
8940 macros (so programmers should be able to use them on any C++ compiler with
8941 a sound support for SFINAE). <footnote id="boost_contract.extras.no_macros__and_no_variadic_macros_.f2">
8943 <emphasis role="bold">Rationale:</emphasis> These macros expand to SFINAE-based
8944 introspection template code that are too complex to be programmed manually
8945 by users (that remains the case even if C++14 generic lambdas were to be
8946 used here). On a related note, in theory using C++14 generic lambdas, the
8947 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_OVERRIDE">BOOST_CONTRACT_OVERRIDE</link></computeroutput>
8948 macro could be re-implemented in a way that can be expanded at function
8949 scope, instead of class scope (but there is not really a need to do that).
8951 </footnote> The <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_OVERRIDES">BOOST_CONTRACT_OVERRIDES</link></computeroutput>
8952 macro is a variadic macro instead but programmes can manually repeat the
8953 non-variadic macro <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_OVERRIDE">BOOST_CONTRACT_OVERRIDE</link></computeroutput>
8954 for each overriding public function name on compilers that do not support
8957 <bridgehead renderas="sect4" id="boost_contract.extras.no_macros__and_no_variadic_macros_.h1">
8958 <phrase id="boost_contract.extras.no_macros__and_no_variadic_macros_.assertions__not_variadic_"/><link linkend="boost_contract.extras.no_macros__and_no_variadic_macros_.assertions__not_variadic_">Assertions
8959 (Not Variadic)</link>
8962 As shown in <link linkend="boost_contract.tutorial.preconditions">Preconditions</link>,
8963 <link linkend="boost_contract.tutorial.postconditions">Postconditions</link>,
8964 <link linkend="boost_contract.tutorial.exception_guarantees">Exception Guarantees</link>,
8965 <link linkend="boost_contract.tutorial.class_invariants">Class Invariants</link>,
8966 etc. this library provides the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_ASSERT">BOOST_CONTRACT_ASSERT</link></computeroutput>
8967 macro to assert contract conditions. This is not a variadic macro and programmers
8968 should be able to use it on all C++ compilers. In any case, the invocation
8969 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase></computeroutput><literal moreinfo="none"><emphasis>cond</emphasis></literal><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">)</phrase></computeroutput> simply expands to code equivalent to the
8970 following: <footnote id="boost_contract.extras.no_macros__and_no_variadic_macros_.f3">
8972 <emphasis role="bold">Rationale:</emphasis> There is no need for the code
8973 expanded by <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_ASSERT">BOOST_CONTRACT_ASSERT</link></computeroutput>
8974 to also use C++11 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">__func__</phrase></computeroutput>.
8975 That is because <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">__func__</phrase></computeroutput>
8976 will always expand to the name <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">operator</phrase><phrase role="special">()</phrase></computeroutput> of the functor used to program the contract
8977 assertions (e.g., the internal name the compiler assigns to lambda functions)
8978 and it will not expand to the name of the actual function enclosing the
8979 contract declaration.
8983 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">if</phrase><phrase role="special">(!(</phrase><literal moreinfo="none"><emphasis>cond</emphasis></literal><phrase role="special">))</phrase> <phrase role="special">{</phrase>
8984 <phrase role="keyword">throw</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">assertion_failure</phrase><phrase role="special">(</phrase><phrase role="identifier">__FILE__</phrase><phrase role="special">,</phrase> <phrase role="identifier">__LINE__</phrase><phrase role="special">,</phrase>
8985 <phrase role="identifier">BOOST_PP_STRINGIZE</phrase><phrase role="special">(</phrase><literal moreinfo="none"><emphasis>cond</emphasis></literal><phrase role="special">));</phrase>
8986 <phrase role="special">}</phrase>
8989 In fact, this library considers any exception thrown from within preconditions,
8990 postconditions, exception guarantees, and class invariants as a contract
8991 failure and reports it calling the related contract failure handler (<computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.precondition_failure">boost::contract::precondition_failure</link></computeroutput>,
8992 etc.). If there is a need for it, programmers can always program contract
8993 assertions that throw specific user-defined exceptions as follow (see <link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__">Throw
8994 on Failures</link>):
8996 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">if</phrase><phrase role="special">(!</phrase><literal moreinfo="none"><emphasis>cond</emphasis></literal><phrase role="special">)</phrase> <phrase role="keyword">throw</phrase> <literal moreinfo="none"><emphasis>exception-object</emphasis></literal><phrase role="special">;</phrase>
8999 However, using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_ASSERT">BOOST_CONTRACT_ASSERT</link></computeroutput>
9000 is convenient because it always allows this library to show an informative
9001 message in case of assertion failure containing the assertion code, file
9002 name, line number, etc.
9005 As shown in <link linkend="boost_contract.extras.assertion_levels">Assertion
9006 Levels</link>, this library pre-defines <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45395000817520">BOOST_CONTRACT_ASSERT_AUDIT</link></computeroutput>
9007 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CO_idm45395027441616">BOOST_CONTRACT_ASSERT_AXIOM</link></computeroutput>
9008 assertion levels. These macros are not variadic macros and programmers should
9009 be able to use them on all C++ compilers. In any case, their implementations
9010 are equivalent to the following:
9012 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#ifdef</phrase> <phrase role="identifier">BOOST_CONTRACT_AUDITS</phrase>
9013 <phrase role="preprocessor">#define</phrase> <phrase role="identifier">BOOST_CONTRACT_ASSERT_AUDIT</phrase><phrase role="special">(</phrase><literal moreinfo="none"><emphasis>cond</emphasis></literal><phrase role="special">)</phrase> <phrase role="special">\</phrase>
9014 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><literal moreinfo="none"><emphasis>cond</emphasis></literal><phrase role="special">)</phrase>
9015 <phrase role="preprocessor">#else</phrase>
9016 <phrase role="preprocessor">#define</phrase> <phrase role="identifier">BOOST_CONTRACT_ASSERT_AUDIT</phrase><phrase role="special">(</phrase><literal moreinfo="none"><emphasis>cond</emphasis></literal><phrase role="special">)</phrase> <phrase role="special">\</phrase>
9017 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="keyword">true</phrase> <phrase role="special">||</phrase> <phrase role="special">(</phrase><literal moreinfo="none"><emphasis>cond</emphasis></literal><phrase role="special">))</phrase>
9018 <phrase role="preprocessor">#endif</phrase>
9020 <phrase role="preprocessor">#define</phrase> <phrase role="identifier">BOOST_CONTRACT_ASSERT_AXIOM</phrase><phrase role="special">(</phrase><literal moreinfo="none"><emphasis>cond</emphasis></literal><phrase role="special">)</phrase> <phrase role="special">\</phrase>
9021 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="keyword">true</phrase> <phrase role="special">||</phrase> <phrase role="special">(</phrase><literal moreinfo="none"><emphasis>cond</emphasis></literal><phrase role="special">))</phrase>
9023 <bridgehead renderas="sect4" id="boost_contract.extras.no_macros__and_no_variadic_macros_.h2">
9024 <phrase id="boost_contract.extras.no_macros__and_no_variadic_macros_.base_types__variadic_"/><link linkend="boost_contract.extras.no_macros__and_no_variadic_macros_.base_types__variadic_">Base
9025 Types (Variadic)</link>
9028 As shown in <link linkend="boost_contract.tutorial.base_classes__subcontracting_">Base
9029 Classes</link>, this library provides the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_BASE_TYPES">BOOST_CONTRACT_BASE_TYPES</link></computeroutput>
9030 variadic macro to declare the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">base_types</phrase></computeroutput>
9031 member type that will expand to the list of all public bases for a derived
9032 class. Programmers can also declare <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">base_types</phrase></computeroutput>
9033 without using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_BASE_TYPES">BOOST_CONTRACT_BASE_TYPES</link></computeroutput>
9034 at the cost of writing a bit more code and increase maintenance efforts.
9035 For example (see <ulink url="../../example/features/base_types_no_macro.cpp"><literal moreinfo="none">base_types_no_macro.cpp</literal></ulink>):
9038 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">mpl</phrase><phrase role="special">/</phrase><phrase role="identifier">vector</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">></phrase>
9040 <phrase role="keyword">class</phrase> <phrase role="identifier">chars</phrase> <phrase role="special">:</phrase>
9041 <phrase role="keyword">private</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor_precondition</phrase><phrase role="special"><</phrase><phrase role="identifier">chars</phrase><phrase role="special">>,</phrase>
9042 <phrase role="keyword">public</phrase> <phrase role="identifier">unique_chars</phrase><phrase role="special">,</phrase>
9043 <phrase role="keyword">public</phrase> <phrase role="keyword">virtual</phrase> <phrase role="identifier">pushable</phrase><phrase role="special"><</phrase><phrase role="keyword">char</phrase><phrase role="special">>,</phrase>
9044 <phrase role="keyword">virtual</phrase> <phrase role="keyword">protected</phrase> <phrase role="identifier">has_size</phrase><phrase role="special">,</phrase>
9045 <phrase role="keyword">private</phrase> <phrase role="identifier">has_empty</phrase>
9046 <phrase role="special">{</phrase>
9047 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
9048 <phrase role="comment">// Program `base_types` without macros (list only public bases).</phrase>
9049 <phrase role="keyword">typedef</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">mpl</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">unique_chars</phrase><phrase role="special">,</phrase> <phrase role="identifier">pushable</phrase><phrase role="special"><</phrase><phrase role="keyword">char</phrase><phrase role="special">></phrase> <phrase role="special">></phrase> <phrase role="identifier">base_types</phrase><phrase role="special">;</phrase>
9051 <phrase role="comment">/* ... */</phrase>
9055 The <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">base_types</phrase></computeroutput> member type
9056 must be a <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">mpl</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase></computeroutput>
9057 which must list <emphasis>all and only</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">public</phrase></computeroutput>
9058 base classes (because only public bases subcontract, see <link linkend="boost_contract.contract_programming_overview.function_calls">Function
9059 Calls</link>), and in the same order these public base classes appear in
9060 the derived class inheritance list. If the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_BASE_TYPES">BOOST_CONTRACT_BASE_TYPES</link></computeroutput>
9061 macro is not used, it is the responsibility of the programmers to maintain
9062 the correct list of bases in the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">mpl</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase></computeroutput> each time the derived class inheritance
9063 list changes (this might significantly complicate maintenance).
9066 In general, it is recommended to use the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_BASE_TYPES">BOOST_CONTRACT_BASE_TYPES</link></computeroutput>
9067 macro whenever possible.
9069 <bridgehead renderas="sect4" id="boost_contract.extras.no_macros__and_no_variadic_macros_.h3">
9070 <phrase id="boost_contract.extras.no_macros__and_no_variadic_macros_.old_values__variadic_"/><link linkend="boost_contract.extras.no_macros__and_no_variadic_macros_.old_values__variadic_">Old
9071 Values (Variadic)</link>
9074 As shown in <link linkend="boost_contract.tutorial.old_values">Old Values</link>,
9075 this library provides the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_OLDOF">BOOST_CONTRACT_OLDOF</link></computeroutput>
9076 variadic macro to assign old value copies. Programmers can also assign old
9077 values without using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_OLDOF">BOOST_CONTRACT_OLDOF</link></computeroutput>
9078 at the cost of writing a bit more code manually. For example (see <ulink url="../../example/features/old_no_macro.cpp"><literal moreinfo="none">old_no_macro.cpp</literal></ulink>):
9081 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">></phrase>
9082 <phrase role="keyword">class</phrase> <phrase role="identifier">vector</phrase> <phrase role="special">{</phrase>
9083 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
9084 <phrase role="keyword">virtual</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">push_back</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">value</phrase><phrase role="special">,</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
9085 <phrase role="comment">// Program old value instead of using `OLD(size())` macro.</phrase>
9086 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">unsigned</phrase><phrase role="special">></phrase> <phrase role="identifier">old_size</phrase> <phrase role="special">=</phrase>
9087 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">make_old</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">copy_old</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">)</phrase> <phrase role="special">?</phrase>
9088 <phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">:</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">null_old</phrase><phrase role="special">())</phrase>
9089 <phrase role="special">;</phrase>
9091 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">)</phrase>
9092 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
9093 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_size</phrase> <phrase role="special">+</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase>
9094 <phrase role="special">})</phrase>
9095 <phrase role="special">;</phrase>
9097 <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">push_back</phrase><phrase role="special">(</phrase><phrase role="identifier">value</phrase><phrase role="special">);</phrase>
9098 <phrase role="special">}</phrase>
9100 <phrase role="comment">/* ... */</phrase>
9104 The ternary operator <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">copy_old</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">)</phrase>
9105 <phrase role="special">?</phrase> <phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">:</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">null_old</phrase><phrase role="special">()</phrase></computeroutput> must be used here to avoid evaluating and
9106 copying the old value expression <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">size</phrase><phrase role="special">()</phrase></computeroutput> when <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.copy_old_idm45394998944672">boost::contract::copy_old</link></computeroutput>
9107 returns <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">false</phrase></computeroutput> (because old values
9108 are not being copied when postcondition and exception guarantee checking
9109 is disabled at run-time, an overridden virtual function call is not checking
9110 postconditions or exception guarantees yet, etc.). The enclosing <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.make_old_idm45394998968720">boost::contract::make_old</link></computeroutput>
9111 copies the old value expression and creates an old value pointer. Otherwise,
9112 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.null_old">boost::contract::null_old</link></computeroutput>
9113 indicates that a null old value pointer should be created.
9116 The <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.make_old_idm45394998968720">boost::contract::make_old</link></computeroutput>
9117 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.copy_old_idm45394998944672">boost::contract::copy_old</link></computeroutput>
9118 functions are used exactly as shown above but without the extra <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">v</phrase></computeroutput> parameter when they are called from within
9119 non-virtual functions (see <link linkend="boost_contract.tutorial.public_function_overrides__subcontracting_">Public
9120 Function Overrides</link>). The old value pointer returned by <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.make_old_idm45394998968720">boost::contract::make_old</link></computeroutput>
9121 can be assigned to either <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.old_ptr">boost::contract::old_ptr</link></computeroutput>
9122 or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.old_ptr_if_copyable">boost::contract::old_ptr_if_copyable</link></computeroutput>
9123 (see <link linkend="boost_contract.extras.old_value_requirements__templates_">Old
9124 Value Requirements</link>).
9127 In general, it is recommended to use the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="BOOST_CONTRACT_OLDOF">BOOST_CONTRACT_OLDOF</link></computeroutput>
9128 macro whenever possible.
9130 <bridgehead renderas="sect4" id="boost_contract.extras.no_macros__and_no_variadic_macros_.h4">
9131 <phrase id="boost_contract.extras.no_macros__and_no_variadic_macros_.macro_interface__variadic_"/><link linkend="boost_contract.extras.no_macros__and_no_variadic_macros_.macro_interface__variadic_">Macro
9132 Interface (Variadic)</link>
9135 Almost all macros defined in <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="header.boost.contract_macro_hpp">boost/contract_macro.hpp</link></computeroutput>
9136 are variadic macros. On compilers that do not support variadic macros, programmers
9137 can manually disable contract code compilation using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#ifndef</phrase>
9138 <phrase role="identifier">BOOST_CONTRACT_NO_</phrase><phrase role="special">...</phrase></computeroutput>
9139 statements as shown in <link linkend="boost_contract.extras.disable_contract_compilation__macro_interface_">Disable
9140 Contract Compilation</link>.
9144 <section id="boost_contract.examples">
9145 <title><link linkend="boost_contract.examples">Examples</link></title>
9147 This section lists some examples taken from different sources discussing contract
9148 programming and implemented here using this library.
9152 Some of these examples might be from old code, containing obsolete coding
9153 practices, not optimized for execution speed, not complete, and they might
9154 be more relevant in the context of programming languages different from C++.
9155 Nevertheless, programmers are encouraged to review these examples to see
9156 a few diverse uses of this library that might be relevant to their needs.
9160 The examples in this sections are taken from the following sources:
9165 <link linkend="N1962_anchor">[N1962]</link>: Examples from a detailed and
9166 complete proposal to add contract programming to C++11 (unfortunately,
9167 this proposal was never accepted into the standard).
9172 <link linkend="Meyer97_anchor">[Meyer97]</link>: Examples from the Eiffel
9173 programming language (reprogrammed here in C++ using this library).
9178 <link linkend="Mitchell02_anchor">[Mitchell02]</link>: Additional examples
9179 from the Eiffel programming language (reprogrammed here in C++ using this
9185 <link linkend="Cline90_anchor">[Cline90]</link>: Examples from a very early
9186 proposal called Annotated C++ (A++) to add contract programming to C++
9187 (A++ was never implemented or proposed for addition to the standard).
9192 The following are some examples of particular interest:
9197 <link linkend="N1962_vector_anchor">[N1962] Vector</link>: Complete set
9198 of contracts for <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase></computeroutput>, plus a comparison with <link linkend="N1962_anchor">[N1962]</link> syntax.
9203 <link linkend="N1962_square_root_anchor">[N1962] Square Root</link>: Comparison
9209 <link linkend="Mitchell02_counter_anchor">[Mitchell02] Counter</link>:
9215 <link linkend="Meyer97_stack4_anchor">[Meyer97] Stack4</link>: Comparison
9221 <link linkend="Cline90_vector_anchor">[Cline90] Vector</link>: Comparison
9227 Most of the examples listed here use old values and class invariants which
9228 are instead not supported by <link linkend="P0380_anchor">[P0380]</link>. Therefore,
9229 there is not meaningful example here that can be directly implemented and compared
9230 using <link linkend="P0380_anchor">[P0380]</link> syntax.
9232 <section id="boost_contract.examples.__n1962___vector__contracts_for_stl_vector_and_comparison_with___n1962___proposed_syntax">
9233 <title><anchor id="N1962_vector_anchor"/>[N1962] Vector: Contracts for STL
9234 vector and comparison with <link linkend="N1962_anchor">[N1962]</link> proposed
9237 On compilers that support C++17 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">if</phrase>
9238 <phrase role="keyword">constexpr</phrase></computeroutput>, the following example using
9239 this library can be simplified removing <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost.contract.condition_if">boost::contract::condition_if</link></computeroutput>
9240 and related functor templates such as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">all_of_equal_to</phrase></computeroutput>,
9241 etc., making it more similar to the pseudo-code on the right-hand side (see
9242 <link linkend="boost_contract.extras.assertion_requirements__templates_">Assertion
9243 Requirements</link>).
9245 <informaltable frame="all">
9256 [N1962] proposal (not accepted in C++) plus C++17 <literal moreinfo="none">if constexpr</literal>
9265 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">contract</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">></phrase>
9266 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">bind</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">></phrase>
9267 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">optional</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">></phrase>
9268 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">algorithm</phrase><phrase role="special">/</phrase><phrase role="identifier">cxx11</phrase><phrase role="special">/</phrase><phrase role="identifier">all_of</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">></phrase>
9269 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">has_equal_to</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">></phrase>
9270 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">next_prior</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">></phrase>
9271 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">vector</phrase><phrase role="special">></phrase>
9272 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">functional</phrase><phrase role="special">></phrase>
9273 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">iterator</phrase><phrase role="special">></phrase>
9274 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">memory</phrase><phrase role="special">></phrase>
9275 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">cassert</phrase><phrase role="special">></phrase>
9277 <phrase role="comment">// Could be programmed at call site with C++14 generic lambdas.</phrase>
9278 <phrase role="keyword">struct</phrase> <phrase role="identifier">all_of_equal_to</phrase> <phrase role="special">{</phrase>
9279 <phrase role="keyword">typedef</phrase> <phrase role="keyword">bool</phrase> <phrase role="identifier">result_type</phrase><phrase role="special">;</phrase>
9281 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">InputIter</phrase><phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">></phrase>
9282 <phrase role="identifier">result_type</phrase> <phrase role="keyword">operator</phrase><phrase role="special">()(</phrase><phrase role="identifier">InputIter</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">InputIter</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">value</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
9283 <phrase role="keyword">return</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">algorithm</phrase><phrase role="special">::</phrase><phrase role="identifier">all_of_equal</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="identifier">value</phrase><phrase role="special">);</phrase>
9284 <phrase role="special">}</phrase>
9286 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">InputIter</phrase><phrase role="special">></phrase>
9287 <phrase role="identifier">result_type</phrase> <phrase role="keyword">operator</phrase><phrase role="special">()(</phrase><phrase role="identifier">InputIter</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">InputIter</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="identifier">InputIter</phrase> <phrase role="identifier">where</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
9288 <phrase role="keyword">for</phrase><phrase role="special">(</phrase><phrase role="identifier">InputIter</phrase> <phrase role="identifier">i</phrase> <phrase role="special">=</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">j</phrase> <phrase role="special">=</phrase> <phrase role="identifier">where</phrase><phrase role="special">;</phrase> <phrase role="identifier">i</phrase> <phrase role="special">!=</phrase> <phrase role="identifier">last</phrase><phrase role="special">;</phrase> <phrase role="special">++</phrase><phrase role="identifier">i</phrase><phrase role="special">,</phrase> <phrase role="special">++</phrase><phrase role="identifier">j</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
9289 <phrase role="keyword">if</phrase><phrase role="special">(*</phrase><phrase role="identifier">i</phrase> <phrase role="special">!=</phrase> <phrase role="special">*</phrase><phrase role="identifier">j</phrase><phrase role="special">)</phrase> <phrase role="keyword">return</phrase> <phrase role="keyword">false</phrase><phrase role="special">;</phrase>
9290 <phrase role="special">}</phrase>
9291 <phrase role="keyword">return</phrase> <phrase role="keyword">true</phrase><phrase role="special">;</phrase>
9292 <phrase role="special">}</phrase>
9293 <phrase role="special">};</phrase>
9295 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">Iter</phrase><phrase role="special">></phrase>
9296 <phrase role="keyword">bool</phrase> <phrase role="identifier">valid</phrase><phrase role="special">(</phrase><phrase role="identifier">Iter</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">Iter</phrase> <phrase role="identifier">last</phrase><phrase role="special">);</phrase> <phrase role="comment">// Cannot implement in C++ (for axiom only).</phrase>
9298 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">Iter</phrase><phrase role="special">></phrase>
9299 <phrase role="keyword">bool</phrase> <phrase role="identifier">contained</phrase><phrase role="special">(</phrase><phrase role="identifier">Iter</phrase> <phrase role="identifier">first1</phrase><phrase role="special">,</phrase> <phrase role="identifier">Iter</phrase> <phrase role="identifier">last1</phrase><phrase role="special">,</phrase> <phrase role="identifier">Iter</phrase> <phrase role="identifier">first2</phrase><phrase role="special">,</phrase> <phrase role="identifier">Iter</phrase> <phrase role="identifier">last2</phrase><phrase role="special">);</phrase> <phrase role="comment">// For axiom.</phrase>
9301 <phrase role="comment">// STL vector requires T copyable but not equality comparable.</phrase>
9302 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">Allocator</phrase> <phrase role="special">=</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">allocator</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase> <phrase role="special">></phrase>
9303 <phrase role="keyword">class</phrase> <phrase role="identifier">vector</phrase> <phrase role="special">{</phrase>
9304 <phrase role="keyword">friend</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">access</phrase><phrase role="special">;</phrase>
9306 <phrase role="keyword">void</phrase> <phrase role="identifier">invariant</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
9307 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">empty</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">0</phrase><phrase role="special">));</phrase>
9308 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">distance</phrase><phrase role="special">(</phrase><phrase role="identifier">begin</phrase><phrase role="special">(),</phrase> <phrase role="identifier">end</phrase><phrase role="special">())</phrase> <phrase role="special">==</phrase> <phrase role="keyword">int</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()));</phrase>
9309 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">distance</phrase><phrase role="special">(</phrase><phrase role="identifier">rbegin</phrase><phrase role="special">(),</phrase> <phrase role="identifier">rend</phrase><phrase role="special">())</phrase> <phrase role="special">==</phrase> <phrase role="keyword">int</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()));</phrase>
9310 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special"><=</phrase> <phrase role="identifier">capacity</phrase><phrase role="special">());</phrase>
9311 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">capacity</phrase><phrase role="special">()</phrase> <phrase role="special"><=</phrase> <phrase role="identifier">max_size</phrase><phrase role="special">());</phrase>
9312 <phrase role="special">}</phrase>
9314 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
9315 <phrase role="keyword">typedef</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="identifier">Allocator</phrase><phrase role="special">>::</phrase><phrase role="identifier">allocator_type</phrase> <phrase role="identifier">allocator_type</phrase><phrase role="special">;</phrase>
9316 <phrase role="keyword">typedef</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="identifier">Allocator</phrase><phrase role="special">>::</phrase><phrase role="identifier">pointer</phrase> <phrase role="identifier">pointer</phrase><phrase role="special">;</phrase>
9317 <phrase role="keyword">typedef</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="identifier">Allocator</phrase><phrase role="special">>::</phrase><phrase role="identifier">const_pointer</phrase> <phrase role="identifier">const_pointer</phrase><phrase role="special">;</phrase>
9318 <phrase role="keyword">typedef</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="identifier">Allocator</phrase><phrase role="special">>::</phrase><phrase role="identifier">reference</phrase> <phrase role="identifier">reference</phrase><phrase role="special">;</phrase>
9319 <phrase role="keyword">typedef</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="identifier">Allocator</phrase><phrase role="special">>::</phrase><phrase role="identifier">const_reference</phrase> <phrase role="identifier">const_reference</phrase><phrase role="special">;</phrase>
9320 <phrase role="keyword">typedef</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="identifier">Allocator</phrase><phrase role="special">>::</phrase><phrase role="identifier">value_type</phrase> <phrase role="identifier">value_type</phrase><phrase role="special">;</phrase>
9321 <phrase role="keyword">typedef</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="identifier">Allocator</phrase><phrase role="special">>::</phrase><phrase role="identifier">iterator</phrase> <phrase role="identifier">iterator</phrase><phrase role="special">;</phrase>
9322 <phrase role="keyword">typedef</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="identifier">Allocator</phrase><phrase role="special">>::</phrase><phrase role="identifier">const_iterator</phrase> <phrase role="identifier">const_iterator</phrase><phrase role="special">;</phrase>
9323 <phrase role="keyword">typedef</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="identifier">Allocator</phrase><phrase role="special">>::</phrase><phrase role="identifier">size_type</phrase> <phrase role="identifier">size_type</phrase><phrase role="special">;</phrase>
9324 <phrase role="keyword">typedef</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="identifier">Allocator</phrase><phrase role="special">>::</phrase><phrase role="identifier">difference_type</phrase> <phrase role="identifier">difference_type</phrase><phrase role="special">;</phrase>
9325 <phrase role="keyword">typedef</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="identifier">Allocator</phrase><phrase role="special">>::</phrase><phrase role="identifier">reverse_iterator</phrase>
9326 <phrase role="identifier">reverse_iterator</phrase><phrase role="special">;</phrase>
9327 <phrase role="keyword">typedef</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="identifier">Allocator</phrase><phrase role="special">>::</phrase><phrase role="identifier">const_reverse_iterator</phrase>
9328 <phrase role="identifier">const_reverse_iterator</phrase><phrase role="special">;</phrase>
9330 <phrase role="identifier">vector</phrase><phrase role="special">()</phrase> <phrase role="special">:</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
9331 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
9332 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
9333 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">empty</phrase><phrase role="special">());</phrase>
9334 <phrase role="special">})</phrase>
9335 <phrase role="special">;</phrase>
9336 <phrase role="special">}</phrase>
9338 <phrase role="keyword">explicit</phrase> <phrase role="identifier">vector</phrase><phrase role="special">(</phrase><phrase role="identifier">Allocator</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">alloc</phrase><phrase role="special">)</phrase> <phrase role="special">:</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">(</phrase><phrase role="identifier">alloc</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
9339 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
9340 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
9341 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">empty</phrase><phrase role="special">());</phrase>
9342 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">get_allocator</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">alloc</phrase><phrase role="special">);</phrase>
9343 <phrase role="special">})</phrase>
9344 <phrase role="special">;</phrase>
9345 <phrase role="special">}</phrase>
9347 <phrase role="keyword">explicit</phrase> <phrase role="identifier">vector</phrase><phrase role="special">(</phrase><phrase role="identifier">size_type</phrase> <phrase role="identifier">count</phrase><phrase role="special">)</phrase> <phrase role="special">:</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
9348 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
9349 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
9350 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">count</phrase><phrase role="special">);</phrase>
9351 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase>
9352 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">condition_if</phrase><phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">has_equal_to</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase> <phrase role="special">>(</phrase>
9353 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">bind</phrase><phrase role="special">(</phrase><phrase role="identifier">all_of_equal_to</phrase><phrase role="special">(),</phrase> <phrase role="identifier">begin</phrase><phrase role="special">(),</phrase> <phrase role="identifier">end</phrase><phrase role="special">(),</phrase> <phrase role="identifier">T</phrase><phrase role="special">())</phrase>
9354 <phrase role="special">)</phrase>
9355 <phrase role="special">);</phrase>
9356 <phrase role="special">})</phrase>
9357 <phrase role="special">;</phrase>
9358 <phrase role="special">}</phrase>
9360 <phrase role="identifier">vector</phrase><phrase role="special">(</phrase><phrase role="identifier">size_type</phrase> <phrase role="identifier">count</phrase><phrase role="special">,</phrase> <phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">value</phrase><phrase role="special">)</phrase> <phrase role="special">:</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">,</phrase> <phrase role="identifier">value</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
9361 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
9362 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
9363 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">count</phrase><phrase role="special">);</phrase>
9364 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase>
9365 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">condition_if</phrase><phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">has_equal_to</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase> <phrase role="special">>(</phrase>
9366 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">bind</phrase><phrase role="special">(</phrase><phrase role="identifier">all_of_equal_to</phrase><phrase role="special">(),</phrase> <phrase role="identifier">begin</phrase><phrase role="special">(),</phrase> <phrase role="identifier">end</phrase><phrase role="special">(),</phrase>
9367 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">cref</phrase><phrase role="special">(</phrase><phrase role="identifier">value</phrase><phrase role="special">))</phrase>
9368 <phrase role="special">)</phrase>
9369 <phrase role="special">);</phrase>
9370 <phrase role="special">})</phrase>
9371 <phrase role="special">;</phrase>
9372 <phrase role="special">}</phrase>
9374 <phrase role="identifier">vector</phrase><phrase role="special">(</phrase><phrase role="identifier">size_type</phrase> <phrase role="identifier">count</phrase><phrase role="special">,</phrase> <phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">value</phrase><phrase role="special">,</phrase> <phrase role="identifier">Allocator</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">alloc</phrase><phrase role="special">)</phrase> <phrase role="special">:</phrase>
9375 <phrase role="identifier">vect_</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">,</phrase> <phrase role="identifier">value</phrase><phrase role="special">,</phrase> <phrase role="identifier">alloc</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
9376 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
9377 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
9378 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">count</phrase><phrase role="special">);</phrase>
9379 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase>
9380 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">condition_if</phrase><phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">has_equal_to</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase> <phrase role="special">>(</phrase>
9381 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">bind</phrase><phrase role="special">(</phrase><phrase role="identifier">all_of_equal_to</phrase><phrase role="special">(),</phrase> <phrase role="identifier">begin</phrase><phrase role="special">(),</phrase> <phrase role="identifier">end</phrase><phrase role="special">(),</phrase>
9382 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">cref</phrase><phrase role="special">(</phrase><phrase role="identifier">value</phrase><phrase role="special">))</phrase>
9383 <phrase role="special">)</phrase>
9384 <phrase role="special">);</phrase>
9385 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">get_allocator</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">alloc</phrase><phrase role="special">);</phrase>
9386 <phrase role="special">})</phrase>
9387 <phrase role="special">;</phrase>
9388 <phrase role="special">}</phrase>
9390 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">InputIter</phrase><phrase role="special">></phrase>
9391 <phrase role="identifier">vector</phrase><phrase role="special">(</phrase><phrase role="identifier">InputIter</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">InputIter</phrase> <phrase role="identifier">last</phrase><phrase role="special">)</phrase> <phrase role="special">:</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">last</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
9392 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
9393 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
9394 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">distance</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">last</phrase><phrase role="special">)</phrase> <phrase role="special">==</phrase>
9395 <phrase role="keyword">int</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()));</phrase>
9396 <phrase role="special">})</phrase>
9397 <phrase role="special">;</phrase>
9398 <phrase role="special">}</phrase>
9400 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">InputIter</phrase><phrase role="special">></phrase>
9401 <phrase role="identifier">vector</phrase><phrase role="special">(</phrase><phrase role="identifier">InputIter</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">InputIter</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="identifier">Allocator</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">alloc</phrase><phrase role="special">)</phrase> <phrase role="special">:</phrase>
9402 <phrase role="identifier">vect_</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="identifier">alloc</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
9403 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
9404 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
9405 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">distance</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">last</phrase><phrase role="special">)</phrase> <phrase role="special">==</phrase>
9406 <phrase role="keyword">int</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()));</phrase>
9407 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">get_allocator</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">alloc</phrase><phrase role="special">);</phrase>
9408 <phrase role="special">})</phrase>
9409 <phrase role="special">;</phrase>
9410 <phrase role="special">}</phrase>
9412 <phrase role="comment">/* implicit */</phrase> <phrase role="identifier">vector</phrase><phrase role="special">(</phrase><phrase role="identifier">vector</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">other</phrase><phrase role="special">)</phrase> <phrase role="special">:</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">(</phrase><phrase role="identifier">other</phrase><phrase role="special">.</phrase><phrase role="identifier">vect_</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
9413 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
9414 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
9415 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase>
9416 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">condition_if</phrase><phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">has_equal_to</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase> <phrase role="special">>(</phrase>
9417 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">bind</phrase><phrase role="special">(</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">equal_to</phrase><phrase role="special"><</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase> <phrase role="special">>(),</phrase>
9418 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">cref</phrase><phrase role="special">(*</phrase><phrase role="keyword">this</phrase><phrase role="special">),</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">cref</phrase><phrase role="special">(</phrase><phrase role="identifier">other</phrase><phrase role="special">))</phrase>
9419 <phrase role="special">)</phrase>
9420 <phrase role="special">);</phrase>
9421 <phrase role="special">})</phrase>
9422 <phrase role="special">;</phrase>
9423 <phrase role="special">}</phrase>
9425 <phrase role="identifier">vector</phrase><phrase role="special">&</phrase> <phrase role="keyword">operator</phrase><phrase role="special">=(</phrase><phrase role="identifier">vector</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">other</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
9426 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">optional</phrase><phrase role="special"><</phrase><phrase role="identifier">vector</phrase><phrase role="special">&></phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
9427 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
9428 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
9429 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase>
9430 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">condition_if</phrase><phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">has_equal_to</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase> <phrase role="special">>(</phrase>
9431 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">bind</phrase><phrase role="special">(</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">equal_to</phrase><phrase role="special"><</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase> <phrase role="special">>(),</phrase>
9432 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">cref</phrase><phrase role="special">(*</phrase><phrase role="keyword">this</phrase><phrase role="special">),</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">cref</phrase><phrase role="special">(</phrase><phrase role="identifier">other</phrase><phrase role="special">))</phrase>
9433 <phrase role="special">)</phrase>
9434 <phrase role="special">);</phrase>
9435 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase>
9436 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">condition_if</phrase><phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">has_equal_to</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase> <phrase role="special">>(</phrase>
9437 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">bind</phrase><phrase role="special">(</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">equal_to</phrase><phrase role="special"><</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase> <phrase role="special">>(),</phrase>
9438 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">cref</phrase><phrase role="special">(*</phrase><phrase role="identifier">result</phrase><phrase role="special">),</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">cref</phrase><phrase role="special">(*</phrase><phrase role="keyword">this</phrase><phrase role="special">))</phrase>
9439 <phrase role="special">)</phrase>
9440 <phrase role="special">);</phrase>
9441 <phrase role="special">})</phrase>
9442 <phrase role="special">;</phrase>
9444 <phrase role="keyword">if</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase> <phrase role="special">!=</phrase> <phrase role="special">&</phrase><phrase role="identifier">other</phrase><phrase role="special">)</phrase> <phrase role="identifier">vect_</phrase> <phrase role="special">=</phrase> <phrase role="identifier">other</phrase><phrase role="special">.</phrase><phrase role="identifier">vect_</phrase><phrase role="special">;</phrase>
9445 <phrase role="keyword">return</phrase> <phrase role="special">*(</phrase><phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="special">*</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
9446 <phrase role="special">}</phrase>
9448 <phrase role="keyword">virtual</phrase> <phrase role="special">~</phrase><phrase role="identifier">vector</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
9449 <phrase role="comment">// Check invariants.</phrase>
9450 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">destructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
9451 <phrase role="special">}</phrase>
9453 <phrase role="keyword">void</phrase> <phrase role="identifier">reserve</phrase><phrase role="special">(</phrase><phrase role="identifier">size_type</phrase> <phrase role="identifier">count</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
9454 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
9455 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
9456 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase> <phrase role="special"><</phrase> <phrase role="identifier">max_size</phrase><phrase role="special">());</phrase>
9457 <phrase role="special">})</phrase>
9458 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
9459 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">capacity</phrase><phrase role="special">()</phrase> <phrase role="special">>=</phrase> <phrase role="identifier">count</phrase><phrase role="special">);</phrase>
9460 <phrase role="special">})</phrase>
9461 <phrase role="special">;</phrase>
9463 <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">reserve</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">);</phrase>
9464 <phrase role="special">}</phrase>
9466 <phrase role="identifier">size_type</phrase> <phrase role="identifier">capacity</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
9467 <phrase role="identifier">size_type</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
9468 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
9469 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
9470 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">result</phrase> <phrase role="special">>=</phrase> <phrase role="identifier">size</phrase><phrase role="special">());</phrase>
9471 <phrase role="special">})</phrase>
9472 <phrase role="special">;</phrase>
9474 <phrase role="keyword">return</phrase> <phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">capacity</phrase><phrase role="special">();</phrase>
9475 <phrase role="special">}</phrase>
9477 <phrase role="identifier">iterator</phrase> <phrase role="identifier">begin</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
9478 <phrase role="identifier">iterator</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
9479 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
9480 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
9481 <phrase role="keyword">if</phrase><phrase role="special">(</phrase><phrase role="identifier">empty</phrase><phrase role="special">())</phrase> <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">result</phrase> <phrase role="special">==</phrase> <phrase role="identifier">end</phrase><phrase role="special">());</phrase>
9482 <phrase role="special">})</phrase>
9483 <phrase role="special">;</phrase>
9485 <phrase role="keyword">return</phrase> <phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">begin</phrase><phrase role="special">();</phrase>
9486 <phrase role="special">}</phrase>
9488 <phrase role="identifier">const_iterator</phrase> <phrase role="identifier">begin</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
9489 <phrase role="identifier">const_iterator</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
9490 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
9491 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
9492 <phrase role="keyword">if</phrase><phrase role="special">(</phrase><phrase role="identifier">empty</phrase><phrase role="special">())</phrase> <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">result</phrase> <phrase role="special">==</phrase> <phrase role="identifier">end</phrase><phrase role="special">());</phrase>
9493 <phrase role="special">})</phrase>
9494 <phrase role="special">;</phrase>
9496 <phrase role="keyword">return</phrase> <phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">begin</phrase><phrase role="special">();</phrase>
9497 <phrase role="special">}</phrase>
9499 <phrase role="identifier">iterator</phrase> <phrase role="identifier">end</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
9500 <phrase role="comment">// Check invariants.</phrase>
9501 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
9502 <phrase role="keyword">return</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">end</phrase><phrase role="special">();</phrase>
9503 <phrase role="special">}</phrase>
9505 <phrase role="identifier">const_iterator</phrase> <phrase role="identifier">end</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
9506 <phrase role="comment">// Check invariants.</phrase>
9507 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
9508 <phrase role="keyword">return</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">end</phrase><phrase role="special">();</phrase>
9509 <phrase role="special">}</phrase>
9511 <phrase role="identifier">reverse_iterator</phrase> <phrase role="identifier">rbegin</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
9512 <phrase role="identifier">iterator</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
9513 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
9514 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
9515 <phrase role="keyword">if</phrase><phrase role="special">(</phrase><phrase role="identifier">empty</phrase><phrase role="special">())</phrase> <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">result</phrase> <phrase role="special">==</phrase> <phrase role="identifier">rend</phrase><phrase role="special">());</phrase>
9516 <phrase role="special">})</phrase>
9517 <phrase role="special">;</phrase>
9519 <phrase role="keyword">return</phrase> <phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">rbegin</phrase><phrase role="special">();</phrase>
9520 <phrase role="special">}</phrase>
9522 <phrase role="identifier">const_reverse_iterator</phrase> <phrase role="identifier">rbegin</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
9523 <phrase role="identifier">const_reverse_iterator</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
9524 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
9525 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
9526 <phrase role="keyword">if</phrase><phrase role="special">(</phrase><phrase role="identifier">empty</phrase><phrase role="special">())</phrase> <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">result</phrase> <phrase role="special">==</phrase> <phrase role="identifier">rend</phrase><phrase role="special">());</phrase>
9527 <phrase role="special">})</phrase>
9528 <phrase role="special">;</phrase>
9530 <phrase role="keyword">return</phrase> <phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">rbegin</phrase><phrase role="special">();</phrase>
9531 <phrase role="special">}</phrase>
9533 <phrase role="identifier">reverse_iterator</phrase> <phrase role="identifier">rend</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
9534 <phrase role="comment">// Check invariants.</phrase>
9535 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
9536 <phrase role="keyword">return</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">rend</phrase><phrase role="special">();</phrase>
9537 <phrase role="special">}</phrase>
9539 <phrase role="identifier">const_reverse_iterator</phrase> <phrase role="identifier">rend</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
9540 <phrase role="comment">// Check invariants.</phrase>
9541 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
9542 <phrase role="keyword">return</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">rend</phrase><phrase role="special">();</phrase>
9543 <phrase role="special">}</phrase>
9545 <phrase role="keyword">void</phrase> <phrase role="identifier">resize</phrase><phrase role="special">(</phrase><phrase role="identifier">size_type</phrase> <phrase role="identifier">count</phrase><phrase role="special">,</phrase> <phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">value</phrase> <phrase role="special">=</phrase> <phrase role="identifier">T</phrase><phrase role="special">())</phrase> <phrase role="special">{</phrase>
9546 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="identifier">size_type</phrase><phrase role="special">></phrase> <phrase role="identifier">old_size</phrase> <phrase role="special">=</phrase>
9547 <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">());</phrase>
9548 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
9549 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
9550 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">count</phrase><phrase role="special">);</phrase>
9551 <phrase role="keyword">if</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase> <phrase role="special">></phrase> <phrase role="special">*</phrase><phrase role="identifier">old_size</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
9552 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase>
9553 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">condition_if</phrase><phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">has_equal_to</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase> <phrase role="special">>(</phrase>
9554 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">bind</phrase><phrase role="special">(</phrase><phrase role="identifier">all_of_equal_to</phrase><phrase role="special">(),</phrase> <phrase role="identifier">begin</phrase><phrase role="special">()</phrase> <phrase role="special">+</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_size</phrase><phrase role="special">,</phrase>
9555 <phrase role="identifier">end</phrase><phrase role="special">(),</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">cref</phrase><phrase role="special">(</phrase><phrase role="identifier">value</phrase><phrase role="special">))</phrase>
9556 <phrase role="special">)</phrase>
9557 <phrase role="special">);</phrase>
9558 <phrase role="special">}</phrase>
9559 <phrase role="special">})</phrase>
9560 <phrase role="special">;</phrase>
9562 <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">resize</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">,</phrase> <phrase role="identifier">value</phrase><phrase role="special">);</phrase>
9563 <phrase role="special">}</phrase>
9565 <phrase role="identifier">size_type</phrase> <phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
9566 <phrase role="identifier">size_type</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
9567 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
9568 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
9569 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">result</phrase> <phrase role="special"><=</phrase> <phrase role="identifier">capacity</phrase><phrase role="special">());</phrase>
9570 <phrase role="special">})</phrase>
9571 <phrase role="special">;</phrase>
9573 <phrase role="keyword">return</phrase> <phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">size</phrase><phrase role="special">();</phrase>
9574 <phrase role="special">}</phrase>
9576 <phrase role="identifier">size_type</phrase> <phrase role="identifier">max_size</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
9577 <phrase role="identifier">size_type</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
9578 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
9579 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
9580 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">result</phrase> <phrase role="special">>=</phrase> <phrase role="identifier">capacity</phrase><phrase role="special">());</phrase>
9581 <phrase role="special">})</phrase>
9582 <phrase role="special">;</phrase>
9584 <phrase role="keyword">return</phrase> <phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">max_size</phrase><phrase role="special">();</phrase>
9585 <phrase role="special">}</phrase>
9587 <phrase role="keyword">bool</phrase> <phrase role="identifier">empty</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
9588 <phrase role="keyword">bool</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
9589 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
9590 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
9591 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">result</phrase> <phrase role="special">==</phrase> <phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">0</phrase><phrase role="special">));</phrase>
9592 <phrase role="special">})</phrase>
9593 <phrase role="special">;</phrase>
9595 <phrase role="keyword">return</phrase> <phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">empty</phrase><phrase role="special">();</phrase>
9596 <phrase role="special">}</phrase>
9598 <phrase role="identifier">Allocator</phrase> <phrase role="identifier">get_allocator</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
9599 <phrase role="comment">// Check invariants.</phrase>
9600 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
9601 <phrase role="keyword">return</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">get_allocator</phrase><phrase role="special">();</phrase>
9602 <phrase role="special">}</phrase>
9604 <phrase role="identifier">reference</phrase> <phrase role="identifier">at</phrase><phrase role="special">(</phrase><phrase role="identifier">size_type</phrase> <phrase role="identifier">index</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
9605 <phrase role="comment">// Check invariants, no pre (throw out_of_range for invalid index).</phrase>
9606 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
9607 <phrase role="keyword">return</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">at</phrase><phrase role="special">(</phrase><phrase role="identifier">index</phrase><phrase role="special">);</phrase>
9608 <phrase role="special">}</phrase>
9610 <phrase role="identifier">const_reference</phrase> <phrase role="identifier">at</phrase><phrase role="special">(</phrase><phrase role="identifier">size_type</phrase> <phrase role="identifier">index</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
9611 <phrase role="comment">// Check invariants, no pre (throw out_of_range for invalid index).</phrase>
9612 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
9613 <phrase role="keyword">return</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">at</phrase><phrase role="special">(</phrase><phrase role="identifier">index</phrase><phrase role="special">);</phrase>
9614 <phrase role="special">}</phrase>
9616 <phrase role="identifier">reference</phrase> <phrase role="keyword">operator</phrase><phrase role="special">[](</phrase><phrase role="identifier">size_type</phrase> <phrase role="identifier">index</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
9617 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
9618 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
9619 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">index</phrase> <phrase role="special"><</phrase> <phrase role="identifier">size</phrase><phrase role="special">());</phrase>
9620 <phrase role="special">})</phrase>
9621 <phrase role="special">;</phrase>
9623 <phrase role="keyword">return</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">[</phrase><phrase role="identifier">index</phrase><phrase role="special">];</phrase>
9624 <phrase role="special">}</phrase>
9626 <phrase role="identifier">const_reference</phrase> <phrase role="keyword">operator</phrase><phrase role="special">[](</phrase><phrase role="identifier">size_type</phrase> <phrase role="identifier">index</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
9627 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
9628 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
9629 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">index</phrase> <phrase role="special"><</phrase> <phrase role="identifier">size</phrase><phrase role="special">());</phrase>
9630 <phrase role="special">})</phrase>
9631 <phrase role="special">;</phrase>
9633 <phrase role="keyword">return</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">[</phrase><phrase role="identifier">index</phrase><phrase role="special">];</phrase>
9634 <phrase role="special">}</phrase>
9636 <phrase role="identifier">reference</phrase> <phrase role="identifier">front</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
9637 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
9638 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
9639 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(!</phrase><phrase role="identifier">empty</phrase><phrase role="special">());</phrase>
9640 <phrase role="special">})</phrase>
9641 <phrase role="special">;</phrase>
9643 <phrase role="keyword">return</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">front</phrase><phrase role="special">();</phrase>
9644 <phrase role="special">}</phrase>
9646 <phrase role="identifier">const_reference</phrase> <phrase role="identifier">front</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
9647 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
9648 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
9649 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(!</phrase><phrase role="identifier">empty</phrase><phrase role="special">());</phrase>
9650 <phrase role="special">})</phrase>
9651 <phrase role="special">;</phrase>
9653 <phrase role="keyword">return</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">front</phrase><phrase role="special">();</phrase>
9654 <phrase role="special">}</phrase>
9656 <phrase role="identifier">reference</phrase> <phrase role="identifier">back</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
9657 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
9658 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
9659 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(!</phrase><phrase role="identifier">empty</phrase><phrase role="special">());</phrase>
9660 <phrase role="special">})</phrase>
9661 <phrase role="special">;</phrase>
9663 <phrase role="keyword">return</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">back</phrase><phrase role="special">();</phrase>
9664 <phrase role="special">}</phrase>
9666 <phrase role="identifier">const_reference</phrase> <phrase role="identifier">back</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
9667 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
9668 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
9669 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(!</phrase><phrase role="identifier">empty</phrase><phrase role="special">());</phrase>
9670 <phrase role="special">})</phrase>
9671 <phrase role="special">;</phrase>
9673 <phrase role="keyword">return</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">back</phrase><phrase role="special">();</phrase>
9674 <phrase role="special">}</phrase>
9676 <phrase role="keyword">void</phrase> <phrase role="identifier">push_back</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">value</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
9677 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="identifier">size_type</phrase><phrase role="special">></phrase> <phrase role="identifier">old_size</phrase> <phrase role="special">=</phrase>
9678 <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">());</phrase>
9679 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="identifier">size_type</phrase><phrase role="special">></phrase> <phrase role="identifier">old_capacity</phrase> <phrase role="special">=</phrase>
9680 <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">capacity</phrase><phrase role="special">());</phrase>
9681 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
9682 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
9683 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special"><</phrase> <phrase role="identifier">max_size</phrase><phrase role="special">());</phrase>
9684 <phrase role="special">})</phrase>
9685 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
9686 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_size</phrase> <phrase role="special">+</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase>
9687 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">capacity</phrase><phrase role="special">()</phrase> <phrase role="special">>=</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_capacity</phrase><phrase role="special">);</phrase>
9688 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase>
9689 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">condition_if</phrase><phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">has_equal_to</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase> <phrase role="special">>(</phrase>
9690 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">bind</phrase><phrase role="special">(</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">equal_to</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">>(),</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">cref</phrase><phrase role="special">(</phrase><phrase role="identifier">back</phrase><phrase role="special">()),</phrase>
9691 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">cref</phrase><phrase role="special">(</phrase><phrase role="identifier">value</phrase><phrase role="special">))</phrase>
9692 <phrase role="special">)</phrase>
9693 <phrase role="special">);</phrase>
9694 <phrase role="special">})</phrase>
9695 <phrase role="special">;</phrase>
9697 <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">push_back</phrase><phrase role="special">(</phrase><phrase role="identifier">value</phrase><phrase role="special">);</phrase>
9698 <phrase role="special">}</phrase>
9700 <phrase role="keyword">void</phrase> <phrase role="identifier">pop_back</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
9701 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="identifier">size_type</phrase><phrase role="special">></phrase> <phrase role="identifier">old_size</phrase> <phrase role="special">=</phrase>
9702 <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">());</phrase>
9703 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
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9706 <phrase role="special">})</phrase>
9707 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
9708 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_size</phrase> <phrase role="special">-</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase>
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9710 <phrase role="special">;</phrase>
9712 <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">pop_back</phrase><phrase role="special">();</phrase>
9713 <phrase role="special">}</phrase>
9715 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">InputIter</phrase><phrase role="special">></phrase>
9716 <phrase role="keyword">void</phrase> <phrase role="identifier">assign</phrase><phrase role="special">(</phrase><phrase role="identifier">InputIter</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">InputIter</phrase> <phrase role="identifier">last</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
9717 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
9718 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
9719 <phrase role="identifier">BOOST_CONTRACT_ASSERT_AXIOM</phrase><phrase role="special">(</phrase>
9720 <phrase role="special">!</phrase><phrase role="identifier">contained</phrase><phrase role="special">(</phrase><phrase role="identifier">begin</phrase><phrase role="special">(),</phrase> <phrase role="identifier">end</phrase><phrase role="special">(),</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">last</phrase><phrase role="special">));</phrase>
9721 <phrase role="special">})</phrase>
9722 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
9723 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">distance</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">last</phrase><phrase role="special">)</phrase> <phrase role="special">==</phrase>
9724 <phrase role="keyword">int</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()));</phrase>
9725 <phrase role="special">})</phrase>
9726 <phrase role="special">;</phrase>
9728 <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">assign</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">last</phrase><phrase role="special">);</phrase>
9729 <phrase role="special">}</phrase>
9731 <phrase role="keyword">void</phrase> <phrase role="identifier">assign</phrase><phrase role="special">(</phrase><phrase role="identifier">size_type</phrase> <phrase role="identifier">count</phrase><phrase role="special">,</phrase> <phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">value</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
9732 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
9733 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
9734 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase> <phrase role="special"><=</phrase> <phrase role="identifier">max_size</phrase><phrase role="special">());</phrase>
9735 <phrase role="special">})</phrase>
9736 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
9737 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase>
9738 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">condition_if</phrase><phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">has_equal_to</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase> <phrase role="special">>(</phrase>
9739 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">bind</phrase><phrase role="special">(</phrase><phrase role="identifier">all_of_equal_to</phrase><phrase role="special">(),</phrase> <phrase role="identifier">begin</phrase><phrase role="special">(),</phrase> <phrase role="identifier">end</phrase><phrase role="special">(),</phrase>
9740 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">cref</phrase><phrase role="special">(</phrase><phrase role="identifier">value</phrase><phrase role="special">))</phrase>
9741 <phrase role="special">)</phrase>
9742 <phrase role="special">);</phrase>
9743 <phrase role="special">})</phrase>
9744 <phrase role="special">;</phrase>
9746 <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">assign</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">,</phrase> <phrase role="identifier">value</phrase><phrase role="special">);</phrase>
9747 <phrase role="special">}</phrase>
9749 <phrase role="identifier">iterator</phrase> <phrase role="identifier">insert</phrase><phrase role="special">(</phrase><phrase role="identifier">iterator</phrase> <phrase role="identifier">where</phrase><phrase role="special">,</phrase> <phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">value</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
9750 <phrase role="identifier">iterator</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
9751 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="identifier">size_type</phrase><phrase role="special">></phrase> <phrase role="identifier">old_size</phrase> <phrase role="special">=</phrase>
9752 <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">());</phrase>
9753 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="identifier">size_type</phrase><phrase role="special">></phrase> <phrase role="identifier">old_capacity</phrase> <phrase role="special">=</phrase>
9754 <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">capacity</phrase><phrase role="special">());</phrase>
9755 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
9756 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
9757 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special"><</phrase> <phrase role="identifier">max_size</phrase><phrase role="special">());</phrase>
9758 <phrase role="special">})</phrase>
9759 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
9760 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_size</phrase> <phrase role="special">+</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase>
9761 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">capacity</phrase><phrase role="special">()</phrase> <phrase role="special">>=</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_capacity</phrase><phrase role="special">);</phrase>
9762 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase>
9763 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">condition_if</phrase><phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">has_equal_to</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase> <phrase role="special">>(</phrase>
9764 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">bind</phrase><phrase role="special">(</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">equal_to</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">>(),</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">cref</phrase><phrase role="special">(*</phrase><phrase role="identifier">result</phrase><phrase role="special">),</phrase>
9765 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">cref</phrase><phrase role="special">(</phrase><phrase role="identifier">value</phrase><phrase role="special">))</phrase>
9766 <phrase role="special">)</phrase>
9767 <phrase role="special">);</phrase>
9768 <phrase role="keyword">if</phrase><phrase role="special">(</phrase><phrase role="identifier">capacity</phrase><phrase role="special">()</phrase> <phrase role="special">></phrase> <phrase role="special">*</phrase><phrase role="identifier">old_capacity</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
9769 <phrase role="identifier">BOOST_CONTRACT_ASSERT_AXIOM</phrase><phrase role="special">(!</phrase><phrase role="identifier">valid</phrase><phrase role="special">(</phrase><phrase role="identifier">begin</phrase><phrase role="special">(),</phrase> <phrase role="identifier">end</phrase><phrase role="special">()));</phrase>
9770 <phrase role="special">}</phrase> <phrase role="keyword">else</phrase> <phrase role="special">{</phrase>
9771 <phrase role="identifier">BOOST_CONTRACT_ASSERT_AXIOM</phrase><phrase role="special">(!</phrase><phrase role="identifier">valid</phrase><phrase role="special">(</phrase><phrase role="identifier">where</phrase><phrase role="special">,</phrase> <phrase role="identifier">end</phrase><phrase role="special">()));</phrase>
9772 <phrase role="special">}</phrase>
9773 <phrase role="special">})</phrase>
9774 <phrase role="special">;</phrase>
9776 <phrase role="keyword">return</phrase> <phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">insert</phrase><phrase role="special">(</phrase><phrase role="identifier">where</phrase><phrase role="special">,</phrase> <phrase role="identifier">value</phrase><phrase role="special">);</phrase>
9777 <phrase role="special">}</phrase>
9779 <phrase role="keyword">void</phrase> <phrase role="identifier">insert</phrase><phrase role="special">(</phrase><phrase role="identifier">iterator</phrase> <phrase role="identifier">where</phrase><phrase role="special">,</phrase> <phrase role="identifier">size_type</phrase> <phrase role="identifier">count</phrase><phrase role="special">,</phrase> <phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">value</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
9780 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="identifier">size_type</phrase><phrase role="special">></phrase> <phrase role="identifier">old_size</phrase> <phrase role="special">=</phrase>
9781 <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">());</phrase>
9782 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="identifier">size_type</phrase><phrase role="special">></phrase> <phrase role="identifier">old_capacity</phrase> <phrase role="special">=</phrase>
9783 <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">capacity</phrase><phrase role="special">());</phrase>
9784 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="identifier">iterator</phrase><phrase role="special">></phrase> <phrase role="identifier">old_where</phrase> <phrase role="special">=</phrase>
9785 <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">where</phrase><phrase role="special">);</phrase>
9786 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
9787 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
9788 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">+</phrase> <phrase role="identifier">count</phrase> <phrase role="special"><</phrase> <phrase role="identifier">max_size</phrase><phrase role="special">());</phrase>
9789 <phrase role="special">})</phrase>
9790 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
9791 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_size</phrase> <phrase role="special">+</phrase> <phrase role="identifier">count</phrase><phrase role="special">);</phrase>
9792 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">capacity</phrase><phrase role="special">()</phrase> <phrase role="special">>=</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_capacity</phrase><phrase role="special">);</phrase>
9793 <phrase role="keyword">if</phrase><phrase role="special">(</phrase><phrase role="identifier">capacity</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_capacity</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
9794 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase>
9795 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">condition_if</phrase><phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">has_equal_to</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase> <phrase role="special">>(</phrase>
9796 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">bind</phrase><phrase role="special">(</phrase><phrase role="identifier">all_of_equal_to</phrase><phrase role="special">(),</phrase>
9797 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">prior</phrase><phrase role="special">(*</phrase><phrase role="identifier">old_where</phrase><phrase role="special">),</phrase>
9798 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">prior</phrase><phrase role="special">(*</phrase><phrase role="identifier">old_where</phrase><phrase role="special">)</phrase> <phrase role="special">+</phrase> <phrase role="identifier">count</phrase><phrase role="special">,</phrase>
9799 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">cref</phrase><phrase role="special">(</phrase><phrase role="identifier">value</phrase><phrase role="special">)</phrase>
9800 <phrase role="special">)</phrase>
9801 <phrase role="special">)</phrase>
9802 <phrase role="special">);</phrase>
9803 <phrase role="identifier">BOOST_CONTRACT_ASSERT_AXIOM</phrase><phrase role="special">(!</phrase><phrase role="identifier">valid</phrase><phrase role="special">(</phrase><phrase role="identifier">where</phrase><phrase role="special">,</phrase> <phrase role="identifier">end</phrase><phrase role="special">()));</phrase>
9804 <phrase role="special">}</phrase> <phrase role="keyword">else</phrase> <phrase role="identifier">BOOST_CONTRACT_ASSERT_AXIOM</phrase><phrase role="special">(!</phrase><phrase role="identifier">valid</phrase><phrase role="special">(</phrase><phrase role="identifier">begin</phrase><phrase role="special">(),</phrase> <phrase role="identifier">end</phrase><phrase role="special">()));</phrase>
9805 <phrase role="special">})</phrase>
9806 <phrase role="special">;</phrase>
9808 <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">insert</phrase><phrase role="special">(</phrase><phrase role="identifier">where</phrase><phrase role="special">,</phrase> <phrase role="identifier">count</phrase><phrase role="special">,</phrase> <phrase role="identifier">value</phrase><phrase role="special">);</phrase>
9809 <phrase role="special">}</phrase>
9811 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">InputIter</phrase><phrase role="special">></phrase>
9812 <phrase role="keyword">void</phrase> <phrase role="identifier">insert</phrase><phrase role="special">(</phrase><phrase role="identifier">iterator</phrase> <phrase role="identifier">where</phrase><phrase role="special">,</phrase> <phrase role="identifier">InputIter</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">InputIter</phrase> <phrase role="identifier">last</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
9813 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="identifier">size_type</phrase><phrase role="special">></phrase> <phrase role="identifier">old_size</phrase> <phrase role="special">=</phrase>
9814 <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">());</phrase>
9815 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="identifier">size_type</phrase><phrase role="special">></phrase> <phrase role="identifier">old_capacity</phrase> <phrase role="special">=</phrase>
9816 <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">capacity</phrase><phrase role="special">());</phrase>
9817 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="identifier">iterator</phrase><phrase role="special">></phrase> <phrase role="identifier">old_where</phrase> <phrase role="special">=</phrase>
9818 <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">where</phrase><phrase role="special">);</phrase>
9819 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
9820 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
9821 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">+</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">distance</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">last</phrase><phrase role="special">)</phrase> <phrase role="special"><</phrase>
9822 <phrase role="identifier">max_size</phrase><phrase role="special">());</phrase>
9823 <phrase role="identifier">BOOST_CONTRACT_ASSERT_AXIOM</phrase><phrase role="special">(</phrase>
9824 <phrase role="special">!</phrase><phrase role="identifier">contained</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="identifier">begin</phrase><phrase role="special">(),</phrase> <phrase role="identifier">end</phrase><phrase role="special">()));</phrase>
9825 <phrase role="special">})</phrase>
9826 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
9827 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_size</phrase><phrase role="special">()</phrase> <phrase role="special">+</phrase>
9828 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">distance</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">last</phrase><phrase role="special">));</phrase>
9829 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">capacity</phrase><phrase role="special">()</phrase> <phrase role="special">>=</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_capacity</phrase><phrase role="special">);</phrase>
9830 <phrase role="keyword">if</phrase><phrase role="special">(</phrase><phrase role="identifier">capacity</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_capacity</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
9831 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase>
9832 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">condition_if</phrase><phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">has_equal_to</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase> <phrase role="special">>(</phrase>
9833 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">bind</phrase><phrase role="special">(</phrase><phrase role="identifier">all_of_equal_to</phrase><phrase role="special">(),</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase>
9834 <phrase role="special">*</phrase><phrase role="identifier">old_where</phrase><phrase role="special">)</phrase>
9835 <phrase role="special">)</phrase>
9836 <phrase role="special">);</phrase>
9837 <phrase role="identifier">BOOST_CONTRACT_ASSERT_AXIOM</phrase><phrase role="special">(!</phrase><phrase role="identifier">valid</phrase><phrase role="special">(</phrase><phrase role="identifier">where</phrase><phrase role="special">,</phrase> <phrase role="identifier">end</phrase><phrase role="special">()));</phrase>
9838 <phrase role="special">}</phrase> <phrase role="keyword">else</phrase> <phrase role="identifier">BOOST_CONTRACT_ASSERT_AXIOM</phrase><phrase role="special">(!</phrase><phrase role="identifier">valid</phrase><phrase role="special">(</phrase><phrase role="identifier">begin</phrase><phrase role="special">(),</phrase> <phrase role="identifier">end</phrase><phrase role="special">()));</phrase>
9839 <phrase role="special">})</phrase>
9840 <phrase role="special">;</phrase>
9842 <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">insert</phrase><phrase role="special">(</phrase><phrase role="identifier">where</phrase><phrase role="special">,</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">last</phrase><phrase role="special">);</phrase>
9843 <phrase role="special">}</phrase>
9845 <phrase role="identifier">iterator</phrase> <phrase role="identifier">erase</phrase><phrase role="special">(</phrase><phrase role="identifier">iterator</phrase> <phrase role="identifier">where</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
9846 <phrase role="identifier">iterator</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
9847 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="identifier">size_type</phrase><phrase role="special">></phrase> <phrase role="identifier">old_size</phrase> <phrase role="special">=</phrase>
9848 <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">());</phrase>
9849 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
9850 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
9851 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(!</phrase><phrase role="identifier">empty</phrase><phrase role="special">());</phrase>
9852 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">where</phrase> <phrase role="special">!=</phrase> <phrase role="identifier">end</phrase><phrase role="special">());</phrase>
9853 <phrase role="special">})</phrase>
9854 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
9855 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_size</phrase> <phrase role="special">-</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase>
9856 <phrase role="keyword">if</phrase><phrase role="special">(</phrase><phrase role="identifier">empty</phrase><phrase role="special">())</phrase> <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">result</phrase> <phrase role="special">==</phrase> <phrase role="identifier">end</phrase><phrase role="special">());</phrase>
9857 <phrase role="identifier">BOOST_CONTRACT_ASSERT_AXIOM</phrase><phrase role="special">(!</phrase><phrase role="identifier">valid</phrase><phrase role="special">(</phrase><phrase role="identifier">where</phrase><phrase role="special">,</phrase> <phrase role="identifier">end</phrase><phrase role="special">()));</phrase>
9858 <phrase role="special">})</phrase>
9859 <phrase role="special">;</phrase>
9861 <phrase role="keyword">return</phrase> <phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">erase</phrase><phrase role="special">(</phrase><phrase role="identifier">where</phrase><phrase role="special">);</phrase>
9862 <phrase role="special">}</phrase>
9864 <phrase role="identifier">iterator</phrase> <phrase role="identifier">erase</phrase><phrase role="special">(</phrase><phrase role="identifier">iterator</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">iterator</phrase> <phrase role="identifier">last</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
9865 <phrase role="identifier">iterator</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
9866 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="identifier">size_type</phrase><phrase role="special">></phrase> <phrase role="identifier">old_size</phrase> <phrase role="special">=</phrase>
9867 <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">());</phrase>
9868 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
9869 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
9870 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">>=</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">distance</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">last</phrase><phrase role="special">));</phrase>
9871 <phrase role="special">})</phrase>
9872 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
9873 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_size</phrase> <phrase role="special">-</phrase>
9874 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">distance</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">last</phrase><phrase role="special">));</phrase>
9875 <phrase role="keyword">if</phrase><phrase role="special">(</phrase><phrase role="identifier">empty</phrase><phrase role="special">())</phrase> <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">result</phrase> <phrase role="special">==</phrase> <phrase role="identifier">end</phrase><phrase role="special">());</phrase>
9876 <phrase role="identifier">BOOST_CONTRACT_ASSERT_AXIOM</phrase><phrase role="special">(!</phrase><phrase role="identifier">valid</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">last</phrase><phrase role="special">));</phrase>
9877 <phrase role="special">})</phrase>
9878 <phrase role="special">;</phrase>
9880 <phrase role="keyword">return</phrase> <phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">erase</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">last</phrase><phrase role="special">);</phrase>
9881 <phrase role="special">}</phrase>
9883 <phrase role="keyword">void</phrase> <phrase role="identifier">clear</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
9884 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
9885 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
9886 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">empty</phrase><phrase role="special">());</phrase>
9887 <phrase role="special">})</phrase>
9888 <phrase role="special">;</phrase>
9890 <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">clear</phrase><phrase role="special">();</phrase>
9891 <phrase role="special">}</phrase>
9893 <phrase role="keyword">void</phrase> <phrase role="identifier">swap</phrase><phrase role="special">(</phrase><phrase role="identifier">vector</phrase><phrase role="special">&</phrase> <phrase role="identifier">other</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
9894 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="identifier">vector</phrase><phrase role="special">></phrase> <phrase role="identifier">old_me</phrase><phrase role="special">,</phrase> <phrase role="identifier">old_other</phrase><phrase role="special">;</phrase>
9895 <phrase role="preprocessor">#ifdef</phrase> <phrase role="identifier">BOOST_CONTRACT_AUDITS</phrase>
9896 <phrase role="identifier">old_me</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(*</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
9897 <phrase role="identifier">old_other</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">other</phrase><phrase role="special">);</phrase>
9898 <phrase role="preprocessor">#endif</phrase>
9899 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
9900 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
9901 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">get_allocator</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">other</phrase><phrase role="special">.</phrase><phrase role="identifier">get_allocator</phrase><phrase role="special">());</phrase>
9902 <phrase role="special">})</phrase>
9903 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
9904 <phrase role="identifier">BOOST_CONTRACT_ASSERT_AUDIT</phrase><phrase role="special">(</phrase>
9905 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">condition_if</phrase><phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">has_equal_to</phrase><phrase role="special"><</phrase>
9906 <phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase> <phrase role="special">></phrase> <phrase role="special">>(</phrase>
9907 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">bind</phrase><phrase role="special">(</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">equal_to</phrase><phrase role="special"><</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase> <phrase role="special">>(),</phrase>
9908 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">cref</phrase><phrase role="special">(*</phrase><phrase role="keyword">this</phrase><phrase role="special">),</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">cref</phrase><phrase role="special">(*</phrase><phrase role="identifier">old_other</phrase><phrase role="special">))</phrase>
9909 <phrase role="special">)</phrase>
9910 <phrase role="special">);</phrase>
9911 <phrase role="identifier">BOOST_CONTRACT_ASSERT_AUDIT</phrase><phrase role="special">(</phrase>
9912 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">condition_if</phrase><phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">has_equal_to</phrase><phrase role="special"><</phrase>
9913 <phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase> <phrase role="special">></phrase> <phrase role="special">>(</phrase>
9914 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">bind</phrase><phrase role="special">(</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">equal_to</phrase><phrase role="special"><</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase> <phrase role="special">>(),</phrase>
9915 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">cref</phrase><phrase role="special">(</phrase><phrase role="identifier">other</phrase><phrase role="special">),</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">cref</phrase><phrase role="special">(*</phrase><phrase role="identifier">old_me</phrase><phrase role="special">))</phrase>
9916 <phrase role="special">)</phrase>
9917 <phrase role="special">);</phrase>
9918 <phrase role="special">})</phrase>
9919 <phrase role="special">;</phrase>
9921 <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">swap</phrase><phrase role="special">(</phrase><phrase role="identifier">other</phrase><phrase role="special">);</phrase>
9922 <phrase role="special">}</phrase>
9924 <phrase role="keyword">friend</phrase> <phrase role="keyword">bool</phrase> <phrase role="keyword">operator</phrase><phrase role="special">==(</phrase><phrase role="identifier">vector</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">left</phrase><phrase role="special">,</phrase> <phrase role="identifier">vector</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">right</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
9925 <phrase role="comment">// Check class invariants for left and right objects.</phrase>
9926 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">left_inv</phrase> <phrase role="special">=</phrase>
9927 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(&</phrase><phrase role="identifier">left</phrase><phrase role="special">);</phrase>
9928 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">right_inv</phrase> <phrase role="special">=</phrase>
9929 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(&</phrase><phrase role="identifier">right</phrase><phrase role="special">);</phrase>
9930 <phrase role="keyword">return</phrase> <phrase role="identifier">left</phrase><phrase role="special">.</phrase><phrase role="identifier">vect_</phrase> <phrase role="special">==</phrase> <phrase role="identifier">right</phrase><phrase role="special">.</phrase><phrase role="identifier">vect_</phrase><phrase role="special">;</phrase>
9931 <phrase role="special">}</phrase>
9933 <phrase role="keyword">private</phrase><phrase role="special">:</phrase>
9934 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="identifier">Allocator</phrase><phrase role="special">></phrase> <phrase role="identifier">vect_</phrase><phrase role="special">;</phrase>
9935 <phrase role="special">};</phrase>
9937 <phrase role="keyword">int</phrase> <phrase role="identifier">main</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
9938 <phrase role="comment">// char type has operator==.</phrase>
9940 <phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="keyword">char</phrase><phrase role="special">></phrase> <phrase role="identifier">v</phrase><phrase role="special">(</phrase><phrase role="number">3</phrase><phrase role="special">);</phrase>
9941 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">.</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">3</phrase><phrase role="special">);</phrase>
9942 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">algorithm</phrase><phrase role="special">::</phrase><phrase role="identifier">all_of_equal</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="char">'\0'</phrase><phrase role="special">));</phrase>
9944 <phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="keyword">char</phrase><phrase role="special">></phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">cv</phrase> <phrase role="special">=</phrase> <phrase role="identifier">v</phrase><phrase role="special">;</phrase>
9945 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">cv</phrase> <phrase role="special">==</phrase> <phrase role="identifier">v</phrase><phrase role="special">);</phrase>
9947 <phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="keyword">char</phrase><phrase role="special">></phrase> <phrase role="identifier">w</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">);</phrase>
9948 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">w</phrase> <phrase role="special">==</phrase> <phrase role="identifier">v</phrase><phrase role="special">);</phrase>
9950 <phrase role="keyword">typename</phrase> <phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="keyword">char</phrase><phrase role="special">>::</phrase><phrase role="identifier">iterator</phrase> <phrase role="identifier">i</phrase> <phrase role="special">=</phrase> <phrase role="identifier">v</phrase><phrase role="special">.</phrase><phrase role="identifier">begin</phrase><phrase role="special">();</phrase>
9951 <phrase role="identifier">assert</phrase><phrase role="special">(*</phrase><phrase role="identifier">i</phrase> <phrase role="special">==</phrase> <phrase role="char">'\0'</phrase><phrase role="special">);</phrase>
9953 <phrase role="keyword">typename</phrase> <phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="keyword">char</phrase><phrase role="special">>::</phrase><phrase role="identifier">const_iterator</phrase> <phrase role="identifier">ci</phrase> <phrase role="special">=</phrase> <phrase role="identifier">cv</phrase><phrase role="special">.</phrase><phrase role="identifier">begin</phrase><phrase role="special">();</phrase>
9954 <phrase role="identifier">assert</phrase><phrase role="special">(*</phrase><phrase role="identifier">ci</phrase> <phrase role="special">==</phrase> <phrase role="char">'\0'</phrase><phrase role="special">);</phrase>
9956 <phrase role="identifier">v</phrase><phrase role="special">.</phrase><phrase role="identifier">insert</phrase><phrase role="special">(</phrase><phrase role="identifier">i</phrase><phrase role="special">,</phrase> <phrase role="number">2</phrase><phrase role="special">,</phrase> <phrase role="char">'a'</phrase><phrase role="special">);</phrase>
9957 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">[</phrase><phrase role="number">0</phrase><phrase role="special">]</phrase> <phrase role="special">==</phrase> <phrase role="char">'a'</phrase><phrase role="special">);</phrase>
9958 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">[</phrase><phrase role="number">1</phrase><phrase role="special">]</phrase> <phrase role="special">==</phrase> <phrase role="char">'a'</phrase><phrase role="special">);</phrase>
9960 <phrase role="identifier">v</phrase><phrase role="special">.</phrase><phrase role="identifier">push_back</phrase><phrase role="special">(</phrase><phrase role="char">'b'</phrase><phrase role="special">);</phrase>
9961 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">.</phrase><phrase role="identifier">back</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="char">'b'</phrase><phrase role="special">);</phrase>
9963 <phrase role="keyword">struct</phrase> <phrase role="identifier">x</phrase> <phrase role="special">{};</phrase> <phrase role="comment">// x type doest not have operator==.</phrase>
9965 <phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">x</phrase><phrase role="special">></phrase> <phrase role="identifier">y</phrase><phrase role="special">(</phrase><phrase role="number">3</phrase><phrase role="special">);</phrase>
9966 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">y</phrase><phrase role="special">.</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">3</phrase><phrase role="special">);</phrase>
9968 <phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">x</phrase><phrase role="special">></phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">cy</phrase> <phrase role="special">=</phrase> <phrase role="identifier">y</phrase><phrase role="special">;</phrase>
9969 <phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">x</phrase><phrase role="special">></phrase> <phrase role="identifier">z</phrase><phrase role="special">(</phrase><phrase role="identifier">y</phrase><phrase role="special">);</phrase>
9971 <phrase role="keyword">typename</phrase> <phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">x</phrase><phrase role="special">>::</phrase><phrase role="identifier">iterator</phrase> <phrase role="identifier">j</phrase> <phrase role="special">=</phrase> <phrase role="identifier">y</phrase><phrase role="special">.</phrase><phrase role="identifier">begin</phrase><phrase role="special">();</phrase>
9972 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">j</phrase> <phrase role="special">!=</phrase> <phrase role="identifier">y</phrase><phrase role="special">.</phrase><phrase role="identifier">end</phrase><phrase role="special">());</phrase>
9973 <phrase role="keyword">typename</phrase> <phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">x</phrase><phrase role="special">>::</phrase><phrase role="identifier">const_iterator</phrase> <phrase role="identifier">cj</phrase> <phrase role="special">=</phrase> <phrase role="identifier">cy</phrase><phrase role="special">.</phrase><phrase role="identifier">begin</phrase><phrase role="special">();</phrase>
9974 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">cj</phrase> <phrase role="special">!=</phrase> <phrase role="identifier">cy</phrase><phrase role="special">.</phrase><phrase role="identifier">end</phrase><phrase role="special">());</phrase>
9976 <phrase role="identifier">y</phrase><phrase role="special">.</phrase><phrase role="identifier">insert</phrase><phrase role="special">(</phrase><phrase role="identifier">j</phrase><phrase role="special">,</phrase> <phrase role="number">2</phrase><phrase role="special">,</phrase> <phrase role="identifier">x</phrase><phrase role="special">());</phrase>
9977 <phrase role="identifier">y</phrase><phrase role="special">.</phrase><phrase role="identifier">push_back</phrase><phrase role="special">(</phrase><phrase role="identifier">x</phrase><phrase role="special">());</phrase>
9979 <phrase role="keyword">return</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase>
9980 <phrase role="special">}</phrase>
9986 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="comment">// Extra spaces, newlines, etc. for visual alignment with this library code.</phrase>
9988 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">algorithm</phrase><phrase role="special">/</phrase><phrase role="identifier">cxx11</phrase><phrase role="special">/</phrase><phrase role="identifier">all_of</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">></phrase>
9989 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">has_equal_to</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">></phrase>
9990 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">next_prior</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">></phrase>
9991 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">vector</phrase><phrase role="special">></phrase>
9992 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">iterator</phrase><phrase role="special">></phrase>
9993 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">memory</phrase><phrase role="special">></phrase>
10023 <phrase role="keyword">template</phrase><phrase role="special"><</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">Allocator</phrase> <phrase role="special">=</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">allocator</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase> <phrase role="special">></phrase>
10024 <phrase role="keyword">class</phrase> <phrase role="identifier">vector</phrase> <phrase role="special">{</phrase>
10027 <phrase role="identifier">invariant</phrase> <phrase role="special">{</phrase>
10028 <phrase role="identifier">empty</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase>
10029 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">distance</phrase><phrase role="special">(</phrase><phrase role="identifier">begin</phrase><phrase role="special">(),</phrase> <phrase role="identifier">end</phrase><phrase role="special">())</phrase> <phrase role="special">==</phrase> <phrase role="keyword">int</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">());</phrase>
10030 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">distance</phrase><phrase role="special">(</phrase><phrase role="identifier">rbegin</phrase><phrase role="special">(),</phrase> <phrase role="identifier">rend</phrase><phrase role="special">())</phrase> <phrase role="special">==</phrase> <phrase role="keyword">int</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">());</phrase>
10031 <phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special"><=</phrase> <phrase role="identifier">capacity</phrase><phrase role="special">();</phrase>
10032 <phrase role="identifier">capacity</phrase><phrase role="special">()</phrase> <phrase role="special"><=</phrase> <phrase role="identifier">max_size</phrase><phrase role="special">();</phrase>
10033 <phrase role="special">}</phrase>
10035 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
10036 <phrase role="keyword">typedef</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="identifier">Allocator</phrase><phrase role="special">>::</phrase><phrase role="identifier">allocator_type</phrase> <phrase role="identifier">allocator_type</phrase><phrase role="special">;</phrase>
10037 <phrase role="keyword">typedef</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="identifier">Allocator</phrase><phrase role="special">>::</phrase><phrase role="identifier">pointer</phrase> <phrase role="identifier">pointer</phrase><phrase role="special">;</phrase>
10038 <phrase role="keyword">typedef</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="identifier">Allocator</phrase><phrase role="special">>::</phrase><phrase role="identifier">const_pointer</phrase> <phrase role="identifier">const_pointer</phrase><phrase role="special">;</phrase>
10039 <phrase role="keyword">typedef</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="identifier">Allocator</phrase><phrase role="special">>::</phrase><phrase role="identifier">reference</phrase> <phrase role="identifier">reference</phrase><phrase role="special">;</phrase>
10040 <phrase role="keyword">typedef</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="identifier">Allocator</phrase><phrase role="special">>::</phrase><phrase role="identifier">const_reference</phrase> <phrase role="identifier">const_reference</phrase><phrase role="special">;</phrase>
10041 <phrase role="keyword">typedef</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="identifier">Allocator</phrase><phrase role="special">>::</phrase><phrase role="identifier">value_type</phrase> <phrase role="identifier">value_type</phrase><phrase role="special">;</phrase>
10042 <phrase role="keyword">typedef</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="identifier">Allocator</phrase><phrase role="special">>::</phrase><phrase role="identifier">iterator</phrase> <phrase role="identifier">iterator</phrase><phrase role="special">;</phrase>
10043 <phrase role="keyword">typedef</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="identifier">Allocator</phrase><phrase role="special">>::</phrase><phrase role="identifier">const_iterator</phrase> <phrase role="identifier">const_iterator</phrase><phrase role="special">;</phrase>
10044 <phrase role="keyword">typedef</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="identifier">Allocator</phrase><phrase role="special">>::</phrase><phrase role="identifier">size_type</phrase> <phrase role="identifier">size_type</phrase><phrase role="special">;</phrase>
10045 <phrase role="keyword">typedef</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="identifier">Allocator</phrase><phrase role="special">>::</phrase><phrase role="identifier">difference_type</phrase> <phrase role="identifier">difference_type</phrase><phrase role="special">;</phrase>
10046 <phrase role="keyword">typedef</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="identifier">Allocator</phrase><phrase role="special">>::</phrase><phrase role="identifier">reverse_iterator</phrase>
10047 <phrase role="identifier">reverse_iterator</phrase><phrase role="special">;</phrase>
10048 <phrase role="keyword">typedef</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="identifier">Allocator</phrase><phrase role="special">>::</phrase><phrase role="identifier">const_reverse_iterator</phrase>
10049 <phrase role="identifier">const_reverse_iterator</phrase><phrase role="special">;</phrase>
10051 <phrase role="identifier">vector</phrase><phrase role="special">()</phrase>
10052 <phrase role="identifier">postcondition</phrase> <phrase role="special">{</phrase>
10053 <phrase role="identifier">empty</phrase><phrase role="special">();</phrase>
10054 <phrase role="special">}</phrase>
10055 <phrase role="special">:</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">()</phrase>
10056 <phrase role="special">{}</phrase>
10059 <phrase role="keyword">explicit</phrase> <phrase role="identifier">vector</phrase><phrase role="special">(</phrase><phrase role="identifier">Allocator</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">alloc</phrase><phrase role="special">)</phrase>
10060 <phrase role="identifier">postcondition</phrase> <phrase role="special">{</phrase>
10061 <phrase role="identifier">empty</phrase><phrase role="special">();</phrase>
10062 <phrase role="identifier">get_allocator</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">alloc</phrase><phrase role="special">;</phrase>
10063 <phrase role="special">}</phrase>
10064 <phrase role="special">:</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">(</phrase><phrase role="identifier">alloc</phrase><phrase role="special">)</phrase>
10065 <phrase role="special">{}</phrase>
10068 <phrase role="keyword">explicit</phrase> <phrase role="identifier">vector</phrase><phrase role="special">(</phrase><phrase role="identifier">size_type</phrase> <phrase role="identifier">count</phrase><phrase role="special">)</phrase>
10069 <phrase role="identifier">postcondition</phrase> <phrase role="special">{</phrase>
10070 <phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">count</phrase><phrase role="special">;</phrase>
10071 <phrase role="keyword">if</phrase> <phrase role="keyword">constexpr</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">has_equal_to</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">>::</phrase><phrase role="identifier">value</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
10072 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">algorithm</phrase><phrase role="special">::</phrase><phrase role="identifier">all_of_equal</phrase><phrase role="special">(</phrase><phrase role="identifier">begin</phrase><phrase role="special">(),</phrase> <phrase role="identifier">end</phrase><phrase role="special">(),</phrase> <phrase role="identifier">T</phrase><phrase role="special">());</phrase>
10073 <phrase role="special">}</phrase>
10074 <phrase role="special">}</phrase>
10075 <phrase role="special">:</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">)</phrase>
10076 <phrase role="special">{}</phrase>
10081 <phrase role="identifier">vector</phrase><phrase role="special">(</phrase><phrase role="identifier">size_type</phrase> <phrase role="identifier">count</phrase><phrase role="special">,</phrase> <phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">value</phrase><phrase role="special">)</phrase>
10082 <phrase role="identifier">postcondition</phrase> <phrase role="special">{</phrase>
10083 <phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">count</phrase><phrase role="special">;</phrase>
10084 <phrase role="keyword">if</phrase> <phrase role="keyword">constexpr</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">has_equal_to</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">>::</phrase><phrase role="identifier">value</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
10085 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">algorithm</phrase><phrase role="special">::</phrase><phrase role="identifier">all_of_equal</phrase><phrase role="special">(</phrase><phrase role="identifier">begin</phrase><phrase role="special">(),</phrase> <phrase role="identifier">end</phrase><phrase role="special">(),</phrase> <phrase role="identifier">value</phrase><phrase role="special">);</phrase>
10086 <phrase role="special">}</phrase>
10087 <phrase role="special">}</phrase>
10088 <phrase role="special">:</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">,</phrase> <phrase role="identifier">value</phrase><phrase role="special">)</phrase>
10089 <phrase role="special">{}</phrase>
10095 <phrase role="identifier">vector</phrase><phrase role="special">(</phrase><phrase role="identifier">size_type</phrase> <phrase role="identifier">count</phrase><phrase role="special">,</phrase> <phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">value</phrase><phrase role="special">,</phrase> <phrase role="identifier">Allocator</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">alloc</phrase><phrase role="special">)</phrase>
10096 <phrase role="identifier">postcondition</phrase> <phrase role="special">{</phrase>
10097 <phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">count</phrase><phrase role="special">;</phrase>
10098 <phrase role="keyword">if</phrase> <phrase role="keyword">constexpr</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">has_equal_to</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">>::</phrase><phrase role="identifier">value</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
10099 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">algorithm</phrase><phrase role="special">::</phrase><phrase role="identifier">all_of_equal</phrase><phrase role="special">(</phrase><phrase role="identifier">begin</phrase><phrase role="special">(),</phrase> <phrase role="identifier">end</phrase><phrase role="special">(),</phrase> <phrase role="identifier">value</phrase><phrase role="special">);</phrase>
10100 <phrase role="special">}</phrase>
10101 <phrase role="identifier">get_allocator</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">alloc</phrase><phrase role="special">;</phrase>
10102 <phrase role="special">}</phrase>
10103 <phrase role="special">:</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">,</phrase> <phrase role="identifier">value</phrase><phrase role="special">,</phrase> <phrase role="identifier">alloc</phrase><phrase role="special">)</phrase>
10104 <phrase role="special">{}</phrase>
10111 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">InputIter</phrase><phrase role="special">></phrase>
10112 <phrase role="identifier">vector</phrase><phrase role="special">(</phrase><phrase role="identifier">InputIter</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">InputIter</phrase> <phrase role="identifier">last</phrase><phrase role="special">)</phrase>
10113 <phrase role="identifier">postcondition</phrase> <phrase role="special">{</phrase>
10114 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">distance</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">last</phrase><phrase role="special">)</phrase> <phrase role="special">==</phrase> <phrase role="keyword">int</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">());</phrase>
10115 <phrase role="special">}</phrase>
10116 <phrase role="special">:</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">last</phrase><phrase role="special">)</phrase>
10117 <phrase role="special">{}</phrase>
10121 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">InputIter</phrase><phrase role="special">></phrase>
10122 <phrase role="identifier">vector</phrase><phrase role="special">(</phrase><phrase role="identifier">InputIter</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">InputIter</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="identifier">Allocator</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">alloc</phrase><phrase role="special">)</phrase>
10123 <phrase role="identifier">postcondition</phrase> <phrase role="special">{</phrase>
10124 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">distance</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">last</phrase><phrase role="special">)</phrase> <phrase role="special">==</phrase> <phrase role="keyword">int</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">());</phrase>
10125 <phrase role="identifier">get_allocator</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">alloc</phrase><phrase role="special">;</phrase>
10126 <phrase role="special">}</phrase>
10127 <phrase role="special">:</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="identifier">alloc</phrase><phrase role="special">)</phrase>
10128 <phrase role="special">{}</phrase>
10133 <phrase role="comment">/* implicit */</phrase> <phrase role="identifier">vector</phrase><phrase role="special">(</phrase><phrase role="identifier">vector</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">other</phrase><phrase role="special">)</phrase>
10134 <phrase role="identifier">postcondition</phrase> <phrase role="special">{</phrase>
10135 <phrase role="keyword">if</phrase> <phrase role="keyword">constexpr</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">has_equal_to</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">>::</phrase><phrase role="identifier">value</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
10136 <phrase role="special">*</phrase><phrase role="keyword">this</phrase> <phrase role="special">==</phrase> <phrase role="identifier">other</phrase><phrase role="special">;</phrase>
10137 <phrase role="special">}</phrase>
10138 <phrase role="special">}</phrase>
10139 <phrase role="special">:</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">(</phrase><phrase role="identifier">other</phrase><phrase role="special">.</phrase><phrase role="identifier">vect_</phrase><phrase role="special">)</phrase>
10140 <phrase role="special">{}</phrase>
10146 <phrase role="identifier">vector</phrase><phrase role="special">&</phrase> <phrase role="keyword">operator</phrase><phrase role="special">=(</phrase><phrase role="identifier">vector</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">other</phrase><phrase role="special">)</phrase>
10147 <phrase role="identifier">postcondition</phrase><phrase role="special">(</phrase><phrase role="identifier">result</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
10148 <phrase role="keyword">if</phrase> <phrase role="keyword">constexpr</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">has_equal_to</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">>::</phrase><phrase role="identifier">value</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
10149 <phrase role="special">*</phrase><phrase role="keyword">this</phrase> <phrase role="special">==</phrase> <phrase role="identifier">other</phrase><phrase role="special">;</phrase>
10150 <phrase role="identifier">result</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="keyword">this</phrase><phrase role="special">;</phrase>
10151 <phrase role="special">}</phrase>
10152 <phrase role="special">}</phrase>
10153 <phrase role="special">{</phrase>
10154 <phrase role="keyword">if</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase> <phrase role="special">!=</phrase> <phrase role="special">&</phrase><phrase role="identifier">other</phrase><phrase role="special">)</phrase> <phrase role="identifier">vect_</phrase> <phrase role="special">=</phrase> <phrase role="identifier">other</phrase><phrase role="special">.</phrase><phrase role="identifier">vect_</phrase><phrase role="special">;</phrase>
10155 <phrase role="keyword">return</phrase> <phrase role="special">*</phrase><phrase role="keyword">this</phrase><phrase role="special">;</phrase>
10156 <phrase role="special">}</phrase>
10169 <phrase role="keyword">virtual</phrase> <phrase role="special">~</phrase><phrase role="identifier">vector</phrase><phrase role="special">()</phrase> <phrase role="special">{}</phrase>
10174 <phrase role="keyword">void</phrase> <phrase role="identifier">reserve</phrase><phrase role="special">(</phrase><phrase role="identifier">size_type</phrase> <phrase role="identifier">count</phrase><phrase role="special">)</phrase>
10175 <phrase role="identifier">precondition</phrase> <phrase role="special">{</phrase>
10176 <phrase role="identifier">count</phrase> <phrase role="special"><</phrase> <phrase role="identifier">max_size</phrase><phrase role="special">();</phrase>
10177 <phrase role="special">}</phrase>
10178 <phrase role="identifier">postcondition</phrase> <phrase role="special">{</phrase>
10179 <phrase role="identifier">capacity</phrase><phrase role="special">()</phrase> <phrase role="special">>=</phrase> <phrase role="identifier">count</phrase><phrase role="special">;</phrase>
10180 <phrase role="special">}</phrase>
10181 <phrase role="special">{</phrase>
10182 <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">reserve</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">);</phrase>
10183 <phrase role="special">}</phrase>
10187 <phrase role="identifier">size_type</phrase> <phrase role="identifier">capacity</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase>
10188 <phrase role="identifier">postcondition</phrase><phrase role="special">(</phrase><phrase role="identifier">result</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
10189 <phrase role="identifier">result</phrase> <phrase role="special">>=</phrase> <phrase role="identifier">size</phrase><phrase role="special">();</phrase>
10190 <phrase role="special">}</phrase>
10191 <phrase role="special">{</phrase>
10192 <phrase role="keyword">return</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">capacity</phrase><phrase role="special">();</phrase>
10193 <phrase role="special">}</phrase>
10198 <phrase role="identifier">iterator</phrase> <phrase role="identifier">begin</phrase><phrase role="special">()</phrase>
10199 <phrase role="identifier">postcondition</phrase> <phrase role="special">{</phrase>
10200 <phrase role="keyword">if</phrase><phrase role="special">(</phrase><phrase role="identifier">empty</phrase><phrase role="special">())</phrase> <phrase role="identifier">result</phrase> <phrase role="special">==</phrase> <phrase role="identifier">end</phrase><phrase role="special">();</phrase>
10201 <phrase role="special">}</phrase>
10202 <phrase role="special">{</phrase>
10203 <phrase role="keyword">return</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">begin</phrase><phrase role="special">();</phrase>
10204 <phrase role="special">}</phrase>
10209 <phrase role="identifier">const_iterator</phrase> <phrase role="identifier">begin</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase>
10210 <phrase role="identifier">postcondition</phrase><phrase role="special">(</phrase><phrase role="identifier">result</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
10211 <phrase role="keyword">if</phrase><phrase role="special">(</phrase><phrase role="identifier">empty</phrase><phrase role="special">())</phrase> <phrase role="identifier">result</phrase> <phrase role="special">==</phrase> <phrase role="identifier">end</phrase><phrase role="special">();</phrase>
10212 <phrase role="special">}</phrase>
10213 <phrase role="special">{</phrase>
10214 <phrase role="keyword">return</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">begin</phrase><phrase role="special">();</phrase>
10215 <phrase role="special">}</phrase>
10220 <phrase role="identifier">iterator</phrase> <phrase role="identifier">end</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
10221 <phrase role="keyword">return</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">end</phrase><phrase role="special">();</phrase>
10222 <phrase role="special">}</phrase>
10226 <phrase role="identifier">const_iterator</phrase> <phrase role="identifier">end</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
10227 <phrase role="keyword">return</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">end</phrase><phrase role="special">();</phrase>
10228 <phrase role="special">}</phrase>
10232 <phrase role="identifier">reverse_iterator</phrase> <phrase role="identifier">rbegin</phrase><phrase role="special">()</phrase>
10233 <phrase role="identifier">postcondition</phrase><phrase role="special">(</phrase><phrase role="identifier">result</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
10234 <phrase role="keyword">if</phrase><phrase role="special">(</phrase><phrase role="identifier">empty</phrase><phrase role="special">())</phrase> <phrase role="identifier">result</phrase> <phrase role="special">==</phrase> <phrase role="identifier">rend</phrase><phrase role="special">();</phrase>
10235 <phrase role="special">}</phrase>
10236 <phrase role="special">{</phrase>
10237 <phrase role="keyword">return</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">rbegin</phrase><phrase role="special">();</phrase>
10238 <phrase role="special">}</phrase>
10243 <phrase role="identifier">const_reverse_iterator</phrase> <phrase role="identifier">rbegin</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase>
10244 <phrase role="identifier">postcondition</phrase><phrase role="special">(</phrase><phrase role="identifier">result</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
10245 <phrase role="keyword">if</phrase><phrase role="special">(</phrase><phrase role="identifier">empty</phrase><phrase role="special">())</phrase> <phrase role="identifier">result</phrase> <phrase role="special">==</phrase> <phrase role="identifier">rend</phrase><phrase role="special">();</phrase>
10246 <phrase role="special">}</phrase>
10247 <phrase role="special">{</phrase>
10248 <phrase role="keyword">return</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">rbegin</phrase><phrase role="special">();</phrase>
10249 <phrase role="special">}</phrase>
10254 <phrase role="identifier">reverse_iterator</phrase> <phrase role="identifier">rend</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
10255 <phrase role="keyword">return</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">rend</phrase><phrase role="special">();</phrase>
10256 <phrase role="special">}</phrase>
10260 <phrase role="identifier">const_reverse_iterator</phrase> <phrase role="identifier">rend</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
10261 <phrase role="keyword">return</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">rend</phrase><phrase role="special">();</phrase>
10262 <phrase role="special">}</phrase>
10266 <phrase role="keyword">void</phrase> <phrase role="identifier">resize</phrase><phrase role="special">(</phrase><phrase role="identifier">size_type</phrase> <phrase role="identifier">count</phrase><phrase role="special">,</phrase> <phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">value</phrase> <phrase role="special">=</phrase> <phrase role="identifier">T</phrase><phrase role="special">())</phrase>
10267 <phrase role="identifier">postcondition</phrase> <phrase role="special">{</phrase>
10268 <phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">count</phrase><phrase role="special">;</phrase>
10269 <phrase role="keyword">if</phrase> <phrase role="keyword">constexpr</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">has_equal_to</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">>::</phrase><phrase role="identifier">value</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
10270 <phrase role="keyword">if</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase> <phrase role="special">></phrase> <phrase role="identifier">oldof</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()))</phrase> <phrase role="special">{</phrase>
10271 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">algorithm</phrase><phrase role="special">::</phrase><phrase role="identifier">all_of_equal</phrase><phrase role="special">(</phrase><phrase role="identifier">begin</phrase><phrase role="special">()</phrase> <phrase role="special">+</phrase> <phrase role="identifier">oldof</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()),</phrase>
10272 <phrase role="identifier">end</phrase><phrase role="special">(),</phrase> <phrase role="identifier">value</phrase><phrase role="special">);</phrase>
10273 <phrase role="special">}</phrase>
10274 <phrase role="special">}</phrase>
10275 <phrase role="special">}</phrase>
10276 <phrase role="special">{</phrase>
10277 <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">resize</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">,</phrase> <phrase role="identifier">value</phrase><phrase role="special">);</phrase>
10278 <phrase role="special">}</phrase>
10286 <phrase role="identifier">size_type</phrase> <phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase>
10287 <phrase role="identifier">postcondition</phrase><phrase role="special">(</phrase><phrase role="identifier">result</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
10288 <phrase role="identifier">result</phrase> <phrase role="special"><=</phrase> <phrase role="identifier">capacity</phrase><phrase role="special">();</phrase>
10289 <phrase role="special">}</phrase>
10290 <phrase role="special">{</phrase>
10291 <phrase role="keyword">return</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">size</phrase><phrase role="special">();</phrase>
10292 <phrase role="special">}</phrase>
10297 <phrase role="identifier">size_type</phrase> <phrase role="identifier">max_size</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase>
10298 <phrase role="identifier">postcondition</phrase><phrase role="special">(</phrase><phrase role="identifier">result</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
10299 <phrase role="identifier">result</phrase> <phrase role="special">>=</phrase> <phrase role="identifier">capacity</phrase><phrase role="special">();</phrase>
10300 <phrase role="special">}</phrase>
10301 <phrase role="special">{</phrase>
10302 <phrase role="keyword">return</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">max_size</phrase><phrase role="special">();</phrase>
10303 <phrase role="special">}</phrase>
10308 <phrase role="keyword">bool</phrase> <phrase role="identifier">empty</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase>
10309 <phrase role="identifier">postcondition</phrase><phrase role="special">(</phrase><phrase role="identifier">result</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
10310 <phrase role="identifier">result</phrase> <phrase role="special">==</phrase> <phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase>
10311 <phrase role="special">}</phrase>
10312 <phrase role="special">{</phrase>
10313 <phrase role="keyword">return</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">empty</phrase><phrase role="special">();</phrase>
10314 <phrase role="special">}</phrase>
10319 <phrase role="identifier">Alloctor</phrase> <phrase role="identifier">get_allocator</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
10320 <phrase role="keyword">return</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">get_allocator</phrase><phrase role="special">();</phrase>
10321 <phrase role="special">}</phrase>
10325 <phrase role="identifier">reference</phrase> <phrase role="identifier">at</phrase><phrase role="special">(</phrase><phrase role="identifier">size_type</phrase> <phrase role="identifier">index</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
10326 <phrase role="comment">// No precondition (throw out_of_range for invalid index).</phrase>
10327 <phrase role="keyword">return</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">at</phrase><phrase role="special">(</phrase><phrase role="identifier">index</phrase><phrase role="special">);</phrase>
10328 <phrase role="special">}</phrase>
10331 <phrase role="identifier">const_reference</phrase> <phrase role="identifier">at</phrase><phrase role="special">(</phrase><phrase role="identifier">size_type</phrase> <phrase role="identifier">index</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
10332 <phrase role="comment">// No precondition (throw out_of_range for invalid index).</phrase>
10333 <phrase role="keyword">return</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">at</phrase><phrase role="special">(</phrase><phrase role="identifier">index</phrase><phrase role="special">);</phrase>
10334 <phrase role="special">}</phrase>
10337 <phrase role="identifier">reference</phrase> <phrase role="keyword">operator</phrase><phrase role="special">[](</phrase><phrase role="identifier">size_type</phrase> <phrase role="identifier">index</phrase><phrase role="special">)</phrase>
10338 <phrase role="identifier">precondition</phrase> <phrase role="special">{</phrase>
10339 <phrase role="identifier">index</phrase> <phrase role="special"><</phrase> <phrase role="identifier">size</phrase><phrase role="special">();</phrase>
10340 <phrase role="special">}</phrase>
10341 <phrase role="special">{</phrase>
10342 <phrase role="keyword">return</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">[</phrase><phrase role="identifier">index</phrase><phrase role="special">];</phrase>
10343 <phrase role="special">}</phrase>
10347 <phrase role="identifier">const_reference</phrase> <phrase role="keyword">operator</phrase><phrase role="special">[](</phrase><phrase role="identifier">size_type</phrase> <phrase role="identifier">index</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase>
10348 <phrase role="identifier">precondition</phrase> <phrase role="special">{</phrase>
10349 <phrase role="identifier">index</phrase> <phrase role="special"><</phrase> <phrase role="identifier">size</phrase><phrase role="special">();</phrase>
10350 <phrase role="special">}</phrase>
10351 <phrase role="special">{</phrase>
10352 <phrase role="keyword">return</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">[</phrase><phrase role="identifier">index</phrase><phrase role="special">];</phrase>
10353 <phrase role="special">}</phrase>
10357 <phrase role="identifier">reference</phrase> <phrase role="identifier">front</phrase><phrase role="special">()</phrase>
10358 <phrase role="identifier">precondition</phrase> <phrase role="special">{</phrase>
10359 <phrase role="special">!</phrase><phrase role="identifier">empty</phrase><phrase role="special">();</phrase>
10360 <phrase role="special">}</phrase>
10361 <phrase role="special">{</phrase>
10362 <phrase role="keyword">return</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">front</phrase><phrase role="special">();</phrase>
10363 <phrase role="special">}</phrase>
10367 <phrase role="identifier">const_reference</phrase> <phrase role="identifier">front</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase>
10368 <phrase role="identifier">precondition</phrase> <phrase role="special">{</phrase>
10369 <phrase role="special">!</phrase><phrase role="identifier">empty</phrase><phrase role="special">();</phrase>
10370 <phrase role="special">}</phrase>
10371 <phrase role="special">{</phrase>
10372 <phrase role="keyword">return</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">front</phrase><phrase role="special">();</phrase>
10373 <phrase role="special">}</phrase>
10377 <phrase role="identifier">reference</phrase> <phrase role="identifier">back</phrase><phrase role="special">()</phrase>
10378 <phrase role="identifier">precondition</phrase> <phrase role="special">{</phrase>
10379 <phrase role="special">!</phrase><phrase role="identifier">empty</phrase><phrase role="special">();</phrase>
10380 <phrase role="special">}</phrase>
10381 <phrase role="special">{</phrase>
10382 <phrase role="keyword">return</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">back</phrase><phrase role="special">();</phrase>
10383 <phrase role="special">}</phrase>
10387 <phrase role="identifier">const_reference</phrase> <phrase role="identifier">back</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase>
10388 <phrase role="identifier">precondition</phrase> <phrase role="special">{</phrase>
10389 <phrase role="special">!</phrase><phrase role="identifier">empty</phrase><phrase role="special">();</phrase>
10390 <phrase role="special">}</phrase>
10391 <phrase role="special">{</phrase>
10392 <phrase role="keyword">return</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">back</phrase><phrase role="special">();</phrase>
10393 <phrase role="special">}</phrase>
10397 <phrase role="keyword">void</phrase> <phrase role="identifier">push_back</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">value</phrase><phrase role="special">)</phrase>
10398 <phrase role="identifier">precondition</phrase> <phrase role="special">{</phrase>
10399 <phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special"><</phrase> <phrase role="identifier">max_size</phrase><phrase role="special">();</phrase>
10400 <phrase role="special">}</phrase>
10401 <phrase role="identifier">postcondition</phrase> <phrase role="special">{</phrase>
10402 <phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">oldof</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">())</phrase> <phrase role="special">+</phrase> <phrase role="number">1</phrase><phrase role="special">;</phrase>
10403 <phrase role="identifier">capacity</phrase><phrase role="special">()</phrase> <phrase role="special">>=</phrase> <phrase role="identifier">oldof</phrase><phrase role="special">(</phrase><phrase role="identifier">capacity</phrase><phrase role="special">())</phrase>
10404 <phrase role="keyword">if</phrase> <phrase role="keyword">constexpr</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">has_equal_to</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">>::</phrase><phrase role="identifier">value</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
10405 <phrase role="identifier">back</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">value</phrase><phrase role="special">;</phrase>
10406 <phrase role="special">}</phrase>
10407 <phrase role="special">}</phrase>
10408 <phrase role="special">{</phrase>
10409 <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">push_back</phrase><phrase role="special">(</phrase><phrase role="identifier">value</phrase><phrase role="special">);</phrase>
10410 <phrase role="special">}</phrase>
10421 <phrase role="keyword">void</phrase> <phrase role="identifier">pop_back</phrase><phrase role="special">()</phrase>
10422 <phrase role="identifier">precondition</phrase> <phrase role="special">{</phrase>
10423 <phrase role="special">!</phrase><phrase role="identifier">empty</phrase><phrase role="special">();</phrase>
10424 <phrase role="special">}</phrase>
10425 <phrase role="identifier">postcondition</phrase> <phrase role="special">{</phrase>
10426 <phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">oldof</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">())</phrase> <phrase role="special">-</phrase> <phrase role="number">1</phrase><phrase role="special">;</phrase>
10427 <phrase role="special">}</phrase>
10428 <phrase role="special">{</phrase>
10429 <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">pop_back</phrase><phrase role="special">();</phrase>
10430 <phrase role="special">}</phrase>
10436 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">InputIter</phrase><phrase role="special">></phrase>
10437 <phrase role="keyword">void</phrase> <phrase role="identifier">assign</phrase><phrase role="special">(</phrase><phrase role="identifier">InputIter</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">InputIter</phrase> <phrase role="identifier">last</phrase><phrase role="special">)</phrase>
10438 <phrase role="comment">// Precondition: [begin(), end()) does not contain [first, last).</phrase>
10439 <phrase role="identifier">postcondition</phrase> <phrase role="special">{</phrase>
10440 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">distance</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">last</phrase><phrase role="special">)</phrase> <phrase role="special">==</phrase> <phrase role="keyword">int</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">());</phrase>
10441 <phrase role="special">}</phrase>
10442 <phrase role="special">{</phrase>
10443 <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">assign</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">last</phrase><phrase role="special">);</phrase>
10444 <phrase role="special">}</phrase>
10452 <phrase role="keyword">void</phrase> <phrase role="identifier">assign</phrase><phrase role="special">(</phrase><phrase role="identifier">size_type</phrase> <phrase role="identifier">count</phrase><phrase role="special">,</phrase> <phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">vallue</phrase><phrase role="special">)</phrase>
10453 <phrase role="identifier">precondition</phrase> <phrase role="special">{</phrase>
10454 <phrase role="identifier">count</phrase> <phrase role="special"><=</phrase> <phrase role="identifier">max_size</phrase><phrase role="special">();</phrase>
10455 <phrase role="special">}</phrase>
10456 <phrase role="identifier">postcondition</phrase> <phrase role="special">{</phrase>
10457 <phrase role="keyword">if</phrase> <phrase role="keyword">constexpr</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">has_equal_to</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">>::</phrase><phrase role="identifier">value</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
10458 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">algorithm</phrase><phrase role="special">::</phrase><phrase role="identifier">all_of_equal</phrase><phrase role="special">(</phrase><phrase role="identifier">begin</phrase><phrase role="special">(),</phrase> <phrase role="identifier">end</phrase><phrase role="special">(),</phrase> <phrase role="identifier">value</phrase><phrase role="special">);</phrase>
10459 <phrase role="special">}</phrase>
10460 <phrase role="special">}</phrase>
10461 <phrase role="special">{</phrase>
10462 <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">assign</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">,</phrase> <phrase role="identifier">value</phrase><phrase role="special">);</phrase>
10463 <phrase role="special">}</phrase>
10470 <phrase role="identifier">iterator</phrase> <phrase role="identifier">insert</phrase><phrase role="special">(</phrase><phrase role="identifier">iterator</phrase> <phrase role="identifier">where</phrase><phrase role="special">,</phrase> <phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">value</phrase><phrase role="special">)</phrase>
10471 <phrase role="identifier">precondition</phrase> <phrase role="special">{</phrase>
10472 <phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special"><</phrase> <phrase role="identifier">max_size</phrase><phrase role="special">();</phrase>
10473 <phrase role="special">}</phrase>
10474 <phrase role="identifier">postcondition</phrase><phrase role="special">(</phrase><phrase role="identifier">result</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
10475 <phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">oldof</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">())</phrase> <phrase role="special">+</phrase> <phrase role="number">1</phrase><phrase role="special">;</phrase>
10476 <phrase role="identifier">capacity</phrase><phrase role="special">()</phrase> <phrase role="special">>=</phrase> <phrase role="identifier">oldof</phrase><phrase role="special">(</phrase><phrase role="identifier">capacity</phrase><phrase role="special">());</phrase>
10477 <phrase role="keyword">if</phrase> <phrase role="keyword">constexpr</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">has_equal_to</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">>::</phrase><phrase role="identifier">value</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
10478 <phrase role="special">*</phrase><phrase role="identifier">result</phrase> <phrase role="special">==</phrase> <phrase role="identifier">value</phrase><phrase role="special">;</phrase>
10479 <phrase role="special">}</phrase>
10480 <phrase role="comment">// if(capacity() > oldof(capacity()))</phrase>
10481 <phrase role="comment">// [begin(), end()) is invalid</phrase>
10482 <phrase role="comment">// else</phrase>
10483 <phrase role="comment">// [where, end()) is invalid</phrase>
10484 <phrase role="special">}</phrase>
10485 <phrase role="special">{</phrase>
10486 <phrase role="keyword">return</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">insert</phrase><phrase role="special">(</phrase><phrase role="identifier">where</phrase><phrase role="special">,</phrase> <phrase role="identifier">value</phrase><phrase role="special">);</phrase>
10487 <phrase role="special">}</phrase>
10500 <phrase role="keyword">void</phrase> <phrase role="identifier">insert</phrase><phrase role="special">(</phrase><phrase role="identifier">iterator</phrase> <phrase role="identifier">where</phrase><phrase role="special">,</phrase> <phrase role="identifier">size_type</phrase> <phrase role="identifier">count</phrase><phrase role="special">,</phrase> <phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">value</phrase><phrase role="special">)</phrase>
10501 <phrase role="identifier">precondition</phrase> <phrase role="special">{</phrase>
10502 <phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">+</phrase> <phrase role="identifier">count</phrase> <phrase role="special"><</phrase> <phrase role="identifier">max_size</phrase><phrase role="special">();</phrase>
10503 <phrase role="special">}</phrase>
10504 <phrase role="identifier">postcondition</phrase> <phrase role="special">{</phrase>
10505 <phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">oldof</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">())</phrase> <phrase role="special">+</phrase> <phrase role="identifier">count</phrase><phrase role="special">;</phrase>
10506 <phrase role="identifier">capacity</phrase><phrase role="special">()</phrase> <phrase role="special">>=</phrase> <phrase role="identifier">oldof</phrase><phrase role="special">(</phrase><phrase role="identifier">capacity</phrase><phrase role="special">());</phrase>
10507 <phrase role="keyword">if</phrase><phrase role="special">(</phrase><phrase role="identifier">capacity</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">oldof</phrase><phrase role="special">(</phrase><phrase role="identifier">capacity</phrase><phrase role="special">()))</phrase> <phrase role="special">{</phrase>
10508 <phrase role="keyword">if</phrase> <phrase role="keyword">constexpr</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">has_equal_to</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">>::</phrase><phrase role="identifier">value</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
10509 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">algorithm</phrase><phrase role="special">::</phrase><phrase role="identifier">all_of_equal</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">prior</phrase><phrase role="special">(</phrase><phrase role="identifier">oldof</phrase><phrase role="special">(</phrase><phrase role="identifier">where</phrase><phrase role="special">)),</phrase>
10510 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">prior</phrase><phrase role="special">(</phrase><phrase role="identifier">oldof</phrase><phrase role="special">(</phrase><phrase role="identifier">where</phrase><phrase role="special">))</phrase> <phrase role="special">+</phrase> <phrase role="identifier">count</phrase><phrase role="special">,</phrase> <phrase role="identifier">value</phrase><phrase role="special">);</phrase>
10511 <phrase role="special">}</phrase>
10512 <phrase role="comment">// [where, end()) is invalid</phrase>
10513 <phrase role="special">}</phrase>
10514 <phrase role="comment">// else [begin(), end()) is invalid</phrase>
10515 <phrase role="special">}</phrase>
10516 <phrase role="special">{</phrase>
10517 <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">insert</phrase><phrase role="special">(</phrase><phrase role="identifier">where</phrase><phrase role="special">,</phrase> <phrase role="identifier">count</phrase><phrase role="special">,</phrase> <phrase role="identifier">value</phrase><phrase role="special">);</phrase>
10518 <phrase role="special">}</phrase>
10532 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">InputIter</phrase><phrase role="special">></phrase>
10533 <phrase role="keyword">void</phrase> <phrase role="identifier">insert</phrase><phrase role="special">(</phrase><phrase role="identifier">iterator</phrase> <phrase role="identifier">where</phrase><phrase role="special">,</phrase> <phrase role="identifier">Iterator</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">Iterator</phrase> <phrase role="identifier">last</phrase><phrase role="special">)</phrase>
10534 <phrase role="identifier">precondition</phrase> <phrase role="special">{</phrase>
10535 <phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">+</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">distance</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">last</phrase><phrase role="special">)</phrase> <phrase role="special"><</phrase> <phrase role="identifier">max_size</phrase><phrase role="special">();</phrase>
10536 <phrase role="comment">// [first, last) is not contained in [begin(), end())</phrase>
10537 <phrase role="special">}</phrase>
10538 <phrase role="identifier">postcondition</phrase> <phrase role="special">{</phrase>
10539 <phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">oldof</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">())</phrase> <phrase role="special">+</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">distance</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">last</phrase><phrase role="special">);</phrase>
10540 <phrase role="identifier">capacity</phrase><phrase role="special">()</phrase> <phrase role="special">>=</phrase> <phrase role="identifier">oldof</phrase><phrase role="special">(</phrase><phrase role="identifier">capacity</phrase><phrase role="special">());</phrase>
10541 <phrase role="keyword">if</phrase><phrase role="special">(</phrase><phrase role="identifier">capacity</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">oldof</phrase><phrase role="special">(</phrase><phrase role="identifier">capacity</phrase><phrase role="special">()))</phrase> <phrase role="special">{</phrase>
10542 <phrase role="keyword">if</phrase> <phrase role="keyword">constexpr</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">has_equal_to</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">>::</phrase><phrase role="identifier">value</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
10543 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">algorithm</phrase><phrase role="special">::</phrase><phrase role="identifier">all_of_equal</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="identifier">oldof</phrase><phrase role="special">(</phrase><phrase role="identifier">where</phrase><phrase role="special">));</phrase>
10544 <phrase role="special">}</phrase>
10545 <phrase role="comment">// [where, end()) is invalid</phrase>
10546 <phrase role="special">}</phrase>
10547 <phrase role="comment">// else [begin(), end()) is invalid</phrase>
10548 <phrase role="special">}</phrase>
10549 <phrase role="special">{</phrase>
10550 <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">insert</phrase><phrase role="special">(</phrase><phrase role="identifier">where</phrase><phrase role="special">,</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">last</phrase><phrase role="special">);</phrase>
10551 <phrase role="special">}</phrase>
10566 <phrase role="identifier">iterator</phrase> <phrase role="identifier">erase</phrase><phrase role="special">(</phrase><phrase role="identifier">iterator</phrase> <phrase role="identifier">where</phrase><phrase role="special">)</phrase>
10567 <phrase role="identifier">precondition</phrase> <phrase role="special">{</phrase>
10568 <phrase role="special">!</phrase><phrase role="identifier">empty</phrase><phrase role="special">();</phrase>
10569 <phrase role="identifier">where</phrase> <phrase role="special">!=</phrase> <phrase role="identifier">end</phrase><phrase role="special">();</phrase>
10570 <phrase role="special">}</phrase>
10571 <phrase role="identifier">postcondition</phrase><phrase role="special">(</phrase><phrase role="identifier">result</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
10572 <phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">oldod</phrase> <phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">-</phrase> <phrase role="number">1</phrase><phrase role="special">;</phrase>
10573 <phrase role="keyword">if</phrase><phrase role="special">(</phrase><phrase role="identifier">empty</phrase><phrase role="special">())</phrase> <phrase role="identifier">result</phrase> <phrase role="special">==</phrase> <phrase role="identifier">end</phrase><phrase role="special">();</phrase>
10574 <phrase role="comment">// [where, end()) is invalid</phrase>
10575 <phrase role="special">}</phrase>
10576 <phrase role="special">{</phrase>
10577 <phrase role="keyword">return</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">erase</phrase><phrase role="special">(</phrase><phrase role="identifier">where</phrase><phrase role="special">);</phrase>
10578 <phrase role="special">}</phrase>
10585 <phrase role="identifier">iterator</phrase> <phrase role="identifier">erase</phrase><phrase role="special">(</phrase><phrase role="identifier">iterator</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">iterator</phrase> <phrase role="identifier">last</phrase><phrase role="special">)</phrase>
10586 <phrase role="identifier">precondition</phrase> <phrase role="special">{</phrase>
10587 <phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">>=</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">distance</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">lasst</phrase><phrase role="special">);</phrase>
10588 <phrase role="special">}</phrase>
10589 <phrase role="identifier">postcondition</phrase><phrase role="special">(</phrase><phrase role="identifier">result</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
10590 <phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">oldof</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">())</phrase> <phrase role="special">-</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">distance</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">last</phrase><phrase role="special">);</phrase>
10591 <phrase role="keyword">if</phrase><phrase role="special">(</phrase><phrase role="identifier">empty</phrase><phrase role="special">())</phrase> <phrase role="identifier">result</phrase> <phrase role="special">==</phrase> <phrase role="identifier">end</phrase><phrase role="special">();</phrase>
10592 <phrase role="comment">// [first, last) is invalid</phrase>
10593 <phrase role="special">}</phrase>
10594 <phrase role="special">{</phrase>
10595 <phrase role="keyword">return</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">erase</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">last</phrase><phrase role="special">);</phrase>
10596 <phrase role="special">}</phrase>
10604 <phrase role="keyword">void</phrase> <phrase role="identifier">clear</phrase><phrase role="special">()</phrase>
10605 <phrase role="identifier">postcondition</phrase> <phrase role="special">{</phrase>
10606 <phrase role="identifier">empty</phrase><phrase role="special">();</phrase>
10607 <phrase role="special">}</phrase>
10608 <phrase role="special">{</phrase>
10609 <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">clear</phrase><phrase role="special">();</phrase>
10610 <phrase role="special">}</phrase>
10614 <phrase role="keyword">void</phrase> <phrase role="identifier">swap</phrase><phrase role="special">(</phrase><phrase role="identifier">vector</phrase><phrase role="special">&</phrase> <phrase role="identifier">other</phrase><phrase role="special">)</phrase>
10615 <phrase role="identifier">precondition</phrase> <phrase role="special">{</phrase>
10616 <phrase role="identifier">get_allocator</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">other</phrase><phrase role="special">.</phrase><phrase role="identifier">get_allocator</phrase><phrase role="special">();</phrase>
10617 <phrase role="special">}</phrase>
10618 <phrase role="identifier">postcondition</phrase> <phrase role="special">{</phrase>
10619 <phrase role="keyword">if</phrase> <phrase role="keyword">constexpr</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">has_equal_to</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">>::</phrase><phrase role="identifier">value</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
10620 <phrase role="special">*</phrase><phrase role="keyword">this</phrase> <phrase role="special">==</phrase> <phrase role="identifier">oldof</phrase><phrase role="special">(</phrase><phrase role="identifier">other</phrase><phrase role="special">);</phrase>
10621 <phrase role="identifier">other</phrase> <phrase role="special">==</phrase> <phrase role="identifier">oldof</phrase><phrase role="special">(*</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
10622 <phrase role="special">}</phrase>
10623 <phrase role="special">}</phrase>
10624 <phrase role="special">{</phrase>
10625 <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">swap</phrase><phrase role="special">(</phrase><phrase role="identifier">other</phrase><phrase role="special">);</phrase>
10626 <phrase role="special">}</phrase>
10645 <phrase role="keyword">friend</phrase> <phrase role="keyword">bool</phrase> <phrase role="keyword">operator</phrase><phrase role="special">==(</phrase><phrase role="identifier">vector</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">left</phrase><phrase role="special">,</phrase> <phrase role="identifier">vector</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">right</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
10646 <phrase role="comment">// Cannot check class invariants for left and right objects.</phrase>
10647 <phrase role="keyword">return</phrase> <phrase role="identifier">left</phrase><phrase role="special">.</phrase><phrase role="identifier">vect_</phrase> <phrase role="special">==</phrase> <phrase role="identifier">right</phrase><phrase role="special">.</phrase><phrase role="identifier">vect_</phrase><phrase role="special">;</phrase>
10648 <phrase role="special">}</phrase>
10654 <phrase role="keyword">private</phrase><phrase role="special">:</phrase>
10655 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="identifier">Allocator</phrase><phrase role="special">></phrase> <phrase role="identifier">vect_</phrase><phrase role="special">;</phrase>
10656 <phrase role="special">};</phrase>
10701 <phrase role="comment">// End.</phrase>
10710 <section id="boost_contract.examples.__n1962___circle__subcontracting">
10711 <title><link linkend="boost_contract.examples.__n1962___circle__subcontracting">[N1962]
10712 Circle: Subcontracting</link></title>
10714 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">contract</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">></phrase>
10715 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">cassert</phrase><phrase role="special">></phrase>
10717 <phrase role="keyword">class</phrase> <phrase role="identifier">shape</phrase> <phrase role="special">{</phrase>
10718 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
10719 <phrase role="keyword">virtual</phrase> <phrase role="special">~</phrase><phrase role="identifier">shape</phrase><phrase role="special">()</phrase> <phrase role="special">{}</phrase>
10721 <phrase role="keyword">virtual</phrase> <phrase role="keyword">unsigned</phrase> <phrase role="identifier">compute_area</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase>
10722 <phrase role="special">};</phrase>
10724 <phrase role="keyword">unsigned</phrase> <phrase role="identifier">shape</phrase><phrase role="special">::</phrase><phrase role="identifier">compute_area</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
10725 <phrase role="keyword">unsigned</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
10726 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">result</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">)</phrase>
10727 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">result</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
10728 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">result</phrase> <phrase role="special">></phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase>
10729 <phrase role="special">})</phrase>
10730 <phrase role="special">;</phrase>
10731 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="keyword">false</phrase><phrase role="special">);</phrase>
10732 <phrase role="keyword">return</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
10733 <phrase role="special">}</phrase>
10735 <phrase role="keyword">class</phrase> <phrase role="identifier">circle</phrase>
10736 <phrase role="preprocessor">#define</phrase> <phrase role="identifier">BASES</phrase> <phrase role="keyword">public</phrase> <phrase role="identifier">shape</phrase>
10737 <phrase role="special">:</phrase> <phrase role="identifier">BASES</phrase>
10738 <phrase role="special">{</phrase>
10739 <phrase role="keyword">friend</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">access</phrase><phrase role="special">;</phrase>
10741 <phrase role="keyword">typedef</phrase> <phrase role="identifier">BOOST_CONTRACT_BASE_TYPES</phrase><phrase role="special">(</phrase><phrase role="identifier">BASES</phrase><phrase role="special">)</phrase> <phrase role="identifier">base_types</phrase><phrase role="special">;</phrase>
10742 <phrase role="preprocessor">#undef</phrase> <phrase role="identifier">BASES</phrase>
10744 <phrase role="identifier">BOOST_CONTRACT_OVERRIDE</phrase><phrase role="special">(</phrase><phrase role="identifier">compute_area</phrase><phrase role="special">);</phrase>
10746 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
10747 <phrase role="keyword">static</phrase> <phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">pi</phrase> <phrase role="special">=</phrase> <phrase role="number">3</phrase><phrase role="special">;</phrase> <phrase role="comment">// Truncated to int from 3.14...</phrase>
10749 <phrase role="keyword">explicit</phrase> <phrase role="identifier">circle</phrase><phrase role="special">(</phrase><phrase role="keyword">unsigned</phrase> <phrase role="identifier">a_radius</phrase><phrase role="special">)</phrase> <phrase role="special">:</phrase> <phrase role="identifier">radius_</phrase><phrase role="special">(</phrase><phrase role="identifier">a_radius</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
10750 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
10751 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
10752 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">radius</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">a_radius</phrase><phrase role="special">);</phrase>
10753 <phrase role="special">})</phrase>
10754 <phrase role="special">;</phrase>
10755 <phrase role="special">}</phrase>
10757 <phrase role="keyword">virtual</phrase> <phrase role="keyword">unsigned</phrase> <phrase role="identifier">compute_area</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase>
10758 <phrase role="comment">/* override */</phrase> <phrase role="special">{</phrase>
10759 <phrase role="keyword">unsigned</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
10760 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special"><</phrase>
10761 <phrase role="identifier">override_compute_area</phrase><phrase role="special">>(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">result</phrase><phrase role="special">,</phrase> <phrase role="special">&</phrase><phrase role="identifier">circle</phrase><phrase role="special">::</phrase><phrase role="identifier">compute_area</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">)</phrase>
10762 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">(</phrase><phrase role="keyword">unsigned</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">result</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
10763 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">result</phrase> <phrase role="special">==</phrase> <phrase role="identifier">pi</phrase> <phrase role="special">*</phrase> <phrase role="identifier">radius</phrase><phrase role="special">()</phrase> <phrase role="special">*</phrase> <phrase role="identifier">radius</phrase><phrase role="special">());</phrase>
10764 <phrase role="special">})</phrase>
10765 <phrase role="special">;</phrase>
10767 <phrase role="keyword">return</phrase> <phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="identifier">pi</phrase> <phrase role="special">*</phrase> <phrase role="identifier">radius</phrase><phrase role="special">()</phrase> <phrase role="special">*</phrase> <phrase role="identifier">radius</phrase><phrase role="special">();</phrase>
10768 <phrase role="special">}</phrase>
10770 <phrase role="keyword">unsigned</phrase> <phrase role="identifier">radius</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
10771 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
10772 <phrase role="keyword">return</phrase> <phrase role="identifier">radius_</phrase><phrase role="special">;</phrase>
10773 <phrase role="special">}</phrase>
10775 <phrase role="keyword">private</phrase><phrase role="special">:</phrase>
10776 <phrase role="keyword">unsigned</phrase> <phrase role="identifier">radius_</phrase><phrase role="special">;</phrase>
10777 <phrase role="special">};</phrase>
10779 <phrase role="keyword">int</phrase> <phrase role="identifier">main</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
10780 <phrase role="identifier">circle</phrase> <phrase role="identifier">c</phrase><phrase role="special">(</phrase><phrase role="number">2</phrase><phrase role="special">);</phrase>
10781 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">c</phrase><phrase role="special">.</phrase><phrase role="identifier">radius</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">2</phrase><phrase role="special">);</phrase>
10782 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">c</phrase><phrase role="special">.</phrase><phrase role="identifier">compute_area</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">12</phrase><phrase role="special">);</phrase>
10783 <phrase role="keyword">return</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase>
10784 <phrase role="special">}</phrase>
10788 <section id="boost_contract.examples.__n1962___factorial__recursion">
10789 <title><anchor id="N1962_factorial_anchor"/><link linkend="boost_contract.examples.__n1962___factorial__recursion">[N1962]
10790 Factorial: Recursion</link></title>
10792 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">contract</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">></phrase>
10793 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">cassert</phrase><phrase role="special">></phrase>
10795 <phrase role="keyword">int</phrase> <phrase role="identifier">factorial</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">n</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
10796 <phrase role="keyword">int</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
10797 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">function</phrase><phrase role="special">()</phrase>
10798 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
10799 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">n</phrase> <phrase role="special">>=</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase> <phrase role="comment">// Non-negative natural number.</phrase>
10800 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">n</phrase> <phrase role="special"><=</phrase> <phrase role="number">12</phrase><phrase role="special">);</phrase> <phrase role="comment">// Max function input.</phrase>
10801 <phrase role="special">})</phrase>
10802 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
10803 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">result</phrase> <phrase role="special">>=</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase>
10804 <phrase role="keyword">if</phrase><phrase role="special">(</phrase><phrase role="identifier">n</phrase> <phrase role="special"><</phrase> <phrase role="number">2</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Select assertion.</phrase>
10805 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">result</phrase> <phrase role="special">==</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase>
10806 <phrase role="special">}</phrase> <phrase role="keyword">else</phrase> <phrase role="special">{</phrase>
10807 <phrase role="comment">// Assertions automatically disabled in other assertions.</phrase>
10808 <phrase role="comment">// Therefore, this postcondition can recursively call the</phrase>
10809 <phrase role="comment">// function without causing infinite recursion.</phrase>
10810 <phrase role="identifier">BOOST_CONTRACT_ASSERT_AUDIT</phrase><phrase role="special">(</phrase><phrase role="identifier">n</phrase> <phrase role="special">*</phrase> <phrase role="identifier">factorial</phrase><phrase role="special">(</phrase><phrase role="identifier">n</phrase> <phrase role="special">-</phrase> <phrase role="number">1</phrase><phrase role="special">));</phrase>
10811 <phrase role="special">}</phrase>
10812 <phrase role="special">})</phrase>
10813 <phrase role="special">;</phrase>
10815 <phrase role="keyword">return</phrase> <phrase role="identifier">n</phrase> <phrase role="special"><</phrase> <phrase role="number">2</phrase> <phrase role="special">?</phrase> <phrase role="special">(</phrase><phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="number">1</phrase><phrase role="special">)</phrase> <phrase role="special">:</phrase> <phrase role="special">(</phrase><phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="identifier">n</phrase> <phrase role="special">*</phrase> <phrase role="identifier">factorial</phrase><phrase role="special">(</phrase><phrase role="identifier">n</phrase> <phrase role="special">-</phrase> <phrase role="number">1</phrase><phrase role="special">));</phrase>
10816 <phrase role="special">}</phrase>
10818 <phrase role="keyword">int</phrase> <phrase role="identifier">main</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
10819 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">factorial</phrase><phrase role="special">(</phrase><phrase role="number">4</phrase><phrase role="special">)</phrase> <phrase role="special">==</phrase> <phrase role="number">24</phrase><phrase role="special">);</phrase>
10820 <phrase role="keyword">return</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase>
10821 <phrase role="special">}</phrase>
10825 <section id="boost_contract.examples.__n1962___equal__operators">
10826 <title><link linkend="boost_contract.examples.__n1962___equal__operators">[N1962]
10827 Equal: Operators</link></title>
10829 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">contract</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">></phrase>
10830 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">cassert</phrase><phrase role="special">></phrase>
10832 <phrase role="comment">// Forward declaration because == and != contracts use one another's function.</phrase>
10833 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">></phrase>
10834 <phrase role="keyword">bool</phrase> <phrase role="keyword">operator</phrase><phrase role="special">==(</phrase><phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">left</phrase><phrase role="special">,</phrase> <phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">right</phrase><phrase role="special">);</phrase>
10836 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">></phrase>
10837 <phrase role="keyword">bool</phrase> <phrase role="keyword">operator</phrase><phrase role="special">!=(</phrase><phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">left</phrase><phrase role="special">,</phrase> <phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">right</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
10838 <phrase role="keyword">bool</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
10839 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">function</phrase><phrase role="special">()</phrase>
10840 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
10841 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">result</phrase> <phrase role="special">==</phrase> <phrase role="special">!(</phrase><phrase role="identifier">left</phrase> <phrase role="special">==</phrase> <phrase role="identifier">right</phrase><phrase role="special">));</phrase>
10842 <phrase role="special">})</phrase>
10843 <phrase role="special">;</phrase>
10845 <phrase role="keyword">return</phrase> <phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="special">(</phrase><phrase role="identifier">left</phrase><phrase role="special">.</phrase><phrase role="identifier">value</phrase> <phrase role="special">!=</phrase> <phrase role="identifier">right</phrase><phrase role="special">.</phrase><phrase role="identifier">value</phrase><phrase role="special">);</phrase>
10846 <phrase role="special">}</phrase>
10848 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">></phrase>
10849 <phrase role="keyword">bool</phrase> <phrase role="keyword">operator</phrase><phrase role="special">==(</phrase><phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">left</phrase><phrase role="special">,</phrase> <phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">right</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
10850 <phrase role="keyword">bool</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
10851 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">function</phrase><phrase role="special">()</phrase>
10852 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
10853 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">result</phrase> <phrase role="special">==</phrase> <phrase role="special">!(</phrase><phrase role="identifier">left</phrase> <phrase role="special">!=</phrase> <phrase role="identifier">right</phrase><phrase role="special">));</phrase>
10854 <phrase role="special">})</phrase>
10855 <phrase role="special">;</phrase>
10857 <phrase role="keyword">return</phrase> <phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="special">(</phrase><phrase role="identifier">left</phrase><phrase role="special">.</phrase><phrase role="identifier">value</phrase> <phrase role="special">==</phrase> <phrase role="identifier">right</phrase><phrase role="special">.</phrase><phrase role="identifier">value</phrase><phrase role="special">);</phrase>
10858 <phrase role="special">}</phrase>
10860 <phrase role="keyword">struct</phrase> <phrase role="identifier">number</phrase> <phrase role="special">{</phrase> <phrase role="keyword">int</phrase> <phrase role="identifier">value</phrase><phrase role="special">;</phrase> <phrase role="special">};</phrase>
10862 <phrase role="keyword">int</phrase> <phrase role="identifier">main</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
10863 <phrase role="identifier">number</phrase> <phrase role="identifier">n</phrase><phrase role="special">;</phrase>
10864 <phrase role="identifier">n</phrase><phrase role="special">.</phrase><phrase role="identifier">value</phrase> <phrase role="special">=</phrase> <phrase role="number">123</phrase><phrase role="special">;</phrase>
10866 <phrase role="identifier">assert</phrase><phrase role="special">((</phrase><phrase role="identifier">n</phrase> <phrase role="special">==</phrase> <phrase role="identifier">n</phrase><phrase role="special">)</phrase> <phrase role="special">==</phrase> <phrase role="keyword">true</phrase><phrase role="special">);</phrase> <phrase role="comment">// Explicitly call operator==.</phrase>
10867 <phrase role="identifier">assert</phrase><phrase role="special">((</phrase><phrase role="identifier">n</phrase> <phrase role="special">!=</phrase> <phrase role="identifier">n</phrase><phrase role="special">)</phrase> <phrase role="special">==</phrase> <phrase role="keyword">false</phrase><phrase role="special">);</phrase> <phrase role="comment">// Explicitly call operator!=.</phrase>
10869 <phrase role="keyword">return</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase>
10870 <phrase role="special">}</phrase>
10874 <section id="boost_contract.examples.__n1962___sum__array_parameter">
10875 <title><link linkend="boost_contract.examples.__n1962___sum__array_parameter">[N1962]
10876 Sum: Array parameter</link></title>
10878 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">contract</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">></phrase>
10879 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">cassert</phrase><phrase role="special">></phrase>
10881 <phrase role="keyword">int</phrase> <phrase role="identifier">sum</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">count</phrase><phrase role="special">,</phrase> <phrase role="keyword">int</phrase><phrase role="special">*</phrase> <phrase role="identifier">array</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
10882 <phrase role="keyword">int</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
10883 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">function</phrase><phrase role="special">()</phrase>
10884 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
10885 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase> <phrase role="special">%</phrase> <phrase role="number">4</phrase> <phrase role="special">==</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase>
10886 <phrase role="special">})</phrase>
10887 <phrase role="special">;</phrase>
10889 <phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase>
10890 <phrase role="keyword">for</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">i</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase> <phrase role="identifier">i</phrase> <phrase role="special"><</phrase> <phrase role="identifier">count</phrase><phrase role="special">;</phrase> <phrase role="special">++</phrase><phrase role="identifier">i</phrase><phrase role="special">)</phrase> <phrase role="identifier">result</phrase> <phrase role="special">+=</phrase> <phrase role="identifier">array</phrase><phrase role="special">[</phrase><phrase role="identifier">i</phrase><phrase role="special">];</phrase>
10891 <phrase role="keyword">return</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
10892 <phrase role="special">}</phrase>
10894 <phrase role="keyword">int</phrase> <phrase role="identifier">main</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
10895 <phrase role="keyword">int</phrase> <phrase role="identifier">a</phrase><phrase role="special">[</phrase><phrase role="number">4</phrase><phrase role="special">]</phrase> <phrase role="special">=</phrase> <phrase role="special">{</phrase><phrase role="number">1</phrase><phrase role="special">,</phrase> <phrase role="number">2</phrase><phrase role="special">,</phrase> <phrase role="number">3</phrase><phrase role="special">,</phrase> <phrase role="number">4</phrase><phrase role="special">};</phrase>
10896 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">sum</phrase><phrase role="special">(</phrase><phrase role="number">4</phrase><phrase role="special">,</phrase> <phrase role="identifier">a</phrase><phrase role="special">)</phrase> <phrase role="special">==</phrase> <phrase role="number">10</phrase><phrase role="special">);</phrase>
10897 <phrase role="keyword">return</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase>
10898 <phrase role="special">}</phrase>
10902 <section id="boost_contract.examples.__n1962___square_root__default_parameters_and_comparison_with_d_syntax">
10903 <title><anchor id="N1962_square_root_anchor"/><link linkend="boost_contract.examples.__n1962___square_root__default_parameters_and_comparison_with_d_syntax">[N1962]
10904 Square Root: Default parameters and comparison with D syntax</link></title>
10905 <informaltable frame="all">
10916 The D Programming Language
10925 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">contract</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">></phrase>
10926 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">cmath</phrase><phrase role="special">></phrase>
10927 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">cassert</phrase><phrase role="special">></phrase>
10929 <phrase role="keyword">long</phrase> <phrase role="identifier">lsqrt</phrase><phrase role="special">(</phrase><phrase role="keyword">long</phrase> <phrase role="identifier">x</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
10930 <phrase role="keyword">long</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
10931 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">function</phrase><phrase role="special">()</phrase>
10932 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
10933 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">x</phrase> <phrase role="special">>=</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase>
10934 <phrase role="special">})</phrase>
10935 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
10936 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">result</phrase> <phrase role="special">*</phrase> <phrase role="identifier">result</phrase> <phrase role="special"><=</phrase> <phrase role="identifier">x</phrase><phrase role="special">);</phrase>
10937 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">((</phrase><phrase role="identifier">result</phrase> <phrase role="special">+</phrase> <phrase role="number">1</phrase><phrase role="special">)</phrase> <phrase role="special">*</phrase> <phrase role="special">(</phrase><phrase role="identifier">result</phrase> <phrase role="special">+</phrase> <phrase role="number">1</phrase><phrase role="special">)</phrase> <phrase role="special">></phrase> <phrase role="identifier">x</phrase><phrase role="special">);</phrase>
10938 <phrase role="special">})</phrase>
10939 <phrase role="special">;</phrase>
10941 <phrase role="keyword">return</phrase> <phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="keyword">long</phrase><phrase role="special">(</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">sqrt</phrase><phrase role="special">(</phrase><phrase role="keyword">double</phrase><phrase role="special">(</phrase><phrase role="identifier">x</phrase><phrase role="special">)));</phrase>
10942 <phrase role="special">}</phrase>
10944 <phrase role="keyword">int</phrase> <phrase role="identifier">main</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
10945 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">lsqrt</phrase><phrase role="special">(</phrase><phrase role="number">4</phrase><phrase role="special">)</phrase> <phrase role="special">==</phrase> <phrase role="number">2</phrase><phrase role="special">);</phrase>
10946 <phrase role="keyword">return</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase>
10947 <phrase role="special">}</phrase>
10953 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="comment">// Extra spaces, newlines, etc. for visual alignment with this library code.</phrase>
10957 <phrase role="keyword">long</phrase> <phrase role="identifier">lsqrt</phrase><phrase role="special">(</phrase><phrase role="keyword">long</phrase> <phrase role="identifier">x</phrase><phrase role="special">)</phrase>
10958 <phrase role="identifier">in</phrase> <phrase role="special">{</phrase>
10959 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">x</phrase> <phrase role="special">>=</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase>
10960 <phrase role="special">}</phrase>
10961 <phrase role="identifier">out</phrase><phrase role="special">(</phrase><phrase role="identifier">result</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
10962 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">result</phrase> <phrase role="special">*</phrase> <phrase role="identifier">result</phrase> <phrase role="special"><=</phrase> <phrase role="identifier">x</phrase><phrase role="special">);</phrase>
10963 <phrase role="identifier">assert</phrase><phrase role="special">((</phrase><phrase role="identifier">result</phrase> <phrase role="special">+</phrase> <phrase role="number">1</phrase><phrase role="special">)</phrase> <phrase role="special">*</phrase> <phrase role="special">(</phrase><phrase role="identifier">result</phrase> <phrase role="special">+</phrase> <phrase role="number">1</phrase><phrase role="special">)</phrase> <phrase role="special">></phrase> <phrase role="identifier">x</phrase><phrase role="special">);</phrase>
10964 <phrase role="special">}</phrase>
10965 <phrase role="keyword">do</phrase> <phrase role="special">{</phrase>
10966 <phrase role="keyword">return</phrase> <phrase role="identifier">cast</phrase><phrase role="special">(</phrase><phrase role="keyword">long</phrase><phrase role="special">)</phrase><phrase role="identifier">std</phrase><phrase role="special">.</phrase><phrase role="identifier">math</phrase><phrase role="special">.</phrase><phrase role="identifier">sqrt</phrase><phrase role="special">(</phrase><phrase role="identifier">cast</phrase><phrase role="special">(</phrase><phrase role="identifier">real</phrase><phrase role="special">)</phrase><phrase role="identifier">x</phrase><phrase role="special">);</phrase>
10967 <phrase role="special">}</phrase>
10976 <phrase role="comment">// End.</phrase>
10985 <section id="boost_contract.examples.__meyer97___stack4__comparison_with_eiffel_syntax">
10986 <title><anchor id="Meyer97_stack4_anchor"/><link linkend="boost_contract.examples.__meyer97___stack4__comparison_with_eiffel_syntax">[Meyer97]
10987 Stack4: Comparison with Eiffel syntax</link></title>
10988 <informaltable frame="all">
10999 The Eiffel Programming Language
11008 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="comment">// File: stack4.hpp</phrase>
11009 <phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">STACK4_HPP_</phrase>
11010 <phrase role="preprocessor">#define</phrase> <phrase role="identifier">STACK4_HPP_</phrase>
11012 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">contract</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">></phrase>
11014 <phrase role="comment">// Dispenser with LIFO access policy and fixed max capacity.</phrase>
11015 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">></phrase>
11016 <phrase role="keyword">class</phrase> <phrase role="identifier">stack4</phrase>
11017 <phrase role="preprocessor">#define</phrase> <phrase role="identifier">BASES</phrase> <phrase role="keyword">private</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor_precondition</phrase><phrase role="special"><</phrase><phrase role="identifier">stack4</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase> <phrase role="special">></phrase>
11018 <phrase role="special">:</phrase> <phrase role="identifier">BASES</phrase>
11019 <phrase role="special">{</phrase>
11020 <phrase role="keyword">friend</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">access</phrase><phrase role="special">;</phrase>
11021 <phrase role="keyword">typedef</phrase> <phrase role="identifier">BOOST_CONTRACT_BASE_TYPES</phrase><phrase role="special">(</phrase><phrase role="identifier">BASES</phrase><phrase role="special">)</phrase> <phrase role="identifier">base_types</phrase><phrase role="special">;</phrase>
11022 <phrase role="preprocessor">#undef</phrase> <phrase role="identifier">BASES</phrase>
11024 <phrase role="keyword">void</phrase> <phrase role="identifier">invariant</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
11025 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="special">>=</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase> <phrase role="comment">// Count non-negative.</phrase>
11026 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="special"><=</phrase> <phrase role="identifier">capacity</phrase><phrase role="special">());</phrase> <phrase role="comment">// Count bounded.</phrase>
11027 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">empty</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">0</phrase><phrase role="special">));</phrase> <phrase role="comment">// Empty if no elem.</phrase>
11028 <phrase role="special">}</phrase>
11030 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
11031 <phrase role="comment">/* Initialization */</phrase>
11033 <phrase role="comment">// Allocate static from a maximum of n elements.</phrase>
11034 <phrase role="keyword">explicit</phrase> <phrase role="identifier">stack4</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">n</phrase><phrase role="special">)</phrase> <phrase role="special">:</phrase>
11035 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor_precondition</phrase><phrase role="special"><</phrase><phrase role="identifier">stack4</phrase><phrase role="special">>([&]</phrase> <phrase role="special">{</phrase>
11036 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">n</phrase> <phrase role="special">>=</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase> <phrase role="comment">// Non-negative capacity.</phrase>
11037 <phrase role="special">})</phrase>
11038 <phrase role="special">{</phrase>
11039 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
11040 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
11041 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">capacity</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">n</phrase><phrase role="special">);</phrase> <phrase role="comment">// Capacity set.</phrase>
11042 <phrase role="special">})</phrase>
11043 <phrase role="special">;</phrase>
11045 <phrase role="identifier">capacity_</phrase> <phrase role="special">=</phrase> <phrase role="identifier">n</phrase><phrase role="special">;</phrase>
11046 <phrase role="identifier">count_</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase>
11047 <phrase role="identifier">array_</phrase> <phrase role="special">=</phrase> <phrase role="keyword">new</phrase> <phrase role="identifier">T</phrase><phrase role="special">[</phrase><phrase role="identifier">n</phrase><phrase role="special">];</phrase>
11048 <phrase role="special">}</phrase>
11050 <phrase role="comment">// Deep copy via constructor.</phrase>
11051 <phrase role="comment">/* implicit */</phrase> <phrase role="identifier">stack4</phrase><phrase role="special">(</phrase><phrase role="identifier">stack4</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">other</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
11052 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
11053 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
11054 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">capacity</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">other</phrase><phrase role="special">.</phrase><phrase role="identifier">capacity</phrase><phrase role="special">());</phrase>
11055 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">other</phrase><phrase role="special">.</phrase><phrase role="identifier">count</phrase><phrase role="special">());</phrase>
11056 <phrase role="identifier">BOOST_CONTRACT_ASSERT_AXIOM</phrase><phrase role="special">(*</phrase><phrase role="keyword">this</phrase> <phrase role="special">==</phrase> <phrase role="identifier">other</phrase><phrase role="special">);</phrase>
11057 <phrase role="special">})</phrase>
11058 <phrase role="special">;</phrase>
11060 <phrase role="identifier">capacity_</phrase> <phrase role="special">=</phrase> <phrase role="identifier">other</phrase><phrase role="special">.</phrase><phrase role="identifier">capacity_</phrase><phrase role="special">;</phrase>
11061 <phrase role="identifier">count_</phrase> <phrase role="special">=</phrase> <phrase role="identifier">other</phrase><phrase role="special">.</phrase><phrase role="identifier">count_</phrase><phrase role="special">;</phrase>
11062 <phrase role="identifier">array_</phrase> <phrase role="special">=</phrase> <phrase role="keyword">new</phrase> <phrase role="identifier">T</phrase><phrase role="special">[</phrase><phrase role="identifier">other</phrase><phrase role="special">.</phrase><phrase role="identifier">capacity_</phrase><phrase role="special">];</phrase>
11063 <phrase role="keyword">for</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">i</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase> <phrase role="identifier">i</phrase> <phrase role="special"><</phrase> <phrase role="identifier">other</phrase><phrase role="special">.</phrase><phrase role="identifier">count_</phrase><phrase role="special">;</phrase> <phrase role="special">++</phrase><phrase role="identifier">i</phrase><phrase role="special">)</phrase> <phrase role="identifier">array_</phrase><phrase role="special">[</phrase><phrase role="identifier">i</phrase><phrase role="special">]</phrase> <phrase role="special">=</phrase> <phrase role="identifier">other</phrase><phrase role="special">.</phrase><phrase role="identifier">array_</phrase><phrase role="special">[</phrase><phrase role="identifier">i</phrase><phrase role="special">];</phrase>
11064 <phrase role="special">}</phrase>
11066 <phrase role="comment">// Deep copy via assignment.</phrase>
11067 <phrase role="identifier">stack4</phrase><phrase role="special">&</phrase> <phrase role="keyword">operator</phrase><phrase role="special">=(</phrase><phrase role="identifier">stack4</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">other</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
11068 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
11069 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
11070 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">capacity</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">other</phrase><phrase role="special">.</phrase><phrase role="identifier">capacity</phrase><phrase role="special">());</phrase>
11071 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">other</phrase><phrase role="special">.</phrase><phrase role="identifier">count</phrase><phrase role="special">());</phrase>
11072 <phrase role="identifier">BOOST_CONTRACT_ASSERT_AXIOM</phrase><phrase role="special">(*</phrase><phrase role="keyword">this</phrase> <phrase role="special">==</phrase> <phrase role="identifier">other</phrase><phrase role="special">);</phrase>
11073 <phrase role="special">})</phrase>
11074 <phrase role="special">;</phrase>
11076 <phrase role="keyword">delete</phrase><phrase role="special">[]</phrase> <phrase role="identifier">array_</phrase><phrase role="special">;</phrase>
11077 <phrase role="identifier">capacity_</phrase> <phrase role="special">=</phrase> <phrase role="identifier">other</phrase><phrase role="special">.</phrase><phrase role="identifier">capacity_</phrase><phrase role="special">;</phrase>
11078 <phrase role="identifier">count_</phrase> <phrase role="special">=</phrase> <phrase role="identifier">other</phrase><phrase role="special">.</phrase><phrase role="identifier">count_</phrase><phrase role="special">;</phrase>
11079 <phrase role="identifier">array_</phrase> <phrase role="special">=</phrase> <phrase role="keyword">new</phrase> <phrase role="identifier">T</phrase><phrase role="special">[</phrase><phrase role="identifier">other</phrase><phrase role="special">.</phrase><phrase role="identifier">capacity_</phrase><phrase role="special">];</phrase>
11080 <phrase role="keyword">for</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">i</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase> <phrase role="identifier">i</phrase> <phrase role="special"><</phrase> <phrase role="identifier">other</phrase><phrase role="special">.</phrase><phrase role="identifier">count_</phrase><phrase role="special">;</phrase> <phrase role="special">++</phrase><phrase role="identifier">i</phrase><phrase role="special">)</phrase> <phrase role="identifier">array_</phrase><phrase role="special">[</phrase><phrase role="identifier">i</phrase><phrase role="special">]</phrase> <phrase role="special">=</phrase> <phrase role="identifier">other</phrase><phrase role="special">.</phrase><phrase role="identifier">array_</phrase><phrase role="special">[</phrase><phrase role="identifier">i</phrase><phrase role="special">];</phrase>
11081 <phrase role="keyword">return</phrase> <phrase role="special">*</phrase><phrase role="keyword">this</phrase><phrase role="special">;</phrase>
11082 <phrase role="special">}</phrase>
11084 <phrase role="comment">// Destroy this stack.</phrase>
11085 <phrase role="keyword">virtual</phrase> <phrase role="special">~</phrase><phrase role="identifier">stack4</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
11086 <phrase role="comment">// Check invariants.</phrase>
11087 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">destructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
11088 <phrase role="keyword">delete</phrase><phrase role="special">[]</phrase> <phrase role="identifier">array_</phrase><phrase role="special">;</phrase>
11089 <phrase role="special">}</phrase>
11091 <phrase role="comment">/* Access */</phrase>
11093 <phrase role="comment">// Max number of stack elements.</phrase>
11094 <phrase role="keyword">int</phrase> <phrase role="identifier">capacity</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
11095 <phrase role="comment">// Check invariants.</phrase>
11096 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
11097 <phrase role="keyword">return</phrase> <phrase role="identifier">capacity_</phrase><phrase role="special">;</phrase>
11098 <phrase role="special">}</phrase>
11100 <phrase role="comment">// Number of stack elements.</phrase>
11101 <phrase role="keyword">int</phrase> <phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
11102 <phrase role="comment">// Check invariants.</phrase>
11103 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
11104 <phrase role="keyword">return</phrase> <phrase role="identifier">count_</phrase><phrase role="special">;</phrase>
11105 <phrase role="special">}</phrase>
11107 <phrase role="comment">// Top element.</phrase>
11108 <phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">item</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
11109 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
11110 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
11111 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(!</phrase><phrase role="identifier">empty</phrase><phrase role="special">());</phrase> <phrase role="comment">// Not empty (i.e., count > 0).</phrase>
11112 <phrase role="special">})</phrase>
11113 <phrase role="special">;</phrase>
11115 <phrase role="keyword">return</phrase> <phrase role="identifier">array_</phrase><phrase role="special">[</phrase><phrase role="identifier">count_</phrase> <phrase role="special">-</phrase> <phrase role="number">1</phrase><phrase role="special">];</phrase>
11116 <phrase role="special">}</phrase>
11118 <phrase role="comment">/* Status Report */</phrase>
11120 <phrase role="comment">// Is stack empty?</phrase>
11121 <phrase role="keyword">bool</phrase> <phrase role="identifier">empty</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
11122 <phrase role="keyword">bool</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
11123 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
11124 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
11125 <phrase role="comment">// Empty definition.</phrase>
11126 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">result</phrase> <phrase role="special">==</phrase> <phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">0</phrase><phrase role="special">));</phrase>
11127 <phrase role="special">})</phrase>
11128 <phrase role="special">;</phrase>
11130 <phrase role="keyword">return</phrase> <phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="special">(</phrase><phrase role="identifier">count_</phrase> <phrase role="special">==</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase>
11131 <phrase role="special">}</phrase>
11133 <phrase role="comment">// Is stack full?</phrase>
11134 <phrase role="keyword">bool</phrase> <phrase role="identifier">full</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
11135 <phrase role="keyword">bool</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
11136 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
11137 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
11138 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase> <phrase role="comment">// Full definition.</phrase>
11139 <phrase role="identifier">result</phrase> <phrase role="special">==</phrase> <phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">capacity</phrase><phrase role="special">()));</phrase>
11140 <phrase role="special">})</phrase>
11141 <phrase role="special">;</phrase>
11143 <phrase role="keyword">return</phrase> <phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="special">(</phrase><phrase role="identifier">count_</phrase> <phrase role="special">==</phrase> <phrase role="identifier">capacity_</phrase><phrase role="special">);</phrase>
11144 <phrase role="special">}</phrase>
11146 <phrase role="comment">/* Element Change */</phrase>
11148 <phrase role="comment">// Add x on top.</phrase>
11149 <phrase role="keyword">void</phrase> <phrase role="identifier">put</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">x</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
11150 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">></phrase> <phrase role="identifier">old_count</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">());</phrase>
11151 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
11152 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
11153 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(!</phrase><phrase role="identifier">full</phrase><phrase role="special">());</phrase> <phrase role="comment">// Not full.</phrase>
11154 <phrase role="special">})</phrase>
11155 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
11156 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(!</phrase><phrase role="identifier">empty</phrase><phrase role="special">());</phrase> <phrase role="comment">// Not empty.</phrase>
11157 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">item</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">x</phrase><phrase role="special">);</phrase> <phrase role="comment">// Added to top.</phrase>
11158 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_count</phrase> <phrase role="special">+</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase> <phrase role="comment">// One more.</phrase>
11159 <phrase role="special">})</phrase>
11160 <phrase role="special">;</phrase>
11162 <phrase role="identifier">array_</phrase><phrase role="special">[</phrase><phrase role="identifier">count_</phrase><phrase role="special">++]</phrase> <phrase role="special">=</phrase> <phrase role="identifier">x</phrase><phrase role="special">;</phrase>
11163 <phrase role="special">}</phrase>
11165 <phrase role="comment">// Remove top element.</phrase>
11166 <phrase role="keyword">void</phrase> <phrase role="identifier">remove</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
11167 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">></phrase> <phrase role="identifier">old_count</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">());</phrase>
11168 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
11169 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
11170 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(!</phrase><phrase role="identifier">empty</phrase><phrase role="special">());</phrase> <phrase role="comment">// Not empty (i.e., count > 0).</phrase>
11171 <phrase role="special">})</phrase>
11172 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
11173 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(!</phrase><phrase role="identifier">full</phrase><phrase role="special">());</phrase> <phrase role="comment">// Not full.</phrase>
11174 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_count</phrase> <phrase role="special">-</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase> <phrase role="comment">// One less.</phrase>
11175 <phrase role="special">})</phrase>
11176 <phrase role="special">;</phrase>
11178 <phrase role="special">--</phrase><phrase role="identifier">count_</phrase><phrase role="special">;</phrase>
11179 <phrase role="special">}</phrase>
11181 <phrase role="comment">/* Friend Helpers */</phrase>
11183 <phrase role="keyword">friend</phrase> <phrase role="keyword">bool</phrase> <phrase role="keyword">operator</phrase><phrase role="special">==(</phrase><phrase role="identifier">stack4</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">left</phrase><phrase role="special">,</phrase> <phrase role="identifier">stack4</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">right</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
11184 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">inv1</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(&</phrase><phrase role="identifier">left</phrase><phrase role="special">);</phrase>
11185 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">inv2</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(&</phrase><phrase role="identifier">right</phrase><phrase role="special">);</phrase>
11186 <phrase role="keyword">if</phrase><phrase role="special">(</phrase><phrase role="identifier">left</phrase><phrase role="special">.</phrase><phrase role="identifier">count_</phrase> <phrase role="special">!=</phrase> <phrase role="identifier">right</phrase><phrase role="special">.</phrase><phrase role="identifier">count_</phrase><phrase role="special">)</phrase> <phrase role="keyword">return</phrase> <phrase role="keyword">false</phrase><phrase role="special">;</phrase>
11187 <phrase role="keyword">for</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">i</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase> <phrase role="identifier">i</phrase> <phrase role="special"><</phrase> <phrase role="identifier">left</phrase><phrase role="special">.</phrase><phrase role="identifier">count_</phrase><phrase role="special">;</phrase> <phrase role="special">++</phrase><phrase role="identifier">i</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
11188 <phrase role="keyword">if</phrase><phrase role="special">(</phrase><phrase role="identifier">left</phrase><phrase role="special">.</phrase><phrase role="identifier">array_</phrase><phrase role="special">[</phrase><phrase role="identifier">i</phrase><phrase role="special">]</phrase> <phrase role="special">!=</phrase> <phrase role="identifier">right</phrase><phrase role="special">.</phrase><phrase role="identifier">array_</phrase><phrase role="special">[</phrase><phrase role="identifier">i</phrase><phrase role="special">])</phrase> <phrase role="keyword">return</phrase> <phrase role="keyword">false</phrase><phrase role="special">;</phrase>
11189 <phrase role="special">}</phrase>
11190 <phrase role="keyword">return</phrase> <phrase role="keyword">true</phrase><phrase role="special">;</phrase>
11191 <phrase role="special">}</phrase>
11193 <phrase role="keyword">private</phrase><phrase role="special">:</phrase>
11194 <phrase role="keyword">int</phrase> <phrase role="identifier">capacity_</phrase><phrase role="special">;</phrase>
11195 <phrase role="keyword">int</phrase> <phrase role="identifier">count_</phrase><phrase role="special">;</phrase>
11196 <phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">array_</phrase><phrase role="special">;</phrase> <phrase role="comment">// Internally use C-style array.</phrase>
11197 <phrase role="special">};</phrase>
11199 <phrase role="preprocessor">#endif</phrase> <phrase role="comment">// #include guard</phrase>
11205 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">--</phrase> <phrase role="identifier">Extra</phrase> <phrase role="identifier">spaces</phrase><phrase role="special">,</phrase> <phrase role="identifier">newlines</phrase><phrase role="special">,</phrase> <phrase role="identifier">etc</phrase><phrase role="special">.</phrase> <phrase role="keyword">for</phrase> <phrase role="identifier">visual</phrase> <phrase role="identifier">alignment</phrase> <phrase role="identifier">with</phrase> <phrase role="keyword">this</phrase> <phrase role="identifier">library</phrase> <phrase role="identifier">code</phrase><phrase role="special">.</phrase>
11211 <phrase role="identifier">indexing</phrase>
11212 <phrase role="identifier">destription</phrase><phrase role="special">:</phrase> <phrase role="string">"Dispenser with LIFO access policy and a fixed max capacity."</phrase>
11213 <phrase role="keyword">class</phrase> <phrase role="identifier">interface</phrase> <phrase role="identifier">STACK4</phrase><phrase role="special">[</phrase><phrase role="identifier">G</phrase><phrase role="special">]</phrase> <phrase role="identifier">creation</phrase> <phrase role="identifier">make</phrase> <phrase role="special">--</phrase> <phrase role="identifier">Interface</phrase> <phrase role="identifier">only</phrase> <phrase role="special">(</phrase><phrase role="identifier">no</phrase> <phrase role="identifier">implementation</phrase><phrase role="special">).</phrase>
11221 <phrase role="identifier">invariant</phrase>
11222 <phrase role="identifier">count_non_negative</phrase><phrase role="special">:</phrase> <phrase role="identifier">count</phrase> <phrase role="special">>=</phrase> <phrase role="number">0</phrase>
11223 <phrase role="identifier">count_bounded</phrase><phrase role="special">:</phrase> <phrase role="identifier">count</phrase> <phrase role="special"><=</phrase> <phrase role="identifier">capacity</phrase>
11224 <phrase role="identifier">empty_if_no_elements</phrase><phrase role="special">:</phrase> <phrase role="identifier">empty</phrase> <phrase role="special">=</phrase> <phrase role="special">(</phrase><phrase role="identifier">count</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase>
11228 <phrase role="identifier">feature</phrase> <phrase role="special">--</phrase> <phrase role="identifier">Initialization</phrase>
11230 <phrase role="special">--</phrase> <phrase role="identifier">Allocate</phrase> <phrase role="identifier">stack</phrase> <phrase role="keyword">for</phrase> <phrase role="identifier">a</phrase> <phrase role="identifier">maximum</phrase> <phrase role="identifier">of</phrase> <phrase role="identifier">n</phrase> <phrase role="identifier">elements</phrase><phrase role="special">.</phrase>
11231 <phrase role="identifier">make</phrase><phrase role="special">(</phrase><phrase role="identifier">n</phrase><phrase role="special">:</phrase> <phrase role="identifier">INTEGER</phrase><phrase role="special">)</phrase> <phrase role="identifier">is</phrase>
11232 <phrase role="identifier">require</phrase>
11233 <phrase role="identifier">non_negative_capacity</phrase><phrase role="special">:</phrase> <phrase role="identifier">n</phrase> <phrase role="special">>=</phrase> <phrase role="number">0</phrase>
11234 <phrase role="identifier">ensure</phrase>
11235 <phrase role="identifier">capacity_set</phrase><phrase role="special">:</phrase> <phrase role="identifier">capacity</phrase> <phrase role="special">=</phrase> <phrase role="identifier">n</phrase>
11236 <phrase role="identifier">end</phrase>
11288 <phrase role="identifier">feature</phrase> <phrase role="special">--</phrase> <phrase role="identifier">Access</phrase>
11290 <phrase role="special">--</phrase> <phrase role="identifier">Max</phrase> <phrase role="identifier">number</phrase> <phrase role="identifier">of</phrase> <phrase role="identifier">stack</phrase> <phrase role="identifier">elements</phrase><phrase role="special">.</phrase>
11291 <phrase role="identifier">capacity</phrase><phrase role="special">:</phrase> <phrase role="identifier">INTEGER</phrase>
11297 <phrase role="special">--</phrase> <phrase role="identifier">Number</phrase> <phrase role="identifier">of</phrase> <phrase role="identifier">stack</phrase> <phrase role="identifier">elements</phrase><phrase role="special">.</phrase>
11298 <phrase role="identifier">count</phrase><phrase role="special">:</phrase> <phrase role="identifier">INTEGER</phrase>
11304 <phrase role="special">--</phrase> <phrase role="identifier">Top</phrase> <phrase role="identifier">element</phrase><phrase role="special">.</phrase>
11305 <phrase role="identifier">item</phrase><phrase role="special">:</phrase> <phrase role="identifier">G</phrase> <phrase role="identifier">is</phrase>
11306 <phrase role="identifier">require</phrase>
11307 <phrase role="identifier">not_empty</phrase><phrase role="special">:</phrase> <phrase role="keyword">not</phrase> <phrase role="identifier">empty</phrase> <phrase role="special">--</phrase> <phrase role="identifier">i</phrase><phrase role="special">.</phrase><phrase role="identifier">e</phrase><phrase role="special">.,</phrase> <phrase role="identifier">count</phrase> <phrase role="special">></phrase> <phrase role="number">0</phrase>
11308 <phrase role="identifier">end</phrase>
11315 <phrase role="identifier">feature</phrase> <phrase role="special">--</phrase> <phrase role="identifier">Status</phrase> <phrase role="identifier">report</phrase>
11317 <phrase role="special">--</phrase> <phrase role="identifier">Is</phrase> <phrase role="identifier">stack</phrase> <phrase role="identifier">empty</phrase><phrase role="special">?</phrase>
11318 <phrase role="identifier">empty</phrase><phrase role="special">:</phrase> <phrase role="identifier">BOOLEAN</phrase> <phrase role="identifier">is</phrase>
11319 <phrase role="identifier">ensure</phrase>
11320 <phrase role="identifier">empty_definition</phrase><phrase role="special">:</phrase> <phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="special">(</phrase><phrase role="identifier">count</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase>
11321 <phrase role="identifier">end</phrase>
11330 <phrase role="special">--</phrase> <phrase role="identifier">Is</phrase> <phrase role="identifier">stack</phrase> <phrase role="identifier">full</phrase><phrase role="special">?</phrase>
11331 <phrase role="identifier">full</phrase><phrase role="special">:</phrase> <phrase role="identifier">BOOLEAN</phrase> <phrase role="identifier">is</phrase>
11332 <phrase role="identifier">ensure</phrase>
11333 <phrase role="identifier">full_definition</phrase><phrase role="special">:</phrase> <phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="special">(</phrase><phrase role="identifier">count</phrase> <phrase role="special">=</phrase> <phrase role="identifier">capacity</phrase><phrase role="special">)</phrase>
11334 <phrase role="identifier">end</phrase>
11343 <phrase role="identifier">feature</phrase> <phrase role="special">--</phrase> <phrase role="identifier">Element</phrase> <phrase role="identifier">change</phrase>
11345 <phrase role="special">--</phrase> <phrase role="identifier">Add</phrase> <phrase role="identifier">x</phrase> <phrase role="identifier">on</phrase> <phrase role="identifier">top</phrase><phrase role="special">.</phrase>
11346 <phrase role="identifier">put</phrase><phrase role="special">(</phrase><phrase role="identifier">x</phrase><phrase role="special">:</phrase> <phrase role="identifier">G</phrase><phrase role="special">)</phrase> <phrase role="identifier">is</phrase>
11347 <phrase role="identifier">require</phrase>
11348 <phrase role="identifier">not_full</phrase><phrase role="special">:</phrase> <phrase role="keyword">not</phrase> <phrase role="identifier">full</phrase>
11349 <phrase role="identifier">ensure</phrase>
11350 <phrase role="identifier">not_empty</phrase><phrase role="special">:</phrase> <phrase role="keyword">not</phrase> <phrase role="identifier">empty</phrase>
11351 <phrase role="identifier">added_to_top</phrase><phrase role="special">:</phrase> <phrase role="identifier">item</phrase> <phrase role="special">=</phrase> <phrase role="identifier">x</phrase>
11352 <phrase role="identifier">one_more_item</phrase><phrase role="special">:</phrase> <phrase role="identifier">count</phrase> <phrase role="special">=</phrase> <phrase role="identifier">old</phrase> <phrase role="identifier">count</phrase> <phrase role="special">+</phrase> <phrase role="number">1</phrase>
11353 <phrase role="identifier">end</phrase>
11362 <phrase role="special">--</phrase> <phrase role="identifier">Remove</phrase> <phrase role="identifier">top</phrase> <phrase role="identifier">element</phrase><phrase role="special">.</phrase>
11363 <phrase role="identifier">remove</phrase> <phrase role="identifier">is</phrase>
11364 <phrase role="identifier">require</phrase>
11365 <phrase role="identifier">not_empty</phrase><phrase role="special">:</phrase> <phrase role="keyword">not</phrase> <phrase role="identifier">empty</phrase> <phrase role="special">--</phrase> <phrase role="identifier">i</phrase><phrase role="special">.</phrase><phrase role="identifier">e</phrase><phrase role="special">.,</phrase> <phrase role="identifier">count</phrase> <phrase role="special">></phrase> <phrase role="number">0</phrase>
11366 <phrase role="identifier">ensure</phrase>
11367 <phrase role="identifier">not_full</phrase><phrase role="special">:</phrase> <phrase role="keyword">not</phrase> <phrase role="identifier">full</phrase>
11368 <phrase role="identifier">one_fewer_item</phrase><phrase role="special">:</phrase> <phrase role="identifier">count</phrase> <phrase role="special">=</phrase> <phrase role="identifier">old</phrase> <phrase role="identifier">count</phrase> <phrase role="special">-</phrase> <phrase role="number">1</phrase>
11370 <phrase role="identifier">end</phrase>
11394 <phrase role="identifier">end</phrase> <phrase role="special">--</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">interface</phrase> <phrase role="identifier">STACK4</phrase>
11396 <phrase role="special">--</phrase> <phrase role="identifier">End</phrase><phrase role="special">.</phrase>
11404 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#include</phrase> <phrase role="string">"stack4.hpp"</phrase>
11405 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">cassert</phrase><phrase role="special">></phrase>
11407 <phrase role="keyword">int</phrase> <phrase role="identifier">main</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
11408 <phrase role="identifier">stack4</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">></phrase> <phrase role="identifier">s</phrase><phrase role="special">(</phrase><phrase role="number">3</phrase><phrase role="special">);</phrase>
11409 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">s</phrase><phrase role="special">.</phrase><phrase role="identifier">capacity</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">3</phrase><phrase role="special">);</phrase>
11410 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">s</phrase><phrase role="special">.</phrase><phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase>
11411 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">s</phrase><phrase role="special">.</phrase><phrase role="identifier">empty</phrase><phrase role="special">());</phrase>
11412 <phrase role="identifier">assert</phrase><phrase role="special">(!</phrase><phrase role="identifier">s</phrase><phrase role="special">.</phrase><phrase role="identifier">full</phrase><phrase role="special">());</phrase>
11414 <phrase role="identifier">s</phrase><phrase role="special">.</phrase><phrase role="identifier">put</phrase><phrase role="special">(</phrase><phrase role="number">123</phrase><phrase role="special">);</phrase>
11415 <phrase role="identifier">assert</phrase><phrase role="special">(!</phrase><phrase role="identifier">s</phrase><phrase role="special">.</phrase><phrase role="identifier">empty</phrase><phrase role="special">());</phrase>
11416 <phrase role="identifier">assert</phrase><phrase role="special">(!</phrase><phrase role="identifier">s</phrase><phrase role="special">.</phrase><phrase role="identifier">full</phrase><phrase role="special">());</phrase>
11417 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">s</phrase><phrase role="special">.</phrase><phrase role="identifier">item</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">123</phrase><phrase role="special">);</phrase>
11419 <phrase role="identifier">s</phrase><phrase role="special">.</phrase><phrase role="identifier">remove</phrase><phrase role="special">();</phrase>
11420 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">s</phrase><phrase role="special">.</phrase><phrase role="identifier">empty</phrase><phrase role="special">());</phrase>
11421 <phrase role="identifier">assert</phrase><phrase role="special">(!</phrase><phrase role="identifier">s</phrase><phrase role="special">.</phrase><phrase role="identifier">full</phrase><phrase role="special">());</phrase>
11423 <phrase role="keyword">return</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase>
11424 <phrase role="special">}</phrase>
11435 <section id="boost_contract.examples.__meyer97___stack3__error_codes_instead_of_preconditions">
11436 <title><link linkend="boost_contract.examples.__meyer97___stack3__error_codes_instead_of_preconditions">[Meyer97]
11437 Stack3: Error codes instead of preconditions</link></title>
11439 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="comment">// File: stack3.cpp</phrase>
11440 <phrase role="preprocessor">#include</phrase> <phrase role="string">"stack4.hpp"</phrase>
11441 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">contract</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">></phrase>
11442 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">optional</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">></phrase>
11443 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">cassert</phrase><phrase role="special">></phrase>
11445 <phrase role="comment">// Dispenser LIFO with max capacity using error codes.</phrase>
11446 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">></phrase>
11447 <phrase role="keyword">class</phrase> <phrase role="identifier">stack3</phrase> <phrase role="special">{</phrase>
11448 <phrase role="keyword">friend</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">access</phrase><phrase role="special">;</phrase>
11450 <phrase role="keyword">void</phrase> <phrase role="identifier">invariant</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
11451 <phrase role="keyword">if</phrase><phrase role="special">(!</phrase><phrase role="identifier">error</phrase><phrase role="special">())</phrase> <phrase role="special">{</phrase>
11452 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="special">>=</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase> <phrase role="comment">// Count non-negative.</phrase>
11453 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="special"><=</phrase> <phrase role="identifier">capacity</phrase><phrase role="special">());</phrase> <phrase role="comment">// Count bounded.</phrase>
11454 <phrase role="comment">// Empty if no element.</phrase>
11455 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">empty</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">0</phrase><phrase role="special">));</phrase>
11456 <phrase role="special">}</phrase>
11457 <phrase role="special">}</phrase>
11459 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
11460 <phrase role="keyword">enum</phrase> <phrase role="identifier">error_code</phrase> <phrase role="special">{</phrase>
11461 <phrase role="identifier">no_error</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">,</phrase>
11462 <phrase role="identifier">overflow_error</phrase><phrase role="special">,</phrase>
11463 <phrase role="identifier">underflow_error</phrase><phrase role="special">,</phrase>
11464 <phrase role="identifier">size_error</phrase>
11465 <phrase role="special">};</phrase>
11467 <phrase role="comment">/* Initialization */</phrase>
11469 <phrase role="comment">// Create stack for max of n elems, if n < 0 set error (no preconditions).</phrase>
11470 <phrase role="keyword">explicit</phrase> <phrase role="identifier">stack3</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">n</phrase><phrase role="special">,</phrase> <phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">default_value</phrase> <phrase role="special">=</phrase> <phrase role="identifier">T</phrase><phrase role="special">())</phrase> <phrase role="special">:</phrase>
11471 <phrase role="identifier">stack_</phrase><phrase role="special">(</phrase><phrase role="number">0</phrase><phrase role="special">),</phrase> <phrase role="identifier">error_</phrase><phrase role="special">(</phrase><phrase role="identifier">no_error</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
11472 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
11473 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
11474 <phrase role="comment">// Error if impossible.</phrase>
11475 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">((</phrase><phrase role="identifier">n</phrase> <phrase role="special"><</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="special">==</phrase> <phrase role="special">(</phrase><phrase role="identifier">error</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">size_error</phrase><phrase role="special">));</phrase>
11476 <phrase role="comment">// No error if possible.</phrase>
11477 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">((</phrase><phrase role="identifier">n</phrase> <phrase role="special">>=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="special">==</phrase> <phrase role="special">!</phrase><phrase role="identifier">error</phrase><phrase role="special">());</phrase>
11478 <phrase role="comment">// Created if no error.</phrase>
11479 <phrase role="keyword">if</phrase><phrase role="special">(!</phrase><phrase role="identifier">error</phrase><phrase role="special">())</phrase> <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">capacity</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">n</phrase><phrase role="special">);</phrase>
11480 <phrase role="special">})</phrase>
11481 <phrase role="special">;</phrase>
11483 <phrase role="keyword">if</phrase><phrase role="special">(</phrase><phrase role="identifier">n</phrase> <phrase role="special">>=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="identifier">stack_</phrase> <phrase role="special">=</phrase> <phrase role="identifier">stack4</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">>(</phrase><phrase role="identifier">n</phrase><phrase role="special">);</phrase>
11484 <phrase role="keyword">else</phrase> <phrase role="identifier">error_</phrase> <phrase role="special">=</phrase> <phrase role="identifier">size_error</phrase><phrase role="special">;</phrase>
11485 <phrase role="special">}</phrase>
11487 <phrase role="comment">/* Access */</phrase>
11489 <phrase role="comment">// Max number of stack elements.</phrase>
11490 <phrase role="keyword">int</phrase> <phrase role="identifier">capacity</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
11491 <phrase role="comment">// Check invariants.</phrase>
11492 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
11493 <phrase role="keyword">return</phrase> <phrase role="identifier">stack_</phrase><phrase role="special">.</phrase><phrase role="identifier">capacity</phrase><phrase role="special">();</phrase>
11494 <phrase role="special">}</phrase>
11496 <phrase role="comment">// Number of stack elements.</phrase>
11497 <phrase role="keyword">int</phrase> <phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
11498 <phrase role="comment">// Check invariants.</phrase>
11499 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
11500 <phrase role="keyword">return</phrase> <phrase role="identifier">stack_</phrase><phrase role="special">.</phrase><phrase role="identifier">count</phrase><phrase role="special">();</phrase>
11501 <phrase role="special">}</phrase>
11503 <phrase role="comment">// Top element if present, otherwise none and set error (no preconditions).</phrase>
11504 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">optional</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&></phrase> <phrase role="identifier">item</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
11505 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
11506 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
11507 <phrase role="comment">// Error if impossible.</phrase>
11508 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">empty</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">(</phrase><phrase role="identifier">error</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">underflow_error</phrase><phrase role="special">));</phrase>
11509 <phrase role="comment">// No error if possible.</phrase>
11510 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(!</phrase><phrase role="identifier">empty</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">!</phrase><phrase role="identifier">error</phrase><phrase role="special">());</phrase>
11511 <phrase role="special">})</phrase>
11512 <phrase role="special">;</phrase>
11514 <phrase role="keyword">if</phrase><phrase role="special">(!</phrase><phrase role="identifier">empty</phrase><phrase role="special">())</phrase> <phrase role="special">{</phrase>
11515 <phrase role="identifier">error_</phrase> <phrase role="special">=</phrase> <phrase role="identifier">no_error</phrase><phrase role="special">;</phrase>
11516 <phrase role="keyword">return</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">optional</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&>(</phrase><phrase role="identifier">stack_</phrase><phrase role="special">.</phrase><phrase role="identifier">item</phrase><phrase role="special">());</phrase>
11517 <phrase role="special">}</phrase> <phrase role="keyword">else</phrase> <phrase role="special">{</phrase>
11518 <phrase role="identifier">error_</phrase> <phrase role="special">=</phrase> <phrase role="identifier">underflow_error</phrase><phrase role="special">;</phrase>
11519 <phrase role="keyword">return</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">optional</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&>();</phrase>
11520 <phrase role="special">}</phrase>
11521 <phrase role="special">}</phrase>
11523 <phrase role="comment">/* Status Report */</phrase>
11525 <phrase role="comment">// Error indicator set by various operations.</phrase>
11526 <phrase role="identifier">error_code</phrase> <phrase role="identifier">error</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
11527 <phrase role="comment">// Check invariants.</phrase>
11528 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
11529 <phrase role="keyword">return</phrase> <phrase role="identifier">error_</phrase><phrase role="special">;</phrase>
11530 <phrase role="special">}</phrase>
11532 <phrase role="keyword">bool</phrase> <phrase role="identifier">empty</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
11533 <phrase role="comment">// Check invariants.</phrase>
11534 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
11535 <phrase role="keyword">return</phrase> <phrase role="identifier">stack_</phrase><phrase role="special">.</phrase><phrase role="identifier">empty</phrase><phrase role="special">();</phrase>
11536 <phrase role="special">}</phrase>
11538 <phrase role="keyword">bool</phrase> <phrase role="identifier">full</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
11539 <phrase role="comment">// Check invariants.</phrase>
11540 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
11541 <phrase role="keyword">return</phrase> <phrase role="identifier">stack_</phrase><phrase role="special">.</phrase><phrase role="identifier">full</phrase><phrase role="special">();</phrase>
11542 <phrase role="special">}</phrase>
11544 <phrase role="comment">/* Element Change */</phrase>
11546 <phrase role="comment">// Add x to top if capacity allows, otherwise set error (no preconditions).</phrase>
11547 <phrase role="keyword">void</phrase> <phrase role="identifier">put</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">x</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
11548 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">bool</phrase><phrase role="special">></phrase> <phrase role="identifier">old_full</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">full</phrase><phrase role="special">());</phrase>
11549 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">></phrase> <phrase role="identifier">old_count</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">());</phrase>
11550 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
11551 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
11552 <phrase role="comment">// Error if impossible.</phrase>
11553 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(*</phrase><phrase role="identifier">old_full</phrase> <phrase role="special">==</phrase> <phrase role="special">(</phrase><phrase role="identifier">error</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">overflow_error</phrase><phrase role="special">));</phrase>
11554 <phrase role="comment">// No error if possible.</phrase>
11555 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(!*</phrase><phrase role="identifier">old_full</phrase> <phrase role="special">==</phrase> <phrase role="special">!</phrase><phrase role="identifier">error</phrase><phrase role="special">());</phrase>
11556 <phrase role="keyword">if</phrase><phrase role="special">(!</phrase><phrase role="identifier">error</phrase><phrase role="special">())</phrase> <phrase role="special">{</phrase> <phrase role="comment">// If no error...</phrase>
11557 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(!</phrase><phrase role="identifier">empty</phrase><phrase role="special">());</phrase> <phrase role="comment">// ...not empty.</phrase>
11558 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(*</phrase><phrase role="identifier">item</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">x</phrase><phrase role="special">);</phrase> <phrase role="comment">// ...added to top.</phrase>
11559 <phrase role="comment">// ...one more.</phrase>
11560 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_count</phrase> <phrase role="special">+</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase>
11561 <phrase role="special">}</phrase>
11562 <phrase role="special">})</phrase>
11563 <phrase role="special">;</phrase>
11565 <phrase role="keyword">if</phrase><phrase role="special">(</phrase><phrase role="identifier">full</phrase><phrase role="special">())</phrase> <phrase role="identifier">error_</phrase> <phrase role="special">=</phrase> <phrase role="identifier">overflow_error</phrase><phrase role="special">;</phrase>
11566 <phrase role="keyword">else</phrase> <phrase role="special">{</phrase>
11567 <phrase role="identifier">stack_</phrase><phrase role="special">.</phrase><phrase role="identifier">put</phrase><phrase role="special">(</phrase><phrase role="identifier">x</phrase><phrase role="special">);</phrase>
11568 <phrase role="identifier">error_</phrase> <phrase role="special">=</phrase> <phrase role="identifier">no_error</phrase><phrase role="special">;</phrase>
11569 <phrase role="special">}</phrase>
11570 <phrase role="special">}</phrase>
11572 <phrase role="comment">// Remove top element if possible, otherwise set error (no preconditions).</phrase>
11573 <phrase role="keyword">void</phrase> <phrase role="identifier">remove</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
11574 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">bool</phrase><phrase role="special">></phrase> <phrase role="identifier">old_empty</phrase> <phrase role="special">=</phrase>
11575 <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">empty</phrase><phrase role="special">());</phrase>
11576 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">></phrase> <phrase role="identifier">old_count</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">());</phrase>
11577 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
11578 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
11579 <phrase role="comment">// Error if impossible.</phrase>
11580 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(*</phrase><phrase role="identifier">old_empty</phrase> <phrase role="special">==</phrase> <phrase role="special">(</phrase><phrase role="identifier">error</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase>
11581 <phrase role="identifier">underflow_error</phrase><phrase role="special">));</phrase>
11582 <phrase role="comment">// No error if possible.</phrase>
11583 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(!*</phrase><phrase role="identifier">old_empty</phrase> <phrase role="special">==</phrase> <phrase role="special">!</phrase><phrase role="identifier">error</phrase><phrase role="special">());</phrase>
11584 <phrase role="keyword">if</phrase><phrase role="special">(!</phrase><phrase role="identifier">error</phrase><phrase role="special">())</phrase> <phrase role="special">{</phrase> <phrase role="comment">// If no error...</phrase>
11585 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(!</phrase><phrase role="identifier">full</phrase><phrase role="special">());</phrase> <phrase role="comment">// ...not full.</phrase>
11586 <phrase role="comment">// ...one less.</phrase>
11587 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_count</phrase> <phrase role="special">-</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase>
11588 <phrase role="special">}</phrase>
11589 <phrase role="special">})</phrase>
11590 <phrase role="special">;</phrase>
11592 <phrase role="keyword">if</phrase><phrase role="special">(</phrase><phrase role="identifier">empty</phrase><phrase role="special">())</phrase> <phrase role="identifier">error_</phrase> <phrase role="special">=</phrase> <phrase role="identifier">underflow_error</phrase><phrase role="special">;</phrase>
11593 <phrase role="keyword">else</phrase> <phrase role="special">{</phrase>
11594 <phrase role="identifier">stack_</phrase><phrase role="special">.</phrase><phrase role="identifier">remove</phrase><phrase role="special">();</phrase>
11595 <phrase role="identifier">error_</phrase> <phrase role="special">=</phrase> <phrase role="identifier">no_error</phrase><phrase role="special">;</phrase>
11596 <phrase role="special">}</phrase>
11597 <phrase role="special">}</phrase>
11599 <phrase role="keyword">private</phrase><phrase role="special">:</phrase>
11600 <phrase role="identifier">stack4</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase> <phrase role="identifier">stack_</phrase><phrase role="special">;</phrase>
11601 <phrase role="keyword">mutable</phrase> <phrase role="identifier">error_code</phrase> <phrase role="identifier">error_</phrase><phrase role="special">;</phrase>
11602 <phrase role="special">};</phrase>
11604 <phrase role="keyword">int</phrase> <phrase role="identifier">main</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
11605 <phrase role="identifier">stack3</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">></phrase> <phrase role="identifier">s</phrase><phrase role="special">(</phrase><phrase role="number">3</phrase><phrase role="special">);</phrase>
11606 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">s</phrase><phrase role="special">.</phrase><phrase role="identifier">capacity</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">3</phrase><phrase role="special">);</phrase>
11607 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">s</phrase><phrase role="special">.</phrase><phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase>
11608 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">s</phrase><phrase role="special">.</phrase><phrase role="identifier">empty</phrase><phrase role="special">());</phrase>
11609 <phrase role="identifier">assert</phrase><phrase role="special">(!</phrase><phrase role="identifier">s</phrase><phrase role="special">.</phrase><phrase role="identifier">full</phrase><phrase role="special">());</phrase>
11611 <phrase role="identifier">s</phrase><phrase role="special">.</phrase><phrase role="identifier">put</phrase><phrase role="special">(</phrase><phrase role="number">123</phrase><phrase role="special">);</phrase>
11612 <phrase role="identifier">assert</phrase><phrase role="special">(!</phrase><phrase role="identifier">s</phrase><phrase role="special">.</phrase><phrase role="identifier">empty</phrase><phrase role="special">());</phrase>
11613 <phrase role="identifier">assert</phrase><phrase role="special">(!</phrase><phrase role="identifier">s</phrase><phrase role="special">.</phrase><phrase role="identifier">full</phrase><phrase role="special">());</phrase>
11614 <phrase role="identifier">assert</phrase><phrase role="special">(*</phrase><phrase role="identifier">s</phrase><phrase role="special">.</phrase><phrase role="identifier">item</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">123</phrase><phrase role="special">);</phrase>
11616 <phrase role="identifier">s</phrase><phrase role="special">.</phrase><phrase role="identifier">remove</phrase><phrase role="special">();</phrase>
11617 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">s</phrase><phrase role="special">.</phrase><phrase role="identifier">empty</phrase><phrase role="special">());</phrase>
11618 <phrase role="identifier">assert</phrase><phrase role="special">(!</phrase><phrase role="identifier">s</phrase><phrase role="special">.</phrase><phrase role="identifier">full</phrase><phrase role="special">());</phrase>
11620 <phrase role="keyword">return</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase>
11621 <phrase role="special">}</phrase>
11625 <section id="boost_contract.examples.__mitchell02___name_list__relaxed_subcontracts">
11626 <title><link linkend="boost_contract.examples.__mitchell02___name_list__relaxed_subcontracts">[Mitchell02]
11627 Name List: Relaxed subcontracts</link></title>
11629 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">contract</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">></phrase>
11630 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">string</phrase><phrase role="special">></phrase>
11631 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">vector</phrase><phrase role="special">></phrase>
11632 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">algorithm</phrase><phrase role="special">></phrase>
11633 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">cassert</phrase><phrase role="special">></phrase>
11635 <phrase role="comment">// List of names.</phrase>
11636 <phrase role="keyword">class</phrase> <phrase role="identifier">name_list</phrase> <phrase role="special">{</phrase>
11637 <phrase role="keyword">friend</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">access</phrase><phrase role="special">;</phrase>
11639 <phrase role="keyword">void</phrase> <phrase role="identifier">invariant</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
11640 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="special">>=</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase> <phrase role="comment">// Non-negative count.</phrase>
11641 <phrase role="special">}</phrase>
11643 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
11644 <phrase role="comment">/* Creation */</phrase>
11646 <phrase role="comment">// Create an empty list.</phrase>
11647 <phrase role="identifier">name_list</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
11648 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
11649 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
11650 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase> <phrase role="comment">// Empty list.</phrase>
11651 <phrase role="special">})</phrase>
11652 <phrase role="special">;</phrase>
11653 <phrase role="special">}</phrase>
11655 <phrase role="comment">// Destroy list.</phrase>
11656 <phrase role="keyword">virtual</phrase> <phrase role="special">~</phrase><phrase role="identifier">name_list</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
11657 <phrase role="comment">// Check invariants.</phrase>
11658 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">destructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
11659 <phrase role="special">}</phrase>
11661 <phrase role="comment">/* Basic Queries */</phrase>
11663 <phrase role="comment">// Number of names in list.</phrase>
11664 <phrase role="keyword">int</phrase> <phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
11665 <phrase role="comment">// Check invariants.</phrase>
11666 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
11667 <phrase role="keyword">return</phrase> <phrase role="identifier">names_</phrase><phrase role="special">.</phrase><phrase role="identifier">size</phrase><phrase role="special">();</phrase>
11668 <phrase role="special">}</phrase>
11670 <phrase role="comment">// Is name in list?</phrase>
11671 <phrase role="keyword">bool</phrase> <phrase role="identifier">has</phrase><phrase role="special">(</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">string</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">name</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
11672 <phrase role="keyword">bool</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
11673 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
11674 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
11675 <phrase role="comment">// If empty, has not.</phrase>
11676 <phrase role="keyword">if</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(!</phrase><phrase role="identifier">result</phrase><phrase role="special">);</phrase>
11677 <phrase role="special">})</phrase>
11678 <phrase role="special">;</phrase>
11680 <phrase role="keyword">return</phrase> <phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="identifier">names_</phrase><phrase role="special">.</phrase><phrase role="identifier">cend</phrase><phrase role="special">()</phrase> <phrase role="special">!=</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">find</phrase><phrase role="special">(</phrase><phrase role="identifier">names_</phrase><phrase role="special">.</phrase><phrase role="identifier">cbegin</phrase><phrase role="special">(),</phrase>
11681 <phrase role="identifier">names_</phrase><phrase role="special">.</phrase><phrase role="identifier">cend</phrase><phrase role="special">(),</phrase> <phrase role="identifier">name</phrase><phrase role="special">);</phrase>
11682 <phrase role="special">}</phrase>
11684 <phrase role="comment">/* Commands */</phrase>
11686 <phrase role="comment">// Add name to list, if name not already in list.</phrase>
11687 <phrase role="keyword">virtual</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">put</phrase><phrase role="special">(</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">string</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">name</phrase><phrase role="special">,</phrase>
11688 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
11689 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">bool</phrase><phrase role="special">></phrase> <phrase role="identifier">old_has_name</phrase> <phrase role="special">=</phrase>
11690 <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">has</phrase><phrase role="special">(</phrase><phrase role="identifier">name</phrase><phrase role="special">));</phrase>
11691 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">></phrase> <phrase role="identifier">old_count</phrase> <phrase role="special">=</phrase>
11692 <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">count</phrase><phrase role="special">());</phrase>
11693 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">)</phrase>
11694 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
11695 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(!</phrase><phrase role="identifier">has</phrase><phrase role="special">(</phrase><phrase role="identifier">name</phrase><phrase role="special">));</phrase> <phrase role="comment">// Not already in list.</phrase>
11696 <phrase role="special">})</phrase>
11697 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
11698 <phrase role="keyword">if</phrase><phrase role="special">(!*</phrase><phrase role="identifier">old_has_name</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase> <phrase role="comment">// If-guard allows to relax subcontracts.</phrase>
11699 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">has</phrase><phrase role="special">(</phrase><phrase role="identifier">name</phrase><phrase role="special">));</phrase> <phrase role="comment">// Name in list.</phrase>
11700 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_count</phrase> <phrase role="special">+</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase> <phrase role="comment">// Inc.</phrase>
11701 <phrase role="special">}</phrase>
11702 <phrase role="special">})</phrase>
11703 <phrase role="special">;</phrase>
11705 <phrase role="identifier">names_</phrase><phrase role="special">.</phrase><phrase role="identifier">push_back</phrase><phrase role="special">(</phrase><phrase role="identifier">name</phrase><phrase role="special">);</phrase>
11706 <phrase role="special">}</phrase>
11708 <phrase role="keyword">private</phrase><phrase role="special">:</phrase>
11709 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">string</phrase><phrase role="special">></phrase> <phrase role="identifier">names_</phrase><phrase role="special">;</phrase>
11710 <phrase role="special">};</phrase>
11712 <phrase role="keyword">class</phrase> <phrase role="identifier">relaxed_name_list</phrase>
11713 <phrase role="preprocessor">#define</phrase> <phrase role="identifier">BASES</phrase> <phrase role="keyword">public</phrase> <phrase role="identifier">name_list</phrase>
11714 <phrase role="special">:</phrase> <phrase role="identifier">BASES</phrase>
11715 <phrase role="special">{</phrase>
11716 <phrase role="keyword">friend</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">access</phrase><phrase role="special">;</phrase>
11718 <phrase role="keyword">typedef</phrase> <phrase role="identifier">BOOST_CONTRACT_BASE_TYPES</phrase><phrase role="special">(</phrase><phrase role="identifier">BASES</phrase><phrase role="special">)</phrase> <phrase role="identifier">base_types</phrase><phrase role="special">;</phrase> <phrase role="comment">// Subcontracting.</phrase>
11719 <phrase role="preprocessor">#undef</phrase> <phrase role="identifier">BASES</phrase>
11721 <phrase role="identifier">BOOST_CONTRACT_OVERRIDE</phrase><phrase role="special">(</phrase><phrase role="identifier">put</phrase><phrase role="special">);</phrase>
11723 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
11724 <phrase role="comment">/* Commands */</phrase>
11726 <phrase role="comment">// Add name to list, or do nothing if name already in list (relaxed).</phrase>
11727 <phrase role="keyword">void</phrase> <phrase role="identifier">put</phrase><phrase role="special">(</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">string</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">name</phrase><phrase role="special">,</phrase>
11728 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="comment">/* override */</phrase> <phrase role="special">{</phrase>
11729 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">bool</phrase><phrase role="special">></phrase> <phrase role="identifier">old_has_name</phrase> <phrase role="special">=</phrase>
11730 <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">has</phrase><phrase role="special">(</phrase><phrase role="identifier">name</phrase><phrase role="special">));</phrase>
11731 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">></phrase> <phrase role="identifier">old_count</phrase> <phrase role="special">=</phrase>
11732 <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">count</phrase><phrase role="special">());</phrase>
11733 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special"><</phrase>
11734 <phrase role="identifier">override_put</phrase><phrase role="special">>(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="special">&</phrase><phrase role="identifier">relaxed_name_list</phrase><phrase role="special">::</phrase><phrase role="identifier">put</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">,</phrase> <phrase role="identifier">name</phrase><phrase role="special">)</phrase>
11735 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Relax inherited preconditions.</phrase>
11736 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">has</phrase><phrase role="special">(</phrase><phrase role="identifier">name</phrase><phrase role="special">));</phrase> <phrase role="comment">// Already in list.</phrase>
11737 <phrase role="special">})</phrase>
11738 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Inherited post. not checked given if-guard.</phrase>
11739 <phrase role="keyword">if</phrase><phrase role="special">(*</phrase><phrase role="identifier">old_has_name</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
11740 <phrase role="comment">// Count unchanged if name already in list.</phrase>
11741 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_count</phrase><phrase role="special">);</phrase>
11742 <phrase role="special">}</phrase>
11743 <phrase role="special">})</phrase>
11744 <phrase role="special">;</phrase>
11746 <phrase role="keyword">if</phrase><phrase role="special">(!</phrase><phrase role="identifier">has</phrase><phrase role="special">(</phrase><phrase role="identifier">name</phrase><phrase role="special">))</phrase> <phrase role="identifier">name_list</phrase><phrase role="special">::</phrase><phrase role="identifier">put</phrase><phrase role="special">(</phrase><phrase role="identifier">name</phrase><phrase role="special">);</phrase> <phrase role="comment">// Else, do nothing.</phrase>
11747 <phrase role="special">}</phrase>
11748 <phrase role="special">};</phrase>
11750 <phrase role="keyword">int</phrase> <phrase role="identifier">main</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
11751 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">string</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">js</phrase> <phrase role="special">=</phrase> <phrase role="string">"John Smith"</phrase><phrase role="special">;</phrase>
11753 <phrase role="identifier">relaxed_name_list</phrase> <phrase role="identifier">rl</phrase><phrase role="special">;</phrase>
11754 <phrase role="identifier">rl</phrase><phrase role="special">.</phrase><phrase role="identifier">put</phrase><phrase role="special">(</phrase><phrase role="identifier">js</phrase><phrase role="special">);</phrase>
11755 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">rl</phrase><phrase role="special">.</phrase><phrase role="identifier">has</phrase><phrase role="special">(</phrase><phrase role="identifier">js</phrase><phrase role="special">));</phrase>
11756 <phrase role="identifier">rl</phrase><phrase role="special">.</phrase><phrase role="identifier">put</phrase><phrase role="special">(</phrase><phrase role="identifier">js</phrase><phrase role="special">);</phrase> <phrase role="comment">// OK, relaxed contracts allow calling this again (do nothing).</phrase>
11758 <phrase role="identifier">name_list</phrase> <phrase role="identifier">nl</phrase><phrase role="special">;</phrase>
11759 <phrase role="identifier">nl</phrase><phrase role="special">.</phrase><phrase role="identifier">put</phrase><phrase role="special">(</phrase><phrase role="identifier">js</phrase><phrase role="special">);</phrase>
11760 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">nl</phrase><phrase role="special">.</phrase><phrase role="identifier">has</phrase><phrase role="special">(</phrase><phrase role="identifier">js</phrase><phrase role="special">));</phrase>
11761 <phrase role="comment">// nl.put(js); // Error, contracts do not allow calling this again.</phrase>
11763 <phrase role="keyword">return</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase>
11764 <phrase role="special">}</phrase>
11768 <section id="boost_contract.examples.__mitchell02___dictionary__key_value_map">
11769 <title><link linkend="boost_contract.examples.__mitchell02___dictionary__key_value_map">[Mitchell02]
11770 Dictionary: Key-value map</link></title>
11772 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">contract</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">></phrase>
11773 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">utility</phrase><phrase role="special">></phrase>
11774 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">map</phrase><phrase role="special">></phrase>
11775 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">cassert</phrase><phrase role="special">></phrase>
11777 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">K</phrase><phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">></phrase>
11778 <phrase role="keyword">class</phrase> <phrase role="identifier">dictionary</phrase> <phrase role="special">{</phrase>
11779 <phrase role="keyword">friend</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">access</phrase><phrase role="special">;</phrase>
11781 <phrase role="keyword">void</phrase> <phrase role="identifier">invariant</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
11782 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="special">>=</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase> <phrase role="comment">// Non-negative count.</phrase>
11783 <phrase role="special">}</phrase>
11785 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
11786 <phrase role="comment">/* Creation */</phrase>
11788 <phrase role="comment">// Create empty dictionary.</phrase>
11789 <phrase role="identifier">dictionary</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
11790 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
11791 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
11792 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase> <phrase role="comment">// Empty.</phrase>
11793 <phrase role="special">})</phrase>
11794 <phrase role="special">;</phrase>
11795 <phrase role="special">}</phrase>
11797 <phrase role="comment">// Destroy dictionary.</phrase>
11798 <phrase role="keyword">virtual</phrase> <phrase role="special">~</phrase><phrase role="identifier">dictionary</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
11799 <phrase role="comment">// Check invariants.</phrase>
11800 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">destructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
11801 <phrase role="special">}</phrase>
11803 <phrase role="comment">/* Basic Queries */</phrase>
11805 <phrase role="comment">// Number of key entries.</phrase>
11806 <phrase role="keyword">int</phrase> <phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
11807 <phrase role="comment">// Check invariants.</phrase>
11808 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
11809 <phrase role="keyword">return</phrase> <phrase role="identifier">items_</phrase><phrase role="special">.</phrase><phrase role="identifier">size</phrase><phrase role="special">();</phrase>
11810 <phrase role="special">}</phrase>
11812 <phrase role="comment">// Has entry for key?</phrase>
11813 <phrase role="keyword">bool</phrase> <phrase role="identifier">has</phrase><phrase role="special">(</phrase><phrase role="identifier">K</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">key</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
11814 <phrase role="keyword">bool</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
11815 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
11816 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
11817 <phrase role="comment">// Empty has no key.</phrase>
11818 <phrase role="keyword">if</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(!</phrase><phrase role="identifier">result</phrase><phrase role="special">);</phrase>
11819 <phrase role="special">})</phrase>
11820 <phrase role="special">;</phrase>
11822 <phrase role="keyword">return</phrase> <phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="special">(</phrase><phrase role="identifier">items_</phrase><phrase role="special">.</phrase><phrase role="identifier">find</phrase><phrase role="special">(</phrase><phrase role="identifier">key</phrase><phrase role="special">)</phrase> <phrase role="special">!=</phrase> <phrase role="identifier">items_</phrase><phrase role="special">.</phrase><phrase role="identifier">end</phrase><phrase role="special">());</phrase>
11823 <phrase role="special">}</phrase>
11825 <phrase role="comment">// Value for a given key.</phrase>
11826 <phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">value_for</phrase><phrase role="special">(</phrase><phrase role="identifier">K</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">key</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
11827 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
11828 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
11829 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">has</phrase><phrase role="special">(</phrase><phrase role="identifier">key</phrase><phrase role="special">));</phrase> <phrase role="comment">// Has key.</phrase>
11830 <phrase role="special">})</phrase>
11831 <phrase role="special">;</phrase>
11833 <phrase role="comment">// Find != end because of precondition (no defensive programming).</phrase>
11834 <phrase role="keyword">return</phrase> <phrase role="identifier">items_</phrase><phrase role="special">.</phrase><phrase role="identifier">find</phrase><phrase role="special">(</phrase><phrase role="identifier">key</phrase><phrase role="special">)-></phrase><phrase role="identifier">second</phrase><phrase role="special">;</phrase>
11835 <phrase role="special">}</phrase>
11837 <phrase role="comment">/* Commands */</phrase>
11839 <phrase role="comment">// Add value of a given key.</phrase>
11840 <phrase role="keyword">void</phrase> <phrase role="identifier">put</phrase><phrase role="special">(</phrase><phrase role="identifier">K</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">key</phrase><phrase role="special">,</phrase> <phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">value</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
11841 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">></phrase> <phrase role="identifier">old_count</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">());</phrase>
11842 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
11843 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
11844 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(!</phrase><phrase role="identifier">has</phrase><phrase role="special">(</phrase><phrase role="identifier">key</phrase><phrase role="special">));</phrase> <phrase role="comment">// Has not key already.</phrase>
11845 <phrase role="special">})</phrase>
11846 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
11847 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_count</phrase> <phrase role="special">+</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase> <phrase role="comment">// Count inc.</phrase>
11848 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">has</phrase><phrase role="special">(</phrase><phrase role="identifier">key</phrase><phrase role="special">));</phrase> <phrase role="comment">// Has key.</phrase>
11849 <phrase role="comment">// Value set for key.</phrase>
11850 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">value_for</phrase><phrase role="special">(</phrase><phrase role="identifier">key</phrase><phrase role="special">)</phrase> <phrase role="special">==</phrase> <phrase role="identifier">value</phrase><phrase role="special">);</phrase>
11851 <phrase role="special">})</phrase>
11852 <phrase role="special">;</phrase>
11854 <phrase role="identifier">items_</phrase><phrase role="special">.</phrase><phrase role="identifier">insert</phrase><phrase role="special">(</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">make_pair</phrase><phrase role="special">(</phrase><phrase role="identifier">key</phrase><phrase role="special">,</phrase> <phrase role="identifier">value</phrase><phrase role="special">));</phrase>
11855 <phrase role="special">}</phrase>
11857 <phrase role="comment">// Remove value for given key.</phrase>
11858 <phrase role="keyword">void</phrase> <phrase role="identifier">remove</phrase><phrase role="special">(</phrase><phrase role="identifier">K</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">key</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
11859 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">></phrase> <phrase role="identifier">old_count</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">());</phrase>
11860 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
11861 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
11862 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">has</phrase><phrase role="special">(</phrase><phrase role="identifier">key</phrase><phrase role="special">));</phrase> <phrase role="comment">// Has key.</phrase>
11863 <phrase role="special">})</phrase>
11864 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
11865 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_count</phrase> <phrase role="special">-</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase> <phrase role="comment">// Count dec.</phrase>
11866 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(!</phrase><phrase role="identifier">has</phrase><phrase role="special">(</phrase><phrase role="identifier">key</phrase><phrase role="special">));</phrase> <phrase role="comment">// Has not key.</phrase>
11867 <phrase role="special">})</phrase>
11868 <phrase role="special">;</phrase>
11870 <phrase role="identifier">items_</phrase><phrase role="special">.</phrase><phrase role="identifier">erase</phrase><phrase role="special">(</phrase><phrase role="identifier">key</phrase><phrase role="special">);</phrase>
11871 <phrase role="special">}</phrase>
11873 <phrase role="keyword">private</phrase><phrase role="special">:</phrase>
11874 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">map</phrase><phrase role="special"><</phrase><phrase role="identifier">K</phrase><phrase role="special">,</phrase> <phrase role="identifier">T</phrase><phrase role="special">></phrase> <phrase role="identifier">items_</phrase><phrase role="special">;</phrase>
11875 <phrase role="special">};</phrase>
11877 <phrase role="keyword">int</phrase> <phrase role="identifier">main</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
11878 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">string</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">js</phrase> <phrase role="special">=</phrase> <phrase role="string">"John Smith"</phrase><phrase role="special">;</phrase>
11880 <phrase role="identifier">dictionary</phrase><phrase role="special"><</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">string</phrase><phrase role="special">,</phrase> <phrase role="keyword">int</phrase><phrase role="special">></phrase> <phrase role="identifier">ages</phrase><phrase role="special">;</phrase>
11881 <phrase role="identifier">assert</phrase><phrase role="special">(!</phrase><phrase role="identifier">ages</phrase><phrase role="special">.</phrase><phrase role="identifier">has</phrase><phrase role="special">(</phrase><phrase role="identifier">js</phrase><phrase role="special">));</phrase>
11883 <phrase role="identifier">ages</phrase><phrase role="special">.</phrase><phrase role="identifier">put</phrase><phrase role="special">(</phrase><phrase role="identifier">js</phrase><phrase role="special">,</phrase> <phrase role="number">23</phrase><phrase role="special">);</phrase>
11884 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">ages</phrase><phrase role="special">.</phrase><phrase role="identifier">value_for</phrase><phrase role="special">(</phrase><phrase role="identifier">js</phrase><phrase role="special">)</phrase> <phrase role="special">==</phrase> <phrase role="number">23</phrase><phrase role="special">);</phrase>
11886 <phrase role="identifier">ages</phrase><phrase role="special">.</phrase><phrase role="identifier">remove</phrase><phrase role="special">(</phrase><phrase role="identifier">js</phrase><phrase role="special">);</phrase>
11887 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">ages</phrase><phrase role="special">.</phrase><phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase>
11889 <phrase role="keyword">return</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase>
11890 <phrase role="special">}</phrase>
11894 <section id="boost_contract.examples.__mitchell02___courier__subcontracting_and_static_class_invariants">
11895 <title><link linkend="boost_contract.examples.__mitchell02___courier__subcontracting_and_static_class_invariants">[Mitchell02]
11896 Courier: Subcontracting and static class invariants</link></title>
11898 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">contract</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">></phrase>
11899 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">string</phrase><phrase role="special">></phrase>
11900 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">cassert</phrase><phrase role="special">></phrase>
11902 <phrase role="keyword">struct</phrase> <phrase role="identifier">package</phrase> <phrase role="special">{</phrase>
11903 <phrase role="keyword">double</phrase> <phrase role="identifier">weight_kg</phrase><phrase role="special">;</phrase>
11904 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">string</phrase> <phrase role="identifier">location</phrase><phrase role="special">;</phrase>
11905 <phrase role="keyword">double</phrase> <phrase role="identifier">accepted_hour</phrase><phrase role="special">;</phrase>
11906 <phrase role="keyword">double</phrase> <phrase role="identifier">delivered_hour</phrase><phrase role="special">;</phrase>
11908 <phrase role="keyword">explicit</phrase> <phrase role="identifier">package</phrase><phrase role="special">(</phrase>
11909 <phrase role="keyword">double</phrase> <phrase role="identifier">_weight_kg</phrase><phrase role="special">,</phrase>
11910 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">string</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">_location</phrase> <phrase role="special">=</phrase> <phrase role="string">""</phrase><phrase role="special">,</phrase>
11911 <phrase role="keyword">double</phrase> <phrase role="identifier">_accepted_hour</phrase> <phrase role="special">=</phrase> <phrase role="number">0.0</phrase><phrase role="special">,</phrase>
11912 <phrase role="keyword">double</phrase> <phrase role="identifier">_delivered_hour</phrase> <phrase role="special">=</phrase> <phrase role="number">0.0</phrase>
11913 <phrase role="special">)</phrase> <phrase role="special">:</phrase>
11914 <phrase role="identifier">weight_kg</phrase><phrase role="special">(</phrase><phrase role="identifier">_weight_kg</phrase><phrase role="special">),</phrase>
11915 <phrase role="identifier">location</phrase><phrase role="special">(</phrase><phrase role="identifier">_location</phrase><phrase role="special">),</phrase>
11916 <phrase role="identifier">accepted_hour</phrase><phrase role="special">(</phrase><phrase role="identifier">_accepted_hour</phrase><phrase role="special">),</phrase>
11917 <phrase role="identifier">delivered_hour</phrase><phrase role="special">(</phrase><phrase role="identifier">_delivered_hour</phrase><phrase role="special">)</phrase>
11918 <phrase role="special">{}</phrase>
11919 <phrase role="special">};</phrase>
11921 <phrase role="comment">// Courier for package delivery.</phrase>
11922 <phrase role="keyword">class</phrase> <phrase role="identifier">courier</phrase>
11923 <phrase role="preprocessor">#define</phrase> <phrase role="identifier">BASES</phrase> <phrase role="keyword">private</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor_precondition</phrase><phrase role="special"><</phrase><phrase role="identifier">courier</phrase><phrase role="special">></phrase>
11924 <phrase role="special">:</phrase> <phrase role="identifier">BASES</phrase>
11925 <phrase role="special">{</phrase>
11926 <phrase role="keyword">friend</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">access</phrase><phrase role="special">;</phrase>
11928 <phrase role="keyword">typedef</phrase> <phrase role="identifier">BOOST_CONTRACT_BASE_TYPES</phrase><phrase role="special">(</phrase><phrase role="identifier">BASES</phrase><phrase role="special">)</phrase> <phrase role="identifier">base_types</phrase><phrase role="special">;</phrase>
11929 <phrase role="preprocessor">#undef</phrase> <phrase role="identifier">BASES</phrase>
11931 <phrase role="keyword">static</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">static_invariant</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
11932 <phrase role="comment">// Positive min. insurance.</phrase>
11933 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">min_insurance_usd</phrase> <phrase role="special">>=</phrase> <phrase role="number">0.0</phrase><phrase role="special">);</phrase>
11934 <phrase role="special">}</phrase>
11936 <phrase role="keyword">void</phrase> <phrase role="identifier">invariant</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
11937 <phrase role="comment">// Above min. insurance.</phrase>
11938 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">insurance_cover_usd</phrase><phrase role="special">()</phrase> <phrase role="special">>=</phrase> <phrase role="identifier">min_insurance_usd</phrase><phrase role="special">);</phrase>
11939 <phrase role="special">}</phrase>
11941 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
11942 <phrase role="keyword">static</phrase> <phrase role="keyword">double</phrase> <phrase role="identifier">min_insurance_usd</phrase><phrase role="special">;</phrase>
11944 <phrase role="comment">/* Creation */</phrase>
11946 <phrase role="comment">// Create courier with specified insurance value.</phrase>
11947 <phrase role="keyword">explicit</phrase> <phrase role="identifier">courier</phrase><phrase role="special">(</phrase><phrase role="keyword">double</phrase> <phrase role="identifier">_insurance_cover_usd</phrase> <phrase role="special">=</phrase> <phrase role="identifier">min_insurance_usd</phrase><phrase role="special">)</phrase> <phrase role="special">:</phrase>
11948 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor_precondition</phrase><phrase role="special"><</phrase><phrase role="identifier">courier</phrase><phrase role="special">>([&]</phrase> <phrase role="special">{</phrase>
11949 <phrase role="comment">// Positive insurance.</phrase>
11950 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">_insurance_cover_usd</phrase> <phrase role="special">>=</phrase> <phrase role="number">0.0</phrase><phrase role="special">);</phrase>
11951 <phrase role="special">}),</phrase>
11952 <phrase role="identifier">insurance_cover_usd_</phrase><phrase role="special">(</phrase><phrase role="identifier">_insurance_cover_usd</phrase><phrase role="special">)</phrase>
11953 <phrase role="special">{</phrase>
11954 <phrase role="comment">// Check invariants.</phrase>
11955 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
11956 <phrase role="special">}</phrase>
11958 <phrase role="comment">// Destroy courier.</phrase>
11959 <phrase role="keyword">virtual</phrase> <phrase role="special">~</phrase><phrase role="identifier">courier</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
11960 <phrase role="comment">// Check invariants.</phrase>
11961 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">destructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
11962 <phrase role="special">}</phrase>
11964 <phrase role="comment">/* Queries */</phrase>
11966 <phrase role="comment">// Return insurance cover.</phrase>
11967 <phrase role="keyword">double</phrase> <phrase role="identifier">insurance_cover_usd</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
11968 <phrase role="comment">// Check invariants.</phrase>
11969 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
11970 <phrase role="keyword">return</phrase> <phrase role="identifier">insurance_cover_usd_</phrase><phrase role="special">;</phrase>
11971 <phrase role="special">}</phrase>
11973 <phrase role="comment">/* Commands */</phrase>
11975 <phrase role="comment">// Deliver package to destination.</phrase>
11976 <phrase role="keyword">virtual</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">deliver</phrase><phrase role="special">(</phrase>
11977 <phrase role="identifier">package</phrase><phrase role="special">&</phrase> <phrase role="identifier">package_delivery</phrase><phrase role="special">,</phrase>
11978 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">string</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">destination</phrase><phrase role="special">,</phrase>
11979 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase>
11980 <phrase role="special">)</phrase> <phrase role="special">{</phrase>
11981 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">)</phrase>
11982 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
11983 <phrase role="comment">// Within max weight of this delivery.</phrase>
11984 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">package_delivery</phrase><phrase role="special">.</phrase><phrase role="identifier">weight_kg</phrase> <phrase role="special"><</phrase> <phrase role="number">5.0</phrase><phrase role="special">);</phrase>
11985 <phrase role="special">})</phrase>
11986 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
11987 <phrase role="comment">// Within max delivery type.</phrase>
11988 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="keyword">double</phrase><phrase role="special">(</phrase><phrase role="identifier">package_delivery</phrase><phrase role="special">.</phrase><phrase role="identifier">delivered_hour</phrase> <phrase role="special">-</phrase>
11989 <phrase role="identifier">package_delivery</phrase><phrase role="special">.</phrase><phrase role="identifier">accepted_hour</phrase><phrase role="special">)</phrase> <phrase role="special"><=</phrase> <phrase role="number">3.0</phrase><phrase role="special">);</phrase>
11990 <phrase role="comment">// Delivered at destination.</phrase>
11991 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">package_delivery</phrase><phrase role="special">.</phrase><phrase role="identifier">location</phrase> <phrase role="special">==</phrase> <phrase role="identifier">destination</phrase><phrase role="special">);</phrase>
11992 <phrase role="special">})</phrase>
11993 <phrase role="special">;</phrase>
11995 <phrase role="identifier">package_delivery</phrase><phrase role="special">.</phrase><phrase role="identifier">location</phrase> <phrase role="special">=</phrase> <phrase role="identifier">destination</phrase><phrase role="special">;</phrase>
11996 <phrase role="comment">// Delivery takes 2.5 hours.</phrase>
11997 <phrase role="identifier">package_delivery</phrase><phrase role="special">.</phrase><phrase role="identifier">delivered_hour</phrase> <phrase role="special">=</phrase> <phrase role="identifier">package_delivery</phrase><phrase role="special">.</phrase><phrase role="identifier">accepted_hour</phrase> <phrase role="special">+</phrase> <phrase role="number">2.5</phrase><phrase role="special">;</phrase>
11998 <phrase role="special">}</phrase>
12000 <phrase role="keyword">private</phrase><phrase role="special">:</phrase>
12001 <phrase role="keyword">double</phrase> <phrase role="identifier">insurance_cover_usd_</phrase><phrase role="special">;</phrase>
12002 <phrase role="special">};</phrase>
12004 <phrase role="keyword">double</phrase> <phrase role="identifier">courier</phrase><phrase role="special">::</phrase><phrase role="identifier">min_insurance_usd</phrase> <phrase role="special">=</phrase> <phrase role="number">10.0e+6</phrase><phrase role="special">;</phrase>
12006 <phrase role="comment">// Different courier for package delivery.</phrase>
12007 <phrase role="keyword">class</phrase> <phrase role="identifier">different_courier</phrase>
12008 <phrase role="preprocessor">#define</phrase> <phrase role="identifier">BASES</phrase> <phrase role="keyword">private</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor_precondition</phrase><phrase role="special"><</phrase> <phrase role="special">\</phrase>
12009 <phrase role="identifier">different_courier</phrase><phrase role="special">>,</phrase> <phrase role="keyword">public</phrase> <phrase role="identifier">courier</phrase>
12010 <phrase role="special">:</phrase> <phrase role="identifier">BASES</phrase>
12011 <phrase role="special">{</phrase>
12012 <phrase role="keyword">friend</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">access</phrase><phrase role="special">;</phrase>
12014 <phrase role="keyword">typedef</phrase> <phrase role="identifier">BOOST_CONTRACT_BASE_TYPES</phrase><phrase role="special">(</phrase><phrase role="identifier">BASES</phrase><phrase role="special">)</phrase> <phrase role="identifier">base_types</phrase><phrase role="special">;</phrase> <phrase role="comment">// Subcontracting.</phrase>
12015 <phrase role="preprocessor">#undef</phrase> <phrase role="identifier">BASES</phrase>
12017 <phrase role="keyword">static</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">static_invariant</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
12018 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase> <phrase role="comment">// Better insurance amount.</phrase>
12019 <phrase role="identifier">different_insurance_usd</phrase> <phrase role="special">>=</phrase> <phrase role="identifier">courier</phrase><phrase role="special">::</phrase><phrase role="identifier">min_insurance_usd</phrase><phrase role="special">);</phrase>
12020 <phrase role="special">}</phrase>
12022 <phrase role="keyword">void</phrase> <phrase role="identifier">invariant</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
12023 <phrase role="comment">// Above different insurance value.</phrase>
12024 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">insurance_cover_usd</phrase><phrase role="special">()</phrase> <phrase role="special">>=</phrase> <phrase role="identifier">different_insurance_usd</phrase><phrase role="special">);</phrase>
12025 <phrase role="special">}</phrase>
12027 <phrase role="identifier">BOOST_CONTRACT_OVERRIDE</phrase><phrase role="special">(</phrase><phrase role="identifier">deliver</phrase><phrase role="special">)</phrase>
12029 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
12030 <phrase role="keyword">static</phrase> <phrase role="keyword">double</phrase> <phrase role="identifier">different_insurance_usd</phrase><phrase role="special">;</phrase>
12032 <phrase role="comment">/* Creation */</phrase>
12034 <phrase role="comment">// Create courier with specified insurance value.</phrase>
12035 <phrase role="keyword">explicit</phrase> <phrase role="identifier">different_courier</phrase><phrase role="special">(</phrase>
12036 <phrase role="keyword">double</phrase> <phrase role="identifier">insurance_cover_usd</phrase> <phrase role="special">=</phrase> <phrase role="identifier">different_insurance_usd</phrase><phrase role="special">)</phrase> <phrase role="special">:</phrase>
12037 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor_precondition</phrase><phrase role="special"><</phrase><phrase role="identifier">different_courier</phrase><phrase role="special">>([&]</phrase> <phrase role="special">{</phrase>
12038 <phrase role="comment">// Positive insurance value.</phrase>
12039 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">insurance_cover_usd</phrase> <phrase role="special">></phrase> <phrase role="number">0.0</phrase><phrase role="special">);</phrase>
12040 <phrase role="special">}),</phrase>
12041 <phrase role="identifier">courier</phrase><phrase role="special">(</phrase><phrase role="identifier">insurance_cover_usd</phrase><phrase role="special">)</phrase>
12042 <phrase role="special">{</phrase>
12043 <phrase role="comment">// Check invariants.</phrase>
12044 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
12045 <phrase role="special">}</phrase>
12047 <phrase role="comment">// Destroy courier.</phrase>
12048 <phrase role="keyword">virtual</phrase> <phrase role="special">~</phrase><phrase role="identifier">different_courier</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
12049 <phrase role="comment">// Check invariants.</phrase>
12050 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">destructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
12051 <phrase role="special">}</phrase>
12053 <phrase role="comment">/* Commands */</phrase>
12055 <phrase role="keyword">virtual</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">deliver</phrase><phrase role="special">(</phrase>
12056 <phrase role="identifier">package</phrase><phrase role="special">&</phrase> <phrase role="identifier">package_delivery</phrase><phrase role="special">,</phrase>
12057 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">string</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">destination</phrase><phrase role="special">,</phrase>
12058 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase>
12059 <phrase role="special">)</phrase> <phrase role="comment">/* override */</phrase> <phrase role="special">{</phrase>
12060 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special"><</phrase>
12061 <phrase role="identifier">override_deliver</phrase>
12062 <phrase role="special">>(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="special">&</phrase><phrase role="identifier">different_courier</phrase><phrase role="special">::</phrase><phrase role="identifier">deliver</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">,</phrase> <phrase role="identifier">package_delivery</phrase><phrase role="special">,</phrase> <phrase role="identifier">destination</phrase><phrase role="special">)</phrase>
12063 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
12064 <phrase role="comment">// Package can weight more (weaker precondition).</phrase>
12065 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">package_delivery</phrase><phrase role="special">.</phrase><phrase role="identifier">weight_kg</phrase> <phrase role="special"><=</phrase> <phrase role="number">8.0</phrase><phrase role="special">);</phrase>
12066 <phrase role="special">})</phrase>
12067 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
12068 <phrase role="comment">// Faster delivery (stronger postcondition).</phrase>
12069 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="keyword">double</phrase><phrase role="special">(</phrase><phrase role="identifier">package_delivery</phrase><phrase role="special">.</phrase><phrase role="identifier">delivered_hour</phrase> <phrase role="special">-</phrase>
12070 <phrase role="identifier">package_delivery</phrase><phrase role="special">.</phrase><phrase role="identifier">accepted_hour</phrase><phrase role="special">)</phrase> <phrase role="special"><=</phrase> <phrase role="number">2.0</phrase><phrase role="special">);</phrase>
12071 <phrase role="comment">// Inherited "delivery at destination" postcondition.</phrase>
12072 <phrase role="special">})</phrase>
12073 <phrase role="special">;</phrase>
12075 <phrase role="identifier">package_delivery</phrase><phrase role="special">.</phrase><phrase role="identifier">location</phrase> <phrase role="special">=</phrase> <phrase role="identifier">destination</phrase><phrase role="special">;</phrase>
12076 <phrase role="comment">// Delivery takes 0.5 hours.</phrase>
12077 <phrase role="identifier">package_delivery</phrase><phrase role="special">.</phrase><phrase role="identifier">delivered_hour</phrase> <phrase role="special">=</phrase> <phrase role="identifier">package_delivery</phrase><phrase role="special">.</phrase><phrase role="identifier">accepted_hour</phrase> <phrase role="special">+</phrase> <phrase role="number">0.5</phrase><phrase role="special">;</phrase>
12078 <phrase role="special">}</phrase>
12079 <phrase role="special">};</phrase>
12081 <phrase role="keyword">double</phrase> <phrase role="identifier">different_courier</phrase><phrase role="special">::</phrase><phrase role="identifier">different_insurance_usd</phrase> <phrase role="special">=</phrase> <phrase role="number">20.0e+6</phrase><phrase role="special">;</phrase>
12083 <phrase role="keyword">int</phrase> <phrase role="identifier">main</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
12084 <phrase role="identifier">package</phrase> <phrase role="identifier">cups</phrase><phrase role="special">(</phrase><phrase role="number">3.6</phrase><phrase role="special">,</phrase> <phrase role="string">"store"</phrase><phrase role="special">);</phrase>
12085 <phrase role="identifier">courier</phrase> <phrase role="identifier">c</phrase><phrase role="special">;</phrase>
12086 <phrase role="identifier">c</phrase><phrase role="special">.</phrase><phrase role="identifier">deliver</phrase><phrase role="special">(</phrase><phrase role="identifier">cups</phrase><phrase role="special">,</phrase> <phrase role="string">"home"</phrase><phrase role="special">);</phrase>
12087 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">cups</phrase><phrase role="special">.</phrase><phrase role="identifier">location</phrase> <phrase role="special">==</phrase> <phrase role="string">"home"</phrase><phrase role="special">);</phrase>
12089 <phrase role="identifier">package</phrase> <phrase role="identifier">desk</phrase><phrase role="special">(</phrase><phrase role="number">7.2</phrase><phrase role="special">,</phrase> <phrase role="string">"store"</phrase><phrase role="special">);</phrase>
12090 <phrase role="identifier">different_courier</phrase> <phrase role="identifier">dc</phrase><phrase role="special">;</phrase>
12091 <phrase role="identifier">dc</phrase><phrase role="special">.</phrase><phrase role="identifier">deliver</phrase><phrase role="special">(</phrase><phrase role="identifier">desk</phrase><phrase role="special">,</phrase> <phrase role="string">"office"</phrase><phrase role="special">);</phrase>
12092 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">desk</phrase><phrase role="special">.</phrase><phrase role="identifier">location</phrase> <phrase role="special">==</phrase> <phrase role="string">"office"</phrase><phrase role="special">);</phrase>
12094 <phrase role="keyword">return</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase>
12095 <phrase role="special">}</phrase>
12099 <section id="boost_contract.examples.__mitchell02___stack__stack_like_container">
12100 <title><link linkend="boost_contract.examples.__mitchell02___stack__stack_like_container">[Mitchell02]
12101 Stack: Stack-like container</link></title>
12103 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">contract</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">></phrase>
12104 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">optional</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">></phrase>
12105 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">vector</phrase><phrase role="special">></phrase>
12106 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">cassert</phrase><phrase role="special">></phrase>
12108 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">></phrase>
12109 <phrase role="keyword">class</phrase> <phrase role="identifier">stack</phrase> <phrase role="special">{</phrase>
12110 <phrase role="keyword">friend</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">access</phrase><phrase role="special">;</phrase>
12112 <phrase role="keyword">void</phrase> <phrase role="identifier">invariant</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
12113 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="special">>=</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase> <phrase role="comment">// Non-negative count.</phrase>
12114 <phrase role="special">}</phrase>
12116 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
12117 <phrase role="comment">/* Creation */</phrase>
12119 <phrase role="comment">// Create empty stack.</phrase>
12120 <phrase role="identifier">stack</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
12121 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
12122 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
12123 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase> <phrase role="comment">// Empty.</phrase>
12124 <phrase role="special">})</phrase>
12125 <phrase role="special">;</phrase>
12126 <phrase role="special">}</phrase>
12128 <phrase role="comment">// Destroy stack.</phrase>
12129 <phrase role="keyword">virtual</phrase> <phrase role="special">~</phrase><phrase role="identifier">stack</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
12130 <phrase role="comment">// Check invariants.</phrase>
12131 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">destructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
12132 <phrase role="special">}</phrase>
12134 <phrase role="comment">/* Basic Queries */</phrase>
12136 <phrase role="comment">// Number of items.</phrase>
12137 <phrase role="keyword">int</phrase> <phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
12138 <phrase role="comment">// Check invariants.</phrase>
12139 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
12140 <phrase role="keyword">return</phrase> <phrase role="identifier">items_</phrase><phrase role="special">.</phrase><phrase role="identifier">size</phrase><phrase role="special">();</phrase>
12141 <phrase role="special">}</phrase>
12143 <phrase role="comment">// Item at index in [1, count()] (as in Eiffel).</phrase>
12144 <phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">item_at</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">index</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
12145 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
12146 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
12147 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">index</phrase> <phrase role="special">></phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase> <phrase role="comment">// Positive index.</phrase>
12148 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">index</phrase> <phrase role="special"><=</phrase> <phrase role="identifier">count</phrase><phrase role="special">());</phrase> <phrase role="comment">// Index within count.</phrase>
12149 <phrase role="special">})</phrase>
12150 <phrase role="special">;</phrase>
12152 <phrase role="keyword">return</phrase> <phrase role="identifier">items_</phrase><phrase role="special">[</phrase><phrase role="identifier">index</phrase> <phrase role="special">-</phrase> <phrase role="number">1</phrase><phrase role="special">];</phrase>
12153 <phrase role="special">}</phrase>
12155 <phrase role="comment">/* Derived Queries */</phrase>
12157 <phrase role="comment">// If no items.</phrase>
12158 <phrase role="keyword">bool</phrase> <phrase role="identifier">is_empty</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
12159 <phrase role="keyword">bool</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
12160 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
12161 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
12162 <phrase role="comment">// Consistent with count.</phrase>
12163 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">result</phrase> <phrase role="special">==</phrase> <phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">0</phrase><phrase role="special">));</phrase>
12164 <phrase role="special">})</phrase>
12165 <phrase role="special">;</phrase>
12167 <phrase role="keyword">return</phrase> <phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase>
12168 <phrase role="special">}</phrase>
12170 <phrase role="comment">// Top item.</phrase>
12171 <phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">item</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
12172 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">optional</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&></phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase> <phrase role="comment">// Avoid extra construction of T.</phrase>
12173 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
12174 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
12175 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="special">></phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase> <phrase role="comment">// Not empty.</phrase>
12176 <phrase role="special">})</phrase>
12177 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
12178 <phrase role="comment">// Item on top.</phrase>
12179 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(*</phrase><phrase role="identifier">result</phrase> <phrase role="special">==</phrase> <phrase role="identifier">item_at</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">()));</phrase>
12180 <phrase role="special">})</phrase>
12181 <phrase role="special">;</phrase>
12183 <phrase role="keyword">return</phrase> <phrase role="special">*(</phrase><phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="identifier">item_at</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">()));</phrase>
12184 <phrase role="special">}</phrase>
12186 <phrase role="comment">/* Commands */</phrase>
12188 <phrase role="comment">// Push item to the top.</phrase>
12189 <phrase role="keyword">void</phrase> <phrase role="identifier">put</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">new_item</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
12190 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">></phrase> <phrase role="identifier">old_count</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">());</phrase>
12191 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
12192 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
12193 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_count</phrase> <phrase role="special">+</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase> <phrase role="comment">// Count inc.</phrase>
12194 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">item</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">new_item</phrase><phrase role="special">);</phrase> <phrase role="comment">// Item set.</phrase>
12195 <phrase role="special">})</phrase>
12196 <phrase role="special">;</phrase>
12198 <phrase role="identifier">items_</phrase><phrase role="special">.</phrase><phrase role="identifier">push_back</phrase><phrase role="special">(</phrase><phrase role="identifier">new_item</phrase><phrase role="special">);</phrase>
12199 <phrase role="special">}</phrase>
12201 <phrase role="comment">// Pop top item.</phrase>
12202 <phrase role="keyword">void</phrase> <phrase role="identifier">remove</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
12203 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">></phrase> <phrase role="identifier">old_count</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">());</phrase>
12204 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
12205 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
12206 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="special">></phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase> <phrase role="comment">// Not empty.</phrase>
12207 <phrase role="special">})</phrase>
12208 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
12209 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_count</phrase> <phrase role="special">-</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase> <phrase role="comment">// Count dec.</phrase>
12210 <phrase role="special">})</phrase>
12211 <phrase role="special">;</phrase>
12213 <phrase role="identifier">items_</phrase><phrase role="special">.</phrase><phrase role="identifier">pop_back</phrase><phrase role="special">();</phrase>
12214 <phrase role="special">}</phrase>
12216 <phrase role="keyword">private</phrase><phrase role="special">:</phrase>
12217 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase> <phrase role="identifier">items_</phrase><phrase role="special">;</phrase>
12218 <phrase role="special">};</phrase>
12220 <phrase role="keyword">int</phrase> <phrase role="identifier">main</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
12221 <phrase role="identifier">stack</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">></phrase> <phrase role="identifier">s</phrase><phrase role="special">;</phrase>
12222 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">s</phrase><phrase role="special">.</phrase><phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase>
12224 <phrase role="identifier">s</phrase><phrase role="special">.</phrase><phrase role="identifier">put</phrase><phrase role="special">(</phrase><phrase role="number">123</phrase><phrase role="special">);</phrase>
12225 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">s</phrase><phrase role="special">.</phrase><phrase role="identifier">item</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">123</phrase><phrase role="special">);</phrase>
12227 <phrase role="identifier">s</phrase><phrase role="special">.</phrase><phrase role="identifier">remove</phrase><phrase role="special">();</phrase>
12228 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">s</phrase><phrase role="special">.</phrase><phrase role="identifier">is_empty</phrase><phrase role="special">());</phrase>
12230 <phrase role="keyword">return</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase>
12231 <phrase role="special">}</phrase>
12235 <section id="boost_contract.examples.__mitchell02___simple_queue__queue_like_container_and_disable_old_value_copies_for_audit_assertions">
12236 <title><link linkend="boost_contract.examples.__mitchell02___simple_queue__queue_like_container_and_disable_old_value_copies_for_audit_assertions">[Mitchell02]
12237 Simple Queue: Queue-like container and disable old value copies for audit assertions</link></title>
12239 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">contract</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">></phrase>
12240 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">optional</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">></phrase>
12241 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">vector</phrase><phrase role="special">></phrase>
12242 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">cassert</phrase><phrase role="special">></phrase>
12244 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">></phrase>
12245 <phrase role="keyword">class</phrase> <phrase role="identifier">simple_queue</phrase>
12246 <phrase role="preprocessor">#define</phrase> <phrase role="identifier">BASES</phrase> <phrase role="keyword">private</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor_precondition</phrase><phrase role="special"><</phrase> <phrase role="special">\</phrase>
12247 <phrase role="identifier">simple_queue</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase> <phrase role="special">></phrase>
12248 <phrase role="special">:</phrase> <phrase role="identifier">BASES</phrase>
12249 <phrase role="special">{</phrase>
12250 <phrase role="keyword">friend</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">access</phrase><phrase role="special">;</phrase>
12252 <phrase role="keyword">typedef</phrase> <phrase role="identifier">BOOST_CONTRACT_BASE_TYPES</phrase><phrase role="special">(</phrase><phrase role="identifier">BASES</phrase><phrase role="special">)</phrase> <phrase role="identifier">base_types</phrase><phrase role="special">;</phrase>
12253 <phrase role="preprocessor">#undef</phrase> <phrase role="identifier">BASES</phrase>
12255 <phrase role="keyword">void</phrase> <phrase role="identifier">invariant</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
12256 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="special">>=</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase> <phrase role="comment">// Non-negative count.</phrase>
12257 <phrase role="special">}</phrase>
12259 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
12260 <phrase role="comment">/* Creation */</phrase>
12262 <phrase role="comment">// Create empty queue.</phrase>
12263 <phrase role="keyword">explicit</phrase> <phrase role="identifier">simple_queue</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">a_capacity</phrase><phrase role="special">)</phrase> <phrase role="special">:</phrase>
12264 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor_precondition</phrase><phrase role="special"><</phrase><phrase role="identifier">simple_queue</phrase><phrase role="special">>([&]</phrase> <phrase role="special">{</phrase>
12265 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">a_capacity</phrase> <phrase role="special">></phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase> <phrase role="comment">// Positive capacity.</phrase>
12266 <phrase role="special">})</phrase>
12267 <phrase role="special">{</phrase>
12268 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
12269 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
12270 <phrase role="comment">// Capacity set.</phrase>
12271 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">capacity</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">a_capacity</phrase><phrase role="special">);</phrase>
12272 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">is_empty</phrase><phrase role="special">());</phrase> <phrase role="comment">// Empty.</phrase>
12273 <phrase role="special">})</phrase>
12274 <phrase role="special">;</phrase>
12276 <phrase role="identifier">items_</phrase><phrase role="special">.</phrase><phrase role="identifier">reserve</phrase><phrase role="special">(</phrase><phrase role="identifier">a_capacity</phrase><phrase role="special">);</phrase>
12277 <phrase role="special">}</phrase>
12279 <phrase role="comment">// Destroy queue.</phrase>
12280 <phrase role="keyword">virtual</phrase> <phrase role="special">~</phrase><phrase role="identifier">simple_queue</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
12281 <phrase role="comment">// Check invariants.</phrase>
12282 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">destructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
12283 <phrase role="special">}</phrase>
12285 <phrase role="comment">/* Basic Queries */</phrase>
12287 <phrase role="comment">// Items in queue (in their order).</phrase>
12288 <phrase role="comment">// (Somewhat exposes implementation but allows to check more contracts.)</phrase>
12289 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">items</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
12290 <phrase role="comment">// Check invariants.</phrase>
12291 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
12292 <phrase role="keyword">return</phrase> <phrase role="identifier">items_</phrase><phrase role="special">;</phrase>
12293 <phrase role="special">}</phrase>
12295 <phrase role="comment">// Max number of items queue can hold.</phrase>
12296 <phrase role="keyword">int</phrase> <phrase role="identifier">capacity</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
12297 <phrase role="comment">// Check invariants.</phrase>
12298 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
12299 <phrase role="keyword">return</phrase> <phrase role="identifier">items_</phrase><phrase role="special">.</phrase><phrase role="identifier">capacity</phrase><phrase role="special">();</phrase>
12300 <phrase role="special">}</phrase>
12302 <phrase role="comment">/* Derived Queries */</phrase>
12304 <phrase role="comment">// Number of items.</phrase>
12305 <phrase role="keyword">int</phrase> <phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
12306 <phrase role="keyword">int</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
12307 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
12308 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
12309 <phrase role="comment">// Return items count.</phrase>
12310 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">result</phrase> <phrase role="special">==</phrase> <phrase role="keyword">int</phrase><phrase role="special">(</phrase><phrase role="identifier">items</phrase><phrase role="special">().</phrase><phrase role="identifier">size</phrase><phrase role="special">()));</phrase>
12311 <phrase role="special">})</phrase>
12312 <phrase role="special">;</phrase>
12314 <phrase role="keyword">return</phrase> <phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="identifier">items_</phrase><phrase role="special">.</phrase><phrase role="identifier">size</phrase><phrase role="special">();</phrase>
12315 <phrase role="special">}</phrase>
12317 <phrase role="comment">// Item at head.</phrase>
12318 <phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">head</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
12319 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">optional</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&></phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
12320 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
12321 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
12322 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(!</phrase><phrase role="identifier">is_empty</phrase><phrase role="special">());</phrase> <phrase role="comment">// Not empty.</phrase>
12323 <phrase role="special">})</phrase>
12324 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
12325 <phrase role="comment">// Return item on top.</phrase>
12326 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(*</phrase><phrase role="identifier">result</phrase> <phrase role="special">==</phrase> <phrase role="identifier">items</phrase><phrase role="special">().</phrase><phrase role="identifier">at</phrase><phrase role="special">(</phrase><phrase role="number">0</phrase><phrase role="special">));</phrase>
12327 <phrase role="special">})</phrase>
12328 <phrase role="special">;</phrase>
12330 <phrase role="keyword">return</phrase> <phrase role="special">*(</phrase><phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="identifier">items_</phrase><phrase role="special">.</phrase><phrase role="identifier">at</phrase><phrase role="special">(</phrase><phrase role="number">0</phrase><phrase role="special">));</phrase>
12331 <phrase role="special">}</phrase>
12333 <phrase role="comment">// If queue contains no item.</phrase>
12334 <phrase role="keyword">bool</phrase> <phrase role="identifier">is_empty</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
12335 <phrase role="keyword">bool</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
12336 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
12337 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
12338 <phrase role="comment">// Consistent with count.</phrase>
12339 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">result</phrase> <phrase role="special">==</phrase> <phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">0</phrase><phrase role="special">));</phrase>
12340 <phrase role="special">})</phrase>
12341 <phrase role="special">;</phrase>
12343 <phrase role="keyword">return</phrase> <phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="special">(</phrase><phrase role="identifier">items_</phrase><phrase role="special">.</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase>
12344 <phrase role="special">}</phrase>
12346 <phrase role="comment">// If queue has no room for another item.</phrase>
12347 <phrase role="keyword">bool</phrase> <phrase role="identifier">is_full</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
12348 <phrase role="keyword">bool</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
12349 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
12350 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
12351 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase> <phrase role="comment">// Consistent with size and capacity.</phrase>
12352 <phrase role="identifier">result</phrase> <phrase role="special">==</phrase> <phrase role="special">(</phrase><phrase role="identifier">capacity</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="keyword">int</phrase><phrase role="special">(</phrase><phrase role="identifier">items</phrase><phrase role="special">().</phrase><phrase role="identifier">size</phrase><phrase role="special">())));</phrase>
12353 <phrase role="special">})</phrase>
12354 <phrase role="special">;</phrase>
12356 <phrase role="keyword">return</phrase> <phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="special">(</phrase><phrase role="identifier">items_</phrase><phrase role="special">.</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">items_</phrase><phrase role="special">.</phrase><phrase role="identifier">capacity</phrase><phrase role="special">());</phrase>
12357 <phrase role="special">}</phrase>
12359 <phrase role="comment">/* Commands */</phrase>
12361 <phrase role="comment">// Remove head itme and shift all other items.</phrase>
12362 <phrase role="keyword">void</phrase> <phrase role="identifier">remove</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
12363 <phrase role="comment">// Expensive all_equal postcond. and old_items copy might be skipped.</phrase>
12364 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase> <phrase role="special">></phrase> <phrase role="identifier">old_items</phrase><phrase role="special">;</phrase>
12365 <phrase role="preprocessor">#ifdef</phrase> <phrase role="identifier">BOOST_CONTRACT_AUDIITS</phrase>
12366 <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">items</phrase><phrase role="special">())</phrase>
12367 <phrase role="preprocessor">#endif</phrase> <phrase role="comment">// Else, leave old pointer null...</phrase>
12368 <phrase role="special">;</phrase>
12369 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">></phrase> <phrase role="identifier">old_count</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">());</phrase>
12370 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
12371 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
12372 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(!</phrase><phrase role="identifier">is_empty</phrase><phrase role="special">());</phrase> <phrase role="comment">// Not empty.</phrase>
12373 <phrase role="special">})</phrase>
12374 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
12375 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_count</phrase> <phrase role="special">-</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase> <phrase role="comment">// Count dec.</phrase>
12376 <phrase role="comment">// ...following skipped #ifndef AUDITS.</phrase>
12377 <phrase role="keyword">if</phrase><phrase role="special">(</phrase><phrase role="identifier">old_items</phrase><phrase role="special">)</phrase> <phrase role="identifier">all_equal</phrase><phrase role="special">(</phrase><phrase role="identifier">items</phrase><phrase role="special">(),</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_items</phrase><phrase role="special">,</phrase> <phrase role="comment">/* shifted = */</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase>
12378 <phrase role="special">})</phrase>
12379 <phrase role="special">;</phrase>
12381 <phrase role="identifier">items_</phrase><phrase role="special">.</phrase><phrase role="identifier">erase</phrase><phrase role="special">(</phrase><phrase role="identifier">items_</phrase><phrase role="special">.</phrase><phrase role="identifier">begin</phrase><phrase role="special">());</phrase>
12382 <phrase role="special">}</phrase>
12384 <phrase role="comment">// Add item to tail.</phrase>
12385 <phrase role="keyword">void</phrase> <phrase role="identifier">put</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">item</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
12386 <phrase role="comment">// Expensive all_equal postcond. and old_items copy might be skipped.</phrase>
12387 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase> <phrase role="special">></phrase> <phrase role="identifier">old_items</phrase><phrase role="special">;</phrase>
12388 <phrase role="preprocessor">#ifdef</phrase> <phrase role="identifier">BOOST_CONTRACT_AUDITS</phrase>
12389 <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">items</phrase><phrase role="special">())</phrase>
12390 <phrase role="preprocessor">#endif</phrase> <phrase role="comment">// Else, leave old pointer null...</phrase>
12391 <phrase role="special">;</phrase>
12392 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">></phrase> <phrase role="identifier">old_count</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">());</phrase>
12393 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
12394 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
12395 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="special"><</phrase> <phrase role="identifier">capacity</phrase><phrase role="special">());</phrase> <phrase role="comment">// Room for add.</phrase>
12396 <phrase role="special">})</phrase>
12397 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
12398 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_count</phrase> <phrase role="special">+</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase> <phrase role="comment">// Count inc.</phrase>
12399 <phrase role="comment">// Second to last item.</phrase>
12400 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">items</phrase><phrase role="special">().</phrase><phrase role="identifier">at</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="special">-</phrase> <phrase role="number">1</phrase><phrase role="special">)</phrase> <phrase role="special">==</phrase> <phrase role="identifier">item</phrase><phrase role="special">);</phrase>
12401 <phrase role="comment">// ...following skipped #ifndef AUDITS.</phrase>
12402 <phrase role="keyword">if</phrase><phrase role="special">(</phrase><phrase role="identifier">old_items</phrase><phrase role="special">)</phrase> <phrase role="identifier">all_equal</phrase><phrase role="special">(</phrase><phrase role="identifier">items</phrase><phrase role="special">(),</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_items</phrase><phrase role="special">);</phrase>
12403 <phrase role="special">})</phrase>
12404 <phrase role="special">;</phrase>
12406 <phrase role="identifier">items_</phrase><phrase role="special">.</phrase><phrase role="identifier">push_back</phrase><phrase role="special">(</phrase><phrase role="identifier">item</phrase><phrase role="special">);</phrase>
12407 <phrase role="special">}</phrase>
12409 <phrase role="keyword">private</phrase><phrase role="special">:</phrase>
12410 <phrase role="comment">// Contract helper.</phrase>
12411 <phrase role="keyword">static</phrase> <phrase role="keyword">bool</phrase> <phrase role="identifier">all_equal</phrase><phrase role="special">(</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">left</phrase><phrase role="special">,</phrase>
12412 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">right</phrase><phrase role="special">,</phrase> <phrase role="keyword">unsigned</phrase> <phrase role="identifier">offset</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
12413 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">function</phrase><phrase role="special">()</phrase>
12414 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
12415 <phrase role="comment">// Correct offset.</phrase>
12416 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">right</phrase><phrase role="special">.</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">left</phrase><phrase role="special">.</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">+</phrase> <phrase role="identifier">offset</phrase><phrase role="special">);</phrase>
12417 <phrase role="special">})</phrase>
12418 <phrase role="special">;</phrase>
12420 <phrase role="keyword">for</phrase><phrase role="special">(</phrase><phrase role="keyword">unsigned</phrase> <phrase role="identifier">i</phrase> <phrase role="special">=</phrase> <phrase role="identifier">offset</phrase><phrase role="special">;</phrase> <phrase role="identifier">i</phrase> <phrase role="special"><</phrase> <phrase role="identifier">right</phrase><phrase role="special">.</phrase><phrase role="identifier">size</phrase><phrase role="special">();</phrase> <phrase role="special">++</phrase><phrase role="identifier">i</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
12421 <phrase role="keyword">if</phrase><phrase role="special">(</phrase><phrase role="identifier">left</phrase><phrase role="special">.</phrase><phrase role="identifier">at</phrase><phrase role="special">(</phrase><phrase role="identifier">i</phrase> <phrase role="special">-</phrase> <phrase role="identifier">offset</phrase><phrase role="special">)</phrase> <phrase role="special">!=</phrase> <phrase role="identifier">right</phrase><phrase role="special">.</phrase><phrase role="identifier">at</phrase><phrase role="special">(</phrase><phrase role="identifier">i</phrase><phrase role="special">))</phrase> <phrase role="keyword">return</phrase> <phrase role="keyword">false</phrase><phrase role="special">;</phrase>
12422 <phrase role="special">}</phrase>
12423 <phrase role="keyword">return</phrase> <phrase role="keyword">true</phrase><phrase role="special">;</phrase>
12424 <phrase role="special">}</phrase>
12426 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase> <phrase role="identifier">items_</phrase><phrase role="special">;</phrase>
12427 <phrase role="special">};</phrase>
12429 <phrase role="keyword">int</phrase> <phrase role="identifier">main</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
12430 <phrase role="identifier">simple_queue</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">></phrase> <phrase role="identifier">q</phrase><phrase role="special">(</phrase><phrase role="number">10</phrase><phrase role="special">);</phrase>
12431 <phrase role="identifier">q</phrase><phrase role="special">.</phrase><phrase role="identifier">put</phrase><phrase role="special">(</phrase><phrase role="number">123</phrase><phrase role="special">);</phrase>
12432 <phrase role="identifier">q</phrase><phrase role="special">.</phrase><phrase role="identifier">put</phrase><phrase role="special">(</phrase><phrase role="number">456</phrase><phrase role="special">);</phrase>
12434 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">q</phrase><phrase role="special">.</phrase><phrase role="identifier">capacity</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">10</phrase><phrase role="special">);</phrase>
12435 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">q</phrase><phrase role="special">.</phrase><phrase role="identifier">head</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">123</phrase><phrase role="special">);</phrase>
12437 <phrase role="identifier">assert</phrase><phrase role="special">(!</phrase><phrase role="identifier">q</phrase><phrase role="special">.</phrase><phrase role="identifier">is_empty</phrase><phrase role="special">());</phrase>
12438 <phrase role="identifier">assert</phrase><phrase role="special">(!</phrase><phrase role="identifier">q</phrase><phrase role="special">.</phrase><phrase role="identifier">is_full</phrase><phrase role="special">());</phrase>
12440 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">></phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">items</phrase> <phrase role="special">=</phrase> <phrase role="identifier">q</phrase><phrase role="special">.</phrase><phrase role="identifier">items</phrase><phrase role="special">();</phrase>
12441 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">items</phrase><phrase role="special">.</phrase><phrase role="identifier">at</phrase><phrase role="special">(</phrase><phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="special">==</phrase> <phrase role="number">123</phrase><phrase role="special">);</phrase>
12442 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">items</phrase><phrase role="special">.</phrase><phrase role="identifier">at</phrase><phrase role="special">(</phrase><phrase role="number">1</phrase><phrase role="special">)</phrase> <phrase role="special">==</phrase> <phrase role="number">456</phrase><phrase role="special">);</phrase>
12444 <phrase role="identifier">q</phrase><phrase role="special">.</phrase><phrase role="identifier">remove</phrase><phrase role="special">();</phrase>
12445 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">q</phrase><phrase role="special">.</phrase><phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase>
12447 <phrase role="keyword">return</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase>
12448 <phrase role="special">}</phrase>
12452 <section id="boost_contract.examples.__mitchell02___customer_manager__contracts_instead_of_defensive_programming">
12453 <title><link linkend="boost_contract.examples.__mitchell02___customer_manager__contracts_instead_of_defensive_programming">[Mitchell02]
12454 Customer Manager: Contracts instead of defensive programming</link></title>
12456 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">contract</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">></phrase>
12457 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">string</phrase><phrase role="special">></phrase>
12458 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">map</phrase><phrase role="special">></phrase>
12459 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">utility</phrase><phrase role="special">></phrase>
12460 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">cassert</phrase><phrase role="special">></phrase>
12462 <phrase role="comment">// Basic customer information.</phrase>
12463 <phrase role="keyword">struct</phrase> <phrase role="identifier">customer_info</phrase> <phrase role="special">{</phrase>
12464 <phrase role="keyword">friend</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">customer_manager</phrase><phrase role="special">;</phrase>
12466 <phrase role="keyword">typedef</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">string</phrase> <phrase role="identifier">identifier</phrase><phrase role="special">;</phrase>
12468 <phrase role="identifier">identifier</phrase> <phrase role="identifier">id</phrase><phrase role="special">;</phrase>
12470 <phrase role="keyword">explicit</phrase> <phrase role="identifier">customer_info</phrase><phrase role="special">(</phrase><phrase role="identifier">identifier</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">_id</phrase><phrase role="special">)</phrase> <phrase role="special">:</phrase>
12471 <phrase role="identifier">id</phrase><phrase role="special">(</phrase><phrase role="identifier">_id</phrase><phrase role="special">),</phrase> <phrase role="identifier">name_</phrase><phrase role="special">(),</phrase> <phrase role="identifier">address_</phrase><phrase role="special">(),</phrase> <phrase role="identifier">birthday_</phrase><phrase role="special">()</phrase> <phrase role="special">{}</phrase>
12473 <phrase role="keyword">private</phrase><phrase role="special">:</phrase>
12474 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">string</phrase> <phrase role="identifier">name_</phrase><phrase role="special">;</phrase>
12475 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">string</phrase> <phrase role="identifier">address_</phrase><phrase role="special">;</phrase>
12476 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">string</phrase> <phrase role="identifier">birthday_</phrase><phrase role="special">;</phrase>
12477 <phrase role="special">};</phrase>
12479 <phrase role="comment">// Manage customers.</phrase>
12480 <phrase role="keyword">class</phrase> <phrase role="identifier">customer_manager</phrase> <phrase role="special">{</phrase>
12481 <phrase role="keyword">friend</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">access</phrase><phrase role="special">;</phrase>
12483 <phrase role="keyword">void</phrase> <phrase role="identifier">invariant</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
12484 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="special">>=</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase> <phrase role="comment">// Non-negative count.</phrase>
12485 <phrase role="special">}</phrase>
12487 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
12488 <phrase role="comment">/* Creation */</phrase>
12490 <phrase role="identifier">customer_manager</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
12491 <phrase role="comment">// Check invariants.</phrase>
12492 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
12493 <phrase role="special">}</phrase>
12495 <phrase role="keyword">virtual</phrase> <phrase role="special">~</phrase><phrase role="identifier">customer_manager</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
12496 <phrase role="comment">// Check invariants.</phrase>
12497 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">destructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
12498 <phrase role="special">}</phrase>
12500 <phrase role="comment">/* Basic Queries */</phrase>
12502 <phrase role="keyword">int</phrase> <phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
12503 <phrase role="comment">// Check invariants.</phrase>
12504 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
12505 <phrase role="keyword">return</phrase> <phrase role="identifier">customers_</phrase><phrase role="special">.</phrase><phrase role="identifier">size</phrase><phrase role="special">();</phrase>
12506 <phrase role="special">}</phrase>
12508 <phrase role="keyword">bool</phrase> <phrase role="identifier">id_active</phrase><phrase role="special">(</phrase><phrase role="identifier">customer_info</phrase><phrase role="special">::</phrase><phrase role="identifier">identifier</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">id</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
12509 <phrase role="comment">// Check invariants.</phrase>
12510 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
12511 <phrase role="keyword">return</phrase> <phrase role="identifier">customers_</phrase><phrase role="special">.</phrase><phrase role="identifier">find</phrase><phrase role="special">(</phrase><phrase role="identifier">id</phrase><phrase role="special">)</phrase> <phrase role="special">!=</phrase> <phrase role="identifier">customers_</phrase><phrase role="special">.</phrase><phrase role="identifier">cend</phrase><phrase role="special">();</phrase>
12512 <phrase role="special">}</phrase>
12514 <phrase role="comment">/* Derived Queries */</phrase>
12516 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">string</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">name_for</phrase><phrase role="special">(</phrase><phrase role="identifier">customer_info</phrase><phrase role="special">::</phrase><phrase role="identifier">identifier</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">id</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
12517 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
12518 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
12519 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">id_active</phrase><phrase role="special">(</phrase><phrase role="identifier">id</phrase><phrase role="special">));</phrase> <phrase role="comment">// Active.</phrase>
12520 <phrase role="special">})</phrase>
12521 <phrase role="special">;</phrase>
12523 <phrase role="comment">// Find != end because of preconditions (no defensive programming).</phrase>
12524 <phrase role="keyword">return</phrase> <phrase role="identifier">customers_</phrase><phrase role="special">.</phrase><phrase role="identifier">find</phrase><phrase role="special">(</phrase><phrase role="identifier">id</phrase><phrase role="special">)-></phrase><phrase role="identifier">second</phrase><phrase role="special">.</phrase><phrase role="identifier">name_</phrase><phrase role="special">;</phrase>
12525 <phrase role="special">}</phrase>
12527 <phrase role="comment">/* Commands */</phrase>
12529 <phrase role="keyword">void</phrase> <phrase role="identifier">add</phrase><phrase role="special">(</phrase><phrase role="identifier">customer_info</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">info</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
12530 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">></phrase> <phrase role="identifier">old_count</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">());</phrase>
12531 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
12532 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
12533 <phrase role="comment">// Not already active.</phrase>
12534 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(!</phrase><phrase role="identifier">id_active</phrase><phrase role="special">(</phrase><phrase role="identifier">info</phrase><phrase role="special">.</phrase><phrase role="identifier">id</phrase><phrase role="special">));</phrase>
12535 <phrase role="special">})</phrase>
12536 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
12537 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_count</phrase> <phrase role="special">+</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase> <phrase role="comment">// Count inc.</phrase>
12538 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">id_active</phrase><phrase role="special">(</phrase><phrase role="identifier">info</phrase><phrase role="special">.</phrase><phrase role="identifier">id</phrase><phrase role="special">));</phrase> <phrase role="comment">// Activated.</phrase>
12539 <phrase role="special">})</phrase>
12540 <phrase role="special">;</phrase>
12542 <phrase role="identifier">customers_</phrase><phrase role="special">.</phrase><phrase role="identifier">insert</phrase><phrase role="special">(</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">make_pair</phrase><phrase role="special">(</phrase><phrase role="identifier">info</phrase><phrase role="special">.</phrase><phrase role="identifier">id</phrase><phrase role="special">,</phrase> <phrase role="identifier">customer</phrase><phrase role="special">(</phrase><phrase role="identifier">info</phrase><phrase role="special">)));</phrase>
12543 <phrase role="special">}</phrase>
12545 <phrase role="keyword">void</phrase> <phrase role="identifier">set_name</phrase><phrase role="special">(</phrase><phrase role="identifier">customer_info</phrase><phrase role="special">::</phrase><phrase role="identifier">identifier</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">id</phrase><phrase role="special">,</phrase>
12546 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">string</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">name</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
12547 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
12548 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
12549 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">id_active</phrase><phrase role="special">(</phrase><phrase role="identifier">id</phrase><phrase role="special">));</phrase> <phrase role="comment">// Already active.</phrase>
12550 <phrase role="special">})</phrase>
12551 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
12552 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">name_for</phrase><phrase role="special">(</phrase><phrase role="identifier">id</phrase><phrase role="special">)</phrase> <phrase role="special">==</phrase> <phrase role="identifier">name</phrase><phrase role="special">);</phrase> <phrase role="comment">// Name set.</phrase>
12553 <phrase role="special">})</phrase>
12554 <phrase role="special">;</phrase>
12556 <phrase role="comment">// Find != end because of precondition (no defensive programming).</phrase>
12557 <phrase role="identifier">customers_</phrase><phrase role="special">.</phrase><phrase role="identifier">find</phrase><phrase role="special">(</phrase><phrase role="identifier">id</phrase><phrase role="special">)-></phrase><phrase role="identifier">second</phrase><phrase role="special">.</phrase><phrase role="identifier">name_</phrase> <phrase role="special">=</phrase> <phrase role="identifier">name</phrase><phrase role="special">;</phrase>
12558 <phrase role="special">}</phrase>
12560 <phrase role="keyword">private</phrase><phrase role="special">:</phrase>
12561 <phrase role="keyword">class</phrase> <phrase role="identifier">agent</phrase> <phrase role="special">{};</phrase> <phrase role="comment">// Customer agent.</phrase>
12563 <phrase role="keyword">struct</phrase> <phrase role="identifier">customer</phrase> <phrase role="special">:</phrase> <phrase role="identifier">customer_info</phrase> <phrase role="special">{</phrase>
12564 <phrase role="identifier">agent</phrase> <phrase role="identifier">managing_agent</phrase><phrase role="special">;</phrase>
12565 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">string</phrase> <phrase role="identifier">last_contact</phrase><phrase role="special">;</phrase>
12567 <phrase role="keyword">explicit</phrase> <phrase role="identifier">customer</phrase><phrase role="special">(</phrase><phrase role="identifier">customer_info</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">info</phrase><phrase role="special">)</phrase> <phrase role="special">:</phrase> <phrase role="identifier">customer_info</phrase><phrase role="special">(</phrase><phrase role="identifier">info</phrase><phrase role="special">),</phrase>
12568 <phrase role="identifier">managing_agent</phrase><phrase role="special">(),</phrase> <phrase role="identifier">last_contact</phrase><phrase role="special">()</phrase> <phrase role="special">{}</phrase>
12569 <phrase role="special">};</phrase>
12571 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">map</phrase><phrase role="special"><</phrase><phrase role="identifier">customer_info</phrase><phrase role="special">::</phrase><phrase role="identifier">identifier</phrase><phrase role="special">,</phrase> <phrase role="identifier">customer</phrase><phrase role="special">></phrase> <phrase role="identifier">customers_</phrase><phrase role="special">;</phrase>
12572 <phrase role="special">};</phrase>
12574 <phrase role="keyword">int</phrase> <phrase role="identifier">main</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
12575 <phrase role="identifier">customer_manager</phrase> <phrase role="identifier">m</phrase><phrase role="special">;</phrase>
12576 <phrase role="identifier">customer_info</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">js</phrase><phrase role="special">(</phrase><phrase role="string">"john_smith_123"</phrase><phrase role="special">);</phrase>
12577 <phrase role="identifier">m</phrase><phrase role="special">.</phrase><phrase role="identifier">add</phrase><phrase role="special">(</phrase><phrase role="identifier">js</phrase><phrase role="special">);</phrase>
12578 <phrase role="identifier">m</phrase><phrase role="special">.</phrase><phrase role="identifier">set_name</phrase><phrase role="special">(</phrase><phrase role="identifier">js</phrase><phrase role="special">.</phrase><phrase role="identifier">id</phrase><phrase role="special">,</phrase> <phrase role="string">"John Smith"</phrase><phrase role="special">);</phrase>
12579 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">m</phrase><phrase role="special">.</phrase><phrase role="identifier">name_for</phrase><phrase role="special">(</phrase><phrase role="identifier">js</phrase><phrase role="special">.</phrase><phrase role="identifier">id</phrase><phrase role="special">)</phrase> <phrase role="special">==</phrase> <phrase role="string">"John Smith"</phrase><phrase role="special">);</phrase>
12580 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">m</phrase><phrase role="special">.</phrase><phrase role="identifier">count</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase>
12581 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">m</phrase><phrase role="special">.</phrase><phrase role="identifier">id_active</phrase><phrase role="special">(</phrase><phrase role="identifier">js</phrase><phrase role="special">.</phrase><phrase role="identifier">id</phrase><phrase role="special">));</phrase>
12582 <phrase role="keyword">return</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase>
12583 <phrase role="special">}</phrase>
12587 <section id="boost_contract.examples.__mitchell02___observer__pure_virtual_functions">
12588 <title><link linkend="boost_contract.examples.__mitchell02___observer__pure_virtual_functions">[Mitchell02]
12589 Observer: Pure virtual functions</link></title>
12591 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">OBSERVER_HPP_</phrase>
12592 <phrase role="preprocessor">#define</phrase> <phrase role="identifier">OBSERVER_HPP_</phrase>
12594 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">contract</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">></phrase>
12595 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">cassert</phrase><phrase role="special">></phrase>
12597 <phrase role="comment">// Observer.</phrase>
12598 <phrase role="keyword">class</phrase> <phrase role="identifier">observer</phrase> <phrase role="special">{</phrase>
12599 <phrase role="keyword">friend</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">subject</phrase><phrase role="special">;</phrase>
12600 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
12601 <phrase role="comment">// No inv and no bases so contracts optional if no pre, post, and override.</phrase>
12603 <phrase role="comment">/* Creation */</phrase>
12605 <phrase role="identifier">observer</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
12606 <phrase role="comment">// Could have omitted contracts here (nothing to check).</phrase>
12607 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
12608 <phrase role="special">}</phrase>
12610 <phrase role="keyword">virtual</phrase> <phrase role="special">~</phrase><phrase role="identifier">observer</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
12611 <phrase role="comment">// Could have omitted contracts here (nothing to check).</phrase>
12612 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">destructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
12613 <phrase role="special">}</phrase>
12615 <phrase role="comment">/* Commands */</phrase>
12617 <phrase role="comment">// If up-to-date with related subject.</phrase>
12618 <phrase role="keyword">virtual</phrase> <phrase role="keyword">bool</phrase> <phrase role="identifier">up_to_date_with_subject</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase>
12619 <phrase role="keyword">const</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase>
12621 <phrase role="comment">// Update this observer.</phrase>
12622 <phrase role="keyword">virtual</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">update</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase>
12623 <phrase role="special">};</phrase>
12625 <phrase role="keyword">bool</phrase> <phrase role="identifier">observer</phrase><phrase role="special">::</phrase><phrase role="identifier">up_to_date_with_subject</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
12626 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">);</phrase>
12627 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="keyword">false</phrase><phrase role="special">);</phrase>
12628 <phrase role="keyword">return</phrase> <phrase role="keyword">false</phrase><phrase role="special">;</phrase>
12629 <phrase role="special">}</phrase>
12631 <phrase role="keyword">void</phrase> <phrase role="identifier">observer</phrase><phrase role="special">::</phrase><phrase role="identifier">update</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
12632 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">)</phrase>
12633 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
12634 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">up_to_date_with_subject</phrase><phrase role="special">());</phrase> <phrase role="comment">// Up-to-date.</phrase>
12635 <phrase role="special">})</phrase>
12636 <phrase role="special">;</phrase>
12637 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="keyword">false</phrase><phrase role="special">);</phrase>
12638 <phrase role="special">}</phrase>
12640 <phrase role="preprocessor">#endif</phrase> <phrase role="comment">// #include guard</phrase>
12644 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">SUBJECT_HPP_</phrase>
12645 <phrase role="preprocessor">#define</phrase> <phrase role="identifier">SUBJECT_HPP_</phrase>
12647 <phrase role="preprocessor">#include</phrase> <phrase role="string">"observer.hpp"</phrase>
12648 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">contract</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">></phrase>
12649 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">vector</phrase><phrase role="special">></phrase>
12650 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">algorithm</phrase><phrase role="special">></phrase>
12651 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">cassert</phrase><phrase role="special">></phrase>
12653 <phrase role="comment">// Subject for observer design pattern.</phrase>
12654 <phrase role="keyword">class</phrase> <phrase role="identifier">subject</phrase> <phrase role="special">{</phrase>
12655 <phrase role="keyword">friend</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">access</phrase><phrase role="special">;</phrase>
12657 <phrase role="keyword">void</phrase> <phrase role="identifier">invariant</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
12658 <phrase role="identifier">BOOST_CONTRACT_ASSERT_AUDIT</phrase><phrase role="special">(</phrase><phrase role="identifier">all_observers_valid</phrase><phrase role="special">(</phrase><phrase role="identifier">observers</phrase><phrase role="special">()));</phrase> <phrase role="comment">// Valid.</phrase>
12659 <phrase role="special">}</phrase>
12661 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
12662 <phrase role="comment">/* Creation */</phrase>
12664 <phrase role="comment">// Construct subject with no observer.</phrase>
12665 <phrase role="identifier">subject</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
12666 <phrase role="comment">// Check invariant.</phrase>
12667 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
12668 <phrase role="special">}</phrase>
12670 <phrase role="comment">// Destroy subject.</phrase>
12671 <phrase role="keyword">virtual</phrase> <phrase role="special">~</phrase><phrase role="identifier">subject</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
12672 <phrase role="comment">// Check invariant.</phrase>
12673 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">destructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
12674 <phrase role="special">}</phrase>
12676 <phrase role="comment">/* Queries */</phrase>
12678 <phrase role="comment">// If given object is attached.</phrase>
12679 <phrase role="keyword">bool</phrase> <phrase role="identifier">attached</phrase><phrase role="special">(</phrase><phrase role="identifier">observer</phrase> <phrase role="keyword">const</phrase><phrase role="special">*</phrase> <phrase role="identifier">ob</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
12680 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
12681 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
12682 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">ob</phrase><phrase role="special">);</phrase> <phrase role="comment">// Not null.</phrase>
12683 <phrase role="special">})</phrase>
12684 <phrase role="special">;</phrase>
12686 <phrase role="keyword">return</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">find</phrase><phrase role="special">(</phrase><phrase role="identifier">observers_</phrase><phrase role="special">.</phrase><phrase role="identifier">cbegin</phrase><phrase role="special">(),</phrase> <phrase role="identifier">observers_</phrase><phrase role="special">.</phrase><phrase role="identifier">cend</phrase><phrase role="special">(),</phrase> <phrase role="identifier">ob</phrase><phrase role="special">)</phrase> <phrase role="special">!=</phrase>
12687 <phrase role="identifier">observers_</phrase><phrase role="special">.</phrase><phrase role="identifier">cend</phrase><phrase role="special">();</phrase>
12688 <phrase role="special">}</phrase>
12690 <phrase role="comment">/* Commands */</phrase>
12692 <phrase role="comment">// Attach given object as an observer.</phrase>
12693 <phrase role="keyword">void</phrase> <phrase role="identifier">attach</phrase><phrase role="special">(</phrase><phrase role="identifier">observer</phrase><phrase role="special">*</phrase> <phrase role="identifier">ob</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
12694 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">observer</phrase> <phrase role="keyword">const</phrase><phrase role="special">*></phrase> <phrase role="special">></phrase> <phrase role="identifier">old_observers</phrase><phrase role="special">;</phrase>
12695 <phrase role="preprocessor">#ifdef</phrase> <phrase role="identifier">BOOST_CONTRACT_AUDITS</phrase>
12696 <phrase role="identifier">old_observers</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">observers</phrase><phrase role="special">());</phrase>
12697 <phrase role="preprocessor">#endif</phrase>
12698 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
12699 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
12700 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">ob</phrase><phrase role="special">);</phrase> <phrase role="comment">// Not null.</phrase>
12701 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(!</phrase><phrase role="identifier">attached</phrase><phrase role="special">(</phrase><phrase role="identifier">ob</phrase><phrase role="special">));</phrase> <phrase role="comment">// Not already attached.</phrase>
12702 <phrase role="special">})</phrase>
12703 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
12704 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">attached</phrase><phrase role="special">(</phrase><phrase role="identifier">ob</phrase><phrase role="special">));</phrase> <phrase role="comment">// Attached.</phrase>
12705 <phrase role="comment">// Others not changed (frame rule).</phrase>
12706 <phrase role="identifier">BOOST_CONTRACT_ASSERT_AUDIT</phrase><phrase role="special">(</phrase><phrase role="identifier">other_observers_unchanged</phrase><phrase role="special">(</phrase>
12707 <phrase role="special">*</phrase><phrase role="identifier">old_observers</phrase><phrase role="special">,</phrase> <phrase role="identifier">observers</phrase><phrase role="special">(),</phrase> <phrase role="identifier">ob</phrase><phrase role="special">));</phrase>
12708 <phrase role="special">})</phrase>
12709 <phrase role="special">;</phrase>
12711 <phrase role="identifier">observers_</phrase><phrase role="special">.</phrase><phrase role="identifier">push_back</phrase><phrase role="special">(</phrase><phrase role="identifier">ob</phrase><phrase role="special">);</phrase>
12712 <phrase role="special">}</phrase>
12714 <phrase role="keyword">protected</phrase><phrase role="special">:</phrase>
12715 <phrase role="comment">// Contracts could have been omitted for protected/private with no pre/post.</phrase>
12717 <phrase role="comment">/* Queries */</phrase>
12719 <phrase role="comment">// All observers attached to this subject.</phrase>
12720 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">observer</phrase> <phrase role="keyword">const</phrase><phrase role="special">*></phrase> <phrase role="identifier">observers</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
12721 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">observer</phrase> <phrase role="keyword">const</phrase><phrase role="special">*></phrase> <phrase role="identifier">obs</phrase><phrase role="special">;</phrase>
12722 <phrase role="keyword">for</phrase><phrase role="special">(</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">observer</phrase><phrase role="special">*>::</phrase><phrase role="identifier">const_iterator</phrase> <phrase role="identifier">i</phrase> <phrase role="special">=</phrase> <phrase role="identifier">observers_</phrase><phrase role="special">.</phrase><phrase role="identifier">cbegin</phrase><phrase role="special">();</phrase>
12723 <phrase role="identifier">i</phrase> <phrase role="special">!=</phrase> <phrase role="identifier">observers_</phrase><phrase role="special">.</phrase><phrase role="identifier">cend</phrase><phrase role="special">();</phrase> <phrase role="special">++</phrase><phrase role="identifier">i</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
12724 <phrase role="identifier">obs</phrase><phrase role="special">.</phrase><phrase role="identifier">push_back</phrase><phrase role="special">(*</phrase><phrase role="identifier">i</phrase><phrase role="special">);</phrase>
12725 <phrase role="special">}</phrase>
12726 <phrase role="keyword">return</phrase> <phrase role="identifier">obs</phrase><phrase role="special">;</phrase>
12727 <phrase role="special">}</phrase>
12729 <phrase role="comment">/* Commands */</phrase>
12731 <phrase role="comment">// Update all attached observers.</phrase>
12732 <phrase role="keyword">void</phrase> <phrase role="identifier">notify</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
12733 <phrase role="comment">// Protected members use `function` (no inv and no subcontracting).</phrase>
12734 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">function</phrase><phrase role="special">()</phrase>
12735 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
12736 <phrase role="comment">// All updated.</phrase>
12737 <phrase role="identifier">BOOST_CONTRACT_ASSERT_AUDIT</phrase><phrase role="special">(</phrase><phrase role="identifier">all_observers_updated</phrase><phrase role="special">(</phrase><phrase role="identifier">observers</phrase><phrase role="special">()));</phrase>
12738 <phrase role="special">})</phrase>
12739 <phrase role="special">;</phrase>
12741 <phrase role="keyword">for</phrase><phrase role="special">(</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">observer</phrase><phrase role="special">*>::</phrase><phrase role="identifier">iterator</phrase> <phrase role="identifier">i</phrase> <phrase role="special">=</phrase> <phrase role="identifier">observers_</phrase><phrase role="special">.</phrase><phrase role="identifier">begin</phrase><phrase role="special">();</phrase>
12742 <phrase role="identifier">i</phrase> <phrase role="special">!=</phrase> <phrase role="identifier">observers_</phrase><phrase role="special">.</phrase><phrase role="identifier">end</phrase><phrase role="special">();</phrase> <phrase role="special">++</phrase><phrase role="identifier">i</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
12743 <phrase role="comment">// Class invariants ensure no null pointers in observers but class</phrase>
12744 <phrase role="comment">// invariants not checked for non-public functions so assert here.</phrase>
12745 <phrase role="identifier">assert</phrase><phrase role="special">(*</phrase><phrase role="identifier">i</phrase><phrase role="special">);</phrase> <phrase role="comment">// Pointer not null (defensive programming).</phrase>
12746 <phrase role="special">(*</phrase><phrase role="identifier">i</phrase><phrase role="special">)-></phrase><phrase role="identifier">update</phrase><phrase role="special">();</phrase>
12747 <phrase role="special">}</phrase>
12748 <phrase role="special">}</phrase>
12750 <phrase role="keyword">private</phrase><phrase role="special">:</phrase>
12751 <phrase role="comment">/* Contract Helpers */</phrase>
12753 <phrase role="keyword">static</phrase> <phrase role="keyword">bool</phrase> <phrase role="identifier">all_observers_valid</phrase><phrase role="special">(</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">observer</phrase> <phrase role="keyword">const</phrase><phrase role="special">*></phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">obs</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
12754 <phrase role="keyword">for</phrase><phrase role="special">(</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">observer</phrase> <phrase role="keyword">const</phrase><phrase role="special">*>::</phrase><phrase role="identifier">const_iterator</phrase> <phrase role="identifier">i</phrase> <phrase role="special">=</phrase> <phrase role="identifier">obs</phrase><phrase role="special">.</phrase><phrase role="identifier">cbegin</phrase><phrase role="special">();</phrase>
12755 <phrase role="identifier">i</phrase> <phrase role="special">!=</phrase> <phrase role="identifier">obs</phrase><phrase role="special">.</phrase><phrase role="identifier">cend</phrase><phrase role="special">();</phrase> <phrase role="special">++</phrase><phrase role="identifier">i</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
12756 <phrase role="keyword">if</phrase><phrase role="special">(!*</phrase><phrase role="identifier">i</phrase><phrase role="special">)</phrase> <phrase role="keyword">return</phrase> <phrase role="keyword">false</phrase><phrase role="special">;</phrase>
12757 <phrase role="special">}</phrase>
12758 <phrase role="keyword">return</phrase> <phrase role="keyword">true</phrase><phrase role="special">;</phrase>
12759 <phrase role="special">}</phrase>
12761 <phrase role="keyword">static</phrase> <phrase role="keyword">bool</phrase> <phrase role="identifier">other_observers_unchanged</phrase><phrase role="special">(</phrase>
12762 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">observer</phrase> <phrase role="keyword">const</phrase><phrase role="special">*></phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">old_obs</phrase><phrase role="special">,</phrase>
12763 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">observer</phrase> <phrase role="keyword">const</phrase><phrase role="special">*></phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">new_obs</phrase><phrase role="special">,</phrase>
12764 <phrase role="identifier">observer</phrase> <phrase role="keyword">const</phrase><phrase role="special">*</phrase> <phrase role="identifier">ob</phrase>
12765 <phrase role="special">)</phrase> <phrase role="special">{</phrase>
12766 <phrase role="comment">// Private members use `function` (no inv and no subcontracting).</phrase>
12767 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">function</phrase><phrase role="special">()</phrase>
12768 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
12769 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">ob</phrase><phrase role="special">);</phrase> <phrase role="comment">// Not null.</phrase>
12770 <phrase role="special">})</phrase>
12771 <phrase role="special">;</phrase>
12773 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">observer</phrase> <phrase role="keyword">const</phrase><phrase role="special">*></phrase> <phrase role="identifier">remaining</phrase> <phrase role="special">=</phrase> <phrase role="identifier">new_obs</phrase><phrase role="special">;</phrase>
12774 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">remove</phrase><phrase role="special">(</phrase><phrase role="identifier">remaining</phrase><phrase role="special">.</phrase><phrase role="identifier">begin</phrase><phrase role="special">(),</phrase> <phrase role="identifier">remaining</phrase><phrase role="special">.</phrase><phrase role="identifier">end</phrase><phrase role="special">(),</phrase> <phrase role="identifier">ob</phrase><phrase role="special">);</phrase>
12776 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">observer</phrase> <phrase role="keyword">const</phrase><phrase role="special">*>::</phrase><phrase role="identifier">const_iterator</phrase> <phrase role="identifier">remaining_it</phrase> <phrase role="special">=</phrase>
12777 <phrase role="identifier">remaining</phrase><phrase role="special">.</phrase><phrase role="identifier">begin</phrase><phrase role="special">();</phrase>
12778 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">observer</phrase> <phrase role="keyword">const</phrase><phrase role="special">*>::</phrase><phrase role="identifier">const_iterator</phrase> <phrase role="identifier">old_it</phrase> <phrase role="special">=</phrase> <phrase role="identifier">old_obs</phrase><phrase role="special">.</phrase><phrase role="identifier">begin</phrase><phrase role="special">();</phrase>
12779 <phrase role="keyword">while</phrase><phrase role="special">(</phrase><phrase role="identifier">remaining</phrase><phrase role="special">.</phrase><phrase role="identifier">cend</phrase><phrase role="special">()</phrase> <phrase role="special">!=</phrase> <phrase role="identifier">remaining_it</phrase> <phrase role="special">&&</phrase> <phrase role="identifier">old_obs</phrase><phrase role="special">.</phrase><phrase role="identifier">cend</phrase><phrase role="special">()</phrase> <phrase role="special">!=</phrase> <phrase role="identifier">old_it</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
12780 <phrase role="keyword">if</phrase><phrase role="special">(*</phrase><phrase role="identifier">remaining_it</phrase> <phrase role="special">!=</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_it</phrase><phrase role="special">)</phrase> <phrase role="keyword">return</phrase> <phrase role="keyword">false</phrase><phrase role="special">;</phrase>
12781 <phrase role="special">++</phrase><phrase role="identifier">remaining_it</phrase><phrase role="special">;</phrase>
12782 <phrase role="special">++</phrase><phrase role="identifier">old_it</phrase><phrase role="special">;</phrase>
12783 <phrase role="special">}</phrase>
12784 <phrase role="keyword">return</phrase> <phrase role="keyword">true</phrase><phrase role="special">;</phrase>
12785 <phrase role="special">}</phrase>
12787 <phrase role="keyword">static</phrase> <phrase role="keyword">bool</phrase> <phrase role="identifier">all_observers_updated</phrase><phrase role="special">(</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">observer</phrase> <phrase role="keyword">const</phrase><phrase role="special">*></phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">obs</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
12788 <phrase role="keyword">for</phrase><phrase role="special">(</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">observer</phrase> <phrase role="keyword">const</phrase><phrase role="special">*>::</phrase><phrase role="identifier">const_iterator</phrase> <phrase role="identifier">i</phrase> <phrase role="special">=</phrase> <phrase role="identifier">obs</phrase><phrase role="special">.</phrase><phrase role="identifier">cbegin</phrase><phrase role="special">();</phrase>
12789 <phrase role="identifier">i</phrase> <phrase role="special">!=</phrase> <phrase role="identifier">obs</phrase><phrase role="special">.</phrase><phrase role="identifier">cend</phrase><phrase role="special">();</phrase> <phrase role="special">++</phrase><phrase role="identifier">i</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
12790 <phrase role="keyword">if</phrase><phrase role="special">(!*</phrase><phrase role="identifier">i</phrase><phrase role="special">)</phrase> <phrase role="keyword">return</phrase> <phrase role="keyword">false</phrase><phrase role="special">;</phrase>
12791 <phrase role="keyword">if</phrase><phrase role="special">(!(*</phrase><phrase role="identifier">i</phrase><phrase role="special">)-></phrase><phrase role="identifier">up_to_date_with_subject</phrase><phrase role="special">())</phrase> <phrase role="keyword">return</phrase> <phrase role="keyword">false</phrase><phrase role="special">;</phrase>
12792 <phrase role="special">}</phrase>
12793 <phrase role="keyword">return</phrase> <phrase role="keyword">true</phrase><phrase role="special">;</phrase>
12794 <phrase role="special">}</phrase>
12796 <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">observer</phrase><phrase role="special">*></phrase> <phrase role="identifier">observers_</phrase><phrase role="special">;</phrase>
12797 <phrase role="special">};</phrase>
12799 <phrase role="preprocessor">#endif</phrase> <phrase role="comment">// #include guard</phrase>
12803 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#include</phrase> <phrase role="string">"observer/observer.hpp"</phrase>
12804 <phrase role="preprocessor">#include</phrase> <phrase role="string">"observer/subject.hpp"</phrase>
12805 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">contract</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">></phrase>
12806 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">cassert</phrase><phrase role="special">></phrase>
12808 <phrase role="keyword">int</phrase> <phrase role="identifier">test_state</phrase><phrase role="special">;</phrase> <phrase role="comment">// For testing only.</phrase>
12810 <phrase role="comment">// Implement an actual subject.</phrase>
12811 <phrase role="keyword">class</phrase> <phrase role="identifier">concrete_subject</phrase>
12812 <phrase role="preprocessor">#define</phrase> <phrase role="identifier">BASES</phrase> <phrase role="keyword">public</phrase> <phrase role="identifier">subject</phrase>
12813 <phrase role="special">:</phrase> <phrase role="identifier">BASES</phrase>
12814 <phrase role="special">{</phrase>
12815 <phrase role="keyword">friend</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">access</phrase><phrase role="special">;</phrase>
12817 <phrase role="keyword">typedef</phrase> <phrase role="identifier">BOOST_CONTRACT_BASE_TYPES</phrase><phrase role="special">(</phrase><phrase role="identifier">BASES</phrase><phrase role="special">)</phrase> <phrase role="identifier">base_types</phrase><phrase role="special">;</phrase> <phrase role="comment">// Subcontracting.</phrase>
12818 <phrase role="preprocessor">#undef</phrase> <phrase role="identifier">BASES</phrase>
12820 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
12821 <phrase role="keyword">typedef</phrase> <phrase role="keyword">int</phrase> <phrase role="identifier">state</phrase><phrase role="special">;</phrase> <phrase role="comment">// Some state being observed.</phrase>
12823 <phrase role="identifier">concrete_subject</phrase><phrase role="special">()</phrase> <phrase role="special">:</phrase> <phrase role="identifier">state_</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
12824 <phrase role="comment">// Could have omitted contracts here (nothing to check).</phrase>
12825 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
12826 <phrase role="special">}</phrase>
12828 <phrase role="keyword">virtual</phrase> <phrase role="special">~</phrase><phrase role="identifier">concrete_subject</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
12829 <phrase role="comment">// Could have omitted contracts here (nothing to check).</phrase>
12830 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">destructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
12831 <phrase role="special">}</phrase>
12833 <phrase role="keyword">void</phrase> <phrase role="identifier">set_state</phrase><phrase role="special">(</phrase><phrase role="identifier">state</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">new_state</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
12834 <phrase role="comment">// Could have omitted contracts here (nothing to check).</phrase>
12835 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
12837 <phrase role="identifier">state_</phrase> <phrase role="special">=</phrase> <phrase role="identifier">new_state</phrase><phrase role="special">;</phrase>
12838 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">state_</phrase> <phrase role="special">==</phrase> <phrase role="identifier">test_state</phrase><phrase role="special">);</phrase>
12839 <phrase role="identifier">notify</phrase><phrase role="special">();</phrase> <phrase role="comment">// Notify all observers.</phrase>
12840 <phrase role="special">}</phrase>
12842 <phrase role="identifier">state</phrase> <phrase role="identifier">get_state</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
12843 <phrase role="comment">// Could have omitted contracts here (nothing to check).</phrase>
12844 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
12845 <phrase role="keyword">return</phrase> <phrase role="identifier">state_</phrase><phrase role="special">;</phrase>
12846 <phrase role="special">}</phrase>
12848 <phrase role="keyword">private</phrase><phrase role="special">:</phrase>
12849 <phrase role="identifier">state</phrase> <phrase role="identifier">state_</phrase><phrase role="special">;</phrase>
12850 <phrase role="special">};</phrase>
12852 <phrase role="comment">// Implement an actual observer.</phrase>
12853 <phrase role="keyword">class</phrase> <phrase role="identifier">concrete_observer</phrase>
12854 <phrase role="preprocessor">#define</phrase> <phrase role="identifier">BASES</phrase> <phrase role="keyword">public</phrase> <phrase role="identifier">observer</phrase>
12855 <phrase role="special">:</phrase> <phrase role="identifier">BASES</phrase>
12856 <phrase role="special">{</phrase>
12857 <phrase role="keyword">friend</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">access</phrase><phrase role="special">;</phrase>
12859 <phrase role="keyword">typedef</phrase> <phrase role="identifier">BOOST_CONTRACT_BASE_TYPES</phrase><phrase role="special">(</phrase><phrase role="identifier">BASES</phrase><phrase role="special">)</phrase> <phrase role="identifier">base_types</phrase><phrase role="special">;</phrase> <phrase role="comment">// Subcontracting.</phrase>
12860 <phrase role="preprocessor">#undef</phrase> <phrase role="identifier">BASES</phrase>
12862 <phrase role="identifier">BOOST_CONTRACT_OVERRIDES</phrase><phrase role="special">(</phrase><phrase role="identifier">up_to_date_with_subject</phrase><phrase role="special">,</phrase> <phrase role="identifier">update</phrase><phrase role="special">)</phrase>
12864 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
12865 <phrase role="comment">// Create concrete observer.</phrase>
12866 <phrase role="keyword">explicit</phrase> <phrase role="identifier">concrete_observer</phrase><phrase role="special">(</phrase><phrase role="identifier">concrete_subject</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">subj</phrase><phrase role="special">)</phrase> <phrase role="special">:</phrase>
12867 <phrase role="identifier">subject_</phrase><phrase role="special">(</phrase><phrase role="identifier">subj</phrase><phrase role="special">),</phrase> <phrase role="identifier">observed_state_</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
12868 <phrase role="comment">// Could have omitted contracts here (nothing to check).</phrase>
12869 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
12870 <phrase role="special">}</phrase>
12872 <phrase role="keyword">virtual</phrase> <phrase role="special">~</phrase><phrase role="identifier">concrete_observer</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
12873 <phrase role="comment">// Could have omitted contracts here (nothing to check).</phrase>
12874 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">destructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
12875 <phrase role="special">}</phrase>
12877 <phrase role="comment">// Implement base virtual functions.</phrase>
12879 <phrase role="keyword">bool</phrase> <phrase role="identifier">up_to_date_with_subject</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase>
12880 <phrase role="keyword">const</phrase> <phrase role="comment">/* override */</phrase> <phrase role="special">{</phrase>
12881 <phrase role="keyword">bool</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
12882 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special"><</phrase>
12883 <phrase role="identifier">override_up_to_date_with_subject</phrase>
12884 <phrase role="special">>(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">result</phrase><phrase role="special">,</phrase> <phrase role="special">&</phrase><phrase role="identifier">concrete_observer</phrase><phrase role="special">::</phrase><phrase role="identifier">up_to_date_with_subject</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">);</phrase>
12886 <phrase role="keyword">return</phrase> <phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="keyword">true</phrase><phrase role="special">;</phrase> <phrase role="comment">// For simplicity, assume always up-to-date.</phrase>
12887 <phrase role="special">}</phrase>
12889 <phrase role="keyword">void</phrase> <phrase role="identifier">update</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="comment">/* override */</phrase> <phrase role="special">{</phrase>
12890 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special"><</phrase>
12891 <phrase role="identifier">override_update</phrase><phrase role="special">>(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="special">&</phrase><phrase role="identifier">concrete_observer</phrase><phrase role="special">::</phrase><phrase role="identifier">update</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">);</phrase>
12893 <phrase role="identifier">observed_state_</phrase> <phrase role="special">=</phrase> <phrase role="identifier">subject_</phrase><phrase role="special">.</phrase><phrase role="identifier">get_state</phrase><phrase role="special">();</phrase>
12894 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">observed_state_</phrase> <phrase role="special">==</phrase> <phrase role="identifier">test_state</phrase><phrase role="special">);</phrase>
12895 <phrase role="special">}</phrase>
12897 <phrase role="keyword">private</phrase><phrase role="special">:</phrase>
12898 <phrase role="identifier">concrete_subject</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">subject_</phrase><phrase role="special">;</phrase>
12899 <phrase role="identifier">concrete_subject</phrase><phrase role="special">::</phrase><phrase role="identifier">state</phrase> <phrase role="identifier">observed_state_</phrase><phrase role="special">;</phrase>
12900 <phrase role="special">};</phrase>
12902 <phrase role="keyword">int</phrase> <phrase role="identifier">main</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
12903 <phrase role="identifier">concrete_subject</phrase> <phrase role="identifier">subj</phrase><phrase role="special">;</phrase>
12904 <phrase role="identifier">concrete_observer</phrase> <phrase role="identifier">ob</phrase><phrase role="special">(</phrase><phrase role="identifier">subj</phrase><phrase role="special">);</phrase>
12905 <phrase role="identifier">subj</phrase><phrase role="special">.</phrase><phrase role="identifier">attach</phrase><phrase role="special">(&</phrase><phrase role="identifier">ob</phrase><phrase role="special">);</phrase>
12907 <phrase role="identifier">subj</phrase><phrase role="special">.</phrase><phrase role="identifier">set_state</phrase><phrase role="special">(</phrase><phrase role="identifier">test_state</phrase> <phrase role="special">=</phrase> <phrase role="number">123</phrase><phrase role="special">);</phrase>
12908 <phrase role="identifier">subj</phrase><phrase role="special">.</phrase><phrase role="identifier">set_state</phrase><phrase role="special">(</phrase><phrase role="identifier">test_state</phrase> <phrase role="special">=</phrase> <phrase role="number">456</phrase><phrase role="special">);</phrase>
12910 <phrase role="keyword">return</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase>
12911 <phrase role="special">}</phrase>
12915 <section id="boost_contract.examples.__mitchell02___counter__subcontracting">
12916 <title><anchor id="Mitchell02_counter_anchor"/><link linkend="boost_contract.examples.__mitchell02___counter__subcontracting">[Mitchell02]
12917 Counter: Subcontracting</link></title>
12919 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">PUSH_BUTTON_HPP_</phrase>
12920 <phrase role="preprocessor">#define</phrase> <phrase role="identifier">PUSH_BUTTON_HPP_</phrase>
12922 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">contract</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">></phrase>
12923 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">cassert</phrase><phrase role="special">></phrase>
12925 <phrase role="keyword">class</phrase> <phrase role="identifier">push_button</phrase> <phrase role="special">{</phrase>
12926 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
12927 <phrase role="comment">// No inv and no bases so contracts optional if no pre, post, and override.</phrase>
12929 <phrase role="comment">/* Creation */</phrase>
12931 <phrase role="comment">// Create an enabled button.</phrase>
12932 <phrase role="identifier">push_button</phrase><phrase role="special">()</phrase> <phrase role="special">:</phrase> <phrase role="identifier">enabled_</phrase><phrase role="special">(</phrase><phrase role="keyword">true</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
12933 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
12934 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
12935 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">enabled</phrase><phrase role="special">());</phrase> <phrase role="comment">// Enabled.</phrase>
12936 <phrase role="special">})</phrase>
12937 <phrase role="special">;</phrase>
12938 <phrase role="special">}</phrase>
12940 <phrase role="comment">// Destroy button.</phrase>
12941 <phrase role="keyword">virtual</phrase> <phrase role="special">~</phrase><phrase role="identifier">push_button</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
12942 <phrase role="comment">// Could have omitted contracts here (nothing to check).</phrase>
12943 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">destructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
12944 <phrase role="special">}</phrase>
12946 <phrase role="comment">/* Queries */</phrase>
12948 <phrase role="comment">// If button is enabled.</phrase>
12949 <phrase role="keyword">bool</phrase> <phrase role="identifier">enabled</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
12950 <phrase role="comment">// Could have omitted contracts here (nothing to check).</phrase>
12951 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
12952 <phrase role="keyword">return</phrase> <phrase role="identifier">enabled_</phrase><phrase role="special">;</phrase>
12953 <phrase role="special">}</phrase>
12955 <phrase role="comment">/* Commands */</phrase>
12957 <phrase role="comment">// Enable button.</phrase>
12958 <phrase role="keyword">void</phrase> <phrase role="identifier">enable</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
12959 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
12960 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
12961 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">enabled</phrase><phrase role="special">());</phrase> <phrase role="comment">// Enabled.</phrase>
12962 <phrase role="special">})</phrase>
12963 <phrase role="special">;</phrase>
12965 <phrase role="identifier">enabled_</phrase> <phrase role="special">=</phrase> <phrase role="keyword">true</phrase><phrase role="special">;</phrase>
12966 <phrase role="special">}</phrase>
12968 <phrase role="comment">// Disable button.</phrase>
12969 <phrase role="keyword">void</phrase> <phrase role="identifier">disable</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
12970 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
12971 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
12972 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(!</phrase><phrase role="identifier">enabled</phrase><phrase role="special">());</phrase> <phrase role="comment">// Disabled.</phrase>
12973 <phrase role="special">})</phrase>
12974 <phrase role="special">;</phrase>
12976 <phrase role="identifier">enabled_</phrase> <phrase role="special">=</phrase> <phrase role="keyword">false</phrase><phrase role="special">;</phrase>
12977 <phrase role="special">}</phrase>
12979 <phrase role="comment">// Invoke externally when button clicked.</phrase>
12980 <phrase role="keyword">virtual</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">on_bn_clicked</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase>
12982 <phrase role="keyword">private</phrase><phrase role="special">:</phrase>
12983 <phrase role="keyword">bool</phrase> <phrase role="identifier">enabled_</phrase><phrase role="special">;</phrase>
12984 <phrase role="special">};</phrase>
12986 <phrase role="keyword">void</phrase> <phrase role="identifier">push_button</phrase><phrase role="special">::</phrase><phrase role="identifier">on_bn_clicked</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
12987 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">)</phrase>
12988 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
12989 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">enabled</phrase><phrase role="special">());</phrase> <phrase role="comment">// Enabled.</phrase>
12990 <phrase role="special">})</phrase>
12991 <phrase role="special">;</phrase>
12992 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="keyword">false</phrase><phrase role="special">);</phrase>
12993 <phrase role="special">}</phrase>
12995 <phrase role="preprocessor">#endif</phrase> <phrase role="comment">// #include guard</phrase>
12999 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">DECREMENT_BUTTON_HPP_</phrase>
13000 <phrase role="preprocessor">#define</phrase> <phrase role="identifier">DECREMENT_BUTTON_HPP_</phrase>
13002 <phrase role="preprocessor">#include</phrase> <phrase role="string">"push_button.hpp"</phrase>
13003 <phrase role="preprocessor">#include</phrase> <phrase role="string">"counter.hpp"</phrase>
13004 <phrase role="preprocessor">#include</phrase> <phrase role="string">"../observer/observer.hpp"</phrase>
13005 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">contract</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">></phrase>
13006 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">noncopyable</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">></phrase>
13008 <phrase role="keyword">class</phrase> <phrase role="identifier">decrement_button</phrase>
13009 <phrase role="preprocessor">#define</phrase> <phrase role="identifier">BASES</phrase> <phrase role="keyword">public</phrase> <phrase role="identifier">push_button</phrase><phrase role="special">,</phrase> <phrase role="keyword">public</phrase> <phrase role="identifier">observer</phrase><phrase role="special">,</phrase> <phrase role="special">\</phrase>
13010 <phrase role="keyword">private</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">noncopyable</phrase>
13011 <phrase role="special">:</phrase> <phrase role="identifier">BASES</phrase>
13012 <phrase role="special">{</phrase>
13013 <phrase role="keyword">friend</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">access</phrase><phrase role="special">;</phrase>
13015 <phrase role="keyword">typedef</phrase> <phrase role="identifier">BOOST_CONTRACT_BASE_TYPES</phrase><phrase role="special">(</phrase><phrase role="identifier">BASES</phrase><phrase role="special">)</phrase> <phrase role="identifier">base_types</phrase><phrase role="special">;</phrase>
13016 <phrase role="preprocessor">#undef</phrase> <phrase role="identifier">BASES</phrase>
13018 <phrase role="identifier">BOOST_CONTRACT_OVERRIDES</phrase><phrase role="special">(</phrase><phrase role="identifier">on_bn_clicked</phrase><phrase role="special">,</phrase> <phrase role="identifier">up_to_date_with_subject</phrase><phrase role="special">,</phrase> <phrase role="identifier">update</phrase><phrase role="special">);</phrase>
13020 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
13021 <phrase role="comment">/* Creation */</phrase>
13023 <phrase role="keyword">explicit</phrase> <phrase role="identifier">decrement_button</phrase><phrase role="special">(</phrase><phrase role="identifier">counter</phrase><phrase role="special">&</phrase> <phrase role="identifier">a_counter</phrase><phrase role="special">)</phrase> <phrase role="special">:</phrase> <phrase role="identifier">counter_</phrase><phrase role="special">(</phrase><phrase role="identifier">a_counter</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
13024 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
13025 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
13026 <phrase role="comment">// Enable iff positive value.</phrase>
13027 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">enabled</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">(</phrase><phrase role="identifier">a_counter</phrase><phrase role="special">.</phrase><phrase role="identifier">value</phrase><phrase role="special">()</phrase> <phrase role="special">></phrase> <phrase role="number">0</phrase><phrase role="special">));</phrase>
13028 <phrase role="special">})</phrase>
13029 <phrase role="special">;</phrase>
13030 <phrase role="identifier">counter_</phrase><phrase role="special">.</phrase><phrase role="identifier">attach</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
13031 <phrase role="special">}</phrase>
13033 <phrase role="comment">// Destroy button.</phrase>
13034 <phrase role="keyword">virtual</phrase> <phrase role="special">~</phrase><phrase role="identifier">decrement_button</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
13035 <phrase role="comment">// Could have omitted contracts here (nothing to check).</phrase>
13036 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">destructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
13037 <phrase role="special">}</phrase>
13039 <phrase role="comment">/* Commands */</phrase>
13041 <phrase role="keyword">virtual</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">on_bn_clicked</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase>
13042 <phrase role="comment">/* override */</phrase> <phrase role="special">{</phrase>
13043 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">></phrase> <phrase role="identifier">old_value</phrase> <phrase role="special">=</phrase>
13044 <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">counter_</phrase><phrase role="special">.</phrase><phrase role="identifier">value</phrase><phrase role="special">());</phrase>
13045 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special"><</phrase>
13046 <phrase role="identifier">override_on_bn_clicked</phrase>
13047 <phrase role="special">>(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="special">&</phrase><phrase role="identifier">decrement_button</phrase><phrase role="special">::</phrase><phrase role="identifier">on_bn_clicked</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">)</phrase>
13048 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
13049 <phrase role="comment">// Counter decremented.</phrase>
13050 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">counter_</phrase><phrase role="special">.</phrase><phrase role="identifier">value</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_value</phrase> <phrase role="special">-</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase>
13051 <phrase role="special">})</phrase>
13052 <phrase role="special">;</phrase>
13053 <phrase role="identifier">counter_</phrase><phrase role="special">.</phrase><phrase role="identifier">decrement</phrase><phrase role="special">();</phrase>
13054 <phrase role="special">}</phrase>
13056 <phrase role="keyword">virtual</phrase> <phrase role="keyword">bool</phrase> <phrase role="identifier">up_to_date_with_subject</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase>
13057 <phrase role="keyword">const</phrase> <phrase role="comment">/* override */</phrase> <phrase role="special">{</phrase>
13058 <phrase role="keyword">bool</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
13059 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special"><</phrase>
13060 <phrase role="identifier">override_up_to_date_with_subject</phrase>
13061 <phrase role="special">>(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">result</phrase><phrase role="special">,</phrase> <phrase role="special">&</phrase><phrase role="identifier">decrement_button</phrase><phrase role="special">::</phrase><phrase role="identifier">up_to_date_with_subject</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">);</phrase>
13063 <phrase role="keyword">return</phrase> <phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="keyword">true</phrase><phrase role="special">;</phrase> <phrase role="comment">// For simplicity, assume always up-to-date.</phrase>
13064 <phrase role="special">}</phrase>
13066 <phrase role="keyword">virtual</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">update</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="comment">/* override */</phrase> <phrase role="special">{</phrase>
13067 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special"><</phrase>
13068 <phrase role="identifier">override_update</phrase><phrase role="special">>(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="special">&</phrase><phrase role="identifier">decrement_button</phrase><phrase role="special">::</phrase><phrase role="identifier">update</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">)</phrase>
13069 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
13070 <phrase role="comment">// Enabled iff positive value.</phrase>
13071 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">enabled</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">(</phrase><phrase role="identifier">counter_</phrase><phrase role="special">.</phrase><phrase role="identifier">value</phrase><phrase role="special">()</phrase> <phrase role="special">></phrase> <phrase role="number">0</phrase><phrase role="special">));</phrase>
13072 <phrase role="special">})</phrase>
13073 <phrase role="special">;</phrase>
13075 <phrase role="keyword">if</phrase><phrase role="special">(</phrase><phrase role="identifier">counter_</phrase><phrase role="special">.</phrase><phrase role="identifier">value</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="identifier">disable</phrase><phrase role="special">();</phrase>
13076 <phrase role="keyword">else</phrase> <phrase role="identifier">enable</phrase><phrase role="special">();</phrase>
13077 <phrase role="special">}</phrase>
13079 <phrase role="keyword">private</phrase><phrase role="special">:</phrase>
13080 <phrase role="identifier">counter</phrase><phrase role="special">&</phrase> <phrase role="identifier">counter_</phrase><phrase role="special">;</phrase>
13081 <phrase role="special">};</phrase>
13083 <phrase role="preprocessor">#endif</phrase> <phrase role="comment">// #include guard</phrase>
13087 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">COUNTER_HPP_</phrase>
13088 <phrase role="preprocessor">#define</phrase> <phrase role="identifier">COUNTER_HPP_</phrase>
13090 <phrase role="preprocessor">#include</phrase> <phrase role="string">"../observer/subject.hpp"</phrase>
13091 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">contract</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">></phrase>
13093 <phrase role="keyword">class</phrase> <phrase role="identifier">counter</phrase>
13094 <phrase role="preprocessor">#define</phrase> <phrase role="identifier">BASES</phrase> <phrase role="keyword">public</phrase> <phrase role="identifier">subject</phrase>
13095 <phrase role="special">:</phrase> <phrase role="identifier">BASES</phrase>
13096 <phrase role="special">{</phrase>
13097 <phrase role="keyword">friend</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">access</phrase><phrase role="special">;</phrase>
13099 <phrase role="keyword">typedef</phrase> <phrase role="identifier">BOOST_CONTRACT_BASE_TYPES</phrase><phrase role="special">(</phrase><phrase role="identifier">BASES</phrase><phrase role="special">)</phrase> <phrase role="identifier">base_types</phrase><phrase role="special">;</phrase>
13100 <phrase role="preprocessor">#undef</phrase> <phrase role="identifier">BASES</phrase>
13102 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
13103 <phrase role="comment">/* Creation */</phrase>
13105 <phrase role="comment">// Construct counter with specified value.</phrase>
13106 <phrase role="keyword">explicit</phrase> <phrase role="identifier">counter</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">a_value</phrase> <phrase role="special">=</phrase> <phrase role="number">10</phrase><phrase role="special">)</phrase> <phrase role="special">:</phrase> <phrase role="identifier">value_</phrase><phrase role="special">(</phrase><phrase role="identifier">a_value</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
13107 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
13108 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
13109 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">value</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">a_value</phrase><phrase role="special">);</phrase> <phrase role="comment">// Value set.</phrase>
13110 <phrase role="special">})</phrase>
13111 <phrase role="special">;</phrase>
13112 <phrase role="special">}</phrase>
13114 <phrase role="comment">// Destroy counter.</phrase>
13115 <phrase role="keyword">virtual</phrase> <phrase role="special">~</phrase><phrase role="identifier">counter</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
13116 <phrase role="comment">// Could have omitted contracts here (nothing to check).</phrase>
13117 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">destructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
13118 <phrase role="special">}</phrase>
13120 <phrase role="comment">/* Queries */</phrase>
13122 <phrase role="comment">// Current counter value.</phrase>
13123 <phrase role="keyword">int</phrase> <phrase role="identifier">value</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
13124 <phrase role="comment">// Could have omitted contracts here (nothing to check).</phrase>
13125 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
13126 <phrase role="keyword">return</phrase> <phrase role="identifier">value_</phrase><phrase role="special">;</phrase>
13127 <phrase role="special">}</phrase>
13129 <phrase role="comment">/* Commands */</phrase>
13131 <phrase role="comment">// Decrement counter value.</phrase>
13132 <phrase role="keyword">void</phrase> <phrase role="identifier">decrement</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
13133 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">></phrase> <phrase role="identifier">old_value</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">value</phrase><phrase role="special">());</phrase>
13134 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
13135 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
13136 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">value</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_value</phrase> <phrase role="special">-</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase> <phrase role="comment">// Decrement.</phrase>
13137 <phrase role="special">})</phrase>
13138 <phrase role="special">;</phrase>
13140 <phrase role="special">--</phrase><phrase role="identifier">value_</phrase><phrase role="special">;</phrase>
13141 <phrase role="identifier">notify</phrase><phrase role="special">();</phrase> <phrase role="comment">// Notify all attached observers.</phrase>
13142 <phrase role="special">}</phrase>
13144 <phrase role="keyword">private</phrase><phrase role="special">:</phrase>
13145 <phrase role="keyword">int</phrase> <phrase role="identifier">value_</phrase><phrase role="special">;</phrase>
13146 <phrase role="special">};</phrase>
13148 <phrase role="preprocessor">#endif</phrase> <phrase role="comment">// #include guard</phrase>
13152 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#include</phrase> <phrase role="string">"counter/counter.hpp"</phrase>
13153 <phrase role="preprocessor">#include</phrase> <phrase role="string">"counter/decrement_button.hpp"</phrase>
13154 <phrase role="preprocessor">#include</phrase> <phrase role="string">"observer/observer.hpp"</phrase>
13155 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">cassert</phrase><phrase role="special">></phrase>
13157 <phrase role="keyword">int</phrase> <phrase role="identifier">test_counter</phrase><phrase role="special">;</phrase>
13159 <phrase role="keyword">class</phrase> <phrase role="identifier">view_of_counter</phrase>
13160 <phrase role="preprocessor">#define</phrase> <phrase role="identifier">BASES</phrase> <phrase role="keyword">public</phrase> <phrase role="identifier">observer</phrase>
13161 <phrase role="special">:</phrase> <phrase role="identifier">BASES</phrase>
13162 <phrase role="special">{</phrase>
13163 <phrase role="keyword">friend</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">access</phrase><phrase role="special">;</phrase>
13165 <phrase role="keyword">typedef</phrase> <phrase role="identifier">BOOST_CONTRACT_BASE_TYPES</phrase><phrase role="special">(</phrase><phrase role="identifier">BASES</phrase><phrase role="special">)</phrase> <phrase role="identifier">base_types</phrase><phrase role="special">;</phrase>
13166 <phrase role="preprocessor">#undef</phrase> <phrase role="identifier">BASES</phrase>
13168 <phrase role="identifier">BOOST_CONTRACT_OVERRIDES</phrase><phrase role="special">(</phrase><phrase role="identifier">up_to_date_with_subject</phrase><phrase role="special">,</phrase> <phrase role="identifier">update</phrase><phrase role="special">)</phrase>
13170 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
13171 <phrase role="comment">/* Creation */</phrase>
13173 <phrase role="comment">// Create view associated with given counter.</phrase>
13174 <phrase role="keyword">explicit</phrase> <phrase role="identifier">view_of_counter</phrase><phrase role="special">(</phrase><phrase role="identifier">counter</phrase><phrase role="special">&</phrase> <phrase role="identifier">a_counter</phrase><phrase role="special">)</phrase> <phrase role="special">:</phrase> <phrase role="identifier">counter_</phrase><phrase role="special">(</phrase><phrase role="identifier">a_counter</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
13175 <phrase role="comment">// Could have omitted contracts here (nothing to check).</phrase>
13176 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
13178 <phrase role="identifier">counter_</phrase><phrase role="special">.</phrase><phrase role="identifier">attach</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
13179 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">counter_</phrase><phrase role="special">.</phrase><phrase role="identifier">value</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">test_counter</phrase><phrase role="special">);</phrase>
13180 <phrase role="special">}</phrase>
13182 <phrase role="comment">// Destroy view.</phrase>
13183 <phrase role="keyword">virtual</phrase> <phrase role="special">~</phrase><phrase role="identifier">view_of_counter</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
13184 <phrase role="comment">// Could have omitted contracts here (nothing to check).</phrase>
13185 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">destructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
13186 <phrase role="special">}</phrase>
13188 <phrase role="comment">/* Commands */</phrase>
13190 <phrase role="keyword">virtual</phrase> <phrase role="keyword">bool</phrase> <phrase role="identifier">up_to_date_with_subject</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase>
13191 <phrase role="keyword">const</phrase> <phrase role="comment">/* override */</phrase> <phrase role="special">{</phrase>
13192 <phrase role="keyword">bool</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
13193 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special"><</phrase>
13194 <phrase role="identifier">override_up_to_date_with_subject</phrase>
13195 <phrase role="special">>(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">result</phrase><phrase role="special">,</phrase> <phrase role="special">&</phrase><phrase role="identifier">view_of_counter</phrase><phrase role="special">::</phrase><phrase role="identifier">up_to_date_with_subject</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">);</phrase>
13197 <phrase role="keyword">return</phrase> <phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="keyword">true</phrase><phrase role="special">;</phrase> <phrase role="comment">// For simplicity, assume always up-to-date.</phrase>
13198 <phrase role="special">}</phrase>
13200 <phrase role="keyword">virtual</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">update</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="comment">/* override */</phrase> <phrase role="special">{</phrase>
13201 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special"><</phrase>
13202 <phrase role="identifier">override_update</phrase><phrase role="special">>(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="special">&</phrase><phrase role="identifier">view_of_counter</phrase><phrase role="special">::</phrase><phrase role="identifier">update</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">);</phrase>
13204 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">counter_</phrase><phrase role="special">.</phrase><phrase role="identifier">value</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">test_counter</phrase><phrase role="special">);</phrase>
13205 <phrase role="special">}</phrase>
13207 <phrase role="keyword">private</phrase><phrase role="special">:</phrase>
13208 <phrase role="identifier">counter</phrase><phrase role="special">&</phrase> <phrase role="identifier">counter_</phrase><phrase role="special">;</phrase>
13209 <phrase role="special">};</phrase>
13211 <phrase role="keyword">int</phrase> <phrase role="identifier">main</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
13212 <phrase role="identifier">counter</phrase> <phrase role="identifier">cnt</phrase><phrase role="special">(</phrase><phrase role="identifier">test_counter</phrase> <phrase role="special">=</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase>
13213 <phrase role="identifier">view_of_counter</phrase> <phrase role="identifier">view</phrase><phrase role="special">(</phrase><phrase role="identifier">cnt</phrase><phrase role="special">);</phrase>
13215 <phrase role="identifier">decrement_button</phrase> <phrase role="identifier">dec</phrase><phrase role="special">(</phrase><phrase role="identifier">cnt</phrase><phrase role="special">);</phrase>
13216 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">dec</phrase><phrase role="special">.</phrase><phrase role="identifier">enabled</phrase><phrase role="special">());</phrase>
13218 <phrase role="identifier">test_counter</phrase><phrase role="special">--;</phrase>
13219 <phrase role="identifier">dec</phrase><phrase role="special">.</phrase><phrase role="identifier">on_bn_clicked</phrase><phrase role="special">();</phrase>
13220 <phrase role="identifier">assert</phrase><phrase role="special">(!</phrase><phrase role="identifier">dec</phrase><phrase role="special">.</phrase><phrase role="identifier">enabled</phrase><phrase role="special">());</phrase>
13222 <phrase role="keyword">return</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase>
13223 <phrase role="special">}</phrase>
13227 <section id="boost_contract.examples.__cline90___vector__comparison_with_a___proposal_syntax">
13228 <title><anchor id="Cline90_vector_anchor"/><link linkend="boost_contract.examples.__cline90___vector__comparison_with_a___proposal_syntax">[Cline90]
13229 Vector: Comparison with A++ proposal syntax</link></title>
13230 <informaltable frame="all">
13241 A++ Proposal (never actually implemented)
13250 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">VECTOR_HPP_</phrase>
13251 <phrase role="preprocessor">#define</phrase> <phrase role="identifier">VECTOR_HPP_</phrase>
13253 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">contract</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">></phrase>
13255 <phrase role="comment">// NOTE: Incomplete contract assertions, addressing only `size`.</phrase>
13256 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">></phrase>
13257 <phrase role="keyword">class</phrase> <phrase role="identifier">vector</phrase>
13258 <phrase role="preprocessor">#define</phrase> <phrase role="identifier">BASES</phrase> <phrase role="keyword">private</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor_precondition</phrase><phrase role="special"><</phrase><phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase> <phrase role="special">></phrase>
13259 <phrase role="special">:</phrase> <phrase role="identifier">BASES</phrase>
13260 <phrase role="special">{</phrase>
13261 <phrase role="keyword">friend</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">access</phrase><phrase role="special">;</phrase>
13263 <phrase role="keyword">typedef</phrase> <phrase role="identifier">BOOST_CONTRACT_BASE_TYPES</phrase><phrase role="special">(</phrase><phrase role="identifier">BASES</phrase><phrase role="special">)</phrase> <phrase role="identifier">base_types</phrase><phrase role="special">;</phrase>
13264 <phrase role="preprocessor">#undef</phrase> <phrase role="identifier">BASES</phrase>
13266 <phrase role="keyword">void</phrase> <phrase role="identifier">invariant</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
13267 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">>=</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase>
13268 <phrase role="special">}</phrase>
13270 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
13271 <phrase role="keyword">explicit</phrase> <phrase role="identifier">vector</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">count</phrase> <phrase role="special">=</phrase> <phrase role="number">10</phrase><phrase role="special">)</phrase> <phrase role="special">:</phrase>
13272 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor_precondition</phrase><phrase role="special"><</phrase><phrase role="identifier">vector</phrase><phrase role="special">>([&]</phrase> <phrase role="special">{</phrase>
13273 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase> <phrase role="special">>=</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase>
13274 <phrase role="special">}),</phrase>
13275 <phrase role="identifier">data_</phrase><phrase role="special">(</phrase><phrase role="keyword">new</phrase> <phrase role="identifier">T</phrase><phrase role="special">[</phrase><phrase role="identifier">count</phrase><phrase role="special">]),</phrase>
13276 <phrase role="identifier">size_</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">)</phrase>
13277 <phrase role="special">{</phrase>
13278 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
13279 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
13280 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">count</phrase><phrase role="special">);</phrase>
13281 <phrase role="special">})</phrase>
13282 <phrase role="special">;</phrase>
13284 <phrase role="keyword">for</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">i</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase> <phrase role="identifier">i</phrase> <phrase role="special"><</phrase> <phrase role="identifier">size_</phrase><phrase role="special">;</phrase> <phrase role="special">++</phrase><phrase role="identifier">i</phrase><phrase role="special">)</phrase> <phrase role="identifier">data_</phrase><phrase role="special">[</phrase><phrase role="identifier">i</phrase><phrase role="special">]</phrase> <phrase role="special">=</phrase> <phrase role="identifier">T</phrase><phrase role="special">();</phrase>
13285 <phrase role="special">}</phrase>
13287 <phrase role="keyword">virtual</phrase> <phrase role="special">~</phrase><phrase role="identifier">vector</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
13288 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">destructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
13289 <phrase role="keyword">delete</phrase><phrase role="special">[]</phrase> <phrase role="identifier">data_</phrase><phrase role="special">;</phrase>
13290 <phrase role="special">}</phrase>
13292 <phrase role="keyword">int</phrase> <phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
13293 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
13294 <phrase role="keyword">return</phrase> <phrase role="identifier">size_</phrase><phrase role="special">;</phrase> <phrase role="comment">// Non-negative result already checked by invariant.</phrase>
13295 <phrase role="special">}</phrase>
13297 <phrase role="keyword">void</phrase> <phrase role="identifier">resize</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">count</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
13298 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
13299 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
13300 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase> <phrase role="special">>=</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase>
13301 <phrase role="special">})</phrase>
13302 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
13303 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">count</phrase><phrase role="special">);</phrase>
13304 <phrase role="special">})</phrase>
13305 <phrase role="special">;</phrase>
13307 <phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">slice</phrase> <phrase role="special">=</phrase> <phrase role="keyword">new</phrase> <phrase role="identifier">T</phrase><phrase role="special">[</phrase><phrase role="identifier">count</phrase><phrase role="special">];</phrase>
13308 <phrase role="keyword">for</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">i</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase> <phrase role="identifier">i</phrase> <phrase role="special"><</phrase> <phrase role="identifier">count</phrase> <phrase role="special">&&</phrase> <phrase role="identifier">i</phrase> <phrase role="special"><</phrase> <phrase role="identifier">size_</phrase><phrase role="special">;</phrase> <phrase role="special">++</phrase><phrase role="identifier">i</phrase><phrase role="special">)</phrase> <phrase role="identifier">slice</phrase><phrase role="special">[</phrase><phrase role="identifier">i</phrase><phrase role="special">]</phrase> <phrase role="special">=</phrase> <phrase role="identifier">data_</phrase><phrase role="special">[</phrase><phrase role="identifier">i</phrase><phrase role="special">];</phrase>
13309 <phrase role="keyword">delete</phrase><phrase role="special">[]</phrase> <phrase role="identifier">data_</phrase><phrase role="special">;</phrase>
13310 <phrase role="identifier">data_</phrase> <phrase role="special">=</phrase> <phrase role="identifier">slice</phrase><phrase role="special">;</phrase>
13311 <phrase role="identifier">size_</phrase> <phrase role="special">=</phrase> <phrase role="identifier">count</phrase><phrase role="special">;</phrase>
13312 <phrase role="special">}</phrase>
13314 <phrase role="identifier">T</phrase><phrase role="special">&</phrase> <phrase role="keyword">operator</phrase><phrase role="special">[](</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">index</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
13315 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
13316 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
13317 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">index</phrase> <phrase role="special">>=</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase>
13318 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">index</phrase> <phrase role="special"><</phrase> <phrase role="identifier">size</phrase><phrase role="special">());</phrase>
13319 <phrase role="special">})</phrase>
13320 <phrase role="special">;</phrase>
13322 <phrase role="keyword">return</phrase> <phrase role="identifier">data_</phrase><phrase role="special">[</phrase><phrase role="identifier">index</phrase><phrase role="special">];</phrase>
13323 <phrase role="special">}</phrase>
13325 <phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="keyword">operator</phrase><phrase role="special">[](</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">index</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
13326 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
13327 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
13328 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">index</phrase> <phrase role="special">>=</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase>
13329 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">index</phrase> <phrase role="special"><</phrase> <phrase role="identifier">size</phrase><phrase role="special">());</phrase>
13330 <phrase role="special">})</phrase>
13331 <phrase role="special">;</phrase>
13333 <phrase role="keyword">return</phrase> <phrase role="identifier">data_</phrase><phrase role="special">[</phrase><phrase role="identifier">index</phrase><phrase role="special">];</phrase>
13334 <phrase role="special">}</phrase>
13336 <phrase role="keyword">private</phrase><phrase role="special">:</phrase>
13337 <phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">data_</phrase><phrase role="special">;</phrase>
13338 <phrase role="keyword">int</phrase> <phrase role="identifier">size_</phrase><phrase role="special">;</phrase>
13339 <phrase role="special">};</phrase>
13341 <phrase role="preprocessor">#endif</phrase> <phrase role="comment">// #include guard</phrase>
13347 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="comment">// Extra spaces, newlines, etc. for visual alignment with this library code.</phrase>
13353 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">></phrase>
13354 <phrase role="keyword">class</phrase> <phrase role="identifier">vector</phrase> <phrase role="special">{</phrase>
13363 <phrase role="identifier">legal</phrase><phrase role="special">:</phrase> <phrase role="comment">// Class invariants (legal).</phrase>
13364 <phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">>=</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase>
13367 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
13368 <phrase role="keyword">explicit</phrase> <phrase role="identifier">vector</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">count</phrase> <phrase role="special">=</phrase> <phrase role="number">10</phrase><phrase role="special">)</phrase> <phrase role="special">:</phrase>
13369 <phrase role="identifier">data_</phrase><phrase role="special">(</phrase><phrase role="keyword">new</phrase> <phrase role="identifier">T</phrase><phrase role="special">[</phrase><phrase role="identifier">count</phrase><phrase role="special">]),</phrase>
13370 <phrase role="identifier">size_</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">)</phrase>
13371 <phrase role="special">{</phrase>
13372 <phrase role="keyword">for</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">i</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase> <phrase role="identifier">i</phrase> <phrase role="special"><</phrase> <phrase role="identifier">size_</phrase><phrase role="special">;</phrase> <phrase role="special">++</phrase><phrase role="identifier">i</phrase><phrase role="special">)</phrase> <phrase role="identifier">data_</phrase><phrase role="special">[</phrase><phrase role="identifier">i</phrase><phrase role="special">]</phrase> <phrase role="special">=</phrase> <phrase role="identifier">T</phrase><phrase role="special">();</phrase>
13373 <phrase role="special">}</phrase>
13384 <phrase role="keyword">virtual</phrase> <phrase role="special">~</phrase><phrase role="identifier">vector</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase> <phrase role="keyword">delete</phrase><phrase role="special">[]</phrase> <phrase role="identifier">data_</phrase><phrase role="special">;</phrase> <phrase role="special">}</phrase>
13389 <phrase role="keyword">int</phrase> <phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase> <phrase role="keyword">return</phrase> <phrase role="identifier">size_</phrase><phrase role="special">;</phrase> <phrase role="special">}</phrase>
13394 <phrase role="keyword">void</phrase> <phrase role="identifier">resize</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">count</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
13395 <phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">slice</phrase> <phrase role="special">=</phrase> <phrase role="keyword">new</phrase> <phrase role="identifier">T</phrase><phrase role="special">[</phrase><phrase role="identifier">count</phrase><phrase role="special">];</phrase>
13396 <phrase role="keyword">for</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">i</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase> <phrase role="identifier">i</phrase> <phrase role="special"><</phrase> <phrase role="identifier">count</phrase> <phrase role="special">&&</phrase> <phrase role="identifier">i</phrase> <phrase role="special"><</phrase> <phrase role="identifier">size_</phrase><phrase role="special">;</phrase> <phrase role="special">++</phrase><phrase role="identifier">i</phrase><phrase role="special">)</phrase> <phrase role="identifier">slice</phrase><phrase role="special">[</phrase><phrase role="identifier">i</phrase><phrase role="special">]</phrase> <phrase role="special">=</phrase> <phrase role="identifier">data_</phrase><phrase role="special">[</phrase><phrase role="identifier">i</phrase><phrase role="special">];</phrase>
13397 <phrase role="keyword">delete</phrase><phrase role="special">[]</phrase> <phrase role="identifier">data_</phrase><phrase role="special">;</phrase>
13398 <phrase role="identifier">data_</phrase> <phrase role="special">=</phrase> <phrase role="identifier">slice</phrase><phrase role="special">;</phrase>
13399 <phrase role="identifier">size_</phrase> <phrase role="special">=</phrase> <phrase role="identifier">count</phrase><phrase role="special">;</phrase>
13400 <phrase role="special">}</phrase>
13411 <phrase role="identifier">T</phrase><phrase role="special">&</phrase> <phrase role="keyword">operator</phrase><phrase role="special">[](</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">index</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase> <phrase role="keyword">return</phrase> <phrase role="identifier">data_</phrase><phrase role="special">[</phrase><phrase role="identifier">index</phrase><phrase role="special">];</phrase> <phrase role="special">}</phrase>
13422 <phrase role="identifier">T</phrase><phrase role="special">&</phrase> <phrase role="keyword">operator</phrase><phrase role="special">[](</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">index</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase> <phrase role="keyword">return</phrase> <phrase role="identifier">data_</phrase><phrase role="special">[</phrase><phrase role="identifier">index</phrase><phrase role="special">];</phrase> <phrase role="special">}</phrase>
13427 <phrase role="identifier">axioms</phrase><phrase role="special">:</phrase> <phrase role="comment">// Preconditions (require) and postconditions (promise) for each func.</phrase>
13428 <phrase role="special">[</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">count</phrase><phrase role="special">;</phrase> <phrase role="identifier">require</phrase> <phrase role="identifier">count</phrase> <phrase role="special">>=</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase> <phrase role="identifier">promise</phrase> <phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">count</phrase><phrase role="special">]</phrase> <phrase role="identifier">vector</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">);</phrase>
13429 <phrase role="special">[</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">count</phrase><phrase role="special">;</phrase> <phrase role="identifier">require</phrase> <phrase role="identifier">count</phrase> <phrase role="special">>=</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase> <phrase role="identifier">promise</phrase> <phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">count</phrase><phrase role="special">]</phrase> <phrase role="identifier">resize</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">);</phrase>
13430 <phrase role="special">[</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">index</phrase><phrase role="special">;</phrase> <phrase role="identifier">require</phrase> <phrase role="identifier">index</phrase> <phrase role="special">>=</phrase> <phrase role="number">0</phrase> <phrase role="special">&&</phrase> <phrase role="identifier">index</phrase> <phrase role="special"><</phrase> <phrase role="identifier">size</phrase><phrase role="special">()]</phrase> <phrase role="special">(*</phrase><phrase role="keyword">this</phrase><phrase role="special">)[</phrase><phrase role="identifier">x</phrase><phrase role="special">];</phrase> <phrase role="comment">// Op[].</phrase>
13431 <phrase role="special">[</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">index</phrase><phrase role="special">;</phrase> <phrase role="identifier">require</phrase> <phrase role="identifier">index</phrase> <phrase role="special">>=</phrase> <phrase role="number">0</phrase> <phrase role="special">&&</phrase> <phrase role="identifier">index</phrase> <phrase role="special"><</phrase> <phrase role="identifier">size</phrase><phrase role="special">()]</phrase> <phrase role="special">(*</phrase><phrase role="keyword">this</phrase><phrase role="special">)[</phrase><phrase role="identifier">x</phrase><phrase role="special">]</phrase> <phrase role="keyword">const</phrase><phrase role="special">;</phrase> <phrase role="comment">// Op[].</phrase>
13433 <phrase role="keyword">private</phrase><phrase role="special">:</phrase>
13434 <phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">data_</phrase><phrase role="special">;</phrase>
13435 <phrase role="keyword">int</phrase> <phrase role="identifier">size_</phrase><phrase role="special">;</phrase>
13436 <phrase role="special">};</phrase>
13438 <phrase role="comment">// End.</phrase>
13446 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#include</phrase> <phrase role="string">"vector.hpp"</phrase>
13447 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">cassert</phrase><phrase role="special">></phrase>
13449 <phrase role="keyword">int</phrase> <phrase role="identifier">main</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
13450 <phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">></phrase> <phrase role="identifier">v</phrase> <phrase role="special">(</phrase><phrase role="number">3</phrase><phrase role="special">);</phrase>
13451 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">.</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">3</phrase><phrase role="special">);</phrase>
13453 <phrase role="identifier">v</phrase><phrase role="special">[</phrase><phrase role="number">0</phrase><phrase role="special">]</phrase> <phrase role="special">=</phrase> <phrase role="number">123</phrase><phrase role="special">;</phrase>
13454 <phrase role="identifier">v</phrase><phrase role="special">.</phrase><phrase role="identifier">resize</phrase><phrase role="special">(</phrase><phrase role="number">2</phrase><phrase role="special">);</phrase>
13455 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">[</phrase><phrase role="number">0</phrase><phrase role="special">]</phrase> <phrase role="special">==</phrase> <phrase role="number">123</phrase><phrase role="special">);</phrase>
13456 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">.</phrase><phrase role="identifier">size</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">2</phrase><phrase role="special">);</phrase>
13458 <phrase role="keyword">return</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase>
13459 <phrase role="special">}</phrase>
13470 <section id="boost_contract.examples.__cline90___stack__stack_like_container">
13471 <title><link linkend="boost_contract.examples.__cline90___stack__stack_like_container">[Cline90]
13472 Stack: Stack-like container</link></title>
13474 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">contract</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">></phrase>
13475 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">cassert</phrase><phrase role="special">></phrase>
13477 <phrase role="comment">// NOTE: Incomplete contract assertions, addressing only `empty` and `full`.</phrase>
13478 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">></phrase>
13479 <phrase role="keyword">class</phrase> <phrase role="identifier">stack</phrase>
13480 <phrase role="preprocessor">#define</phrase> <phrase role="identifier">BASES</phrase> <phrase role="keyword">private</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor_precondition</phrase><phrase role="special"><</phrase><phrase role="identifier">stack</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase> <phrase role="special">></phrase>
13481 <phrase role="special">:</phrase> <phrase role="identifier">BASES</phrase>
13482 <phrase role="special">{</phrase>
13483 <phrase role="keyword">friend</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">access</phrase><phrase role="special">;</phrase>
13485 <phrase role="keyword">typedef</phrase> <phrase role="identifier">BOOST_CONTRACT_BASE_TYPES</phrase><phrase role="special">(</phrase><phrase role="identifier">BASES</phrase><phrase role="special">)</phrase> <phrase role="identifier">base_types</phrase><phrase role="special">;</phrase>
13486 <phrase role="preprocessor">#undef</phrase> <phrase role="identifier">BASES</phrase>
13488 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
13489 <phrase role="keyword">explicit</phrase> <phrase role="identifier">stack</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">capacity</phrase><phrase role="special">)</phrase> <phrase role="special">:</phrase>
13490 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor_precondition</phrase><phrase role="special"><</phrase><phrase role="identifier">stack</phrase><phrase role="special">>([&]</phrase> <phrase role="special">{</phrase>
13491 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">capacity</phrase> <phrase role="special">>=</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase>
13492 <phrase role="special">}),</phrase>
13493 <phrase role="identifier">data_</phrase><phrase role="special">(</phrase><phrase role="keyword">new</phrase> <phrase role="identifier">T</phrase><phrase role="special">[</phrase><phrase role="identifier">capacity</phrase><phrase role="special">]),</phrase> <phrase role="identifier">capacity_</phrase><phrase role="special">(</phrase><phrase role="identifier">capacity</phrase><phrase role="special">),</phrase> <phrase role="identifier">size_</phrase><phrase role="special">(</phrase><phrase role="number">0</phrase><phrase role="special">)</phrase>
13494 <phrase role="special">{</phrase>
13495 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
13496 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
13497 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">empty</phrase><phrase role="special">());</phrase>
13498 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">full</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="special">(</phrase><phrase role="identifier">capacity</phrase> <phrase role="special">==</phrase> <phrase role="number">0</phrase><phrase role="special">));</phrase>
13499 <phrase role="special">})</phrase>
13500 <phrase role="special">;</phrase>
13502 <phrase role="keyword">for</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">i</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase> <phrase role="identifier">i</phrase> <phrase role="special"><</phrase> <phrase role="identifier">capacity_</phrase><phrase role="special">;</phrase> <phrase role="special">++</phrase><phrase role="identifier">i</phrase><phrase role="special">)</phrase> <phrase role="identifier">data_</phrase><phrase role="special">[</phrase><phrase role="identifier">i</phrase><phrase role="special">]</phrase> <phrase role="special">=</phrase> <phrase role="identifier">T</phrase><phrase role="special">();</phrase>
13503 <phrase role="special">}</phrase>
13505 <phrase role="keyword">virtual</phrase> <phrase role="special">~</phrase><phrase role="identifier">stack</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
13506 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">destructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
13507 <phrase role="keyword">delete</phrase><phrase role="special">[]</phrase> <phrase role="identifier">data_</phrase><phrase role="special">;</phrase>
13508 <phrase role="special">}</phrase>
13510 <phrase role="keyword">bool</phrase> <phrase role="identifier">empty</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
13511 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
13512 <phrase role="keyword">return</phrase> <phrase role="identifier">size_</phrase> <phrase role="special">==</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase>
13513 <phrase role="special">}</phrase>
13515 <phrase role="keyword">bool</phrase> <phrase role="identifier">full</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
13516 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
13517 <phrase role="keyword">return</phrase> <phrase role="identifier">size_</phrase> <phrase role="special">==</phrase> <phrase role="identifier">capacity_</phrase><phrase role="special">;</phrase>
13518 <phrase role="special">}</phrase>
13520 <phrase role="keyword">void</phrase> <phrase role="identifier">push</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">value</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
13521 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
13522 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
13523 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(!</phrase><phrase role="identifier">full</phrase><phrase role="special">());</phrase>
13524 <phrase role="special">})</phrase>
13525 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
13526 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(!</phrase><phrase role="identifier">empty</phrase><phrase role="special">());</phrase>
13527 <phrase role="special">})</phrase>
13528 <phrase role="special">;</phrase>
13530 <phrase role="identifier">data_</phrase><phrase role="special">[</phrase><phrase role="identifier">size_</phrase><phrase role="special">++]</phrase> <phrase role="special">=</phrase> <phrase role="identifier">value</phrase><phrase role="special">;</phrase>
13531 <phrase role="special">}</phrase>
13533 <phrase role="identifier">T</phrase> <phrase role="identifier">pop</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
13534 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
13535 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
13536 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(!</phrase><phrase role="identifier">empty</phrase><phrase role="special">());</phrase>
13537 <phrase role="special">})</phrase>
13538 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
13539 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(!</phrase><phrase role="identifier">full</phrase><phrase role="special">());</phrase>
13540 <phrase role="special">})</phrase>
13541 <phrase role="special">;</phrase>
13543 <phrase role="keyword">return</phrase> <phrase role="identifier">data_</phrase><phrase role="special">[--</phrase><phrase role="identifier">size_</phrase><phrase role="special">];</phrase>
13544 <phrase role="special">}</phrase>
13546 <phrase role="keyword">private</phrase><phrase role="special">:</phrase>
13547 <phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">data_</phrase><phrase role="special">;</phrase>
13548 <phrase role="keyword">int</phrase> <phrase role="identifier">capacity_</phrase><phrase role="special">;</phrase>
13549 <phrase role="keyword">int</phrase> <phrase role="identifier">size_</phrase><phrase role="special">;</phrase>
13550 <phrase role="special">};</phrase>
13552 <phrase role="keyword">int</phrase> <phrase role="identifier">main</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
13553 <phrase role="identifier">stack</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">></phrase> <phrase role="identifier">s</phrase><phrase role="special">(</phrase><phrase role="number">3</phrase><phrase role="special">);</phrase>
13554 <phrase role="identifier">s</phrase><phrase role="special">.</phrase><phrase role="identifier">push</phrase><phrase role="special">(</phrase><phrase role="number">123</phrase><phrase role="special">);</phrase>
13555 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">s</phrase><phrase role="special">.</phrase><phrase role="identifier">pop</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">123</phrase><phrase role="special">);</phrase>
13556 <phrase role="keyword">return</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase>
13557 <phrase role="special">}</phrase>
13561 <section id="boost_contract.examples.__cline90___vector_stack__subcontracting">
13562 <title><link linkend="boost_contract.examples.__cline90___vector_stack__subcontracting">[Cline90]
13563 Vector-Stack: Subcontracting</link></title>
13565 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#include</phrase> <phrase role="string">"vector.hpp"</phrase>
13566 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">contract</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">></phrase>
13567 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">optional</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">></phrase>
13568 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">cassert</phrase><phrase role="special">></phrase>
13570 <phrase role="comment">// NOTE: Incomplete contract assertions, addressing only `empty` and `full`.</phrase>
13571 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">></phrase>
13572 <phrase role="keyword">class</phrase> <phrase role="identifier">abstract_stack</phrase> <phrase role="special">{</phrase>
13573 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
13574 <phrase role="identifier">abstract_stack</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
13575 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
13576 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
13577 <phrase role="comment">// AXIOM as empty() cannot actually be checked here to avoid</phrase>
13578 <phrase role="comment">// calling pure virtual function length() during construction).</phrase>
13579 <phrase role="identifier">BOOST_CONTRACT_ASSERT_AXIOM</phrase><phrase role="special">(</phrase><phrase role="identifier">empty</phrase><phrase role="special">());</phrase>
13580 <phrase role="special">})</phrase>
13581 <phrase role="special">;</phrase>
13582 <phrase role="special">}</phrase>
13584 <phrase role="keyword">virtual</phrase> <phrase role="special">~</phrase><phrase role="identifier">abstract_stack</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
13585 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">destructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
13586 <phrase role="special">}</phrase>
13588 <phrase role="keyword">bool</phrase> <phrase role="identifier">full</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
13589 <phrase role="keyword">bool</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
13590 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
13591 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
13592 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">result</phrase> <phrase role="special">==</phrase> <phrase role="special">(</phrase><phrase role="identifier">length</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">capacity</phrase><phrase role="special">()));</phrase>
13593 <phrase role="special">})</phrase>
13594 <phrase role="special">;</phrase>
13596 <phrase role="keyword">return</phrase> <phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="special">(</phrase><phrase role="identifier">length</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">capacity</phrase><phrase role="special">());</phrase>
13597 <phrase role="special">}</phrase>
13599 <phrase role="keyword">bool</phrase> <phrase role="identifier">empty</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
13600 <phrase role="keyword">bool</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
13601 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
13602 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
13603 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="special">(</phrase><phrase role="identifier">length</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">0</phrase><phrase role="special">));</phrase>
13604 <phrase role="special">})</phrase>
13605 <phrase role="special">;</phrase>
13607 <phrase role="keyword">return</phrase> <phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="special">(</phrase><phrase role="identifier">length</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase>
13608 <phrase role="special">}</phrase>
13610 <phrase role="keyword">virtual</phrase> <phrase role="keyword">int</phrase> <phrase role="identifier">length</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase>
13611 <phrase role="keyword">virtual</phrase> <phrase role="keyword">int</phrase> <phrase role="identifier">capacity</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase>
13613 <phrase role="keyword">virtual</phrase> <phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">item</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase>
13615 <phrase role="keyword">virtual</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">push</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">value</phrase><phrase role="special">,</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase>
13616 <phrase role="keyword">virtual</phrase> <phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">pop</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase>
13618 <phrase role="keyword">virtual</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">clear</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase>
13619 <phrase role="special">};</phrase>
13621 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">></phrase>
13622 <phrase role="keyword">int</phrase> <phrase role="identifier">abstract_stack</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">>::</phrase><phrase role="identifier">length</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
13623 <phrase role="keyword">int</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
13624 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">result</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">)</phrase>
13625 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">result</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
13626 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">result</phrase> <phrase role="special">>=</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase>
13627 <phrase role="special">})</phrase>
13628 <phrase role="special">;</phrase>
13629 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="keyword">false</phrase><phrase role="special">);</phrase>
13630 <phrase role="keyword">return</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
13631 <phrase role="special">}</phrase>
13633 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">></phrase>
13634 <phrase role="keyword">int</phrase> <phrase role="identifier">abstract_stack</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">>::</phrase><phrase role="identifier">capacity</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
13635 <phrase role="keyword">int</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
13636 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">result</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">)</phrase>
13637 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">result</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
13638 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">result</phrase> <phrase role="special">>=</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase>
13639 <phrase role="special">})</phrase>
13640 <phrase role="special">;</phrase>
13641 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="keyword">false</phrase><phrase role="special">);</phrase>
13642 <phrase role="keyword">return</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
13643 <phrase role="special">}</phrase>
13645 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">></phrase>
13646 <phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">abstract_stack</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">>::</phrase><phrase role="identifier">item</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
13647 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">optional</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&></phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
13648 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">result</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">)</phrase>
13649 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
13650 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(!</phrase><phrase role="identifier">empty</phrase><phrase role="special">());</phrase>
13651 <phrase role="special">})</phrase>
13652 <phrase role="special">;</phrase>
13653 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="keyword">false</phrase><phrase role="special">);</phrase>
13654 <phrase role="keyword">return</phrase> <phrase role="special">*</phrase><phrase role="identifier">result</phrase><phrase role="special">;</phrase>
13655 <phrase role="special">}</phrase>
13657 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">></phrase>
13658 <phrase role="keyword">void</phrase> <phrase role="identifier">abstract_stack</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">>::</phrase><phrase role="identifier">push</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">value</phrase><phrase role="special">,</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
13659 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">)</phrase>
13660 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
13661 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(!</phrase><phrase role="identifier">full</phrase><phrase role="special">());</phrase>
13662 <phrase role="special">})</phrase>
13663 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
13664 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(!</phrase><phrase role="identifier">empty</phrase><phrase role="special">());</phrase>
13665 <phrase role="special">})</phrase>
13666 <phrase role="special">;</phrase>
13667 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="keyword">false</phrase><phrase role="special">);</phrase>
13668 <phrase role="special">}</phrase>
13670 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">></phrase>
13671 <phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">abstract_stack</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">>::</phrase><phrase role="identifier">pop</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
13672 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">optional</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&></phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
13673 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase> <phrase role="identifier">old_item</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">item</phrase><phrase role="special">());</phrase>
13674 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">result</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">)</phrase>
13675 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
13676 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(!</phrase><phrase role="identifier">empty</phrase><phrase role="special">());</phrase>
13677 <phrase role="special">})</phrase>
13678 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">optional</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&></phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">result</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
13679 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(!</phrase><phrase role="identifier">full</phrase><phrase role="special">());</phrase>
13680 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(*</phrase><phrase role="identifier">result</phrase> <phrase role="special">==</phrase> <phrase role="special">*</phrase><phrase role="identifier">old_item</phrase><phrase role="special">);</phrase>
13681 <phrase role="special">})</phrase>
13682 <phrase role="special">;</phrase>
13683 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="keyword">false</phrase><phrase role="special">);</phrase>
13684 <phrase role="keyword">return</phrase> <phrase role="special">*</phrase><phrase role="identifier">result</phrase><phrase role="special">;</phrase>
13685 <phrase role="special">}</phrase>
13687 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">></phrase>
13688 <phrase role="keyword">void</phrase> <phrase role="identifier">abstract_stack</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">>::</phrase><phrase role="identifier">clear</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
13689 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">)</phrase>
13690 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
13691 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">empty</phrase><phrase role="special">());</phrase>
13692 <phrase role="special">})</phrase>
13693 <phrase role="special">;</phrase>
13694 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="keyword">false</phrase><phrase role="special">);</phrase>
13695 <phrase role="special">}</phrase>
13697 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">></phrase>
13698 <phrase role="keyword">class</phrase> <phrase role="identifier">vstack</phrase>
13699 <phrase role="preprocessor">#define</phrase> <phrase role="identifier">BASES</phrase> <phrase role="keyword">private</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor_precondition</phrase><phrase role="special"><</phrase> <phrase role="special">\</phrase>
13700 <phrase role="identifier">vstack</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase> <phrase role="special">>,</phrase> <phrase role="keyword">public</phrase> <phrase role="identifier">abstract_stack</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase>
13701 <phrase role="special">:</phrase> <phrase role="identifier">BASES</phrase>
13702 <phrase role="special">{</phrase>
13703 <phrase role="keyword">friend</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">access</phrase><phrase role="special">;</phrase>
13705 <phrase role="keyword">typedef</phrase> <phrase role="identifier">BOOST_CONTRACT_BASE_TYPES</phrase><phrase role="special">(</phrase><phrase role="identifier">BASES</phrase><phrase role="special">)</phrase> <phrase role="identifier">base_types</phrase><phrase role="special">;</phrase>
13706 <phrase role="preprocessor">#undef</phrase> <phrase role="identifier">BASES</phrase>
13708 <phrase role="keyword">void</phrase> <phrase role="identifier">invariant</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
13709 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">length</phrase><phrase role="special">()</phrase> <phrase role="special">>=</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase>
13710 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">length</phrase><phrase role="special">()</phrase> <phrase role="special"><</phrase> <phrase role="identifier">capacity</phrase><phrase role="special">());</phrase>
13711 <phrase role="special">}</phrase>
13713 <phrase role="identifier">BOOST_CONTRACT_OVERRIDES</phrase><phrase role="special">(</phrase><phrase role="identifier">length</phrase><phrase role="special">,</phrase> <phrase role="identifier">capacity</phrase><phrase role="special">,</phrase> <phrase role="identifier">item</phrase><phrase role="special">,</phrase> <phrase role="identifier">push</phrase><phrase role="special">,</phrase> <phrase role="identifier">pop</phrase><phrase role="special">,</phrase> <phrase role="identifier">clear</phrase><phrase role="special">)</phrase>
13715 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
13716 <phrase role="keyword">explicit</phrase> <phrase role="identifier">vstack</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">count</phrase> <phrase role="special">=</phrase> <phrase role="number">10</phrase><phrase role="special">)</phrase> <phrase role="special">:</phrase>
13717 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor_precondition</phrase><phrase role="special"><</phrase><phrase role="identifier">vstack</phrase><phrase role="special">>([&]</phrase> <phrase role="special">{</phrase>
13718 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase> <phrase role="special">>=</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase>
13719 <phrase role="special">}),</phrase>
13720 <phrase role="identifier">vect_</phrase><phrase role="special">(</phrase><phrase role="identifier">count</phrase><phrase role="special">),</phrase> <phrase role="comment">// OK, executed after precondition so count >= 0.</phrase>
13721 <phrase role="identifier">len_</phrase><phrase role="special">(</phrase><phrase role="number">0</phrase><phrase role="special">)</phrase>
13722 <phrase role="special">{</phrase>
13723 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
13724 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
13725 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">length</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">0</phrase><phrase role="special">);</phrase>
13726 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">capacity</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">count</phrase><phrase role="special">);</phrase>
13727 <phrase role="special">})</phrase>
13728 <phrase role="special">;</phrase>
13729 <phrase role="special">}</phrase>
13731 <phrase role="keyword">virtual</phrase> <phrase role="special">~</phrase><phrase role="identifier">vstack</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
13732 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">destructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
13733 <phrase role="special">}</phrase>
13735 <phrase role="comment">// Inherited from abstract_stack.</phrase>
13737 <phrase role="keyword">virtual</phrase> <phrase role="keyword">int</phrase> <phrase role="identifier">length</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase> <phrase role="comment">/* override */</phrase> <phrase role="special">{</phrase>
13738 <phrase role="keyword">int</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
13739 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special"><</phrase>
13740 <phrase role="identifier">override_length</phrase><phrase role="special">>(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">result</phrase><phrase role="special">,</phrase> <phrase role="special">&</phrase><phrase role="identifier">vstack</phrase><phrase role="special">::</phrase><phrase role="identifier">length</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">);</phrase>
13741 <phrase role="keyword">return</phrase> <phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="identifier">len_</phrase><phrase role="special">;</phrase>
13742 <phrase role="special">}</phrase>
13744 <phrase role="keyword">virtual</phrase> <phrase role="keyword">int</phrase> <phrase role="identifier">capacity</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase>
13745 <phrase role="keyword">const</phrase> <phrase role="comment">/* override */</phrase> <phrase role="special">{</phrase>
13746 <phrase role="keyword">int</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
13747 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special"><</phrase>
13748 <phrase role="identifier">override_capacity</phrase><phrase role="special">>(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">result</phrase><phrase role="special">,</phrase> <phrase role="special">&</phrase><phrase role="identifier">vstack</phrase><phrase role="special">::</phrase><phrase role="identifier">capacity</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">);</phrase>
13749 <phrase role="keyword">return</phrase> <phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">.</phrase><phrase role="identifier">size</phrase><phrase role="special">();</phrase>
13750 <phrase role="special">}</phrase>
13752 <phrase role="keyword">virtual</phrase> <phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">item</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase>
13753 <phrase role="keyword">const</phrase> <phrase role="comment">/* override */</phrase> <phrase role="special">{</phrase>
13754 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">optional</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&></phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
13755 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special"><</phrase>
13756 <phrase role="identifier">override_item</phrase><phrase role="special">>(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">result</phrase><phrase role="special">,</phrase> <phrase role="special">&</phrase><phrase role="identifier">vstack</phrase><phrase role="special">::</phrase><phrase role="identifier">item</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">);</phrase>
13757 <phrase role="keyword">return</phrase> <phrase role="special">*(</phrase><phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">[</phrase><phrase role="identifier">len_</phrase> <phrase role="special">-</phrase> <phrase role="number">1</phrase><phrase role="special">]);</phrase>
13758 <phrase role="special">}</phrase>
13760 <phrase role="keyword">virtual</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">push</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">value</phrase><phrase role="special">,</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase>
13761 <phrase role="comment">/* override */</phrase> <phrase role="special">{</phrase>
13762 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special"><</phrase>
13763 <phrase role="identifier">override_push</phrase><phrase role="special">>(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="special">&</phrase><phrase role="identifier">vstack</phrase><phrase role="special">::</phrase><phrase role="identifier">push</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">,</phrase> <phrase role="identifier">value</phrase><phrase role="special">);</phrase>
13764 <phrase role="identifier">vect_</phrase><phrase role="special">[</phrase><phrase role="identifier">len_</phrase><phrase role="special">++]</phrase> <phrase role="special">=</phrase> <phrase role="identifier">value</phrase><phrase role="special">;</phrase>
13765 <phrase role="special">}</phrase>
13767 <phrase role="keyword">virtual</phrase> <phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">pop</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="comment">/* override */</phrase> <phrase role="special">{</phrase>
13768 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">optional</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&></phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
13769 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special"><</phrase>
13770 <phrase role="identifier">override_pop</phrase><phrase role="special">>(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">result</phrase><phrase role="special">,</phrase> <phrase role="special">&</phrase><phrase role="identifier">vstack</phrase><phrase role="special">::</phrase><phrase role="identifier">pop</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">);</phrase>
13771 <phrase role="keyword">return</phrase> <phrase role="special">*(</phrase><phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="identifier">vect_</phrase><phrase role="special">[--</phrase><phrase role="identifier">len_</phrase><phrase role="special">]);</phrase>
13772 <phrase role="special">}</phrase>
13774 <phrase role="keyword">virtual</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">clear</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="comment">/* override */</phrase> <phrase role="special">{</phrase>
13775 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special"><</phrase>
13776 <phrase role="identifier">override_clear</phrase><phrase role="special">>(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="special">&</phrase><phrase role="identifier">vstack</phrase><phrase role="special">::</phrase><phrase role="identifier">clear</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">);</phrase>
13777 <phrase role="identifier">len_</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase>
13778 <phrase role="special">}</phrase>
13780 <phrase role="keyword">private</phrase><phrase role="special">:</phrase>
13781 <phrase role="identifier">vector</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase> <phrase role="identifier">vect_</phrase><phrase role="special">;</phrase>
13782 <phrase role="keyword">int</phrase> <phrase role="identifier">len_</phrase><phrase role="special">;</phrase>
13783 <phrase role="special">};</phrase>
13785 <phrase role="keyword">int</phrase> <phrase role="identifier">main</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
13786 <phrase role="identifier">vstack</phrase><phrase role="special"><</phrase><phrase role="keyword">int</phrase><phrase role="special">></phrase> <phrase role="identifier">s</phrase><phrase role="special">(</phrase><phrase role="number">3</phrase><phrase role="special">);</phrase>
13787 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">s</phrase><phrase role="special">.</phrase><phrase role="identifier">capacity</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">3</phrase><phrase role="special">);</phrase>
13789 <phrase role="identifier">s</phrase><phrase role="special">.</phrase><phrase role="identifier">push</phrase><phrase role="special">(</phrase><phrase role="number">123</phrase><phrase role="special">);</phrase>
13790 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">s</phrase><phrase role="special">.</phrase><phrase role="identifier">length</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase>
13791 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">s</phrase><phrase role="special">.</phrase><phrase role="identifier">pop</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">123</phrase><phrase role="special">);</phrase>
13793 <phrase role="keyword">return</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase>
13794 <phrase role="special">}</phrase>
13798 <section id="boost_contract.examples.__cline90___calendar__a_very_simple_calendar">
13799 <title><link linkend="boost_contract.examples.__cline90___calendar__a_very_simple_calendar">[Cline90]
13800 Calendar: A very simple calendar</link></title>
13802 <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">contract</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">></phrase>
13803 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">cassert</phrase><phrase role="special">></phrase>
13805 <phrase role="keyword">class</phrase> <phrase role="identifier">calendar</phrase> <phrase role="special">{</phrase>
13806 <phrase role="keyword">friend</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">access</phrase><phrase role="special">;</phrase>
13808 <phrase role="keyword">void</phrase> <phrase role="identifier">invariant</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
13809 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">month</phrase><phrase role="special">()</phrase> <phrase role="special">>=</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase>
13810 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">month</phrase><phrase role="special">()</phrase> <phrase role="special"><=</phrase> <phrase role="number">12</phrase><phrase role="special">);</phrase>
13811 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">date</phrase><phrase role="special">()</phrase> <phrase role="special">>=</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase>
13812 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">date</phrase><phrase role="special">()</phrase> <phrase role="special"><=</phrase> <phrase role="identifier">days_in</phrase><phrase role="special">(</phrase><phrase role="identifier">month</phrase><phrase role="special">()));</phrase>
13813 <phrase role="special">}</phrase>
13815 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
13816 <phrase role="identifier">calendar</phrase><phrase role="special">()</phrase> <phrase role="special">:</phrase> <phrase role="identifier">month_</phrase><phrase role="special">(</phrase><phrase role="number">1</phrase><phrase role="special">),</phrase> <phrase role="identifier">date_</phrase><phrase role="special">(</phrase><phrase role="number">31</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
13817 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
13818 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
13819 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">month</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase>
13820 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">date</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">31</phrase><phrase role="special">);</phrase>
13821 <phrase role="special">})</phrase>
13822 <phrase role="special">;</phrase>
13823 <phrase role="special">}</phrase>
13825 <phrase role="keyword">virtual</phrase> <phrase role="special">~</phrase><phrase role="identifier">calendar</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
13826 <phrase role="comment">// Check invariants.</phrase>
13827 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">destructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
13828 <phrase role="special">}</phrase>
13830 <phrase role="keyword">int</phrase> <phrase role="identifier">month</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
13831 <phrase role="comment">// Check invariants.</phrase>
13832 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
13833 <phrase role="keyword">return</phrase> <phrase role="identifier">month_</phrase><phrase role="special">;</phrase>
13834 <phrase role="special">}</phrase>
13836 <phrase role="keyword">int</phrase> <phrase role="identifier">date</phrase><phrase role="special">()</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
13837 <phrase role="comment">// Check invariants.</phrase>
13838 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">);</phrase>
13839 <phrase role="keyword">return</phrase> <phrase role="identifier">date_</phrase><phrase role="special">;</phrase>
13840 <phrase role="special">}</phrase>
13842 <phrase role="keyword">void</phrase> <phrase role="identifier">reset</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">new_month</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
13843 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
13844 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
13845 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">new_month</phrase> <phrase role="special">>=</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase>
13846 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">new_month</phrase> <phrase role="special"><=</phrase> <phrase role="number">12</phrase><phrase role="special">);</phrase>
13847 <phrase role="special">})</phrase>
13848 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
13849 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">month</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="identifier">new_month</phrase><phrase role="special">);</phrase>
13850 <phrase role="special">})</phrase>
13851 <phrase role="special">;</phrase>
13853 <phrase role="identifier">month_</phrase> <phrase role="special">=</phrase> <phrase role="identifier">new_month</phrase><phrase role="special">;</phrase>
13854 <phrase role="special">}</phrase>
13856 <phrase role="keyword">private</phrase><phrase role="special">:</phrase>
13857 <phrase role="keyword">static</phrase> <phrase role="keyword">int</phrase> <phrase role="identifier">days_in</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">month</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
13858 <phrase role="keyword">int</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
13859 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">function</phrase><phrase role="special">()</phrase>
13860 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
13861 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">month</phrase> <phrase role="special">>=</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase>
13862 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">month</phrase> <phrase role="special"><=</phrase> <phrase role="number">12</phrase><phrase role="special">);</phrase>
13863 <phrase role="special">})</phrase>
13864 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">([&]</phrase> <phrase role="special">{</phrase>
13865 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">result</phrase> <phrase role="special">>=</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase>
13866 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">result</phrase> <phrase role="special"><=</phrase> <phrase role="number">31</phrase><phrase role="special">);</phrase>
13867 <phrase role="special">})</phrase>
13868 <phrase role="special">;</phrase>
13870 <phrase role="keyword">return</phrase> <phrase role="identifier">result</phrase> <phrase role="special">=</phrase> <phrase role="number">31</phrase><phrase role="special">;</phrase> <phrase role="comment">// For simplicity, assume all months have 31 days.</phrase>
13871 <phrase role="special">}</phrase>
13873 <phrase role="keyword">int</phrase> <phrase role="identifier">month_</phrase><phrase role="special">,</phrase> <phrase role="identifier">date_</phrase><phrase role="special">;</phrase>
13874 <phrase role="special">};</phrase>
13876 <phrase role="keyword">int</phrase> <phrase role="identifier">main</phrase><phrase role="special">()</phrase> <phrase role="special">{</phrase>
13877 <phrase role="identifier">calendar</phrase> <phrase role="identifier">cal</phrase><phrase role="special">;</phrase>
13878 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">cal</phrase><phrase role="special">.</phrase><phrase role="identifier">date</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">31</phrase><phrase role="special">);</phrase>
13879 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">cal</phrase><phrase role="special">.</phrase><phrase role="identifier">month</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">1</phrase><phrase role="special">);</phrase>
13881 <phrase role="identifier">cal</phrase><phrase role="special">.</phrase><phrase role="identifier">reset</phrase><phrase role="special">(</phrase><phrase role="number">8</phrase><phrase role="special">);</phrase> <phrase role="comment">// Set month </phrase>
13882 <phrase role="identifier">assert</phrase><phrase role="special">(</phrase><phrase role="identifier">cal</phrase><phrase role="special">.</phrase><phrase role="identifier">month</phrase><phrase role="special">()</phrase> <phrase role="special">==</phrase> <phrase role="number">8</phrase><phrase role="special">);</phrase>
13884 <phrase role="keyword">return</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase>
13885 <phrase role="special">}</phrase>
13890 <section id="reference"><title>Reference</title><section id="header.boost.contract_hpp"><title>Header <<ulink url="../../../../boost/contract.hpp">boost/contract.hpp</ulink>></title><para>Include all header files required by this library at once (for convenience). </para><para>All header files <computeroutput>boost/contract/*.hpp</computeroutput> are independent from one another and can be included one-by-one to reduce the amount of code to compile from this library in user code (but this was measured to not make an appreciable difference in compile-time so <computeroutput>boost/contract.hpp</computeroutput> can be included directly in most cases). Instead the headers <computeroutput>boost/contract/core/*.hpp</computeroutput> are not independent from other library headers and they are automatically included by the <computeroutput>boost/contract/*.hpp</computeroutput> headers (so the <computeroutput>boost/contract/core/*.hpp</computeroutput> headers are usually not directly included by programmers).</para><para>All files under the <computeroutput>boost/contract/detail/</computeroutput> directory, names within the <computeroutput>boost::contract::detail</computeroutput> namespace, names prefixed by <computeroutput>boost_contract_detail</computeroutput>... and <computeroutput>BOOST_CONTRACT_DETAIL</computeroutput>... (in any namesapce, including user's code) are reserved for internal use of this library and should never be used directly by programmers.</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.getting_started"> Getting Started</link> </para>
13894 <section id="header.boost.contract.assert_hpp"><title>Header <<ulink url="../../../../boost/contract/assert.hpp">boost/contract/assert.hpp</ulink>></title><para>Assert contract conditions. </para><synopsis xmlns:xi="http://www.w3.org/2001/XInclude">
13896 <link linkend="BOOST_CONTRACT_ASSERT">BOOST_CONTRACT_ASSERT</link>(cond)
13897 <link linkend="BOOST_CO_idm45395000817520">BOOST_CONTRACT_ASSERT_AUDIT</link>(cond)
13898 <link linkend="BOOST_CO_idm45395027441616">BOOST_CONTRACT_ASSERT_AXIOM</link>(cond)</synopsis>
13899 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CONTRACT_ASSERT"><refmeta><refentrytitle>Macro BOOST_CONTRACT_ASSERT</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_ASSERT</refname><refpurpose>Preferred way to assert contract conditions. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.assert_hpp">boost/contract/assert.hpp</link>>
13901 </phrase>BOOST_CONTRACT_ASSERT(cond)</synopsis></refsynopsisdiv><refsect1><title>Description</title><para>Any exception thrown from within a contract (preconditions, postconditions, exception guarantees, old value copies at body, class invariants, etc.) is interpreted by this library as a contract failure. Therefore, users can program contract assertions manually throwing an exception when an asserted condition is checked to be <computeroutput>false</computeroutput> (this library will then call the appropriate contract failure handler <computeroutput><link linkend="boost.contract.precondition_failure">boost::contract::precondition_failure</link></computeroutput>, etc.). However, it is preferred to use this macro because it expands to code that throws <computeroutput><link linkend="boost.contract.assertion_failure">boost::contract::assertion_failure</link></computeroutput> with the correct assertion file name (using <computeroutput>__FILE__</computeroutput>), line number (using <computeroutput>__LINE__</computeroutput>), and asserted condition code so to produce informative error messages (C++11 <computeroutput>__func__</computeroutput> is not used here because in most cases it will simply expand to the internal compiler name of the lambda function used to program the contract conditions adding no specificity to the error message).</para><para> <computeroutput><link linkend="BOOST_CONTRACT_ASSERT">BOOST_CONTRACT_ASSERT</link></computeroutput>, <computeroutput><link linkend="BOOST_CO_idm45395000817520">BOOST_CONTRACT_ASSERT_AUDIT</link></computeroutput>, and <computeroutput><link linkend="BOOST_CO_idm45395027441616">BOOST_CONTRACT_ASSERT_AXIOM</link></computeroutput> are the three assertion levels predefined by this library.</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.tutorial.preconditions"> Preconditions</link>, <link linkend="boost_contract.tutorial.postconditions"> Postconditions</link>, <link linkend="boost_contract.tutorial.exception_guarantees"> Exceptions Guarantees</link>, <link linkend="boost_contract.tutorial.class_invariants"> Class Invariants</link>, <link linkend="boost_contract.extras.no_macros__and_no_variadic_macros_"> No Macros</link></para>
13904 </para><variablelist spacing="compact"><?dbhtml
13905 list-presentation="table"
13906 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
13907 list-presentation="table"
13908 ?><varlistentry><term><computeroutput>cond</computeroutput></term><listitem><para>Boolean contract condition to check. (This is not a variadic macro parameter so any comma it might contain must be protected by round parenthesis and <computeroutput>BOOST_CONTRACT_ASSERT((cond))</computeroutput> will always work.) </para></listitem></varlistentry></variablelist></listitem></varlistentry></variablelist></refsect1></refentry>
13909 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CO_idm45395000817520"><refmeta><refentrytitle>Macro BOOST_CONTRACT_ASSERT_AUDIT</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_ASSERT_AUDIT</refname><refpurpose>Preferred way to assert contract conditions that are computationally expensive, at least compared to the computational cost of executing the function body. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.assert_hpp">boost/contract/assert.hpp</link>>
13911 </phrase>BOOST_CONTRACT_ASSERT_AUDIT(cond)</synopsis></refsynopsisdiv><refsect1><title>Description</title><para>The asserted condition will always be compiled and validated syntactically, but it will not be checked at run-time unless <computeroutput><link linkend="BOOST_CONTRACT_AUDITS">BOOST_CONTRACT_AUDITS</link></computeroutput> is defined (undefined by default). This macro is defined by code equivalent to:</para><para><programlisting><phrase role="preprocessor">#ifdef</phrase> <phrase role="identifier">BOOST_CONTRACT_AUDITS</phrase>
13912 <phrase role="preprocessor">#define</phrase> <phrase role="identifier">BOOST_CONTRACT_ASSERT_AUDIT</phrase><phrase role="special">(</phrase><phrase role="identifier">cond</phrase><phrase role="special">)</phrase> \
13913 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">cond</phrase><phrase role="special">)</phrase>
13914 <phrase role="preprocessor">#else</phrase>
13915 <phrase role="preprocessor">#define</phrase> <phrase role="identifier">BOOST_CONTRACT_ASSERT_AUDIT</phrase><phrase role="special">(</phrase><phrase role="identifier">cond</phrase><phrase role="special">)</phrase> \
13916 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="keyword">true</phrase> <phrase role="special">||</phrase> <phrase role="identifier">cond</phrase><phrase role="special">)</phrase>
13917 <phrase role="preprocessor">#endif</phrase>
13918 </programlisting></para><para> <computeroutput><link linkend="BOOST_CONTRACT_ASSERT">BOOST_CONTRACT_ASSERT</link></computeroutput>, <computeroutput><link linkend="BOOST_CO_idm45395000817520">BOOST_CONTRACT_ASSERT_AUDIT</link></computeroutput>, and <computeroutput><link linkend="BOOST_CO_idm45395027441616">BOOST_CONTRACT_ASSERT_AXIOM</link></computeroutput> are the three assertion levels predefined by this library. If there is a need, programmers are free to implement their own assertion levels defining macros similar to the one above.</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.extras.assertion_levels"> Assertion Levels</link>, <link linkend="boost_contract.extras.no_macros__and_no_variadic_macros_"> No Macros</link></para>
13921 </para><variablelist spacing="compact"><?dbhtml
13922 list-presentation="table"
13923 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
13924 list-presentation="table"
13925 ?><varlistentry><term><computeroutput>cond</computeroutput></term><listitem><para>Boolean contract condition to check. (This is not a variadic macro parameter so any comma it might contain must be protected by round parenthesis and <computeroutput>BOOST_CONTRACT_ASSERT_AUDIT((cond))</computeroutput> will always work.) </para></listitem></varlistentry></variablelist></listitem></varlistentry></variablelist></refsect1></refentry>
13926 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CO_idm45395027441616"><refmeta><refentrytitle>Macro BOOST_CONTRACT_ASSERT_AXIOM</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_ASSERT_AXIOM</refname><refpurpose>Preferred way to document in the code contract conditions that are computationally prohibitive, at least compared to the computational cost of executing the function body. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.assert_hpp">boost/contract/assert.hpp</link>>
13928 </phrase>BOOST_CONTRACT_ASSERT_AXIOM(cond)</synopsis></refsynopsisdiv><refsect1><title>Description</title><para>The asserted condition will always be compiled and validated syntactically, but it will never be checked at run-time. This macro is defined by code equivalent to:</para><para><programlisting><phrase role="preprocessor">#define</phrase> <phrase role="identifier">BOOST_CONTRACT_ASSERT_AXIOM</phrase><phrase role="special">(</phrase><phrase role="identifier">cond</phrase><phrase role="special">)</phrase> \
13929 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="keyword">true</phrase> <phrase role="special">||</phrase> <phrase role="identifier">cond</phrase><phrase role="special">)</phrase>
13930 </programlisting></para><para> <computeroutput><link linkend="BOOST_CONTRACT_ASSERT">BOOST_CONTRACT_ASSERT</link></computeroutput>, <computeroutput><link linkend="BOOST_CO_idm45395000817520">BOOST_CONTRACT_ASSERT_AUDIT</link></computeroutput>, and <computeroutput><link linkend="BOOST_CO_idm45395027441616">BOOST_CONTRACT_ASSERT_AXIOM</link></computeroutput> are the three assertion levels predefined by this library. If there is a need, programmers are free to implement their own assertion levels defining macros similar to the one above.</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.extras.assertion_levels"> Assertion Levels</link>, <link linkend="boost_contract.extras.no_macros__and_no_variadic_macros_"> No Macros</link></para>
13933 </para><variablelist spacing="compact"><?dbhtml
13934 list-presentation="table"
13935 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
13936 list-presentation="table"
13937 ?><varlistentry><term><computeroutput>cond</computeroutput></term><listitem><para>Boolean contract condition to check. (This is not a variadic macro parameter so any comma it might contain must be protected by round parenthesis and <computeroutput>BOOST_CONTRACT_ASSERT_AXIOM((cond))</computeroutput> will always work.) </para></listitem></varlistentry></variablelist></listitem></varlistentry></variablelist></refsect1></refentry>
13939 <section id="header.boost.contract.base_types_hpp"><title>Header <<ulink url="../../../../boost/contract/base_types.hpp">boost/contract/base_types.hpp</ulink>></title><para>Specify inheritance form base classes (for subcontracting). </para><synopsis xmlns:xi="http://www.w3.org/2001/XInclude">
13941 <link linkend="BOOST_CONTRACT_BASE_TYPES">BOOST_CONTRACT_BASE_TYPES</link>(...)</synopsis>
13942 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CONTRACT_BASE_TYPES"><refmeta><refentrytitle>Macro BOOST_CONTRACT_BASE_TYPES</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_BASE_TYPES</refname><refpurpose>Used to program the <computeroutput>typedef</computeroutput> that lists the bases of a derived class. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.base_types_hpp">boost/contract/base_types.hpp</link>>
13944 </phrase>BOOST_CONTRACT_BASE_TYPES(...)</synopsis></refsynopsisdiv><refsect1><title>Description</title><para>In order to support subcontracting, a derived class that specifies contracts for one or more overriding public functions must declare a <computeroutput>typedef</computeroutput> named <computeroutput>base_types</computeroutput> (or <computeroutput><link linkend="BOOST_CO_idm45394999732400">BOOST_CONTRACT_BASES_TYPEDEF</link></computeroutput>) using this macro:</para><para><programlisting><phrase role="keyword">class</phrase> <phrase role="identifier">u</phrase>
13945 <phrase role="preprocessor">#define</phrase> <phrase role="identifier">BASES</phrase> <phrase role="keyword">public</phrase> <phrase role="identifier">b</phrase><phrase role="special">,</phrase> <phrase role="keyword">protected</phrase> <phrase role="keyword">virtual</phrase> <phrase role="identifier">w1</phrase><phrase role="special">,</phrase> <phrase role="keyword">private</phrase> <phrase role="identifier">w2</phrase>
13946 <phrase role="special">:</phrase> <phrase role="identifier">BASES</phrase>
13947 <phrase role="special">{</phrase>
13948 <phrase role="keyword">friend</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">:</phrase><phrase role="identifier">access</phrase><phrase role="special">;</phrase>
13950 <phrase role="keyword">typedef</phrase> <phrase role="identifier">BOOST_CONTRACT_BASE_TYPES</phrase><phrase role="special">(</phrase><phrase role="identifier">BASES</phrase><phrase role="special">)</phrase> <phrase role="identifier">base_types</phrase><phrase role="special">;</phrase>
13951 <phrase role="preprocessor">#undef</phrase> <phrase role="identifier">BASES</phrase>
13953 <phrase role="special">...</phrase>
13954 <phrase role="special">}</phrase><phrase role="special">;</phrase>
13955 </programlisting></para><para>This <computeroutput>typedef</computeroutput> must be <computeroutput>public</computeroutput> unless <computeroutput><link linkend="boost.contract.access">boost::contract::access</link></computeroutput> is used.</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.tutorial.base_classes__subcontracting_"> Base Classes</link></para>
13958 </para><variablelist spacing="compact"><?dbhtml
13959 list-presentation="table"
13960 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
13961 list-presentation="table"
13962 ?><varlistentry><term><computeroutput>...</computeroutput></term><listitem><para>Comma separated list of base classes. Each base must explicitly specify its access specifier <computeroutput>public</computeroutput>, <computeroutput>protected</computeroutput>, or <computeroutput>private</computeroutput>, and also <computeroutput>virtual</computeroutput> when present (this not always required in C++ instead). There is a limit of about 20 maximum bases that can be listed (because of similar limits in Boost.MPL internally used by this library). This is a variadic macro parameter, on compilers that do not support variadic macros, the <computeroutput>typedef</computeroutput> for base classes can be programmed manually without using this macro (see <link linkend="boost_contract.extras.no_macros__and_no_variadic_macros_"> No Macros</link>). </para></listitem></varlistentry></variablelist></listitem></varlistentry></variablelist></refsect1></refentry>
13964 <section id="header.boost.contract.call_if_hpp"><title>Header <<ulink url="../../../../boost/contract/call_if.hpp">boost/contract/call_if.hpp</ulink>></title><para>Statically disable compilation and execution of functor calls. </para><para><note><para>These facilities allow to emulate C++17 <computeroutput>if constexpr</computeroutput> statements when used together with functor templates (and C++14 generic lambdas). Therefore, they are not useful on C++17 compilers where <computeroutput> if constexpr</computeroutput> can be directly used instead. </para>
13966 </para><synopsis xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">namespace</phrase> <phrase role="identifier">boost</phrase> <phrase role="special">{</phrase>
13967 <phrase role="keyword">namespace</phrase> <phrase role="identifier">contract</phrase> <phrase role="special">{</phrase>
13968 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">bool</phrase> Pred<phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> Then<phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> ThenResult <phrase role="special">=</phrase> <phrase role="identifier">internal_type</phrase><phrase role="special">></phrase>
13969 <phrase role="keyword">struct</phrase> <link linkend="boost.contract.call_if_statement">call_if_statement</link><phrase role="special">;</phrase>
13971 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> Then<phrase role="special">></phrase>
13972 <phrase role="keyword">struct</phrase> <link linkend="boost.contract.call_if__idm45395000098448">call_if_statement</link><phrase role="special"><</phrase><phrase role="keyword">false</phrase><phrase role="special">,</phrase> <phrase role="identifier">Then</phrase><phrase role="special">,</phrase> <phrase role="identifier">internal_type</phrase><phrase role="special">></phrase><phrase role="special">;</phrase>
13973 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> Then<phrase role="special">></phrase> <phrase role="keyword">struct</phrase> <link linkend="boost.contract.call_if__idm45395000058976">call_if_statement</link><phrase role="special"><</phrase><phrase role="keyword">true</phrase><phrase role="special">,</phrase> <phrase role="identifier">Then</phrase><phrase role="special">,</phrase> <phrase role="identifier">internal_type</phrase><phrase role="special">></phrase><phrase role="special">;</phrase>
13974 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> Then<phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> ThenResult<phrase role="special">></phrase>
13975 <phrase role="keyword">struct</phrase> <link linkend="boost.contract.call_if__idm45395000042848">call_if_statement</link><phrase role="special"><</phrase><phrase role="keyword">true</phrase><phrase role="special">,</phrase> <phrase role="identifier">Then</phrase><phrase role="special">,</phrase> <phrase role="identifier">ThenResult</phrase><phrase role="special">></phrase><phrase role="special">;</phrase>
13976 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> Then<phrase role="special">></phrase> <phrase role="keyword">struct</phrase> <link linkend="boost.contract.call_if__idm45395000002720">call_if_statement</link><phrase role="special"><</phrase><phrase role="keyword">true</phrase><phrase role="special">,</phrase> <phrase role="identifier">Then</phrase><phrase role="special">,</phrase> <phrase role="keyword">void</phrase><phrase role="special">></phrase><phrase role="special">;</phrase>
13977 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">bool</phrase> Pred<phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> Then<phrase role="special">></phrase>
13978 <link linkend="boost.contract.call_if_statement">call_if_statement</link><phrase role="special"><</phrase> <phrase role="identifier">Pred</phrase><phrase role="special">,</phrase> <phrase role="identifier">Then</phrase> <phrase role="special">></phrase> <link linkend="boost.contract.call_if_c"><phrase role="identifier">call_if_c</phrase></link><phrase role="special">(</phrase><phrase role="identifier">Then</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
13979 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> Pred<phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> Then<phrase role="special">></phrase>
13980 <link linkend="boost.contract.call_if_statement">call_if_statement</link><phrase role="special"><</phrase> <phrase role="identifier">Pred</phrase><phrase role="special">::</phrase><phrase role="identifier">value</phrase><phrase role="special">,</phrase> <phrase role="identifier">Then</phrase> <phrase role="special">></phrase> <link linkend="boost.contract.call_if"><phrase role="identifier">call_if</phrase></link><phrase role="special">(</phrase><phrase role="identifier">Then</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
13981 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">bool</phrase> Pred<phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> Then<phrase role="special">></phrase> <phrase role="keyword">bool</phrase> <link linkend="boost.contract.condition_if_c"><phrase role="identifier">condition_if_c</phrase></link><phrase role="special">(</phrase><phrase role="identifier">Then</phrase><phrase role="special">,</phrase> <phrase role="keyword">bool</phrase> <phrase role="special">=</phrase> <phrase role="keyword">true</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
13982 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> Pred<phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> Then<phrase role="special">></phrase>
13983 <phrase role="keyword">bool</phrase> <link linkend="boost.contract.condition_if"><phrase role="identifier">condition_if</phrase></link><phrase role="special">(</phrase><phrase role="identifier">Then</phrase><phrase role="special">,</phrase> <phrase role="keyword">bool</phrase> <phrase role="special">=</phrase> <phrase role="keyword">true</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
13984 <phrase role="special">}</phrase>
13985 <phrase role="special">}</phrase></synopsis>
13986 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.call_if_statement"><refmeta><refentrytitle>Struct template call_if_statement</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::call_if_statement</refname><refpurpose>Select compilation and execution of functor template calls using a static boolean predicate (not needed on C++17 compilers, use <computeroutput>if constexpr</computeroutput> instead). </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.call_if_hpp">boost/contract/call_if.hpp</link>>
13988 </phrase><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">bool</phrase> Pred<phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> Then<phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> ThenResult <phrase role="special">=</phrase> <phrase role="identifier">internal_type</phrase><phrase role="special">></phrase>
13989 <phrase role="keyword">struct</phrase> <link linkend="boost.contract.call_if_statement">call_if_statement</link> <phrase role="special">{</phrase>
13990 <phrase role="special">}</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This class template has no members because it is never used directly, it is only used via its specializations. Usually this class template is instantiated only via the return value of <computeroutput><link linkend="boost.contract.call_if">boost::contract::call_if</link></computeroutput> and <computeroutput><link linkend="boost.contract.call_if_c">boost::contract::call_if_c</link></computeroutput>.</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.extras.assertion_requirements__templates_">
13991 Assertion Requirements</link></para>
13994 </para><refsect2><title>Template Parameters</title><orderedlist><listitem><para><literallayout class="monospaced"><phrase role="keyword">bool</phrase> Pred</literallayout></para><para><para>Static boolean predicate that selects which functor template call to compile and execute. </para></para></listitem><listitem><para><literallayout class="monospaced"><phrase role="keyword">typename</phrase> Then</literallayout></para><para><para>Type of the functor template to call if the static predicate <computeroutput>Pred</computeroutput> is <computeroutput>true</computeroutput>. </para></para></listitem><listitem><para><literallayout class="monospaced"><phrase role="keyword">typename</phrase> ThenResult <phrase role="special">=</phrase> <phrase role="identifier">internal_type</phrase></literallayout></para><para><para>Return type of then-branch functor template call (this is usually automatically deduced by this library so it is never explicitly specified by the user, and that is why it is often marked as <computeroutput>internal_type</computeroutput> in this documentation). </para></para></listitem></orderedlist></refsect2></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.call_if__idm45395000098448"><refmeta><refentrytitle>Struct template call_if_statement<false, Then, internal_type></refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::call_if_statement<false, Then, internal_type></refname><refpurpose>Template specialization to handle static predicates that are <computeroutput>false</computeroutput> (not needed on C++17 compilers, use <computeroutput>if constexpr</computeroutput> instead). </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.call_if_hpp">boost/contract/call_if.hpp</link>>
13996 </phrase><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> Then<phrase role="special">></phrase>
13997 <phrase role="keyword">struct</phrase> <link linkend="boost.contract.call_if__idm45395000098448">call_if_statement</link><phrase role="special"><</phrase><phrase role="keyword">false</phrase><phrase role="special">,</phrase> <phrase role="identifier">Then</phrase><phrase role="special">,</phrase> <phrase role="identifier">internal_type</phrase><phrase role="special">></phrase> <phrase role="special">{</phrase>
13998 <phrase role="comment">// <link linkend="boost.contract.call_if__idm45395000098448construct-copy-destruct">construct/copy/destruct</link></phrase>
13999 <phrase role="keyword">explicit</phrase> <link linkend="idm45395000063008-bb"><phrase role="identifier">call_if_statement</phrase></link><phrase role="special">(</phrase><phrase role="identifier">Then</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14001 <phrase role="comment">// <link linkend="idm45395000089616-bb">public member functions</link></phrase>
14002 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> Else<phrase role="special">></phrase> <phrase role="identifier">result_of</phrase><phrase role="special"><</phrase> <phrase role="identifier">Else</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">></phrase><phrase role="special">::</phrase><phrase role="identifier">type</phrase> <link linkend="idm45395000089056-bb"><phrase role="identifier">else_</phrase></link><phrase role="special">(</phrase><phrase role="identifier">Else</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase><phrase role="special">;</phrase>
14003 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">bool</phrase> ElseIfPred<phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> ElseIfThen<phrase role="special">></phrase>
14004 <link linkend="boost.contract.call_if_statement">call_if_statement</link><phrase role="special"><</phrase> <phrase role="identifier">ElseIfPred</phrase><phrase role="special">,</phrase> <phrase role="identifier">ElseIfThen</phrase> <phrase role="special">></phrase> <link linkend="idm45395000080400-bb"><phrase role="identifier">else_if_c</phrase></link><phrase role="special">(</phrase><phrase role="identifier">ElseIfThen</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase><phrase role="special">;</phrase>
14005 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> ElseIfPred<phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> ElseIfThen<phrase role="special">></phrase>
14006 <link linkend="boost.contract.call_if_statement">call_if_statement</link><phrase role="special"><</phrase> <phrase role="identifier">ElseIfPred</phrase><phrase role="special">::</phrase><phrase role="identifier">value</phrase><phrase role="special">,</phrase> <phrase role="identifier">ElseIfThen</phrase> <phrase role="special">></phrase>
14007 <link linkend="idm45395000071648-bb"><phrase role="identifier">else_if</phrase></link><phrase role="special">(</phrase><phrase role="identifier">ElseIfThen</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase><phrase role="special">;</phrase>
14008 <phrase role="special">}</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This template specialization handles all else-branch functor template calls (whether they return void or not). Usually this class template is instantiated only via the return value of <computeroutput><link linkend="boost.contract.call_if">boost::contract::call_if</link></computeroutput> and <computeroutput><link linkend="boost.contract.call_if_c">boost::contract::call_if_c</link></computeroutput>.</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.extras.assertion_requirements__templates_">
14009 Assertion Requirements</link></para>
14012 </para><refsect2><title>Template Parameters</title><orderedlist><listitem><para><literallayout class="monospaced"><phrase role="keyword">typename</phrase> Then</literallayout></para><para><para>Type of functor template to call when the static predicate is <computeroutput>true</computeroutput> (never the case for this template specialization). </para></para></listitem></orderedlist></refsect2><refsect2><title><anchor id="boost.contract.call_if__idm45395000098448construct-copy-destruct"/><computeroutput>call_if_statement</computeroutput>
14014 construct/copy/destruct</title><orderedlist><listitem><para><literallayout class="monospaced"><phrase role="keyword">explicit</phrase> <anchor id="idm45395000063008-bb"/><phrase role="identifier">call_if_statement</phrase><phrase role="special">(</phrase><phrase role="identifier">Then</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase> f<phrase role="special">)</phrase><phrase role="special">;</phrase></literallayout></para>Construct this object with the then-branch functor template. <para>
14015 </para><variablelist spacing="compact"><?dbhtml
14016 list-presentation="table"
14017 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
14018 list-presentation="table"
14019 ?><varlistentry><term><computeroutput>f</computeroutput></term><listitem><para>Then-branch nullary functor template. The functor template call <computeroutput>f()</computeroutput> is never compiled or executed for this template specialization (because the if-statement static predicate is <computeroutput>false</computeroutput>). The return type of <computeroutput>f()</computeroutput> must be the same as (or implicitly convertible to) the return type of all other functor template calls specified for this call-if object. </para></listitem></varlistentry></variablelist></listitem></varlistentry></variablelist></listitem></orderedlist></refsect2><refsect2><title><anchor id="idm45395000089616-bb"/><computeroutput>call_if_statement</computeroutput> public member functions</title><orderedlist><listitem><para><literallayout class="monospaced"><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> Else<phrase role="special">></phrase> <phrase role="identifier">result_of</phrase><phrase role="special"><</phrase> <phrase role="identifier">Else</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">></phrase><phrase role="special">::</phrase><phrase role="identifier">type</phrase> <anchor id="idm45395000089056-bb"/><phrase role="identifier">else_</phrase><phrase role="special">(</phrase><phrase role="identifier">Else</phrase> f<phrase role="special">)</phrase> <phrase role="keyword">const</phrase><phrase role="special">;</phrase></literallayout></para>Specify the else-branch functor template. <para><note><para>The <computeroutput>result_of<Else()>::type</computeroutput> expression needs be evaluated only when the static predicate is already checked to be <computeroutput>false</computeroutput> (because <computeroutput>Else()</computeroutput> is required to compile only in that case). Thus, this result-of expression is evaluated lazily and only in instantiations of this template specialization.</para>
14023 </para><variablelist spacing="compact"><?dbhtml
14024 list-presentation="table"
14025 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
14026 list-presentation="table"
14027 ?><varlistentry><term><computeroutput>f</computeroutput></term><listitem><para>Else-branch nullary functor template. The functor template call <computeroutput>f()</computeroutput> is actually compiled and executed for this template specialization (because the if-statement static predicate is <computeroutput>false</computeroutput>). The return type of <computeroutput>f()</computeroutput> must be the same as (or implicitly convertible to) the return type of all other functor template calls specified for this call-if object.</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Returns:</term><listitem><para>A copy of the value returned by the call to the else-branch functor template <computeroutput>f()</computeroutput>. </para></listitem></varlistentry></variablelist></listitem><listitem><para><literallayout class="monospaced"><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">bool</phrase> ElseIfPred<phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> ElseIfThen<phrase role="special">></phrase>
14028 <link linkend="boost.contract.call_if_statement">call_if_statement</link><phrase role="special"><</phrase> <phrase role="identifier">ElseIfPred</phrase><phrase role="special">,</phrase> <phrase role="identifier">ElseIfThen</phrase> <phrase role="special">></phrase> <anchor id="idm45395000080400-bb"/><phrase role="identifier">else_if_c</phrase><phrase role="special">(</phrase><phrase role="identifier">ElseIfThen</phrase> f<phrase role="special">)</phrase> <phrase role="keyword">const</phrase><phrase role="special">;</phrase></literallayout></para>Specify an else-if-branch functor template (using a static boolean predicate). <para>
14031 </para><variablelist spacing="compact"><?dbhtml
14032 list-presentation="table"
14033 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
14034 list-presentation="table"
14035 ?><varlistentry><term><computeroutput>f</computeroutput></term><listitem><para>Else-if-branch nullary functor template. The functor template call <computeroutput>f()</computeroutput> is actually compiled and executed if and only if <computeroutput>ElseIfPred</computeroutput> is <computeroutput>true</computeroutput> (because the if-statement static predicate is already <computeroutput>false</computeroutput> for this template specialization). The return type of <computeroutput>f()</computeroutput> must be the same as (or implicitly convertible to) the return type of all other functor template calls specified for this call-if object.</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Template Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
14036 list-presentation="table"
14037 ?><varlistentry><term><computeroutput>ElseIfPred</computeroutput></term><listitem><para>Static boolean predicate selecting which functor template call to compile and execute.</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Returns:</term><listitem><para>A call-if statement so the else statement and additional else-if statements can be specified if needed. Eventually, this will be the return value of the one functor template call being compiled and executed. </para></listitem></varlistentry></variablelist></listitem><listitem><para><literallayout class="monospaced"><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> ElseIfPred<phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> ElseIfThen<phrase role="special">></phrase>
14038 <link linkend="boost.contract.call_if_statement">call_if_statement</link><phrase role="special"><</phrase> <phrase role="identifier">ElseIfPred</phrase><phrase role="special">::</phrase><phrase role="identifier">value</phrase><phrase role="special">,</phrase> <phrase role="identifier">ElseIfThen</phrase> <phrase role="special">></phrase>
14039 <anchor id="idm45395000071648-bb"/><phrase role="identifier">else_if</phrase><phrase role="special">(</phrase><phrase role="identifier">ElseIfThen</phrase> f<phrase role="special">)</phrase> <phrase role="keyword">const</phrase><phrase role="special">;</phrase></literallayout></para>Specify an else-if-branch functor template (using a nullary boolen meta-function). <para>
14042 </para><variablelist spacing="compact"><?dbhtml
14043 list-presentation="table"
14044 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
14045 list-presentation="table"
14046 ?><varlistentry><term><computeroutput>f</computeroutput></term><listitem><para>Else-if-branch nullary functor template. The functor template call <computeroutput>f()</computeroutput> is actually compiled and executed if and only if <computeroutput>ElseIfPred::value</computeroutput> is <computeroutput>true</computeroutput> (because the if-statement static predicate is already <computeroutput>false</computeroutput> for this template specialization). The return type of <computeroutput>f()</computeroutput> must be the same as (or implicitly convertible to) the return type of all other functor template calls specified for this call-if object.</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Template Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
14047 list-presentation="table"
14048 ?><varlistentry><term><computeroutput>ElseIfPred</computeroutput></term><listitem><para>Nullary boolean meta-function selecting which functor template call to compile and execute.</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Returns:</term><listitem><para>A call-if statement so the else statement and additional else-if statements can be specified if needed. Eventually, this will be the return value of the one functor template call being compiled and executed. </para></listitem></varlistentry></variablelist></listitem></orderedlist></refsect2></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.call_if__idm45395000058976"><refmeta><refentrytitle>Struct template call_if_statement<true, Then, internal_type></refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::call_if_statement<true, Then, internal_type></refname><refpurpose>Template specialization to dispatch between then-branch functor template calls that return void and the ones that return non-void (not needed on C++17 compilers, use <computeroutput>if constexpr</computeroutput> instead). </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.call_if_hpp">boost/contract/call_if.hpp</link>>
14050 </phrase><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> Then<phrase role="special">></phrase>
14051 <phrase role="keyword">struct</phrase> <link linkend="boost.contract.call_if__idm45395000058976">call_if_statement</link><phrase role="special"><</phrase><phrase role="keyword">true</phrase><phrase role="special">,</phrase> <phrase role="identifier">Then</phrase><phrase role="special">,</phrase> <phrase role="identifier">internal_type</phrase><phrase role="special">></phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> boost::contract::call_if_statement< true, Then, result_of< Then()>::type >
14052 <phrase role="special">{</phrase>
14053 <phrase role="comment">// <link linkend="boost.contract.call_if__idm45395000058976construct-copy-destruct">construct/copy/destruct</link></phrase>
14054 <phrase role="keyword">explicit</phrase> <link linkend="idm45395000046864-bb"><phrase role="identifier">call_if_statement</phrase></link><phrase role="special">(</phrase><phrase role="identifier">Then</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14055 <phrase role="special">}</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>The base class is a call-if statement so the else and else-if statements can be specified if needed. Usually this class template is instantiated only via the return value of <computeroutput><link linkend="boost.contract.call_if">boost::contract::call_if</link></computeroutput> and <computeroutput><link linkend="boost.contract.call_if_c">boost::contract::call_if_c</link></computeroutput>.</para><para><note><para>The <computeroutput>result_of<Then()>::type</computeroutput> expression needs be evaluated only when the static predicate is already checked to be <computeroutput>true</computeroutput> (because <computeroutput>Then()</computeroutput> is required to compile only in that case). Thus, this template specialization introduces an extra level of indirection necessary for proper lazy evaluation of this result-of expression.</para>
14057 <para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.extras.assertion_requirements__templates_">
14058 Assertion Requirements</link></para>
14061 </para><refsect2><title>Template Parameters</title><orderedlist><listitem><para><literallayout class="monospaced"><phrase role="keyword">typename</phrase> Then</literallayout></para><para><para>Type of functor template to call when the static predicate is <computeroutput>true</computeroutput> (as it is for this template specialization). </para></para></listitem></orderedlist></refsect2><refsect2><title><anchor id="boost.contract.call_if__idm45395000058976construct-copy-destruct"/><computeroutput>call_if_statement</computeroutput>
14063 construct/copy/destruct</title><orderedlist><listitem><para><literallayout class="monospaced"><phrase role="keyword">explicit</phrase> <anchor id="idm45395000046864-bb"/><phrase role="identifier">call_if_statement</phrase><phrase role="special">(</phrase><phrase role="identifier">Then</phrase> f<phrase role="special">)</phrase><phrase role="special">;</phrase></literallayout></para>Construct this object with the then-branch functor template. <para>
14064 </para><variablelist spacing="compact"><?dbhtml
14065 list-presentation="table"
14066 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
14067 list-presentation="table"
14068 ?><varlistentry><term><computeroutput>f</computeroutput></term><listitem><para>Then-branch nullary functor template. The functor template call <computeroutput>f()</computeroutput> is compiled and called for this template specialization (because the if-statement static predicate is <computeroutput>true</computeroutput>). The return type of <computeroutput>f()</computeroutput> must be the same as (or implicitly convertible to) the return type of all other functor template calls specified for this call-if object. </para></listitem></varlistentry></variablelist></listitem></varlistentry></variablelist></listitem></orderedlist></refsect2></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.call_if__idm45395000042848"><refmeta><refentrytitle>Struct template call_if_statement<true, Then, ThenResult></refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::call_if_statement<true, Then, ThenResult></refname><refpurpose>Template specialization to handle static predicates that are <computeroutput>true</computeroutput> for then-branch functor template calls that do not return void (not needed on C++17 compilers, use <computeroutput>if constexpr</computeroutput> instead). </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.call_if_hpp">boost/contract/call_if.hpp</link>>
14070 </phrase><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> Then<phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> ThenResult<phrase role="special">></phrase>
14071 <phrase role="keyword">struct</phrase> <link linkend="boost.contract.call_if__idm45395000042848">call_if_statement</link><phrase role="special"><</phrase><phrase role="keyword">true</phrase><phrase role="special">,</phrase> <phrase role="identifier">Then</phrase><phrase role="special">,</phrase> <phrase role="identifier">ThenResult</phrase><phrase role="special">></phrase> <phrase role="special">{</phrase>
14072 <phrase role="comment">// <link linkend="boost.contract.call_if__idm45395000042848construct-copy-destruct">construct/copy/destruct</link></phrase>
14073 <phrase role="keyword">explicit</phrase> <link linkend="idm45395000007120-bb"><phrase role="identifier">call_if_statement</phrase></link><phrase role="special">(</phrase><phrase role="identifier">Then</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14075 <phrase role="comment">// <link linkend="idm45395000033040-bb">public member functions</link></phrase>
14076 <link linkend="idm45395000032480-bb"><phrase role="keyword">operator</phrase> <phrase role="identifier">ThenResult</phrase></link><phrase role="special">(</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase><phrase role="special">;</phrase>
14077 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> Else<phrase role="special">></phrase> <phrase role="identifier">ThenResult</phrase> <link linkend="idm45395000030976-bb"><phrase role="identifier">else_</phrase></link><phrase role="special">(</phrase><phrase role="identifier">Else</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase><phrase role="special">;</phrase>
14078 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">bool</phrase> ElseIfPred<phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> ElseIfThen<phrase role="special">></phrase>
14079 <link linkend="boost.contract.call_if_statement">call_if_statement</link><phrase role="special"><</phrase> <phrase role="keyword">true</phrase><phrase role="special">,</phrase> <phrase role="identifier">Then</phrase><phrase role="special">,</phrase> <phrase role="identifier">ThenResult</phrase> <phrase role="special">></phrase>
14080 <link linkend="idm45395000024480-bb"><phrase role="identifier">else_if_c</phrase></link><phrase role="special">(</phrase><phrase role="identifier">ElseIfThen</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase><phrase role="special">;</phrase>
14081 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> ElseIfPred<phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> ElseIfThen<phrase role="special">></phrase>
14082 <link linkend="boost.contract.call_if_statement">call_if_statement</link><phrase role="special"><</phrase> <phrase role="keyword">true</phrase><phrase role="special">,</phrase> <phrase role="identifier">Then</phrase><phrase role="special">,</phrase> <phrase role="identifier">ThenResult</phrase> <phrase role="special">></phrase>
14083 <link linkend="idm45395000015744-bb"><phrase role="identifier">else_if</phrase></link><phrase role="special">(</phrase><phrase role="identifier">ElseIfThen</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase><phrase role="special">;</phrase>
14084 <phrase role="special">}</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>Usually this class template is instantiated only via the return value of <computeroutput><link linkend="boost.contract.call_if">boost::contract::call_if</link></computeroutput> and <computeroutput><link linkend="boost.contract.call_if_c">boost::contract::call_if_c</link></computeroutput>.</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.extras.assertion_requirements__templates_">
14085 Assertion Requirements</link></para>
14088 </para><refsect2><title>Template Parameters</title><orderedlist><listitem><para><literallayout class="monospaced"><phrase role="keyword">typename</phrase> Then</literallayout></para><para><para>Type of functor template to call when the static predicate is <computeroutput>true</computeroutput> (as it is for this template specialization). </para></para></listitem><listitem><para><literallayout class="monospaced"><phrase role="keyword">typename</phrase> ThenResult</literallayout></para><para><para>Non-void return type of the then-branch functor template call. </para></para></listitem></orderedlist></refsect2><refsect2><title><anchor id="boost.contract.call_if__idm45395000042848construct-copy-destruct"/><computeroutput>call_if_statement</computeroutput>
14090 construct/copy/destruct</title><orderedlist><listitem><para><literallayout class="monospaced"><phrase role="keyword">explicit</phrase> <anchor id="idm45395000007120-bb"/><phrase role="identifier">call_if_statement</phrase><phrase role="special">(</phrase><phrase role="identifier">Then</phrase> f<phrase role="special">)</phrase><phrase role="special">;</phrase></literallayout></para>Construct this object with the then-branch functor template. <para>
14091 </para><variablelist spacing="compact"><?dbhtml
14092 list-presentation="table"
14093 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
14094 list-presentation="table"
14095 ?><varlistentry><term><computeroutput>f</computeroutput></term><listitem><para>Then-branch nullary functor template. The functor template call <computeroutput>f()</computeroutput> is actually compiled and executed for this template specialization (because the if-statement static predicate is <computeroutput>true</computeroutput>). The return type of <computeroutput>f()</computeroutput> must be the same as (or implicitly convertible to) the <computeroutput>ThenResult</computeroutput> type. </para></listitem></varlistentry></variablelist></listitem></varlistentry></variablelist></listitem></orderedlist></refsect2><refsect2><title><anchor id="idm45395000033040-bb"/><computeroutput>call_if_statement</computeroutput> public member functions</title><orderedlist><listitem><para><literallayout class="monospaced"><anchor id="idm45395000032480-bb"/><phrase role="keyword">operator</phrase> <phrase role="identifier">ThenResult</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase><phrase role="special">;</phrase></literallayout></para>This implicit type conversion returns a copy of the value returned by the call to the then-branch functor template. </listitem><listitem><para><literallayout class="monospaced"><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> Else<phrase role="special">></phrase> <phrase role="identifier">ThenResult</phrase> <anchor id="idm45395000030976-bb"/><phrase role="identifier">else_</phrase><phrase role="special">(</phrase><phrase role="identifier">Else</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase> f<phrase role="special">)</phrase> <phrase role="keyword">const</phrase><phrase role="special">;</phrase></literallayout></para>Specify the else-branch functor template. <para>
14097 </para><variablelist spacing="compact"><?dbhtml
14098 list-presentation="table"
14099 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
14100 list-presentation="table"
14101 ?><varlistentry><term><computeroutput>f</computeroutput></term><listitem><para>Else-branch nullary functor template. The functor template call <computeroutput>f()</computeroutput> is never compiled or executed for this template specialization (because the if-statement static predicate is <computeroutput>true</computeroutput>). The return type of <computeroutput>f()</computeroutput> must be the same as (or implicitly convertible to) the <computeroutput>ThenResult</computeroutput> type.</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Returns:</term><listitem><para>A copy of the value returned by the call to the then-branch functor template (because the else-branch functor template call is not executed). </para></listitem></varlistentry></variablelist></listitem><listitem><para><literallayout class="monospaced"><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">bool</phrase> ElseIfPred<phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> ElseIfThen<phrase role="special">></phrase>
14102 <link linkend="boost.contract.call_if_statement">call_if_statement</link><phrase role="special"><</phrase> <phrase role="keyword">true</phrase><phrase role="special">,</phrase> <phrase role="identifier">Then</phrase><phrase role="special">,</phrase> <phrase role="identifier">ThenResult</phrase> <phrase role="special">></phrase>
14103 <anchor id="idm45395000024480-bb"/><phrase role="identifier">else_if_c</phrase><phrase role="special">(</phrase><phrase role="identifier">ElseIfThen</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase> f<phrase role="special">)</phrase> <phrase role="keyword">const</phrase><phrase role="special">;</phrase></literallayout></para>Specify an else-if-branch functor template (using a static boolean predicate). <para>
14106 </para><variablelist spacing="compact"><?dbhtml
14107 list-presentation="table"
14108 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
14109 list-presentation="table"
14110 ?><varlistentry><term><computeroutput>f</computeroutput></term><listitem><para>Else-if-branch nullary functor template. The functor template call <computeroutput>f()</computeroutput> is never compiled or executed for this template specialization (because the if-statement static predicate is <computeroutput>true</computeroutput>). The return type of <computeroutput>f()</computeroutput> must be the same as (or implicitly convertible to) the <computeroutput>ThenResult</computeroutput> type.</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Template Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
14111 list-presentation="table"
14112 ?><varlistentry><term><computeroutput>ElseIfPred</computeroutput></term><listitem><para>Static boolean predicate selecting which functor template call to compile and execute.</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Returns:</term><listitem><para>A call-if statement so the else statement and additional else-if statements can be specified if needed. Eventually, it will be the return value of the then-branch functor template call for this template specialization (because the if-statement static predicate is <computeroutput>true</computeroutput>). </para></listitem></varlistentry></variablelist></listitem><listitem><para><literallayout class="monospaced"><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> ElseIfPred<phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> ElseIfThen<phrase role="special">></phrase>
14113 <link linkend="boost.contract.call_if_statement">call_if_statement</link><phrase role="special"><</phrase> <phrase role="keyword">true</phrase><phrase role="special">,</phrase> <phrase role="identifier">Then</phrase><phrase role="special">,</phrase> <phrase role="identifier">ThenResult</phrase> <phrase role="special">></phrase>
14114 <anchor id="idm45395000015744-bb"/><phrase role="identifier">else_if</phrase><phrase role="special">(</phrase><phrase role="identifier">ElseIfThen</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase> f<phrase role="special">)</phrase> <phrase role="keyword">const</phrase><phrase role="special">;</phrase></literallayout></para>Specify an else-if-branch functor template (using a nullary boolean meta-function). <para>
14117 </para><variablelist spacing="compact"><?dbhtml
14118 list-presentation="table"
14119 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
14120 list-presentation="table"
14121 ?><varlistentry><term><computeroutput>f</computeroutput></term><listitem><para>Else-if-branch nullary functor template. The functor template call <computeroutput>f()</computeroutput> is never compiled or executed for this template specialization (because the if-statement static predicate is <computeroutput>true</computeroutput>). The return type of <computeroutput>f()</computeroutput> must be the same as (or implicitly convertible to) the <computeroutput>ThenResult</computeroutput> type.</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Template Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
14122 list-presentation="table"
14123 ?><varlistentry><term><computeroutput>ElseIfPred</computeroutput></term><listitem><para>Nullary boolean meta-function selecting which functor template call to compile and execute.</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Returns:</term><listitem><para>A call-if statement so the else statement and additional else-if statements can be specified if needed. Eventually, it will be the return value of the then-branch functor template call for this template specialization (because the if-statement static predicate is <computeroutput>true</computeroutput>). </para></listitem></varlistentry></variablelist></listitem></orderedlist></refsect2></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.call_if__idm45395000002720"><refmeta><refentrytitle>Struct template call_if_statement<true, Then, void></refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::call_if_statement<true, Then, void></refname><refpurpose>Template specialization to handle static predicates that are <computeroutput>true</computeroutput> for then-branch functor template calls that return void (not needed on C++17 compilers, use <computeroutput>if constexpr</computeroutput> instead). </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.call_if_hpp">boost/contract/call_if.hpp</link>>
14125 </phrase><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> Then<phrase role="special">></phrase>
14126 <phrase role="keyword">struct</phrase> <link linkend="boost.contract.call_if__idm45395000002720">call_if_statement</link><phrase role="special"><</phrase><phrase role="keyword">true</phrase><phrase role="special">,</phrase> <phrase role="identifier">Then</phrase><phrase role="special">,</phrase> <phrase role="keyword">void</phrase><phrase role="special">></phrase> <phrase role="special">{</phrase>
14127 <phrase role="comment">// <link linkend="boost.contract.call_if__idm45395000002720construct-copy-destruct">construct/copy/destruct</link></phrase>
14128 <phrase role="keyword">explicit</phrase> <link linkend="idm45394999971152-bb"><phrase role="identifier">call_if_statement</phrase></link><phrase role="special">(</phrase><phrase role="identifier">Then</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14130 <phrase role="comment">// <link linkend="idm45394999993936-bb">public member functions</link></phrase>
14131 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> Else<phrase role="special">></phrase> <phrase role="keyword">void</phrase> <link linkend="idm45394999993376-bb"><phrase role="identifier">else_</phrase></link><phrase role="special">(</phrase><phrase role="identifier">Else</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase><phrase role="special">;</phrase>
14132 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">bool</phrase> ElseIfPred<phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> ElseIfThen<phrase role="special">></phrase>
14133 <link linkend="boost.contract.call_if_statement">call_if_statement</link><phrase role="special"><</phrase> <phrase role="keyword">true</phrase><phrase role="special">,</phrase> <phrase role="identifier">Then</phrase><phrase role="special">,</phrase> <phrase role="keyword">void</phrase> <phrase role="special">></phrase> <link linkend="idm45394999987552-bb"><phrase role="identifier">else_if_c</phrase></link><phrase role="special">(</phrase><phrase role="identifier">ElseIfThen</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase><phrase role="special">;</phrase>
14134 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> ElseIfPred<phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> ElseIfThen<phrase role="special">></phrase>
14135 <link linkend="boost.contract.call_if_statement">call_if_statement</link><phrase role="special"><</phrase> <phrase role="keyword">true</phrase><phrase role="special">,</phrase> <phrase role="identifier">Then</phrase><phrase role="special">,</phrase> <phrase role="keyword">void</phrase> <phrase role="special">></phrase> <link linkend="idm45394999979296-bb"><phrase role="identifier">else_if</phrase></link><phrase role="special">(</phrase><phrase role="identifier">ElseIfThen</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase><phrase role="special">;</phrase>
14136 <phrase role="special">}</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>Usually this class template is instantiated only via the return value of <computeroutput><link linkend="boost.contract.call_if">boost::contract::call_if</link></computeroutput> and <computeroutput><link linkend="boost.contract.call_if_c">boost::contract::call_if_c</link></computeroutput>.</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.extras.assertion_requirements__templates_">
14137 Assertion Requirements</link></para>
14140 </para><refsect2><title>Template Parameters</title><orderedlist><listitem><para><literallayout class="monospaced"><phrase role="keyword">typename</phrase> Then</literallayout></para><para><para>Type of functor template to call when the static predicate if <computeroutput>true</computeroutput> (as it is for this template specialization). </para></para></listitem></orderedlist></refsect2><refsect2><title><anchor id="boost.contract.call_if__idm45395000002720construct-copy-destruct"/><computeroutput>call_if_statement</computeroutput>
14142 construct/copy/destruct</title><orderedlist><listitem><para><literallayout class="monospaced"><phrase role="keyword">explicit</phrase> <anchor id="idm45394999971152-bb"/><phrase role="identifier">call_if_statement</phrase><phrase role="special">(</phrase><phrase role="identifier">Then</phrase> f<phrase role="special">)</phrase><phrase role="special">;</phrase></literallayout></para>Construct this object with the then-branch functor template. <para>
14143 </para><variablelist spacing="compact"><?dbhtml
14144 list-presentation="table"
14145 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
14146 list-presentation="table"
14147 ?><varlistentry><term><computeroutput>f</computeroutput></term><listitem><para>Then-branch nullary functor template. The functor template call <computeroutput>f()</computeroutput> is actually compiled and executed for this template specialization (because the if-statement static predicate is <computeroutput>true</computeroutput>). The return type of <computeroutput>f()</computeroutput> must be <computeroutput>void</computeroutput> for this template specialization (because the then-branch functor template calls return void). </para></listitem></varlistentry></variablelist></listitem></varlistentry></variablelist></listitem></orderedlist></refsect2><refsect2><title><anchor id="idm45394999993936-bb"/><computeroutput>call_if_statement</computeroutput> public member functions</title><orderedlist><listitem><para><literallayout class="monospaced"><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> Else<phrase role="special">></phrase> <phrase role="keyword">void</phrase> <anchor id="idm45394999993376-bb"/><phrase role="identifier">else_</phrase><phrase role="special">(</phrase><phrase role="identifier">Else</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase> f<phrase role="special">)</phrase> <phrase role="keyword">const</phrase><phrase role="special">;</phrase></literallayout></para>Specify the else-branch functor template. <para>
14148 </para><variablelist spacing="compact"><?dbhtml
14149 list-presentation="table"
14150 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
14151 list-presentation="table"
14152 ?><varlistentry><term><computeroutput>f</computeroutput></term><listitem><para>Else-branch nullary functor template. The functor template call <computeroutput>f()</computeroutput> is never compiled or executed for this template specialization (because the if-statement static predicate is <computeroutput>true</computeroutput>). The return type of <computeroutput>f()</computeroutput> must be <computeroutput>void</computeroutput> for this template specialization (because the then-branch functor template calls return void). </para></listitem></varlistentry></variablelist></listitem></varlistentry></variablelist></listitem><listitem><para><literallayout class="monospaced"><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">bool</phrase> ElseIfPred<phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> ElseIfThen<phrase role="special">></phrase>
14153 <link linkend="boost.contract.call_if_statement">call_if_statement</link><phrase role="special"><</phrase> <phrase role="keyword">true</phrase><phrase role="special">,</phrase> <phrase role="identifier">Then</phrase><phrase role="special">,</phrase> <phrase role="keyword">void</phrase> <phrase role="special">></phrase> <anchor id="idm45394999987552-bb"/><phrase role="identifier">else_if_c</phrase><phrase role="special">(</phrase><phrase role="identifier">ElseIfThen</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase> f<phrase role="special">)</phrase> <phrase role="keyword">const</phrase><phrase role="special">;</phrase></literallayout></para>Specify an else-if-branch functor template (using a static boolean predicate). <para>
14156 </para><variablelist spacing="compact"><?dbhtml
14157 list-presentation="table"
14158 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
14159 list-presentation="table"
14160 ?><varlistentry><term><computeroutput>f</computeroutput></term><listitem><para>Else-if-branch nullary functor template. The functor template call <computeroutput>f()</computeroutput> is never compiled or executed for this template specialization (because the if-statement static predicate is <computeroutput>true</computeroutput>). The return type of <computeroutput>f()</computeroutput> must be <computeroutput>void</computeroutput> for this template specialization (because the then-branch functor template calls return void).</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Template Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
14161 list-presentation="table"
14162 ?><varlistentry><term><computeroutput>ElseIfPred</computeroutput></term><listitem><para>Static boolean predicate selecting which functor template call to compile and execute.</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Returns:</term><listitem><para>A call-if statement so the else statement and additional else-if statements can be specified if needed. Eventually, it will return void for this template specialization (because the then-branch functor template calls return void). </para></listitem></varlistentry></variablelist></listitem><listitem><para><literallayout class="monospaced"><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> ElseIfPred<phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> ElseIfThen<phrase role="special">></phrase>
14163 <link linkend="boost.contract.call_if_statement">call_if_statement</link><phrase role="special"><</phrase> <phrase role="keyword">true</phrase><phrase role="special">,</phrase> <phrase role="identifier">Then</phrase><phrase role="special">,</phrase> <phrase role="keyword">void</phrase> <phrase role="special">></phrase> <anchor id="idm45394999979296-bb"/><phrase role="identifier">else_if</phrase><phrase role="special">(</phrase><phrase role="identifier">ElseIfThen</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase> f<phrase role="special">)</phrase> <phrase role="keyword">const</phrase><phrase role="special">;</phrase></literallayout></para>Specify an else-if-branch functor template (using a nullary boolean meta-function). <para>
14166 </para><variablelist spacing="compact"><?dbhtml
14167 list-presentation="table"
14168 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
14169 list-presentation="table"
14170 ?><varlistentry><term><computeroutput>f</computeroutput></term><listitem><para>Else-if-branch nullary functor template. The functor template call <computeroutput>f()</computeroutput> is never compiled or executed for this template specialization (because the if-statement static predicate is <computeroutput>true</computeroutput>). The return type of <computeroutput>f()</computeroutput> must be <computeroutput>void</computeroutput> for this template specialization (because the then-branch functor template calls return void).</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Template Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
14171 list-presentation="table"
14172 ?><varlistentry><term><computeroutput>ElseIfPred</computeroutput></term><listitem><para>Nullary boolean meta-function selecting which functor template call to compile and execute.</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Returns:</term><listitem><para>A call-if statement so the else statement and additional else-if statements can be specified if needed. Eventually, it will return void for this template specialization (because the then-branch functor template calls return void). </para></listitem></varlistentry></variablelist></listitem></orderedlist></refsect2></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.call_if_c"><refmeta><refentrytitle>Function template call_if_c</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::call_if_c</refname><refpurpose>Select compilation and execution of functor template calls using a static boolean predicate (not needed on C++17 compilers, use <computeroutput>if constexpr</computeroutput> instead). </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.call_if_hpp">boost/contract/call_if.hpp</link>>
14175 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">bool</phrase> Pred<phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> Then<phrase role="special">></phrase>
14176 <link linkend="boost.contract.call_if_statement">call_if_statement</link><phrase role="special"><</phrase> <phrase role="identifier">Pred</phrase><phrase role="special">,</phrase> <phrase role="identifier">Then</phrase> <phrase role="special">></phrase> <phrase role="identifier">call_if_c</phrase><phrase role="special">(</phrase><phrase role="identifier">Then</phrase> f<phrase role="special">)</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>Create a call-if object with the specified then-branch functor template:</para><para><programlisting><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">call_if_c</phrase><phrase role="special"><</phrase><phrase role="identifier">Pred1</phrase><phrase role="special">></phrase><phrase role="special">(</phrase>
14177 <phrase role="identifier">then_functor_template1</phrase>
14178 <phrase role="special">)</phrase><phrase role="special">.</phrase><phrase role="keyword">template</phrase> <phrase role="identifier">else_if_c</phrase><phrase role="special"><</phrase><phrase role="identifier">Pred2</phrase><phrase role="special">></phrase><phrase role="special">(</phrase> <phrase role="comment">// Optional.</phrase>
14179 <phrase role="identifier">then_functor_template2</phrase>
14180 <phrase role="special">)</phrase> <phrase role="comment">// Optionally, other `else_if_c` or</phrase>
14181 <phrase role="special">...</phrase> <phrase role="comment">// `else_if`.</phrase>
14182 <phrase role="special">.</phrase><phrase role="identifier">else_</phrase><phrase role="special">(</phrase> <phrase role="comment">// Optional for `void` functors,</phrase>
14183 <phrase role="identifier">else_functor_template</phrase> <phrase role="comment">// but required for non `void`.</phrase>
14184 <phrase role="special">)</phrase>
14185 </programlisting></para><para>Optional functor templates for else-if-branches and the else-branch can be specified as needed (the else-branch function template is required if <computeroutput>f</computeroutput> returns non-void).</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.extras.assertion_requirements__templates_">
14186 Assertion Requirements</link></para>
14191 </para><variablelist spacing="compact"><?dbhtml
14192 list-presentation="table"
14193 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
14194 list-presentation="table"
14195 ?><varlistentry><term><computeroutput>f</computeroutput></term><listitem><para>Then-branch nullary functor template. The functor template call <computeroutput>f()</computeroutput> is compiled and executed if and only if <computeroutput>Pred</computeroutput> is <computeroutput>true</computeroutput>. The return type of other functor template calls specified for this call-if statement (else-branch, else-if-branches, etc.) must be the same as (or implicitly convertible to) the return type of then-branch functor call <computeroutput>f()</computeroutput>.</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Template Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
14196 list-presentation="table"
14197 ?><varlistentry><term><computeroutput>Pred</computeroutput></term><listitem><para>Static boolean predicate selecting which functor template call to compile and execute.</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Returns:</term><listitem><para>A call-if statement so else and else-if statements can be specified if needed. Eventually, this will be the return value of the one functor template call being compiled and executed (which could also be <computeroutput>void</computeroutput>). </para></listitem></varlistentry></variablelist></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.call_if"><refmeta><refentrytitle>Function template call_if</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::call_if</refname><refpurpose>Select compilation and execution of functor template calls using a nullary boolean meta-function (not needed on C++17 compilers, use <computeroutput>if constexpr</computeroutput> instead). </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.call_if_hpp">boost/contract/call_if.hpp</link>>
14200 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> Pred<phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> Then<phrase role="special">></phrase>
14201 <link linkend="boost.contract.call_if_statement">call_if_statement</link><phrase role="special"><</phrase> <phrase role="identifier">Pred</phrase><phrase role="special">::</phrase><phrase role="identifier">value</phrase><phrase role="special">,</phrase> <phrase role="identifier">Then</phrase> <phrase role="special">></phrase> <phrase role="identifier">call_if</phrase><phrase role="special">(</phrase><phrase role="identifier">Then</phrase> f<phrase role="special">)</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This is equivalent to <computeroutput>boost::contract::call_if_c<Pred::value>(f)</computeroutput>. Create a call-if object with the specified then-branch functor template:</para><para><programlisting><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">call_if</phrase><phrase role="special"><</phrase><phrase role="identifier">Pred1</phrase><phrase role="special">></phrase><phrase role="special">(</phrase>
14202 <phrase role="identifier">then_functor_template1</phrase>
14203 <phrase role="special">)</phrase><phrase role="special">.</phrase><phrase role="keyword">template</phrase> <phrase role="identifier">else_if</phrase><phrase role="special"><</phrase><phrase role="identifier">Pred2</phrase><phrase role="special">></phrase><phrase role="special">(</phrase> <phrase role="comment">// Optional.</phrase>
14204 <phrase role="identifier">then_functor_template2</phrase>
14205 <phrase role="special">)</phrase> <phrase role="comment">// Optionally, other `else_if` or</phrase>
14206 <phrase role="special">...</phrase> <phrase role="comment">// `else_if_c`.</phrase>
14207 <phrase role="special">.</phrase><phrase role="identifier">else_</phrase><phrase role="special">(</phrase> <phrase role="comment">// Optional for `void` functors,</phrase>
14208 <phrase role="identifier">else_functor_template</phrase> <phrase role="comment">// but required for non `void`.</phrase>
14209 <phrase role="special">)</phrase>
14210 </programlisting></para><para>Optional functor templates for else-if-branches and the else-branch can be specified as needed (the else-branch functor template is required if <computeroutput>f</computeroutput> returns non-void).</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.extras.assertion_requirements__templates_">
14211 Assertion Requirements</link></para>
14216 </para><variablelist spacing="compact"><?dbhtml
14217 list-presentation="table"
14218 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
14219 list-presentation="table"
14220 ?><varlistentry><term><computeroutput>f</computeroutput></term><listitem><para>Then-branch nullary functor template. The functor template call <computeroutput>f()</computeroutput> is compiled and executed if and only if <computeroutput>Pred::value</computeroutput> is <computeroutput>true</computeroutput>. The return type of other functor template calls specified for this call-if statement (else-branch, else-if-branches, etc.) must be the same as (or implicitly convertible to) the return type of then-branch functor template call <computeroutput>f()</computeroutput>.</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Template Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
14221 list-presentation="table"
14222 ?><varlistentry><term><computeroutput>Pred</computeroutput></term><listitem><para>Nullary boolean meta-function selecting which functor template call to compile and execute.</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Returns:</term><listitem><para>A call-if statement so else and else-if statements can be specified if needed. Eventually, this will be the return value of the one functor template call being compiled and executed (which could also be <computeroutput>void</computeroutput>). </para></listitem></varlistentry></variablelist></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.condition_if_c"><refmeta><refentrytitle>Function template condition_if_c</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::condition_if_c</refname><refpurpose>Select compilation and execution of a boolean functor template condition using a static boolean predicate (not needed on C++17 compilers, use <computeroutput>if constexpr</computeroutput> instead). </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.call_if_hpp">boost/contract/call_if.hpp</link>>
14225 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">bool</phrase> Pred<phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> Then<phrase role="special">></phrase>
14226 <phrase role="keyword">bool</phrase> <phrase role="identifier">condition_if_c</phrase><phrase role="special">(</phrase><phrase role="identifier">Then</phrase> f<phrase role="special">,</phrase> <phrase role="keyword">bool</phrase> else_ <phrase role="special">=</phrase> <phrase role="keyword">true</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>Compile and execute the nullary boolean functor template call <computeroutput>f()</computeroutput> if and only if the specified static boolean predicate <computeroutput>Pred</computeroutput> is <computeroutput>true</computeroutput>, otherwise trivially return <computeroutput>else_</computeroutput> (<computeroutput>true</computeroutput> by default) at run-time.</para><para>A call to <computeroutput>boost::contract::condition_if_c<Pred>(f, else_)</computeroutput> is logically equivalent to <computeroutput>boost::contract::call_if_c<Pred>(f, [] { return else_; })</computeroutput> (but its internal implementation is optimized and it does not actually use <computeroutput>call_if_c</computeroutput>).</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.extras.assertion_requirements__templates_">
14227 Assertion Requirements</link></para>
14233 </para><variablelist spacing="compact"><?dbhtml
14234 list-presentation="table"
14235 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
14236 list-presentation="table"
14237 ?><varlistentry><term><computeroutput>else_</computeroutput></term><listitem><para>Boolean value to return when <computeroutput>Pred</computeroutput> is <computeroutput>false</computeroutput> (instead of compiling and executing the functor template call <computeroutput>f()</computeroutput>).</para></listitem></varlistentry><varlistentry><term><computeroutput>f</computeroutput></term><listitem><para>Nullary boolean functor template. The functor template call <computeroutput>f()</computeroutput> is compiled and executed if and only if <computeroutput>Pred</computeroutput> is <computeroutput>true</computeroutput>.</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Template Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
14238 list-presentation="table"
14239 ?><varlistentry><term><computeroutput>Pred</computeroutput></term><listitem><para>Static boolean predicate selecting when the functor template call <computeroutput>f()</computeroutput> should be compiled and executed. </para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Returns:</term><listitem><para>Boolean value returned by <computeroutput>f()</computeroutput> if the static predicate <computeroutput>Pred</computeroutput> is <computeroutput>true</computeroutput>. Otherwise, trivially return <computeroutput>else_</computeroutput>. </para></listitem></varlistentry></variablelist></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.condition_if"><refmeta><refentrytitle>Function template condition_if</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::condition_if</refname><refpurpose>Select compilation and execution of a boolean functor template condition using a nullary boolean meta-function (not needed on C++17 compilers, use <computeroutput>if constexpr</computeroutput> instead). </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.call_if_hpp">boost/contract/call_if.hpp</link>>
14242 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> Pred<phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> Then<phrase role="special">></phrase>
14243 <phrase role="keyword">bool</phrase> <phrase role="identifier">condition_if</phrase><phrase role="special">(</phrase><phrase role="identifier">Then</phrase> f<phrase role="special">,</phrase> <phrase role="keyword">bool</phrase> else_ <phrase role="special">=</phrase> <phrase role="keyword">true</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This is equivalent to <computeroutput>boost::contract::condition_if_c<Pred::value>(f, else_)</computeroutput>. Compile and execute the nullary boolean functor template call <computeroutput>f()</computeroutput> if and only if the specified nullary boolean meta-function <computeroutput>Pred::value</computeroutput> is <computeroutput>true</computeroutput>, otherwise trivially return <computeroutput>else_</computeroutput> (<computeroutput>true</computeroutput> by default) at run-time.</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.extras.assertion_requirements__templates_">
14244 Assertion Requirements</link></para>
14249 </para><variablelist spacing="compact"><?dbhtml
14250 list-presentation="table"
14251 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
14252 list-presentation="table"
14253 ?><varlistentry><term><computeroutput>else_</computeroutput></term><listitem><para>Boolean value to return when <computeroutput>Pred::value</computeroutput> is <computeroutput>false</computeroutput> (instead of compiling and executing the functor template call <computeroutput>f()</computeroutput>).</para></listitem></varlistentry><varlistentry><term><computeroutput>f</computeroutput></term><listitem><para>Nullary boolean functor template. The functor template call <computeroutput>f()</computeroutput> is compiled and executed if and only if <computeroutput>Pred::value</computeroutput> is <computeroutput>true</computeroutput>. </para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Template Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
14254 list-presentation="table"
14255 ?><varlistentry><term><computeroutput>Pred</computeroutput></term><listitem><para>Nullary boolean meta-function selecting when the functor template call <computeroutput>f()</computeroutput> should be compiled and executed.</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Returns:</term><listitem><para>Boolean value returned by <computeroutput>f()</computeroutput> if the static predicate <computeroutput>Pred::value</computeroutput> is <computeroutput>true</computeroutput>. Otherwise, trivially return <computeroutput>else_</computeroutput>. </para></listitem></varlistentry></variablelist></refsect1></refentry>
14257 <section id="header.boost.contract.check_hpp"><title>Header <<ulink url="../../../../boost/contract/check.hpp">boost/contract/check.hpp</ulink>></title><para>RAII object that checks contracts. </para><synopsis xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">namespace</phrase> <phrase role="identifier">boost</phrase> <phrase role="special">{</phrase>
14258 <phrase role="keyword">namespace</phrase> <phrase role="identifier">contract</phrase> <phrase role="special">{</phrase>
14259 <phrase role="keyword">class</phrase> <link linkend="boost.contract.check">check</link><phrase role="special">;</phrase>
14260 <phrase role="special">}</phrase>
14261 <phrase role="special">}</phrase></synopsis>
14262 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.check"><refmeta><refentrytitle>Class check</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::check</refname><refpurpose>RAII object that checks the contracts. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.check_hpp">boost/contract/check.hpp</link>>
14265 <phrase role="keyword">class</phrase> <link linkend="boost.contract.check">check</link> <phrase role="special">{</phrase>
14266 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
14267 <phrase role="comment">// <link linkend="boost.contract.checkconstruct-copy-destruct">construct/copy/destruct</link></phrase>
14268 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> F<phrase role="special">></phrase> <link linkend="idm45394999887520-bb"><phrase role="identifier">check</phrase></link><phrase role="special">(</phrase><phrase role="identifier">F</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14269 <link linkend="idm45394999880144-bb"><phrase role="identifier">check</phrase></link><phrase role="special">(</phrase><link linkend="boost.contract.check">check</link> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14270 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> VirtualResult<phrase role="special">></phrase>
14271 <link linkend="idm45394999877248-bb"><phrase role="identifier">check</phrase></link><phrase role="special">(</phrase><link linkend="boost.contract.specify__idm45394999179040">specify_precondition_old_postcondition_except</link><phrase role="special"><</phrase> <phrase role="identifier">VirtualResult</phrase> <phrase role="special">></phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14272 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> VirtualResult<phrase role="special">></phrase>
14273 <link linkend="idm45394999867968-bb"><phrase role="identifier">check</phrase></link><phrase role="special">(</phrase><link linkend="boost.contract.specify__idm45394999245856">specify_old_postcondition_except</link><phrase role="special"><</phrase> <phrase role="identifier">VirtualResult</phrase> <phrase role="special">></phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14274 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> VirtualResult<phrase role="special">></phrase>
14275 <link linkend="idm45394999856928-bb"><phrase role="identifier">check</phrase></link><phrase role="special">(</phrase><link linkend="boost.contract.specify__idm45394999207792">specify_postcondition_except</link><phrase role="special"><</phrase> <phrase role="identifier">VirtualResult</phrase> <phrase role="special">></phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14276 <link linkend="idm45394999845840-bb"><phrase role="identifier">check</phrase></link><phrase role="special">(</phrase><link linkend="boost.contract.specify_except">specify_except</link> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14277 <link linkend="idm45394999836656-bb"><phrase role="identifier">check</phrase></link><phrase role="special">(</phrase><link linkend="boost.contract.specify_nothing">specify_nothing</link> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14278 <link linkend="idm45394999827456-bb"><phrase role="special">~</phrase><phrase role="identifier">check</phrase></link><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14279 <phrase role="special">}</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>In general, when this object is constructed it checks class invariants at entry, preconditions, and makes old value copies at body. When it is destructed, it checks class invariants at exist, postconditions, and exception guarantees. This object enforces the following (see <link linkend="boost_contract.contract_programming_overview"> Contract Programming Overview</link>):</para><para><itemizedlist>
14280 <listitem><para>Postconditions are checked only if the body does not throw an exception. </para>
14282 <listitem><para>Exceptions guarantees are checked only if the body throws an exception. </para>
14284 <listitem><para>Constructor entry never checks class invariants. </para>
14286 <listitem><para>Destructor exit checks class invariants only if the body throws an exception (even if destructors should usually not be programmed to throw exceptions in C++ and they are implicitly declared <computeroutput>noexcept</computeroutput> since C++11). </para>
14288 <listitem><para>Static invariants are always checked at entry and exit (and regardless of the body throwing exceptions or not).</para>
14291 When used this way, this object is constructed and initialized to the return value of one of the contract functions <computeroutput><link linkend="boost.contract.function">boost::contract::function</link></computeroutput>, <computeroutput><link linkend="boost.contract.constructor">boost::contract::constructor</link></computeroutput>, <computeroutput><link linkend="boost.contract.destructor">boost::contract::destructor</link></computeroutput>, or <computeroutput><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>. In addition to that, this object can be constructed from a nullary functor when it is used to program implementation checks.</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.tutorial"> Tutorial</link>, <link linkend="boost_contract.advanced.implementation_checks"> Implementation Checks</link> </para>
14293 </para><refsect2><title><anchor id="boost.contract.checkconstruct-copy-destruct"/><computeroutput>check</computeroutput>
14295 construct/copy/destruct</title><orderedlist><listitem><para><literallayout class="monospaced"><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> F<phrase role="special">></phrase> <anchor id="idm45394999887520-bb"/><phrase role="identifier">check</phrase><phrase role="special">(</phrase><phrase role="identifier">F</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase> f<phrase role="special">)</phrase><phrase role="special">;</phrase></literallayout></para>Construct this object for implementation checks. <para>This can be used to program checks within implementation code (body, etc.). This constructor is not declared <computeroutput>explicit</computeroutput> so initializations can use assignment syntax <computeroutput>=</computeroutput>.</para><para><emphasis role="bold">Throws:</emphasis> This can throw in case programmers specify contract failure handlers that throw exceptions instead of terminating the program (see <link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__">
14296 Throw on Failure</link>).</para><para>
14297 </para><variablelist spacing="compact"><?dbhtml
14298 list-presentation="table"
14299 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
14300 list-presentation="table"
14301 ?><varlistentry><term><computeroutput>f</computeroutput></term><listitem><para>Nullary functor that asserts implementation checks. <computeroutput>f()</computeroutput> will be called as soon as this object is constructed at the point it is declared within the implementation code (see <link linkend="boost_contract.advanced.implementation_checks">
14302 Implementation Checks</link>). </para></listitem></varlistentry></variablelist></listitem></varlistentry></variablelist></listitem><listitem><para><literallayout class="monospaced"><anchor id="idm45394999880144-bb"/><phrase role="identifier">check</phrase><phrase role="special">(</phrase><link linkend="boost.contract.check">check</link> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase> other<phrase role="special">)</phrase><phrase role="special">;</phrase></literallayout></para>Construct this object copying it from the specified one. <para>This object will check the contract, the copied-from object will not (i.e., contract check ownership is transferred from the copied object to the new object being created by this constructor).</para><para>
14303 </para><variablelist spacing="compact"><?dbhtml
14304 list-presentation="table"
14305 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
14306 list-presentation="table"
14307 ?><varlistentry><term><computeroutput>other</computeroutput></term><listitem><para>Copied-from object. </para></listitem></varlistentry></variablelist></listitem></varlistentry></variablelist></listitem><listitem><para><literallayout class="monospaced"><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> VirtualResult<phrase role="special">></phrase>
14308 <anchor id="idm45394999877248-bb"/><phrase role="identifier">check</phrase><phrase role="special">(</phrase><link linkend="boost.contract.specify__idm45394999179040">specify_precondition_old_postcondition_except</link><phrase role="special"><</phrase> <phrase role="identifier">VirtualResult</phrase> <phrase role="special">></phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase> contract<phrase role="special">)</phrase><phrase role="special">;</phrase></literallayout></para>Construct this object to check the specified contract. <para>This checks class invariants at entry (if those were specified for the given contract). This constructor is not declared <computeroutput>explicit</computeroutput> so initializations can use assignment syntax <computeroutput>=</computeroutput>.</para><para><emphasis role="bold">Throws:</emphasis> This can throw in case programmers specify contract failure handlers that throw exceptions instead of terminating the program (see <link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__">
14309 Throw on Failure</link>).</para><para>
14311 </para><variablelist spacing="compact"><?dbhtml
14312 list-presentation="table"
14313 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
14314 list-presentation="table"
14315 ?><varlistentry><term><computeroutput>contract</computeroutput></term><listitem><para>Contract to be checked (usually the return value of <computeroutput><computeroutput><link linkend="boost.contract.function">boost::contract::function</link></computeroutput></computeroutput> or <computeroutput><computeroutput><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput></computeroutput>).</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Template Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
14316 list-presentation="table"
14317 ?><varlistentry><term><computeroutput>VirtualResult</computeroutput></term><listitem><para>Return type of the enclosing function declaring the contract if that is either a virtual or an overriding public function, otherwise this is always <computeroutput>void</computeroutput>. (Usually this template parameter is automatically deduced by C++ and it does not need to be explicitly specified by programmers.) </para></listitem></varlistentry></variablelist></listitem></varlistentry></variablelist></listitem><listitem><para><literallayout class="monospaced"><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> VirtualResult<phrase role="special">></phrase>
14318 <anchor id="idm45394999867968-bb"/><phrase role="identifier">check</phrase><phrase role="special">(</phrase><link linkend="boost.contract.specify__idm45394999245856">specify_old_postcondition_except</link><phrase role="special"><</phrase> <phrase role="identifier">VirtualResult</phrase> <phrase role="special">></phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase> contract<phrase role="special">)</phrase><phrase role="special">;</phrase></literallayout></para>Construct this object to check the specified contract. <para>This checks class invariants at entry and preconditions (if any of those were specified for the given contract). This constructor is not declared <computeroutput>explicit</computeroutput> so initializations can use assignment syntax <computeroutput>=</computeroutput>.</para><para><emphasis role="bold">Throws:</emphasis> This can throw in case programmers specify contract failure handlers that throw exceptions instead of terminating the program (see <link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__">
14319 Throw on Failure</link>).</para><para>
14321 </para><variablelist spacing="compact"><?dbhtml
14322 list-presentation="table"
14323 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
14324 list-presentation="table"
14325 ?><varlistentry><term><computeroutput>contract</computeroutput></term><listitem><para>Contract to be checked (usually the return value of <computeroutput><computeroutput><link linkend="boost.contract.function">boost::contract::function</link></computeroutput></computeroutput>, <computeroutput><computeroutput><link linkend="boost.contract.constructor">boost::contract::constructor</link></computeroutput></computeroutput>, <computeroutput><computeroutput><link linkend="boost.contract.destructor">boost::contract::destructor</link></computeroutput></computeroutput>, or <computeroutput><computeroutput><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput></computeroutput>).</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Template Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
14326 list-presentation="table"
14327 ?><varlistentry><term><computeroutput>VirtualResult</computeroutput></term><listitem><para>Return type of the enclosing function declaring the contract if that is either a virtual or an overriding public function, otherwise this is always <computeroutput>void</computeroutput>. (Usually this template parameter is automatically deduced by C++ and it does not need to be explicitly specified by programmers.) </para></listitem></varlistentry></variablelist></listitem></varlistentry></variablelist></listitem><listitem><para><literallayout class="monospaced"><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> VirtualResult<phrase role="special">></phrase>
14328 <anchor id="idm45394999856928-bb"/><phrase role="identifier">check</phrase><phrase role="special">(</phrase><link linkend="boost.contract.specify__idm45394999207792">specify_postcondition_except</link><phrase role="special"><</phrase> <phrase role="identifier">VirtualResult</phrase> <phrase role="special">></phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase> contract<phrase role="special">)</phrase><phrase role="special">;</phrase></literallayout></para>Construct this object to check the specified contract. <para>This checks class invariants at entry and preconditions then it makes old value copies at body (if any of those were specified for the given contract). This constructor is not declared <computeroutput>explicit</computeroutput> so initializations can use assignment syntax <computeroutput>=</computeroutput>.</para><para><emphasis role="bold">Throws:</emphasis> This can throw in case programmers specify contract failure handlers that throw exceptions instead of terminating te program (see <link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__">
14329 Throw on Failure</link>).</para><para>
14331 </para><variablelist spacing="compact"><?dbhtml
14332 list-presentation="table"
14333 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
14334 list-presentation="table"
14335 ?><varlistentry><term><computeroutput>contract</computeroutput></term><listitem><para>Contract to be checked (usually the return value of <computeroutput><computeroutput><link linkend="boost.contract.function">boost::contract::function</link></computeroutput></computeroutput>, <computeroutput><computeroutput><link linkend="boost.contract.constructor">boost::contract::constructor</link></computeroutput></computeroutput>, <computeroutput><computeroutput><link linkend="boost.contract.destructor">boost::contract::destructor</link></computeroutput></computeroutput>, or <computeroutput><computeroutput><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput></computeroutput>).</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Template Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
14336 list-presentation="table"
14337 ?><varlistentry><term><computeroutput>VirtualResult</computeroutput></term><listitem><para>Return type of the enclosing function declaring the contract if that is either a virtual or an overriding public function, otherwise this is always <computeroutput>void</computeroutput>. (Usually this template parameter is automatically deduced by C++ and it does not need to be explicitly specified by programmers.) </para></listitem></varlistentry></variablelist></listitem></varlistentry></variablelist></listitem><listitem><para><literallayout class="monospaced"><anchor id="idm45394999845840-bb"/><phrase role="identifier">check</phrase><phrase role="special">(</phrase><link linkend="boost.contract.specify_except">specify_except</link> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase> contract<phrase role="special">)</phrase><phrase role="special">;</phrase></literallayout></para>Construct this object to check the specified contract. <para>This checks class invariants at entry and preconditions then it makes old value copies at body, plus the destructor of this object will also check postconditions in this case (if any of those were specified for the given contract). This constructor is not declared <computeroutput>explicit</computeroutput> so initializations can use assignment syntax <computeroutput>=</computeroutput>.</para><para><emphasis role="bold">Throws:</emphasis> This can throw in case programmers specify contract failure handlers that throw exceptions instead of terminating the program (see <link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__">
14338 Throw on Failure</link>).</para><para>
14340 </para><variablelist spacing="compact"><?dbhtml
14341 list-presentation="table"
14342 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
14343 list-presentation="table"
14344 ?><varlistentry><term><computeroutput>contract</computeroutput></term><listitem><para>Contract to be checked (usually the return value of <computeroutput><computeroutput><link linkend="boost.contract.function">boost::contract::function</link></computeroutput></computeroutput>, <computeroutput><computeroutput><link linkend="boost.contract.constructor">boost::contract::constructor</link></computeroutput></computeroutput>, <computeroutput><computeroutput><link linkend="boost.contract.destructor">boost::contract::destructor</link></computeroutput></computeroutput>, or <computeroutput><computeroutput><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput></computeroutput>).</para></listitem></varlistentry></variablelist></listitem></varlistentry></variablelist></listitem><listitem><para><literallayout class="monospaced"><anchor id="idm45394999836656-bb"/><phrase role="identifier">check</phrase><phrase role="special">(</phrase><link linkend="boost.contract.specify_nothing">specify_nothing</link> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase> contract<phrase role="special">)</phrase><phrase role="special">;</phrase></literallayout></para>Construct this object to check the specified contract. <para>This checks class invariants at entry and preconditions then it makes old value copies at body, plus the destructor of this object will also check postconditions and exception guarantees in this case (if any of those were specified for the given contract). This constructor is not declared <computeroutput>explicit</computeroutput> so initializations can use assignment syntax <computeroutput>=</computeroutput>.</para><para><emphasis role="bold">Throws:</emphasis> This can throw in case programmers specify contract failure handlers that throw exceptions instead of terminating the program (see <link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__">
14345 Throw on Failure</link>).</para><para>
14347 </para><variablelist spacing="compact"><?dbhtml
14348 list-presentation="table"
14349 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
14350 list-presentation="table"
14351 ?><varlistentry><term><computeroutput>contract</computeroutput></term><listitem><para>Contract to be checked (usually the return value of <computeroutput><computeroutput><link linkend="boost.contract.function">boost::contract::function</link></computeroutput></computeroutput>, <computeroutput><computeroutput><link linkend="boost.contract.constructor">boost::contract::constructor</link></computeroutput></computeroutput>, <computeroutput><computeroutput><link linkend="boost.contract.destructor">boost::contract::destructor</link></computeroutput></computeroutput>, or <computeroutput><computeroutput><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput></computeroutput>).</para></listitem></varlistentry></variablelist></listitem></varlistentry></variablelist></listitem><listitem><para><literallayout class="monospaced"><anchor id="idm45394999827456-bb"/><phrase role="special">~</phrase><phrase role="identifier">check</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase></literallayout></para>Destruct this object. <para>This checks class invariants at exit and either postconditions when the enclosing function body did not throw an exception, or exception guarantees when the function body threw an exception (if class invariants, postconditions, and exception guarantees respectively were specified for the enclosing class and the contract parameter given when constructing this object).</para><para><emphasis role="bold">Throws:</emphasis> This can throw in case programmers specify contract failure handlers that throw exceptions instead of terminating the program (see <link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__">
14352 Throw on Failure</link>). (This is declared <computeroutput>noexcept(false)</computeroutput> since C++11.) </para></listitem></orderedlist></refsect2></refsect1></refentry>
14354 <section id="header.boost.contract.constructor_hpp"><title>Header <<ulink url="../../../../boost/contract/constructor.hpp">boost/contract/constructor.hpp</ulink>></title><para>Program contracts for constructors. </para><synopsis xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">namespace</phrase> <phrase role="identifier">boost</phrase> <phrase role="special">{</phrase>
14355 <phrase role="keyword">namespace</phrase> <phrase role="identifier">contract</phrase> <phrase role="special">{</phrase>
14356 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> Class<phrase role="special">></phrase>
14357 <link linkend="boost.contract.specify__idm45394999245856">specify_old_postcondition_except</link> <link linkend="boost.contract.constructor"><phrase role="identifier">constructor</phrase></link><phrase role="special">(</phrase><phrase role="identifier">Class</phrase> <phrase role="special">*</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14358 <phrase role="special">}</phrase>
14359 <phrase role="special">}</phrase></synopsis>
14360 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.constructor"><refmeta><refentrytitle>Function template constructor</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::constructor</refname><refpurpose>Program contracts for constructors. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.constructor_hpp">boost/contract/constructor.hpp</link>>
14363 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> Class<phrase role="special">></phrase>
14364 <link linkend="boost.contract.specify__idm45394999245856">specify_old_postcondition_except</link> <phrase role="identifier">constructor</phrase><phrase role="special">(</phrase><phrase role="identifier">Class</phrase> <phrase role="special">*</phrase> obj<phrase role="special">)</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This is used to specify postconditions, exception guarantees, old value copies at body, and check class invariants for constructors (see <computeroutput><computeroutput><link linkend="boost.contract.constructor_precondition">boost::contract::constructor_precondition</link></computeroutput></computeroutput> to specify preconditions for constructors):</para><para><programlisting><phrase role="keyword">class</phrase> <phrase role="identifier">u</phrase> <phrase role="special">{</phrase>
14365 <phrase role="keyword">friend</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">:</phrase><phrase role="identifier">access</phrase><phrase role="special">;</phrase>
14367 <phrase role="keyword">void</phrase> <phrase role="identifier">invariant</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional (as for static and volatile).</phrase>
14368 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14369 <phrase role="special">...</phrase>
14370 <phrase role="special">}</phrase>
14372 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
14373 <phrase role="identifier">u</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
14374 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="identifier">old_type</phrase><phrase role="special">></phrase> <phrase role="identifier">old_var</phrase><phrase role="special">;</phrase>
14375 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
14376 <phrase role="comment">// No `.precondition` (use `constructor_precondition` instead).</phrase>
14377 <phrase role="special">.</phrase><phrase role="identifier">old</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
14378 <phrase role="identifier">old_var</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">old_expr</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14379 <phrase role="special">...</phrase>
14380 <phrase role="special">}</phrase><phrase role="special">)</phrase>
14381 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
14382 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14383 <phrase role="special">...</phrase>
14384 <phrase role="special">}</phrase><phrase role="special">)</phrase>
14385 <phrase role="special">.</phrase><phrase role="identifier">except</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
14386 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14387 <phrase role="special">...</phrase>
14388 <phrase role="special">}</phrase><phrase role="special">)</phrase>
14389 <phrase role="special">;</phrase>
14391 <phrase role="special">...</phrase> <phrase role="comment">// Constructor body.</phrase>
14392 <phrase role="special">}</phrase>
14394 <phrase role="special">...</phrase>
14395 <phrase role="special">}</phrase><phrase role="special">;</phrase>
14396 </programlisting></para><para>For optimization, this can be omitted for constructors that do not have postconditions and exception guarantees, within classes that have no invariants.</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.tutorial.constructors"> Constructors</link></para>
14401 </para><variablelist spacing="compact"><?dbhtml
14402 list-presentation="table"
14403 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
14404 list-presentation="table"
14405 ?><varlistentry><term><computeroutput>obj</computeroutput></term><listitem><para>The object <computeroutput>this</computeroutput> from the scope of the enclosing constructor declaring the contract. (Constructors check all class invariants, including static and volatile invariants, see <link linkend="boost_contract.tutorial.class_invariants">
14406 Class Invariants</link> and <link linkend="boost_contract.extras.volatile_public_functions">
14407 Volatile Public Functions</link>).</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Template Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
14408 list-presentation="table"
14409 ?><varlistentry><term><computeroutput>Class</computeroutput></term><listitem><para>The type of the class containing the constructor declaring the contract. (Usually this template parameter is automatically deduced by C++ and it does not need to be explicitly specified by programmers.)</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Returns:</term><listitem><para>The result of this function must be assigned to a variable of type <computeroutput><link linkend="boost.contract.check">boost::contract::check</link></computeroutput> declared explicitly (i.e., without using C++11 <computeroutput>auto</computeroutput> declarations) and locally just before the code of the constructor body (otherwise this library will generate a run-time error, see <computeroutput><link linkend="BOOST_CO_idm45394999694064">BOOST_CONTRACT_ON_MISSING_CHECK_DECL</link></computeroutput>). </para></listitem></varlistentry></variablelist></refsect1></refentry>
14411 <section id="header.boost.contract.core.access_hpp"><title>Header <<ulink url="../../../../boost/contract/core/access.hpp">boost/contract/core/access.hpp</ulink>></title><para>Allow to declare invariants, base types, etc all as private members. </para><synopsis xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">namespace</phrase> <phrase role="identifier">boost</phrase> <phrase role="special">{</phrase>
14412 <phrase role="keyword">namespace</phrase> <phrase role="identifier">contract</phrase> <phrase role="special">{</phrase>
14413 <phrase role="keyword">class</phrase> <link linkend="boost.contract.access">access</link><phrase role="special">;</phrase>
14414 <phrase role="special">}</phrase>
14415 <phrase role="special">}</phrase></synopsis>
14416 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.access"><refmeta><refentrytitle>Class access</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::access</refname><refpurpose>Declare this class as friend to program invariants and base types as private members. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.access_hpp">boost/contract/core/access.hpp</link>>
14419 <phrase role="keyword">class</phrase> <link linkend="boost.contract.access">access</link> <phrase role="special">{</phrase>
14420 <phrase role="special">}</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>Declare this class a friend of the user-defined class specifying the contracts and then invariant functions and the base types <computeroutput>typedef</computeroutput> can be declared as non-public members:</para><para><programlisting><phrase role="keyword">class</phrase> <phrase role="identifier">u</phrase>
14421 <phrase role="preprocessor">#define</phrase> <phrase role="identifier">BASES</phrase> <phrase role="keyword">public</phrase> <phrase role="identifier">b</phrase><phrase role="special">,</phrase> <phrase role="keyword">private</phrase> <phrase role="identifier">w</phrase>
14422 <phrase role="special">:</phrase> <phrase role="identifier">BASES</phrase>
14423 <phrase role="special">{</phrase>
14424 <phrase role="keyword">friend</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">access</phrase><phrase role="special">;</phrase>
14426 <phrase role="keyword">typedef</phrase> <phrase role="identifier">BOOST_CONTRACT_BASE_TYPES</phrase><phrase role="special">(</phrase><phrase role="identifier">BASES</phrase><phrase role="special">)</phrase> <phrase role="identifier">base_types</phrase><phrase role="special">;</phrase> <phrase role="comment">// Private.</phrase>
14427 <phrase role="preprocessor">#undef</phrase> <phrase role="identifier">BASES</phrase>
14429 <phrase role="keyword">void</phrase> <phrase role="identifier">invariant</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase> <phrase role="special">...</phrase> <phrase role="special">}</phrase> <phrase role="comment">// Private (same for static and volatile).</phrase>
14431 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
14432 <phrase role="special">...</phrase>
14433 <phrase role="special">}</phrase><phrase role="special">;</phrase>
14434 </programlisting></para><para>In real code, programmers will likely chose to declare this class as friend so to fully control public interfaces of their user-defined classes (this is not extensively done in the examples of this documentation only for brevity). This class is not intended to be directly used by programmers a part from being declared as <computeroutput>friend</computeroutput> (and that is why this class does not have any public member and it is not copyable).</para><para><warning><para>Not declaring this class friend of user-defined classes will cause compiler errors on some compilers (e.g., MSVC) because the private members needed to check the contracts will not be accessible. On other compilers (e.g., GCC and CLang), the private access will instead fail SFINAE and no compiler error will be reported while invariants and subcontracting will be silently skipped at run-time. Therefore, programmers must make sure to either declare this class as friend or to always declare invariant functions and base types <computeroutput>typedef</computeroutput> as public members.</para>
14436 <para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.advanced.access_specifiers"> Access Specifiers</link> </para>
14438 </para></refsect1></refentry>
14440 <section id="header.boost.contract.core.check_macro_hpp"><title>Header <<ulink url="../../../../boost/contract/core/check_macro.hpp">boost/contract/core/check_macro.hpp</ulink>></title><para>Macros for implementation checks. </para><synopsis xmlns:xi="http://www.w3.org/2001/XInclude">
14442 <link linkend="BOOST_CONTRACT_CHECK">BOOST_CONTRACT_CHECK</link>(cond)
14443 <link linkend="BOOST_CONTRACT_CHECK_AUDIT">BOOST_CONTRACT_CHECK_AUDIT</link>(cond)
14444 <link linkend="BOOST_CONTRACT_CHECK_AXIOM">BOOST_CONTRACT_CHECK_AXIOM</link>(cond)</synopsis>
14445 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CONTRACT_CHECK"><refmeta><refentrytitle>Macro BOOST_CONTRACT_CHECK</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_CHECK</refname><refpurpose>Preferred way to assert implementation check conditions. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.check_macro_hpp">boost/contract/core/check_macro.hpp</link>>
14447 </phrase>BOOST_CONTRACT_CHECK(cond)</synopsis></refsynopsisdiv><refsect1><title>Description</title><para>It is preferred to use this macro instead of programming implementation checks in a nullary functor passed to <computeroutput><link linkend="boost.contract.check">boost::contract::check</link></computeroutput> constructor because this macro will completely remove implementation checks from the code when <computeroutput><link linkend="BOOST_CONTRACT_NO_CHECKS">BOOST_CONTRACT_NO_CHECKS</link></computeroutput> is defined:</para><para><programlisting><phrase role="keyword">void</phrase> <phrase role="identifier">f</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
14448 <phrase role="special">...</phrase>
14449 <phrase role="identifier">BOOST_CONTRACT_CHECK</phrase><phrase role="special">(</phrase><phrase role="identifier">cond</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14450 <phrase role="special">...</phrase>
14451 <phrase role="special">}</phrase>
14452 </programlisting></para><para> <computeroutput><link linkend="BOOST_CONTRACT_CHECK">BOOST_CONTRACT_CHECK</link></computeroutput>, <computeroutput><link linkend="BOOST_CONTRACT_CHECK_AUDIT">BOOST_CONTRACT_CHECK_AUDIT</link></computeroutput>, and <computeroutput><link linkend="BOOST_CONTRACT_CHECK_AXIOM">BOOST_CONTRACT_CHECK_AXIOM</link></computeroutput> are the three assertion levels predefined by this library for implementation checks.</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.advanced.implementation_checks"> Implementation Checks</link></para>
14455 </para><variablelist spacing="compact"><?dbhtml
14456 list-presentation="table"
14457 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
14458 list-presentation="table"
14459 ?><varlistentry><term><computeroutput>cond</computeroutput></term><listitem><para>Boolean condition to check within implementation code (function body, etc.). (This is not a variadic macro parameter so any comma it might contain must be protected by round parenthesis and <computeroutput>BOOST_CONTRACT_CHECK((cond))</computeroutput> will always work.) </para></listitem></varlistentry></variablelist></listitem></varlistentry></variablelist></refsect1></refentry>
14460 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CONTRACT_CHECK_AUDIT"><refmeta><refentrytitle>Macro BOOST_CONTRACT_CHECK_AUDIT</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_CHECK_AUDIT</refname><refpurpose>Preferred way to assert implementation check conditions that are computationally expensive, at least compared to the computational cost of executing the function body. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.check_macro_hpp">boost/contract/core/check_macro.hpp</link>>
14462 </phrase>BOOST_CONTRACT_CHECK_AUDIT(cond)</synopsis></refsynopsisdiv><refsect1><title>Description</title><para>The specified condition will always be compiled and validated syntactically, but it will not be checked at run-time unless <computeroutput><link linkend="BOOST_CONTRACT_AUDITS">BOOST_CONTRACT_AUDITS</link></computeroutput> is defined (undefined by default). This macro is defined by code equivalent to:</para><para><programlisting><phrase role="preprocessor">#ifdef</phrase> <phrase role="identifier">BOOST_CONTRACT_AUDITS</phrase>
14463 <phrase role="preprocessor">#define</phrase> <phrase role="identifier">BOOST_CONTRACT_CHECK_AUDIT</phrase><phrase role="special">(</phrase><phrase role="identifier">cond</phrase><phrase role="special">)</phrase> \
14464 <phrase role="identifier">BOOST_CONTRACT_CHECK</phrase><phrase role="special">(</phrase><phrase role="identifier">cond</phrase><phrase role="special">)</phrase>
14465 <phrase role="preprocessor">#else</phrase>
14466 <phrase role="preprocessor">#define</phrase> <phrase role="identifier">BOOST_CONTRACT_CHECK_AUDIT</phrase><phrase role="special">(</phrase><phrase role="identifier">cond</phrase><phrase role="special">)</phrase> \
14467 <phrase role="identifier">BOOST_CONTRACT_CHECK</phrase><phrase role="special">(</phrase><phrase role="keyword">true</phrase> <phrase role="special">||</phrase> <phrase role="identifier">cond</phrase><phrase role="special">)</phrase>
14468 <phrase role="preprocessor">#endif</phrase>
14469 </programlisting></para><para> <computeroutput><link linkend="BOOST_CONTRACT_CHECK">BOOST_CONTRACT_CHECK</link></computeroutput>, <computeroutput><link linkend="BOOST_CONTRACT_CHECK_AUDIT">BOOST_CONTRACT_CHECK_AUDIT</link></computeroutput>, and <computeroutput><link linkend="BOOST_CONTRACT_CHECK_AXIOM">BOOST_CONTRACT_CHECK_AXIOM</link></computeroutput> are the three assertion levels predefined by this library for implementation checks. If there is a need, programmers are free to implement their own assertion levels defining macros similar to the one above.</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.extras.assertion_levels"> Assertion Levels</link></para>
14472 </para><variablelist spacing="compact"><?dbhtml
14473 list-presentation="table"
14474 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
14475 list-presentation="table"
14476 ?><varlistentry><term><computeroutput>cond</computeroutput></term><listitem><para>Boolean condition to check within implementation code (function body, etc.). (This is not a variadic macro parameter so any comma it might contain must be protected by round parenthesis and <computeroutput>BOOST_CONTRACT_CHECK_AUDIT((cond))</computeroutput> will always work.) </para></listitem></varlistentry></variablelist></listitem></varlistentry></variablelist></refsect1></refentry>
14477 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CONTRACT_CHECK_AXIOM"><refmeta><refentrytitle>Macro BOOST_CONTRACT_CHECK_AXIOM</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_CHECK_AXIOM</refname><refpurpose>Preferred way to document in the code implementation check conditions that are computationally prohibitive, at least compared to the computational cost of executing the function body. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.check_macro_hpp">boost/contract/core/check_macro.hpp</link>>
14479 </phrase>BOOST_CONTRACT_CHECK_AXIOM(cond)</synopsis></refsynopsisdiv><refsect1><title>Description</title><para>The specified condition will always be compiled and validated syntactically, but it will never be checked at run-time. This macro is defined by code equivalent to:</para><para><programlisting><phrase role="preprocessor">#define</phrase> <phrase role="identifier">BOOST_CONTRACT_CHECK_AXIOM</phrase><phrase role="special">(</phrase><phrase role="identifier">cond</phrase><phrase role="special">)</phrase> \
14480 <phrase role="identifier">BOOST_CONTRACT_CHECK</phrase><phrase role="special">(</phrase><phrase role="keyword">true</phrase> <phrase role="special">||</phrase> <phrase role="identifier">cond</phrase><phrase role="special">)</phrase>
14481 </programlisting></para><para> <computeroutput><link linkend="BOOST_CONTRACT_CHECK">BOOST_CONTRACT_CHECK</link></computeroutput>, <computeroutput><link linkend="BOOST_CONTRACT_CHECK_AUDIT">BOOST_CONTRACT_CHECK_AUDIT</link></computeroutput>, and <computeroutput><link linkend="BOOST_CONTRACT_CHECK_AXIOM">BOOST_CONTRACT_CHECK_AXIOM</link></computeroutput> are the three assertion levels predefined by this library for implementation checks. If there is a need, programmers are free to implement their own assertion levels defining macros similar to the one above.</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.extras.assertion_levels"> Assertion Levels</link></para>
14484 </para><variablelist spacing="compact"><?dbhtml
14485 list-presentation="table"
14486 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
14487 list-presentation="table"
14488 ?><varlistentry><term><computeroutput>cond</computeroutput></term><listitem><para>Boolean condition to check within implementation code (function body, etc.). (This is not a variadic macro parameter so any comma it might contain must be protected by round parenthesis and <computeroutput>BOOST_CONTRACT_CHECK_AXIOM((cond))</computeroutput> will always work.) </para></listitem></varlistentry></variablelist></listitem></varlistentry></variablelist></refsect1></refentry>
14490 <section id="header.boost.contract.core.config_hpp"><title>Header <<ulink url="../../../../boost/contract/core/config.hpp">boost/contract/core/config.hpp</ulink>></title><para>Configure this library compile-time and run-time behaviours. </para><synopsis xmlns:xi="http://www.w3.org/2001/XInclude">
14492 <link linkend="BOOST_CONTRACT_DYN_LINK">BOOST_CONTRACT_DYN_LINK</link>
14493 <link linkend="BOOST_CONTRACT_STATIC_LINK">BOOST_CONTRACT_STATIC_LINK</link>
14494 <link linkend="BOOST_CONTRACT_HEADER_ONLY">BOOST_CONTRACT_HEADER_ONLY</link>
14495 <link linkend="BOOST_CO_idm45394999743888">BOOST_CONTRACT_DISABLE_THREADS</link>
14496 <link linkend="BOOST_CONTRACT_MAX_ARGS">BOOST_CONTRACT_MAX_ARGS</link>
14497 <link linkend="BOOST_CO_idm45394999732400">BOOST_CONTRACT_BASES_TYPEDEF</link>
14498 <link linkend="BOOST_CO_idm45394999724496">BOOST_CONTRACT_INVARIANT_FUNC</link>
14499 <link linkend="BOOST_CO_idm45394999714768">BOOST_CONTRACT_STATIC_INVARIANT_FUNC</link>
14500 <link linkend="BOOST_CONTRACT_PERMISSIVE">BOOST_CONTRACT_PERMISSIVE</link>
14501 <link linkend="BOOST_CO_idm45394999694064">BOOST_CONTRACT_ON_MISSING_CHECK_DECL</link>
14502 <link linkend="BOOST_CO_idm45394999685184">BOOST_CONTRACT_PRECONDITIONS_DISABLE_NO_ASSERTION</link>
14503 <link linkend="BOOST_CO_idm45394999679376">BOOST_CONTRACT_ALL_DISABLE_NO_ASSERTION</link>
14504 <link linkend="BOOST_CONTRACT_AUDITS">BOOST_CONTRACT_AUDITS</link>
14505 <link linkend="BOOST_CONTRACT_NO_CHECKS">BOOST_CONTRACT_NO_CHECKS</link>
14506 <link linkend="BOOST_CO_idm45394999662416">BOOST_CONTRACT_NO_PRECONDITIONS</link>
14507 <link linkend="BOOST_CO_idm45394999656032">BOOST_CONTRACT_NO_POSTCONDITIONS</link>
14508 <link linkend="BOOST_CONTRACT_NO_EXCEPTS">BOOST_CONTRACT_NO_EXCEPTS</link>
14509 <link linkend="BOOST_CO_idm45394999637264">BOOST_CONTRACT_NO_ENTRY_INVARIANTS</link>
14510 <link linkend="BOOST_CO_idm45394999629648">BOOST_CONTRACT_NO_EXIT_INVARIANTS</link>
14511 <link linkend="BOOST_CO_idm45394999622032">BOOST_CONTRACT_NO_INVARIANTS</link>
14512 <link linkend="BOOST_CONTRACT_NO_OLDS">BOOST_CONTRACT_NO_OLDS</link>
14513 <link linkend="BOOST_CO_idm45394999605408">BOOST_CONTRACT_NO_CONSTRUCTORS</link>
14514 <link linkend="BOOST_CO_idm45394999594544">BOOST_CONTRACT_NO_DESTRUCTORS</link>
14515 <link linkend="BOOST_CO_idm45394999586272">BOOST_CONTRACT_NO_PUBLIC_FUNCTIONS</link>
14516 <link linkend="BOOST_CO_idm45394999577072">BOOST_CONTRACT_NO_FUNCTIONS</link>
14517 <link linkend="BOOST_CO_idm45394999566736">BOOST_CONTRACT_NO_CONDITIONS</link>
14518 <link linkend="BOOST_CONTRACT_NO_ALL">BOOST_CONTRACT_NO_ALL</link></synopsis>
14519 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CONTRACT_DYN_LINK"><refmeta><refentrytitle>Macro BOOST_CONTRACT_DYN_LINK</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_DYN_LINK</refname><refpurpose>Define this macro to compile this library as a shared library (recommended). </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.config_hpp">boost/contract/core/config.hpp</link>>
14521 </phrase>BOOST_CONTRACT_DYN_LINK</synopsis></refsynopsisdiv><refsect1><title>Description</title><para>If this macro is defined, this library is compiled so it can be linked as a shared library (a.k.a., Dynamically Linked Library or DLL) to user code. This library will automatically define this macro when Boost libraries are built as shared libraries (e.g., defining <computeroutput>BOOST_ALL_DYN_LINK</computeroutput> or using <computeroutput>bjam link=shared ...</computeroutput>).</para><para><warning><para>In general this library will correctly check contracts at run-time only when compiled as a shared library, unless user code checks contracts in a single program unit (e.g., a single program with only statically linked libraries). Therefore, it is recommended to build and use this library as a shared library by defining this macro (or equivalently by building all Boost libraries as shared libraries).</para>
14523 <para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.getting_started"> Getting Started</link> </para>
14525 </para></refsect1></refentry>
14526 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CONTRACT_STATIC_LINK"><refmeta><refentrytitle>Macro BOOST_CONTRACT_STATIC_LINK</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_STATIC_LINK</refname><refpurpose>Define this macro to compile this library as a static library (not recommended). </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.config_hpp">boost/contract/core/config.hpp</link>>
14528 </phrase>BOOST_CONTRACT_STATIC_LINK</synopsis></refsynopsisdiv><refsect1><title>Description</title><para>If this macro is defined, this library is compiled so it can be linked statically to user code. This library will automatically define this macro when Boost libraries are built as static libraries.</para><para><warning><para>This library is not guaranteed to always work correctly at run-time when this macro is defined (define <computeroutput><link linkend="BOOST_CONTRACT_DYN_LINK">BOOST_CONTRACT_DYN_LINK</link></computeroutput> or <computeroutput>BOOST_ALL_DYN_LINK</computeroutput> instead). However, this macro can be defined and this library can be safely used as a static library for user code that checks contracts in a single program unit (e.g., a single program with only statically linked libraries).</para>
14530 <para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.getting_started"> Getting Started</link> </para>
14532 </para></refsect1></refentry>
14533 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CONTRACT_HEADER_ONLY"><refmeta><refentrytitle>Macro BOOST_CONTRACT_HEADER_ONLY</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_HEADER_ONLY</refname><refpurpose>Automatically defined by this library when it is being used as a header-only library (not recommended). </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.config_hpp">boost/contract/core/config.hpp</link>>
14535 </phrase>BOOST_CONTRACT_HEADER_ONLY</synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This macro is not a configuration macro and this library will generate a compile-time error if users try to define it directly. This library will automatically define this macro when users do not define <computeroutput><link linkend="BOOST_CONTRACT_DYN_LINK">BOOST_CONTRACT_DYN_LINK</link></computeroutput> (or <computeroutput>BOOST_ALL_DYN_LINK</computeroutput>) and <computeroutput><link linkend="BOOST_CONTRACT_STATIC_LINK">BOOST_CONTRACT_STATIC_LINK</link></computeroutput>. When used as a header-only library, this library code does not have to be compiled separately from user code, this library headers are simply included and compiled as part of the user program.</para><para><warning><para>This library is not guaranteed to always work correctly at run-time when this macro is defined (define <computeroutput><link linkend="BOOST_CONTRACT_DYN_LINK">BOOST_CONTRACT_DYN_LINK</link></computeroutput> or <computeroutput>BOOST_ALL_DYN_LINK</computeroutput> instead). However, this macro can be defined and this library can be safely used as a header-only library for user code that checks contracts in a single program unit (e.g., a single program with only statically linked libraries).</para>
14537 <para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.getting_started"> Getting Started</link> </para>
14539 </para></refsect1></refentry>
14540 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CO_idm45394999743888"><refmeta><refentrytitle>Macro BOOST_CONTRACT_DISABLE_THREADS</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_DISABLE_THREADS</refname><refpurpose>Define this macro to not lock internal library data for thread safety (undefined by default). </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.config_hpp">boost/contract/core/config.hpp</link>>
14542 </phrase>BOOST_CONTRACT_DISABLE_THREADS</synopsis></refsynopsisdiv><refsect1><title>Description</title><para>Defining this macro will make the library implementation code not thread safe so this macro should not be defined unless the library is being used by single-threaded applications only. This library will automatically define this macro when Boost libraries are built without threads (e.g., defining <computeroutput>BOOST_DISABLE_THREADS</computeroutput>).</para><para><note><para>When this macro is left undefined this library needs to internally use some sort of global lock (to ensure contract checking is globally disabled when other contracts are being checked and also to safely access failure handler functors). That could introduce an undesired amount of synchronization in some multi-threaded applications.</para>
14544 <para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.contract_programming_overview.assertions"> Assertions</link> </para>
14546 </para></refsect1></refentry>
14547 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CONTRACT_MAX_ARGS"><refmeta><refentrytitle>Macro BOOST_CONTRACT_MAX_ARGS</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_MAX_ARGS</refname><refpurpose>Maximum number of arguments for public function overrides on compilers that do not support variadic templates (default to <computeroutput>10</computeroutput>). </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.config_hpp">boost/contract/core/config.hpp</link>>
14549 </phrase>BOOST_CONTRACT_MAX_ARGS</synopsis></refsynopsisdiv><refsect1><title>Description</title><para>On compilers that do not support C++11 variadic templates, this macro is defined to the maximum number of arguments that public function overrides can have and pass to <computeroutput><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput> (users can redefine this macro to a different value). On compilers that support variadic templates, this macro has no effect.</para><para><note><para>Regardless of the value of this macro and of compiler support for variadic templates, there might be an intrinsic limit of about 18 arguments for public function overrides (because of similar limits in Boost.MPL and Boost.FunctionTypes internally used by this library).</para>
14551 <para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.extras.no_macros__and_no_variadic_macros_"> No Macros</link> </para>
14553 </para></refsect1></refentry>
14554 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CO_idm45394999732400"><refmeta><refentrytitle>Macro BOOST_CONTRACT_BASES_TYPEDEF</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_BASES_TYPEDEF</refname><refpurpose>Define the name of the base type <computeroutput>typedef</computeroutput> (<computeroutput>base_types</computeroutput> by default). </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.config_hpp">boost/contract/core/config.hpp</link>>
14556 </phrase>BOOST_CONTRACT_BASES_TYPEDEF</synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This macro expands to the name of the <computeroutput>typedef</computeroutput> that lists the base classes for subcontracting via <computeroutput><link linkend="BOOST_CONTRACT_BASE_TYPES">BOOST_CONTRACT_BASE_TYPES</link></computeroutput>:</para><para><programlisting><phrase role="keyword">class</phrase> <phrase role="identifier">u</phrase>
14557 <phrase role="preprocessor">#define</phrase> <phrase role="identifier">BASES</phrase> <phrase role="keyword">public</phrase> <phrase role="identifier">b</phrase><phrase role="special">,</phrase> <phrase role="keyword">private</phrase> <phrase role="identifier">w</phrase>
14558 <phrase role="special">:</phrase> <phrase role="identifier">BASES</phrase>
14559 <phrase role="special">{</phrase>
14560 <phrase role="keyword">friend</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">:</phrase><phrase role="identifier">access</phrase><phrase role="special">;</phrase>
14562 <phrase role="keyword">typedef</phrase> <phrase role="identifier">BOOST_CONTRACT_BASE_TYPES</phrase><phrase role="special">(</phrase><phrase role="identifier">BASES</phrase><phrase role="special">)</phrase> <phrase role="identifier">BOOST_CONTRACT_TYPEDEF</phrase><phrase role="special">;</phrase>
14563 <phrase role="preprocessor">#undef</phrase> <phrase role="identifier">BASES</phrase>
14565 <phrase role="special">...</phrase>
14566 <phrase role="special">}</phrase><phrase role="special">;</phrase>
14567 </programlisting></para><para>When used this way, users can redefine this macro if the <computeroutput>typedef</computeroutput> must have a name different from <computeroutput>base_types</computeroutput> (because of name clashes in user code, etc.).</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.tutorial.base_classes__subcontracting_"> Base Classes</link> </para>
14569 </para></refsect1></refentry>
14570 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CO_idm45394999724496"><refmeta><refentrytitle>Macro BOOST_CONTRACT_INVARIANT_FUNC</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_INVARIANT_FUNC</refname><refpurpose>Define the name of the class invariant member function (<computeroutput>invariant</computeroutput> by default). </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.config_hpp">boost/contract/core/config.hpp</link>>
14572 </phrase>BOOST_CONTRACT_INVARIANT_FUNC</synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This macro expands to the name of the <computeroutput>const</computeroutput> and <computeroutput>const volatile</computeroutput> member functions that check class invariants and volatile class invariants respectively:</para><para><programlisting><phrase role="keyword">class</phrase> <phrase role="identifier">u</phrase> <phrase role="special">{</phrase>
14573 <phrase role="keyword">friend</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">access</phrase><phrase role="special">;</phrase>
14575 <phrase role="keyword">void</phrase> <phrase role="identifier">BOOST_CONTRACT_INVARIANT_FUNC</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
14576 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14577 <phrase role="special">...</phrase>
14578 <phrase role="special">}</phrase>
14580 <phrase role="keyword">void</phrase> <phrase role="identifier">BOOST_CONTRACT_INVARIANT_FUNC</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase> <phrase role="special">{</phrase>
14581 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14582 <phrase role="special">...</phrase>
14583 <phrase role="special">}</phrase>
14585 <phrase role="special">...</phrase>
14586 <phrase role="special">}</phrase><phrase role="special">;</phrase>
14587 </programlisting></para><para>When used this way, users can redefine this macro if the invariant functions must have a name different from <computeroutput>invariant</computeroutput> (because of name clashes in user code, etc.).</para><para><note><para>C++ does not allow to overload member functions based on the <computeroutput>static</computeroutput> classifier, so this macro must always be defined to be different than the function name defined for <computeroutput><link linkend="BOOST_CO_idm45394999714768">BOOST_CONTRACT_STATIC_INVARIANT_FUNC</link></computeroutput>.</para>
14589 <para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.tutorial.class_invariants"> Class Invariants</link>, <link linkend="boost_contract.extras.volatile_public_functions">
14590 Volatile Public Functions</link> </para>
14592 </para></refsect1></refentry>
14593 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CO_idm45394999714768"><refmeta><refentrytitle>Macro BOOST_CONTRACT_STATIC_INVARIANT_FUNC</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_STATIC_INVARIANT_FUNC</refname><refpurpose>Define the name of the static invariant member function (<computeroutput>static_invariant</computeroutput> by default). </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.config_hpp">boost/contract/core/config.hpp</link>>
14595 </phrase>BOOST_CONTRACT_STATIC_INVARIANT_FUNC</synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This macro expands to the name of the <computeroutput>static</computeroutput> member function that checks static class invariants:</para><para><programlisting><phrase role="keyword">class</phrase> <phrase role="identifier">u</phrase> <phrase role="special">{</phrase>
14596 <phrase role="keyword">friend</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">access</phrase><phrase role="special">;</phrase>
14598 <phrase role="keyword">static</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">BOOST_CONTRACT_STATIC_INVARIANT_FUNC</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
14599 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14600 <phrase role="special">...</phrase>
14601 <phrase role="special">}</phrase>
14603 <phrase role="special">...</phrase>
14604 <phrase role="special">}</phrase><phrase role="special">;</phrase>
14605 </programlisting></para><para>When used this way, users can redefine this macro if the static invariant function must have a name different from <computeroutput>static_invariant</computeroutput> (because of name clashes in user code, etc.).</para><para><note><para>C++ does not allow to overload member functions based on the <computeroutput>static</computeroutput> classifier, so this macro must always be defined to be different than the function name defined for <computeroutput><link linkend="BOOST_CO_idm45394999724496">BOOST_CONTRACT_INVARIANT_FUNC</link></computeroutput>.</para>
14607 <para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.tutorial.class_invariants"> Class Invariants</link> </para>
14609 </para></refsect1></refentry>
14610 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CONTRACT_PERMISSIVE"><refmeta><refentrytitle>Macro BOOST_CONTRACT_PERMISSIVE</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_PERMISSIVE</refname><refpurpose>Disable some compile-time errors generated by this library (undefined by default). </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.config_hpp">boost/contract/core/config.hpp</link>>
14612 </phrase>BOOST_CONTRACT_PERMISSIVE</synopsis></refsynopsisdiv><refsect1><title>Description</title><para>Defining this macro disables a number of static checks and related compile-time errors generated by this library, for example:</para><para><itemizedlist>
14613 <listitem><para>The static invariant member function named as <computeroutput>BOOST_CONTRACT_STATIC_INVARIANT_FUNC</computeroutput> must be declared <computeroutput>static</computeroutput>. </para>
14615 <listitem><para>Non-static invariant member functions named as <computeroutput>BOOST_CONTRACT_INVARIANT_FUNC</computeroutput> must be declared either <computeroutput>const</computeroutput>, <computeroutput>const volatile</computeroutput>, or <computeroutput>volatile const</computeroutput>. </para>
14617 <listitem><para>Derived classes that program contracts for one or more public function overrides via <computeroutput><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput> must also define the <computeroutput><link linkend="BOOST_CONTRACT_BASE_TYPES">BOOST_CONTRACT_BASE_TYPES</link></computeroutput> <computeroutput>typedef</computeroutput>.</para>
14620 In general, it is not recommended to define this macro because these compile-time checks can guard against misuses of this library.</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.tutorial.class_invariants"> Class Invariants</link>, <link linkend="boost_contract.tutorial.base_classes__subcontracting_"> Base Classes</link> </para>
14622 </para></refsect1></refentry>
14623 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CO_idm45394999694064"><refmeta><refentrytitle>Macro BOOST_CONTRACT_ON_MISSING_CHECK_DECL</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_ON_MISSING_CHECK_DECL</refname><refpurpose>Code block to execute if contracts are not assigned to a <computeroutput><link linkend="boost.contract.check">boost::contract::check</link></computeroutput> variable (undefined and executes <computeroutput>BOOST_ASSERT(false)</computeroutput> by default). </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.config_hpp">boost/contract/core/config.hpp</link>>
14625 </phrase>BOOST_CONTRACT_ON_MISSING_CHECK_DECL</synopsis></refsynopsisdiv><refsect1><title>Description</title><para>In general, there is a logic error in the program when contracts are not explicitly assigned to a local variable of type <computeroutput><link linkend="boost.contract.check">boost::contract::check</link></computeroutput> and without using C++11 <computeroutput>auto</computeroutput> declarations (because that is a misuse of this library). Therefore, by default (i.e., when this macro is not defined) this library calls <computeroutput>BOOST_ASSERT(false)</computeroutput> in those cases. If this macro is defined, this library will execute the code expanded by this macro instead of calling <computeroutput>BOOST_ASSERT(false)</computeroutput> (if programmers prefer to throw an exception, etc.).</para><para>This macro can also be defined to be any block of code (and use empty curly brackets <computeroutput>{}</computeroutput> to generate no error, not recommended), for example (on GCC): <programlisting><phrase role="identifier">gcc</phrase> <phrase role="special">-</phrase><phrase role="identifier">DBOOST_CONTRACT_ON_MISSING_CHECK_DECL</phrase><phrase role="special">=</phrase><phrase role="char">'{ throw std::logic_error("missing contract check declaration"); }'</phrase> <phrase role="special">...</phrase>
14626 </programlisting></para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.tutorial"> Tutorial</link> </para>
14628 </para></refsect1></refentry>
14629 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CO_idm45394999685184"><refmeta><refentrytitle>Macro BOOST_CONTRACT_PRECONDITIONS_DISABLE_NO_ASSERTION</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_PRECONDITIONS_DISABLE_NO_ASSERTION</refname><refpurpose>Define this macro to not disable other assertions while checking preconditions (undefined by default). </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.config_hpp">boost/contract/core/config.hpp</link>>
14631 </phrase>BOOST_CONTRACT_PRECONDITIONS_DISABLE_NO_ASSERTION</synopsis></refsynopsisdiv><refsect1><title>Description</title><para>Not disabling other assertions while checking preconditions can lead to infinite recursion in user code so by default this macro is not defined.</para><para>However, the <link linkend="boost_contract.bibliography"> [N1962]</link> proposal does not disable assertions while checking preconditions because arguments can reach the function body unchecked if assertions are disabled while checking preconditions (e.g., when these same functions bodies are called to check the preconditions in question). This macro can be defined to obtain the behaviour specified in <link linkend="boost_contract.bibliography"> [N1962]</link> (at the risk of infinite recursion).</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.contract_programming_overview.feature_summary">
14632 Feature Summary</link> </para>
14634 </para></refsect1></refentry>
14635 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CO_idm45394999679376"><refmeta><refentrytitle>Macro BOOST_CONTRACT_ALL_DISABLE_NO_ASSERTION</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_ALL_DISABLE_NO_ASSERTION</refname><refpurpose>Define this macro to not disable any assertion while checking other assertions (undefined by default). </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.config_hpp">boost/contract/core/config.hpp</link>>
14637 </phrase>BOOST_CONTRACT_ALL_DISABLE_NO_ASSERTION</synopsis></refsynopsisdiv><refsect1><title>Description</title><para>Not disabling assertions while checking other assertions can lead to infinite recursion in user code so by default this macro is not defined. (Defining this macro automatically implies that other assertion checking is disabled while checking preconditions as if <computeroutput><link linkend="BOOST_CO_idm45394999685184">BOOST_CONTRACT_PRECONDITIONS_DISABLE_NO_ASSERTION</link></computeroutput> was also defined.)</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.contract_programming_overview.feature_summary">
14638 Feature Summary</link> </para>
14640 </para></refsect1></refentry>
14641 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CONTRACT_AUDITS"><refmeta><refentrytitle>Macro BOOST_CONTRACT_AUDITS</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_AUDITS</refname><refpurpose>Define this macro to evaluate and check audit assertions at run-time (undefined by default). </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.config_hpp">boost/contract/core/config.hpp</link>>
14643 </phrase>BOOST_CONTRACT_AUDITS</synopsis></refsynopsisdiv><refsect1><title>Description</title><para>Audit assertions and implementation checks programmed via <computeroutput><link linkend="BOOST_CO_idm45395000817520">BOOST_CONTRACT_ASSERT_AUDIT</link></computeroutput> and <computeroutput><link linkend="BOOST_CONTRACT_CHECK_AUDIT">BOOST_CONTRACT_CHECK_AUDIT</link></computeroutput> are always compiled and validated syntactically. However, they are not evaluated and checked at run-time unless this macro is defined (because these conditions can be computationally expensive, at least compared to the computational cost of executing the function body).</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.extras.assertion_levels"> Assertion Levels</link> </para>
14645 </para></refsect1></refentry>
14646 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CONTRACT_NO_CHECKS"><refmeta><refentrytitle>Macro BOOST_CONTRACT_NO_CHECKS</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_NO_CHECKS</refname><refpurpose>If defined, this library disables implementation checks (undefined by default). </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.config_hpp">boost/contract/core/config.hpp</link>>
14648 </phrase>BOOST_CONTRACT_NO_CHECKS</synopsis></refsynopsisdiv><refsect1><title>Description</title><para>If this macro is defined, this library internal code is also optimized to reduce compile-time (not just run-time) overhead associated with implementation checks. In addition, users can manually program <computeroutput>#ifndef</computeroutput> statements in their code using this macro to completely disable compilation of implementation checks or use <computeroutput><link linkend="BOOST_CONTRACT_CHECK">BOOST_CONTRACT_CHECK</link></computeroutput> (recommended).</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.advanced.implementation_checks">
14649 Implementation Checks</link>, <link linkend="boost_contract.extras.disable_contract_checking">
14650 Disable Contract Checking</link>, <link linkend="boost_contract.extras.disable_contract_compilation__macro_interface_">
14651 Disable Contract Compilation</link> </para>
14653 </para></refsect1></refentry>
14654 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CO_idm45394999662416"><refmeta><refentrytitle>Macro BOOST_CONTRACT_NO_PRECONDITIONS</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_NO_PRECONDITIONS</refname><refpurpose>If defined, this library does not check preconditions (undefined by default). </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.config_hpp">boost/contract/core/config.hpp</link>>
14656 </phrase>BOOST_CONTRACT_NO_PRECONDITIONS</synopsis></refsynopsisdiv><refsect1><title>Description</title><para>If this macro is defined, this library internal code is also optimized to reduce compile-time (not just run-time) overhead associated with checking preconditions. In addition, users can manually program <computeroutput>#ifndef</computeroutput> statements in their code using this macro to completely disable compilation of preconditions or use the macros defined in <computeroutput>boost/contract_macro.hpp</computeroutput> (recommended only for applications where it is truly necessary to completely remove contract code compilation from production code).</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.tutorial.preconditions"> Preconditions</link>, <link linkend="boost_contract.extras.disable_contract_checking">
14657 Disable Contract Checking</link>, <link linkend="boost_contract.extras.disable_contract_compilation__macro_interface_">
14658 Disable Contract Compilation</link> </para>
14660 </para></refsect1></refentry>
14661 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CO_idm45394999656032"><refmeta><refentrytitle>Macro BOOST_CONTRACT_NO_POSTCONDITIONS</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_NO_POSTCONDITIONS</refname><refpurpose>If defined, this library does not check postconditions (undefined by default). </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.config_hpp">boost/contract/core/config.hpp</link>>
14663 </phrase>BOOST_CONTRACT_NO_POSTCONDITIONS</synopsis></refsynopsisdiv><refsect1><title>Description</title><para>If this macro is defined, this library internal code is also optimized to reduce compile-time (not just run-time) overhead associated with checking postconditions. In addition, users can manually program <computeroutput>#ifndef</computeroutput> statements in their code using this macro to completely disable compilation of postconditions or use the macros defined in <computeroutput>boost/contract_macro.hpp</computeroutput> (recommended only for applications where it is truly necessary to completely remove contract code compilation from production code).</para><para>It is necessary to disable both postconditions and exception guarantees defining <computeroutput><link linkend="BOOST_CO_idm45394999656032">BOOST_CONTRACT_NO_POSTCONDITIONS</link></computeroutput> and <computeroutput><link linkend="BOOST_CONTRACT_NO_EXCEPTS">BOOST_CONTRACT_NO_EXCEPTS</link></computeroutput> in order to disable old value copies (see <computeroutput><link linkend="BOOST_CONTRACT_NO_OLDS">BOOST_CONTRACT_NO_OLDS</link></computeroutput>).</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.tutorial.postconditions"> Postconditions</link>, <link linkend="boost_contract.extras.disable_contract_checking">
14664 Disable Contract Checking</link>, <link linkend="boost_contract.extras.disable_contract_compilation__macro_interface_">
14665 Disable Contract Compilation</link> </para>
14667 </para></refsect1></refentry>
14668 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CONTRACT_NO_EXCEPTS"><refmeta><refentrytitle>Macro BOOST_CONTRACT_NO_EXCEPTS</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_NO_EXCEPTS</refname><refpurpose>If defined, this library does not check exception guarantees (undefined by default). </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.config_hpp">boost/contract/core/config.hpp</link>>
14670 </phrase>BOOST_CONTRACT_NO_EXCEPTS</synopsis></refsynopsisdiv><refsect1><title>Description</title><para>If this macro is defined, this library internal code is also optimized to reduce compile-time (not just run-time) overhead associated with checking exception guarantees. In addition, users can manually program <computeroutput>#ifndef</computeroutput> statements in their code using this macro to completely disable compilation of exception guarantees or use the macros defined in <computeroutput>boost/contract_macro.hpp</computeroutput> (recommended only for applications where it is truly necessary to completely remove contract code compilation from production code).</para><para>It is necessary to disable both postconditions and exception guarantees defining <computeroutput><link linkend="BOOST_CO_idm45394999656032">BOOST_CONTRACT_NO_POSTCONDITIONS</link></computeroutput> and <computeroutput><link linkend="BOOST_CONTRACT_NO_EXCEPTS">BOOST_CONTRACT_NO_EXCEPTS</link></computeroutput> in order to disable old value copies (see <computeroutput><link linkend="BOOST_CONTRACT_NO_OLDS">BOOST_CONTRACT_NO_OLDS</link></computeroutput>).</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.tutorial.exception_guarantees"> Exception Guarantees</link>, <link linkend="boost_contract.extras.disable_contract_checking">
14671 Disable Contract Checking</link>, <link linkend="boost_contract.extras.disable_contract_compilation__macro_interface_">
14672 Disable Contract Compilation</link> </para>
14674 </para></refsect1></refentry>
14675 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CO_idm45394999637264"><refmeta><refentrytitle>Macro BOOST_CONTRACT_NO_ENTRY_INVARIANTS</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_NO_ENTRY_INVARIANTS</refname><refpurpose>If defined, this library does not check class invariants at entry (undefined by default). </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.config_hpp">boost/contract/core/config.hpp</link>>
14677 </phrase>BOOST_CONTRACT_NO_ENTRY_INVARIANTS</synopsis></refsynopsisdiv><refsect1><title>Description</title><para>If this macro is defined, this library internal code is also optimized to reduce compile-time (not just run-time) overhead associated with checking class invariants at entry. In addition, users can manually program <computeroutput>#ifndef</computeroutput> statements in their code using this macro to completely disable compilation of entry class invariants or use the macros defined in <computeroutput>boost/contract_macro.hpp</computeroutput> (recommended only for applications where it is truly necessary to completely remove contract code compilation from production code).</para><para>This macro is automatically defined when <computeroutput><link linkend="BOOST_CO_idm45394999622032">BOOST_CONTRACT_NO_INVARIANTS</link></computeroutput> is defined.</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.tutorial.class_invariants"> Class Invariants</link>, <link linkend="boost_contract.extras.disable_contract_checking">
14678 Disable Contract Checking</link>, <link linkend="boost_contract.extras.disable_contract_compilation__macro_interface_">
14679 Disable Contract Compilation</link> </para>
14681 </para></refsect1></refentry>
14682 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CO_idm45394999629648"><refmeta><refentrytitle>Macro BOOST_CONTRACT_NO_EXIT_INVARIANTS</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_NO_EXIT_INVARIANTS</refname><refpurpose>If defined, this library does not check class invariants at exit (undefined by default). </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.config_hpp">boost/contract/core/config.hpp</link>>
14684 </phrase>BOOST_CONTRACT_NO_EXIT_INVARIANTS</synopsis></refsynopsisdiv><refsect1><title>Description</title><para>If this macro is defined, this library internal code is also optimized to reduce compile-time (not just run-time) overhead associated with checking class invariants at exit. In addition, users can manually program <computeroutput>#ifndef</computeroutput> statements in their code using this macro to completely disable compilation of exit class invariants or use the macros defined in <computeroutput>boost/contract_macro.hpp</computeroutput> (recommended only for applications where it is truly necessary to completely remove contract code compilation from production code).</para><para>This macro is automatically defined when <computeroutput><link linkend="BOOST_CO_idm45394999622032">BOOST_CONTRACT_NO_INVARIANTS</link></computeroutput> is defined.</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.tutorial.class_invariants"> Class Invariants</link>, <link linkend="boost_contract.extras.disable_contract_checking">
14685 Disable Contract Checking</link>, <link linkend="boost_contract.extras.disable_contract_compilation__macro_interface_">
14686 Disable Contract Compilation</link> </para>
14688 </para></refsect1></refentry>
14689 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CO_idm45394999622032"><refmeta><refentrytitle>Macro BOOST_CONTRACT_NO_INVARIANTS</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_NO_INVARIANTS</refname><refpurpose>If defined, this library does not check class invariants (undefined by default). </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.config_hpp">boost/contract/core/config.hpp</link>>
14691 </phrase>BOOST_CONTRACT_NO_INVARIANTS</synopsis></refsynopsisdiv><refsect1><title>Description</title><para>If this macro is defined, this library internal code is also optimized to reduce compile-time (not just run-time) overhead associated with checking class invariants. In addition, users can manually program <computeroutput>#ifndef</computeroutput> statements in their code using this macro to completely disable compilation of class invariants or use the macros defined in <computeroutput>boost/contract_macro.hpp</computeroutput> (recommended only for applications where it is truly necessary to completely remove contract code compilation from production code).</para><para>Defining this macro is equivalent to defining both <computeroutput><link linkend="BOOST_CO_idm45394999637264">BOOST_CONTRACT_NO_ENTRY_INVARIANTS</link></computeroutput> and <computeroutput><link linkend="BOOST_CO_idm45394999629648">BOOST_CONTRACT_NO_EXIT_INVARIANTS</link></computeroutput>.</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.tutorial.class_invariants"> Class Invariants</link>, <link linkend="boost_contract.extras.disable_contract_checking">
14692 Disable Contract Checking</link>, <link linkend="boost_contract.extras.disable_contract_compilation__macro_interface_">
14693 Disable Contract Compilation</link> </para>
14695 </para></refsect1></refentry>
14696 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CONTRACT_NO_OLDS"><refmeta><refentrytitle>Macro BOOST_CONTRACT_NO_OLDS</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_NO_OLDS</refname><refpurpose>Automatically defined by this library when old value copies are not to be performed. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.config_hpp">boost/contract/core/config.hpp</link>>
14698 </phrase>BOOST_CONTRACT_NO_OLDS</synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This macro is not a configuration macro and this library will generate a compile-time error if users try to define it directly. This library will automatically define this macro when users define both <computeroutput><link linkend="BOOST_CO_idm45394999656032">BOOST_CONTRACT_NO_POSTCONDITIONS</link></computeroutput> and <computeroutput><link linkend="BOOST_CONTRACT_NO_EXCEPTS">BOOST_CONTRACT_NO_EXCEPTS</link></computeroutput>. Users can manually program <computeroutput>#ifndef</computeroutput> statements in their code using this macro to completely disable compilation of old value copies or use the macros defined in <computeroutput>boost/contract_macro.hpp</computeroutput> (recommended only for applications where it is truly necessary to completely remove contract code compilation from production code).</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.tutorial.old_values"> Old Values</link>, <link linkend="boost_contract.advanced.old_values_copied_at_body">
14699 Old Values Copied at Body</link>, <link linkend="boost_contract.extras.disable_contract_compilation__macro_interface_">
14700 Disable Contract Compilation</link> </para>
14702 </para></refsect1></refentry>
14703 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CO_idm45394999605408"><refmeta><refentrytitle>Macro BOOST_CONTRACT_NO_CONSTRUCTORS</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_NO_CONSTRUCTORS</refname><refpurpose>Automatically defined by this library when contracts are not checked for constructors. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.config_hpp">boost/contract/core/config.hpp</link>>
14705 </phrase>BOOST_CONTRACT_NO_CONSTRUCTORS</synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This macro is not a configuration macro and this library will generate a compile-time error if users try to define it directly. This library will automatically define this macro when users define all <computeroutput><link linkend="BOOST_CO_idm45394999622032">BOOST_CONTRACT_NO_INVARIANTS</link></computeroutput>, <computeroutput><link linkend="BOOST_CO_idm45394999656032">BOOST_CONTRACT_NO_POSTCONDITIONS</link></computeroutput>, and <computeroutput><link linkend="BOOST_CONTRACT_NO_EXCEPTS">BOOST_CONTRACT_NO_EXCEPTS</link></computeroutput>. Users can manually program <computeroutput>#ifndef</computeroutput> statements in their code using this macro to completely disable compilation of contracts for constructors or use the macros defined in <computeroutput>boost/contract_macro.hpp</computeroutput> (recommended only for applications where it is truly necessary to completely remove contract code compilation from production code).</para><para><note><para>Constructor preconditions are checked separately by <computeroutput><link linkend="boost.contract.constructor_precondition">boost::contract::constructor_precondition</link></computeroutput> so they are disabled by <computeroutput><link linkend="BOOST_CO_idm45394999662416">BOOST_CONTRACT_NO_PRECONDITIONS</link></computeroutput> instead.</para>
14707 <para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.tutorial.constructors"> Constructors</link>, <link linkend="boost_contract.extras.disable_contract_compilation__macro_interface_">
14708 Disable Contract Compilation</link> </para>
14710 </para></refsect1></refentry>
14711 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CO_idm45394999594544"><refmeta><refentrytitle>Macro BOOST_CONTRACT_NO_DESTRUCTORS</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_NO_DESTRUCTORS</refname><refpurpose>Automatically defined by this library when contracts are not checked for destructors. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.config_hpp">boost/contract/core/config.hpp</link>>
14713 </phrase>BOOST_CONTRACT_NO_DESTRUCTORS</synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This macro is not a configuration macro and this library will generate a compile-time error if users try to define it directly. This library will automatically define this macro when users define all <computeroutput><link linkend="BOOST_CO_idm45394999622032">BOOST_CONTRACT_NO_INVARIANTS</link></computeroutput>, <computeroutput><link linkend="BOOST_CO_idm45394999656032">BOOST_CONTRACT_NO_POSTCONDITIONS</link></computeroutput>, and <computeroutput><link linkend="BOOST_CONTRACT_NO_EXCEPTS">BOOST_CONTRACT_NO_EXCEPTS</link></computeroutput>. Users can manually program <computeroutput>#ifndef</computeroutput> statements in their code using this macro to completely disable compilation of contracts for destructors or use the macros defined in <computeroutput>boost/contract_macro.hpp</computeroutput> (recommended only for applications where it is truly necessary to completely remove contract code compilation from production code).</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.tutorial.destructors"> Destructors</link>, <link linkend="boost_contract.extras.disable_contract_compilation__macro_interface_">
14714 Disable Contract Compilation</link> </para>
14716 </para></refsect1></refentry>
14717 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CO_idm45394999586272"><refmeta><refentrytitle>Macro BOOST_CONTRACT_NO_PUBLIC_FUNCTIONS</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_NO_PUBLIC_FUNCTIONS</refname><refpurpose>Automatically defined by this library when contracts are not checked for public functions. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.config_hpp">boost/contract/core/config.hpp</link>>
14719 </phrase>BOOST_CONTRACT_NO_PUBLIC_FUNCTIONS</synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This macro is not a configuration macro and this library will generate a compile-time error if users try to define it directly. This library will automatically define this macro when users define all <computeroutput><link linkend="BOOST_CO_idm45394999622032">BOOST_CONTRACT_NO_INVARIANTS</link></computeroutput>, <computeroutput><link linkend="BOOST_CO_idm45394999662416">BOOST_CONTRACT_NO_PRECONDITIONS</link></computeroutput>, <computeroutput><link linkend="BOOST_CO_idm45394999656032">BOOST_CONTRACT_NO_POSTCONDITIONS</link></computeroutput>, and <computeroutput><link linkend="BOOST_CONTRACT_NO_EXCEPTS">BOOST_CONTRACT_NO_EXCEPTS</link></computeroutput>. Users can manually program <computeroutput>#ifndef</computeroutput> statements in their code using this macro to completely disable compilation of contracts for public functions or use the macros defined in <computeroutput>boost/contract_macro.hpp</computeroutput> (recommended only for applications where it is truly necessary to completely remove contract code compilation from production code).</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.tutorial.public_functions"> Public Functions</link>, <link linkend="boost_contract.extras.disable_contract_compilation__macro_interface_">
14720 Disable Contract Compilation</link> </para>
14722 </para></refsect1></refentry>
14723 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CO_idm45394999577072"><refmeta><refentrytitle>Macro BOOST_CONTRACT_NO_FUNCTIONS</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_NO_FUNCTIONS</refname><refpurpose>Automatically defined by this library when contracts are not checked for non-member, private, or protected functions. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.config_hpp">boost/contract/core/config.hpp</link>>
14725 </phrase>BOOST_CONTRACT_NO_FUNCTIONS</synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This macro is not a configuration macro and this library will generate a compile-time error if users try to define it directly. This library will automatically define this macro when users define all <computeroutput><link linkend="BOOST_CO_idm45394999662416">BOOST_CONTRACT_NO_PRECONDITIONS</link></computeroutput>, <computeroutput><link linkend="BOOST_CO_idm45394999656032">BOOST_CONTRACT_NO_POSTCONDITIONS</link></computeroutput>, and <computeroutput><link linkend="BOOST_CONTRACT_NO_EXCEPTS">BOOST_CONTRACT_NO_EXCEPTS</link></computeroutput>. Users can manually program <computeroutput>#ifndef</computeroutput> statements in their code using this macro to completely disable compilation of contracts for non-member, private and protected functions, or use the macros defined in <computeroutput>boost/contract_macro.hpp</computeroutput> (recommended only for applications where it is truly necessary to completely remove contract code compilation from production code).</para><para>This macro is also used when contracts are not checked for private or protected functions, lambda functions, code blocks, loops, etc.</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.tutorial.non_member_functions"> Non-Member Functions</link>, <link linkend="boost_contract.advanced.private_and_protected_functions">
14726 Private and Protected Functions</link>, <link linkend="boost_contract.advanced.lambdas__loops__code_blocks__and__constexpr__">
14727 Lambdas, Loops, Code Blocks</link>, <link linkend="boost_contract.extras.disable_contract_compilation__macro_interface_">
14728 Disable Contract Compilation</link> </para>
14730 </para></refsect1></refentry>
14731 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CO_idm45394999566736"><refmeta><refentrytitle>Macro BOOST_CONTRACT_NO_CONDITIONS</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_NO_CONDITIONS</refname><refpurpose>Automatically defined by this library when contracts are not checked for preconditions, postconditions, exceptions guarantees, and class invariants (excluding implementation checks). </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.config_hpp">boost/contract/core/config.hpp</link>>
14733 </phrase>BOOST_CONTRACT_NO_CONDITIONS</synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This macro is not a configuration macro and this library will generate a compile-time error if users try to define it directly. This library will automatically define this macro when users define all <computeroutput><link linkend="BOOST_CO_idm45394999662416">BOOST_CONTRACT_NO_PRECONDITIONS</link></computeroutput>, <computeroutput><link linkend="BOOST_CO_idm45394999656032">BOOST_CONTRACT_NO_POSTCONDITIONS</link></computeroutput>, <computeroutput><link linkend="BOOST_CONTRACT_NO_EXCEPTS">BOOST_CONTRACT_NO_EXCEPTS</link></computeroutput>, and <computeroutput><link linkend="BOOST_CO_idm45394999622032">BOOST_CONTRACT_NO_INVARIANTS</link></computeroutput>. Users can manually program <computeroutput>#ifndef</computeroutput> statements in their code using this macro to completely disable compilation of contracts within specifications (so excluding implementation checks which are contracts within implementations instead), or use the macros defined in <computeroutput>boost/contract_macro.hpp</computeroutput> (recommended only for applications where it is truly necessary to completely remove contract code compilation from production code).</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.extras.disable_contract_compilation__macro_interface_">
14734 Disable Contract Compilation</link> </para>
14736 </para></refsect1></refentry>
14737 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CONTRACT_NO_ALL"><refmeta><refentrytitle>Macro BOOST_CONTRACT_NO_ALL</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_NO_ALL</refname><refpurpose>Automatically defined by this library when contracts are not checked at all (neither for specifications nor for implementations). </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.config_hpp">boost/contract/core/config.hpp</link>>
14739 </phrase>BOOST_CONTRACT_NO_ALL</synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This macro is not a configuration macro and this library will generate a compile-time error if users try to define it directly. This library will automatically define this macro when users define all <computeroutput><link linkend="BOOST_CO_idm45394999622032">BOOST_CONTRACT_NO_INVARIANTS</link></computeroutput>, <computeroutput><link linkend="BOOST_CO_idm45394999662416">BOOST_CONTRACT_NO_PRECONDITIONS</link></computeroutput>, <computeroutput><link linkend="BOOST_CO_idm45394999656032">BOOST_CONTRACT_NO_POSTCONDITIONS</link></computeroutput>, <computeroutput><link linkend="BOOST_CONTRACT_NO_EXCEPTS">BOOST_CONTRACT_NO_EXCEPTS</link></computeroutput>, and <computeroutput><link linkend="BOOST_CONTRACT_NO_CHECKS">BOOST_CONTRACT_NO_CHECKS</link></computeroutput>. For example, users can manually program <computeroutput>#ifndef</computeroutput> statements in their code using this macro to avoid including the <computeroutput>boost/contract.hpp</computeroutput> header all together:</para><para><programlisting><phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">contract</phrase><phrase role="special">/</phrase><phrase role="identifier">core</phrase><phrase role="special">/</phrase><phrase role="identifier">config</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">></phrase>
14740 <phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_ALL</phrase>
14741 <phrase role="preprocessor">#include</phrase> <phrase role="special"><</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">contract</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">></phrase>
14742 <phrase role="preprocessor">#endif</phrase>
14743 </programlisting></para><para>Or, use the <computeroutput>boost/contract_macro.hpp</computeroutput> header and related macros instead (because the <computeroutput>boost/contract_macro.hpp</computeroutput> header is already optimized to not include other headers from this library when contracts are not checked, but recommended only for applications where it is truly necessary to completely remove contract code compilation from production code).</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.extras.disable_contract_compilation__macro_interface_">
14744 Disable Contract Compilation</link> </para>
14746 </para></refsect1></refentry>
14748 <section id="header.boost.contract.core.constructor_precondition_hpp"><title>Header <<ulink url="../../../../boost/contract/core/constructor_precondition.hpp">boost/contract/core/constructor_precondition.hpp</ulink>></title><para>Program preconditions for constructors. </para><synopsis xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">namespace</phrase> <phrase role="identifier">boost</phrase> <phrase role="special">{</phrase>
14749 <phrase role="keyword">namespace</phrase> <phrase role="identifier">contract</phrase> <phrase role="special">{</phrase>
14750 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> Class<phrase role="special">></phrase> <phrase role="keyword">class</phrase> <link linkend="boost.contract.constructor_precondition">constructor_precondition</link><phrase role="special">;</phrase>
14751 <phrase role="special">}</phrase>
14752 <phrase role="special">}</phrase></synopsis>
14753 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.constructor_precondition"><refmeta><refentrytitle>Class template constructor_precondition</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::constructor_precondition</refname><refpurpose>Program preconditions for constructors. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.constructor_precondition_hpp">boost/contract/core/constructor_precondition.hpp</link>>
14755 </phrase><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> Class<phrase role="special">></phrase>
14756 <phrase role="keyword">class</phrase> <link linkend="boost.contract.constructor_precondition">constructor_precondition</link> <phrase role="special">{</phrase>
14757 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
14758 <phrase role="comment">// <link linkend="boost.contract.constructor_preconditionconstruct-copy-destruct">construct/copy/destruct</link></phrase>
14759 <link linkend="idm45394999534384-bb"><phrase role="identifier">constructor_precondition</phrase></link><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14760 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> F<phrase role="special">></phrase> <phrase role="keyword">explicit</phrase> <link linkend="idm45394999532192-bb"><phrase role="identifier">constructor_precondition</phrase></link><phrase role="special">(</phrase><phrase role="identifier">F</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14761 <phrase role="special">}</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This class must be the very first base of the class declaring the constructor for which preconditions are programmed (that way constructor arguments can be checked by preconditions even before they are used to initialize other base classes):</para><para><programlisting><phrase role="keyword">class</phrase> <phrase role="identifier">u</phrase>
14762 <phrase role="preprocessor">#define</phrase> <phrase role="identifier">BASES</phrase> <phrase role="keyword">private</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor_precondition</phrase><phrase role="special"><</phrase><phrase role="identifier">u</phrase><phrase role="special">></phrase><phrase role="special">,</phrase> \
14763 <phrase role="keyword">public</phrase> <phrase role="identifier">b</phrase>
14764 <phrase role="special">:</phrase> <phrase role="identifier">BASES</phrase>
14765 <phrase role="special">{</phrase>
14766 <phrase role="keyword">friend</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">access</phrase><phrase role="special">;</phrase>
14768 <phrase role="keyword">typedef</phrase> <phrase role="identifier">BOOST_CONTRACT_BASE_TYPES</phrase><phrase role="special">(</phrase><phrase role="identifier">BASES</phrase><phrase role="special">)</phrase> <phrase role="identifier">base_types</phrase><phrase role="special">;</phrase>
14769 <phrase role="preprocessor">#undef</phrase> <phrase role="identifier">BASES</phrase>
14771 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
14772 <phrase role="keyword">explicit</phrase> <phrase role="identifier">u</phrase><phrase role="special">(</phrase><phrase role="keyword">unsigned</phrase> <phrase role="identifier">x</phrase><phrase role="special">)</phrase> <phrase role="special">:</phrase>
14773 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor_precondition</phrase><phrase role="special"><</phrase><phrase role="identifier">u</phrase><phrase role="special">></phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase>
14774 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">x</phrase> <phrase role="special">!=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14775 <phrase role="special">...</phrase>
14776 <phrase role="special">}</phrase><phrase role="special">)</phrase><phrase role="special">,</phrase>
14777 <phrase role="identifier">b</phrase><phrase role="special">(</phrase><phrase role="number">1</phrase><phrase role="special">.</phrase><phrase role="number">0</phrase> <phrase role="special">/</phrase> <phrase role="keyword">float</phrase><phrase role="special">(</phrase><phrase role="identifier">x</phrase><phrase role="special">)</phrase><phrase role="special">)</phrase>
14778 <phrase role="special">{</phrase>
14779 <phrase role="special">...</phrase>
14780 <phrase role="special">}</phrase>
14782 <phrase role="special">...</phrase>
14783 <phrase role="special">}</phrase><phrase role="special">;</phrase>
14784 </programlisting></para><para>User-defined classes should inherit privately from this class (to not alter the public interface of user-defined classes). In addition, this class should never be declared as a virtual base (because virtual bases are initialized only once across the entire inheritance hierarchy preventing preconditions of other base classes from being checked).</para><para>This class cannot be used this way in a <computeroutput>union</computeroutput> because unions cannot have base classes in C++. Instead, this class is used in a <computeroutput>union</computeroutput> to declare a local object within the constructor definition just before <computeroutput><link linkend="boost.contract.constructor">boost::contract::constructor</link></computeroutput> is used (see <link linkend="boost_contract.extras.unions"> Unions</link>).</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.tutorial.constructors"> Constructors</link></para>
14787 </para><refsect2><title>Template Parameters</title><orderedlist><listitem><para><literallayout class="monospaced"><phrase role="keyword">typename</phrase> Class</literallayout></para><para><para>The class type of the constructor for which preconditions are being programmed. </para></para></listitem></orderedlist></refsect2><refsect2><title><anchor id="boost.contract.constructor_preconditionconstruct-copy-destruct"/><computeroutput>constructor_precondition</computeroutput>
14789 construct/copy/destruct</title><orderedlist><listitem><para><literallayout class="monospaced"><anchor id="idm45394999534384-bb"/><phrase role="identifier">constructor_precondition</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase></literallayout></para>Construct this object without specifying constructor preconditions. <para>This is implicitly called for those constructors of the contracted class that do not specify preconditions.</para><para><note><para>The implementation of this library is optimized so that calling this default constructor should amount to negligible compile-time and run-time overheads (likely to be optimized away completely by most compilers). </para>
14791 </para></listitem><listitem><para><literallayout class="monospaced"><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> F<phrase role="special">></phrase> <phrase role="keyword">explicit</phrase> <anchor id="idm45394999532192-bb"/><phrase role="identifier">constructor_precondition</phrase><phrase role="special">(</phrase><phrase role="identifier">F</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase> f<phrase role="special">)</phrase><phrase role="special">;</phrase></literallayout></para>Construct this object specifying constructor preconditions. <para>
14792 </para><variablelist spacing="compact"><?dbhtml
14793 list-presentation="table"
14794 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
14795 list-presentation="table"
14796 ?><varlistentry><term><computeroutput>f</computeroutput></term><listitem><para>Nullary functor called by this library to check constructor preconditions <computeroutput>f()</computeroutput>. Assertions within this functor call are usually programmed using <computeroutput><computeroutput><link linkend="BOOST_CONTRACT_ASSERT">BOOST_CONTRACT_ASSERT</link></computeroutput></computeroutput>, but any exception thrown by a call to this functor indicates a contract failure (and will result in this library calling <computeroutput><computeroutput><link linkend="boost.contract.precondition_failure">boost::contract::precondition_failure</link></computeroutput></computeroutput>). This functor should capture variables by (constant) value, or better by (constant) reference to avoid extra copies. </para></listitem></varlistentry></variablelist></listitem></varlistentry></variablelist></listitem></orderedlist></refsect2></refsect1></refentry>
14798 <section id="header.boost.contract.core.exception_hpp"><title>Header <<ulink url="../../../../boost/contract/core/exception.hpp">boost/contract/core/exception.hpp</ulink>></title><para>Handle contract assertion failures. </para><synopsis xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">namespace</phrase> <phrase role="identifier">boost</phrase> <phrase role="special">{</phrase>
14799 <phrase role="keyword">namespace</phrase> <phrase role="identifier">contract</phrase> <phrase role="special">{</phrase>
14800 <phrase role="keyword">class</phrase> <link linkend="boost.contract.assertion_failure">assertion_failure</link><phrase role="special">;</phrase>
14801 <phrase role="keyword">class</phrase> <link linkend="boost.contract.bad_virtual_result_cast">bad_virtual_result_cast</link><phrase role="special">;</phrase>
14802 <phrase role="keyword">class</phrase> <link linkend="boost.contract.exception">exception</link><phrase role="special">;</phrase>
14804 <phrase role="keyword">enum</phrase> <link linkend="boost.contract.from">from</link><phrase role="special">;</phrase>
14805 <phrase role="keyword">typedef</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">function</phrase><phrase role="special"><</phrase> <phrase role="keyword">void</phrase><phrase role="special">(</phrase><phrase role="identifier">from</phrase><phrase role="special">)</phrase><phrase role="special">></phrase> <link linkend="boost.contract.from_failure_handler"><phrase role="identifier">from_failure_handler</phrase></link><phrase role="special">;</phrase>
14806 <phrase role="keyword">typedef</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">function</phrase><phrase role="special"><</phrase> <phrase role="keyword">void</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">></phrase> <link linkend="boost.contract.failure_handler"><phrase role="identifier">failure_handler</phrase></link><phrase role="special">;</phrase>
14807 <phrase role="identifier">failure_handler</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase> <link linkend="boost.contract.set_check_failure"><phrase role="identifier">set_check_failure</phrase></link><phrase role="special">(</phrase><phrase role="identifier">failure_handler</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14808 <phrase role="identifier">failure_handler</phrase> <link linkend="boost.contract.get_check_failure"><phrase role="identifier">get_check_failure</phrase></link><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14809 <phrase role="keyword">void</phrase> <link linkend="boost.contract.check_failure"><phrase role="identifier">check_failure</phrase></link><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14810 <phrase role="identifier">from_failure_handler</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase>
14811 <link linkend="boost.contract.set_precondition_failure"><phrase role="identifier">set_precondition_failure</phrase></link><phrase role="special">(</phrase><phrase role="identifier">from_failure_handler</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14812 <phrase role="identifier">from_failure_handler</phrase> <link linkend="boost.contract.get_precondition_failure"><phrase role="identifier">get_precondition_failure</phrase></link><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14813 <phrase role="keyword">void</phrase> <link linkend="boost.contract.precondition_failure"><phrase role="identifier">precondition_failure</phrase></link><phrase role="special">(</phrase><phrase role="identifier">from</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14814 <phrase role="identifier">from_failure_handler</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase>
14815 <link linkend="boost.contract.set_postcondition_failure"><phrase role="identifier">set_postcondition_failure</phrase></link><phrase role="special">(</phrase><phrase role="identifier">from_failure_handler</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14816 <phrase role="identifier">from_failure_handler</phrase> <link linkend="boost.contract.get_postcondition_failure"><phrase role="identifier">get_postcondition_failure</phrase></link><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14817 <phrase role="keyword">void</phrase> <link linkend="boost.contract.postcondition_failure"><phrase role="identifier">postcondition_failure</phrase></link><phrase role="special">(</phrase><phrase role="identifier">from</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14818 <phrase role="identifier">from_failure_handler</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase>
14819 <link linkend="boost.contract.set_except_failure"><phrase role="identifier">set_except_failure</phrase></link><phrase role="special">(</phrase><phrase role="identifier">from_failure_handler</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14820 <phrase role="identifier">from_failure_handler</phrase> <link linkend="boost.contract.get_except_failure"><phrase role="identifier">get_except_failure</phrase></link><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14821 <phrase role="keyword">void</phrase> <link linkend="boost.contract.except_failure"><phrase role="identifier">except_failure</phrase></link><phrase role="special">(</phrase><phrase role="identifier">from</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14822 <phrase role="identifier">from_failure_handler</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase>
14823 <link linkend="boost.contract.set_old_failure"><phrase role="identifier">set_old_failure</phrase></link><phrase role="special">(</phrase><phrase role="identifier">from_failure_handler</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14824 <phrase role="identifier">from_failure_handler</phrase> <link linkend="boost.contract.get_old_failure"><phrase role="identifier">get_old_failure</phrase></link><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14825 <phrase role="keyword">void</phrase> <link linkend="boost.contract.old_failure"><phrase role="identifier">old_failure</phrase></link><phrase role="special">(</phrase><phrase role="identifier">from</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14826 <phrase role="identifier">from_failure_handler</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase>
14827 <link linkend="boost.contract.set_entr_idm45394999333872"><phrase role="identifier">set_entry_invariant_failure</phrase></link><phrase role="special">(</phrase><phrase role="identifier">from_failure_handler</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14828 <phrase role="identifier">from_failure_handler</phrase> <link linkend="boost.contract.get_entr_idm45394999324384"><phrase role="identifier">get_entry_invariant_failure</phrase></link><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14829 <phrase role="keyword">void</phrase> <link linkend="boost.contract.entry_invariant_failure"><phrase role="identifier">entry_invariant_failure</phrase></link><phrase role="special">(</phrase><phrase role="identifier">from</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14830 <phrase role="identifier">from_failure_handler</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase>
14831 <link linkend="boost.contract.set_exit_invariant_failure"><phrase role="identifier">set_exit_invariant_failure</phrase></link><phrase role="special">(</phrase><phrase role="identifier">from_failure_handler</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14832 <phrase role="identifier">from_failure_handler</phrase> <link linkend="boost.contract.get_exit_invariant_failure"><phrase role="identifier">get_exit_invariant_failure</phrase></link><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14833 <phrase role="keyword">void</phrase> <link linkend="boost.contract.exit_invariant_failure"><phrase role="identifier">exit_invariant_failure</phrase></link><phrase role="special">(</phrase><phrase role="identifier">from</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14834 <phrase role="identifier">from_failure_handler</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase>
14835 <link linkend="boost.contract.set_invariant_failure"><phrase role="identifier">set_invariant_failure</phrase></link><phrase role="special">(</phrase><phrase role="identifier">from_failure_handler</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14836 <phrase role="special">}</phrase>
14837 <phrase role="special">}</phrase></synopsis>
14838 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.assertion_failure"><refmeta><refentrytitle>Class assertion_failure</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::assertion_failure</refname><refpurpose>Exception typically used to report a contract assertion failure. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.exception_hpp">boost/contract/core/exception.hpp</link>>
14841 <phrase role="keyword">class</phrase> <link linkend="boost.contract.assertion_failure">assertion_failure</link> <phrase role="special">:</phrase>
14842 <phrase role="keyword">public</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">exception</phrase>, <phrase role="keyword">public</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">exception</phrase>
14843 <phrase role="special">{</phrase>
14844 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
14845 <phrase role="comment">// <link linkend="boost.contract.assertion_failureconstruct-copy-destruct">construct/copy/destruct</link></phrase>
14846 <phrase role="keyword">explicit</phrase> <link linkend="idm45394999500624-bb"><phrase role="identifier">assertion_failure</phrase></link><phrase role="special">(</phrase><phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase> <phrase role="special">*</phrase> <phrase role="special">=</phrase> <phrase role="string">""</phrase><phrase role="special">,</phrase> <phrase role="keyword">unsigned</phrase> <phrase role="keyword">long</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">,</phrase>
14847 <phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase> <phrase role="special">*</phrase> <phrase role="special">=</phrase> <phrase role="string">""</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14848 <phrase role="keyword">explicit</phrase> <link linkend="idm45394999493584-bb"><phrase role="identifier">assertion_failure</phrase></link><phrase role="special">(</phrase><phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase> <phrase role="special">*</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14849 <link linkend="idm45394999491104-bb"><phrase role="special">~</phrase><phrase role="identifier">assertion_failure</phrase></link><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14851 <phrase role="comment">// <link linkend="idm45394999515280-bb">public member functions</link></phrase>
14852 <phrase role="keyword">virtual</phrase> <phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase> <phrase role="special">*</phrase> <link linkend="idm45394999514720-bb"><phrase role="identifier">what</phrase></link><phrase role="special">(</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase><phrase role="special">;</phrase>
14853 <phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase> <phrase role="special">*</phrase> <link linkend="idm45394999509616-bb"><phrase role="identifier">file</phrase></link><phrase role="special">(</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase><phrase role="special">;</phrase>
14854 <phrase role="keyword">unsigned</phrase> <phrase role="keyword">long</phrase> <link linkend="idm45394999506688-bb"><phrase role="identifier">line</phrase></link><phrase role="special">(</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase><phrase role="special">;</phrase>
14855 <phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase> <phrase role="special">*</phrase> <link linkend="idm45394999503760-bb"><phrase role="identifier">code</phrase></link><phrase role="special">(</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase><phrase role="special">;</phrase>
14856 <phrase role="special">}</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This exception is thrown by code expanded by <computeroutput><link linkend="BOOST_CONTRACT_ASSERT">BOOST_CONTRACT_ASSERT</link></computeroutput> (but it can also be thrown by user code programmed manually without that macro). This exception is typically used to report contract assertion failures because it contains detailed information about the file name, line number, and source code of the asserted condition (so it can be used by this library to provide detailed error messages when handling contract assertion failures).</para><para>However, any other exception can be used to report a contract assertion failure (including user-defined exceptions). This library will call the appropriate contract failure handler function ( <computeroutput><link linkend="boost.contract.precondition_failure">boost::contract::precondition_failure</link></computeroutput>, etc.) when this or any other exception is thrown while checking contracts (by default, these failure handler functions print an error message to <computeroutput>std::cerr</computeroutput> and terminate the program, but they can be customized to take any other action).</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__"> Throw on Failure</link>, <link linkend="boost_contract.extras.no_macros__and_no_variadic_macros_"> No Macros</link> </para>
14858 </para><refsect2><title><anchor id="boost.contract.assertion_failureconstruct-copy-destruct"/><computeroutput>assertion_failure</computeroutput>
14860 construct/copy/destruct</title><orderedlist><listitem><para><literallayout class="monospaced"><phrase role="keyword">explicit</phrase> <anchor id="idm45394999500624-bb"/><phrase role="identifier">assertion_failure</phrase><phrase role="special">(</phrase><phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase> <phrase role="special">*</phrase> file <phrase role="special">=</phrase> <phrase role="string">""</phrase><phrase role="special">,</phrase> <phrase role="keyword">unsigned</phrase> <phrase role="keyword">long</phrase> line <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">,</phrase>
14861 <phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase> <phrase role="special">*</phrase> code <phrase role="special">=</phrase> <phrase role="string">""</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase></literallayout></para>Construct this object with file name, line number, and source code text of an assertion condition (all optional). <para>This constructor can also be used to specify no information (default constructor), or to specify only file name and line number but not source code text (because of the parameter default values).</para><para>
14862 </para><variablelist spacing="compact"><?dbhtml
14863 list-presentation="table"
14864 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
14865 list-presentation="table"
14866 ?><varlistentry><term><computeroutput>code</computeroutput></term><listitem><para>Text listing the source code of the assertion condition. </para></listitem></varlistentry><varlistentry><term><computeroutput>file</computeroutput></term><listitem><para>Name of the file containing the assertion (usually set using <computeroutput>__FILE__</computeroutput>). </para></listitem></varlistentry><varlistentry><term><computeroutput>line</computeroutput></term><listitem><para>Number of the line containing the assertion (usually set using <computeroutput>__LINE__</computeroutput>). </para></listitem></varlistentry></variablelist></listitem></varlistentry></variablelist></listitem><listitem><para><literallayout class="monospaced"><phrase role="keyword">explicit</phrase> <anchor id="idm45394999493584-bb"/><phrase role="identifier">assertion_failure</phrase><phrase role="special">(</phrase><phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase> <phrase role="special">*</phrase> code<phrase role="special">)</phrase><phrase role="special">;</phrase></literallayout></para>Construct this object only with the source code text of the assertion condition. <para>
14867 </para><variablelist spacing="compact"><?dbhtml
14868 list-presentation="table"
14869 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
14870 list-presentation="table"
14871 ?><varlistentry><term><computeroutput>code</computeroutput></term><listitem><para>Text listing the source code of the assertion condition. </para></listitem></varlistentry></variablelist></listitem></varlistentry></variablelist></listitem><listitem><para><literallayout class="monospaced"><anchor id="idm45394999491104-bb"/><phrase role="special">~</phrase><phrase role="identifier">assertion_failure</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase></literallayout></para>Destruct this object. <para><emphasis role="bold">Throws:</emphasis> This is declared <computeroutput>noexcept</computeroutput> (or <computeroutput>throw()</computeroutput> before C++11). </para></listitem></orderedlist></refsect2><refsect2><title><anchor id="idm45394999515280-bb"/><computeroutput>assertion_failure</computeroutput> public member functions</title><orderedlist><listitem><para><literallayout class="monospaced"><phrase role="keyword">virtual</phrase> <phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase> <phrase role="special">*</phrase> <anchor id="idm45394999514720-bb"/><phrase role="identifier">what</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase><phrase role="special">;</phrase></literallayout></para>String describing the failed assertion. <para><emphasis role="bold">Throws:</emphasis> This is declared <computeroutput>noexcept</computeroutput> (or <computeroutput>throw()</computeroutput> before C++11).</para><para>
14872 </para><variablelist spacing="compact"><?dbhtml
14873 list-presentation="table"
14874 ?><varlistentry><term>Returns:</term><listitem><para>A string formatted similarly to the following: <computeroutput>assertion "`code()`" failed: file "`file()`", line `line()`</computeroutput> (where `` indicate execution quotes). File, line, and code will be omitted from this string if they were not specified when constructing this object. </para></listitem></varlistentry></variablelist></listitem><listitem><para><literallayout class="monospaced"><phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase> <phrase role="special">*</phrase> <anchor id="idm45394999509616-bb"/><phrase role="identifier">file</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase><phrase role="special">;</phrase></literallayout></para>Name of the file containing the assertion. <para>
14875 </para><variablelist spacing="compact"><?dbhtml
14876 list-presentation="table"
14877 ?><varlistentry><term>Returns:</term><listitem><para>File name as specified at construction (or <computeroutput>""</computeroutput> if no file was specified). </para></listitem></varlistentry></variablelist></listitem><listitem><para><literallayout class="monospaced"><phrase role="keyword">unsigned</phrase> <phrase role="keyword">long</phrase> <anchor id="idm45394999506688-bb"/><phrase role="identifier">line</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase><phrase role="special">;</phrase></literallayout></para>Number of the line containing the assertion. <para>
14878 </para><variablelist spacing="compact"><?dbhtml
14879 list-presentation="table"
14880 ?><varlistentry><term>Returns:</term><listitem><para>Line number as specified at construction (or <computeroutput>0</computeroutput> if no line number was specified). </para></listitem></varlistentry></variablelist></listitem><listitem><para><literallayout class="monospaced"><phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase> <phrase role="special">*</phrase> <anchor id="idm45394999503760-bb"/><phrase role="identifier">code</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase><phrase role="special">;</phrase></literallayout></para>Text listing the source code of the assertion condition. <para>
14881 </para><variablelist spacing="compact"><?dbhtml
14882 list-presentation="table"
14883 ?><varlistentry><term>Returns:</term><listitem><para>Assertion condition source code as specified at construction (or <computeroutput>""</computeroutput> if no source code text was specified). </para></listitem></varlistentry></variablelist></listitem></orderedlist></refsect2></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.bad_virtual_result_cast"><refmeta><refentrytitle>Class bad_virtual_result_cast</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::bad_virtual_result_cast</refname><refpurpose>Exception thrown when inconsistent return values are passed to overridden virtual public functions. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.exception_hpp">boost/contract/core/exception.hpp</link>>
14886 <phrase role="keyword">class</phrase> <link linkend="boost.contract.bad_virtual_result_cast">bad_virtual_result_cast</link> <phrase role="special">:</phrase>
14887 <phrase role="keyword">public</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">bad_cast</phrase>, <phrase role="keyword">public</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">exception</phrase>
14888 <phrase role="special">{</phrase>
14889 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
14890 <phrase role="comment">// <link linkend="boost.contract.bad_virtual_result_castconstruct-copy-destruct">construct/copy/destruct</link></phrase>
14891 <phrase role="keyword">explicit</phrase> <link linkend="idm45394999479088-bb"><phrase role="identifier">bad_virtual_result_cast</phrase></link><phrase role="special">(</phrase><phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase> <phrase role="special">*</phrase><phrase role="special">,</phrase> <phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase> <phrase role="special">*</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14892 <link linkend="idm45394999475504-bb"><phrase role="special">~</phrase><phrase role="identifier">bad_virtual_result_cast</phrase></link><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14894 <phrase role="comment">// <link linkend="idm45394999483408-bb">public member functions</link></phrase>
14895 <phrase role="keyword">virtual</phrase> <phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase> <phrase role="special">*</phrase> <link linkend="idm45394999482848-bb"><phrase role="identifier">what</phrase></link><phrase role="special">(</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase><phrase role="special">;</phrase>
14896 <phrase role="special">}</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This exception is thrown when programmers pass to this library return value parameters for public function overrides in derived classes that are not consistent with the return type parameter passed for the virtual public function being overridden from the base classes. This allows this library to give more descriptive error messages in such cases of misuse.</para><para>This exception is internally thrown by this library and programmers should not need to throw it from user code.</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.tutorial.public_function_overrides__subcontracting_">
14897 Public Function Overrides</link> </para>
14899 </para><refsect2><title><anchor id="boost.contract.bad_virtual_result_castconstruct-copy-destruct"/><computeroutput>bad_virtual_result_cast</computeroutput>
14901 construct/copy/destruct</title><orderedlist><listitem><para><literallayout class="monospaced"><phrase role="keyword">explicit</phrase> <anchor id="idm45394999479088-bb"/><phrase role="identifier">bad_virtual_result_cast</phrase><phrase role="special">(</phrase><phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase> <phrase role="special">*</phrase> from_type_name<phrase role="special">,</phrase>
14902 <phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase> <phrase role="special">*</phrase> to_type_name<phrase role="special">)</phrase><phrase role="special">;</phrase></literallayout></para>Construct this object with the name of the from- and to- result types. <para>
14903 </para><variablelist spacing="compact"><?dbhtml
14904 list-presentation="table"
14905 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
14906 list-presentation="table"
14907 ?><varlistentry><term><computeroutput>from_type_name</computeroutput></term><listitem><para>Name of the from-type (source of the cast). </para></listitem></varlistentry><varlistentry><term><computeroutput>to_type_name</computeroutput></term><listitem><para>Name of the to-type (destination of the cast). </para></listitem></varlistentry></variablelist></listitem></varlistentry></variablelist></listitem><listitem><para><literallayout class="monospaced"><anchor id="idm45394999475504-bb"/><phrase role="special">~</phrase><phrase role="identifier">bad_virtual_result_cast</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase></literallayout></para>Destruct this object. <para><emphasis role="bold">Throws:</emphasis> This is declared <computeroutput>noexcept</computeroutput> (or <computeroutput>throw()</computeroutput> before C++11). </para></listitem></orderedlist></refsect2><refsect2><title><anchor id="idm45394999483408-bb"/><computeroutput>bad_virtual_result_cast</computeroutput> public member functions</title><orderedlist><listitem><para><literallayout class="monospaced"><phrase role="keyword">virtual</phrase> <phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase> <phrase role="special">*</phrase> <anchor id="idm45394999482848-bb"/><phrase role="identifier">what</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase><phrase role="special">;</phrase></literallayout></para>Description for this error (containing both from- and to- type names). <para><emphasis role="bold">Throws:</emphasis> This is declared <computeroutput>noexcept</computeroutput> (or <computeroutput>throw()</computeroutput> before C++11). </para></listitem></orderedlist></refsect2></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.exception"><refmeta><refentrytitle>Class exception</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::exception</refname><refpurpose>Public base class for all exceptions directly thrown by this library. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.exception_hpp">boost/contract/core/exception.hpp</link>>
14910 <phrase role="keyword">class</phrase> <link linkend="boost.contract.exception">exception</link> <phrase role="special">{</phrase>
14911 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
14912 <phrase role="comment">// <link linkend="boost.contract.exceptionconstruct-copy-destruct">construct/copy/destruct</link></phrase>
14913 <link linkend="idm45394999466544-bb"><phrase role="special">~</phrase><phrase role="identifier">exception</phrase></link><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
14914 <phrase role="special">}</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This class does not inherit from <computeroutput>std::exception</computeroutput> because exceptions deriving from this class will do that (inheriting from <computeroutput>std::exception</computeroutput>, <computeroutput>std::bad_cast</computeroutput>, etc.).</para><para><para><emphasis role="bold">See Also:</emphasis><para> <computeroutput><link linkend="boost.contract.assertion_failure">boost::contract::assertion_failure</link></computeroutput>, <computeroutput><link linkend="boost.contract.bad_virtual_result_cast">boost::contract::bad_virtual_result_cast</link></computeroutput>, etc. </para>
14916 </para><refsect2><title><anchor id="boost.contract.exceptionconstruct-copy-destruct"/><computeroutput>exception</computeroutput>
14918 construct/copy/destruct</title><orderedlist><listitem><para><literallayout class="monospaced"><anchor id="idm45394999466544-bb"/><phrase role="special">~</phrase><phrase role="identifier">exception</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase></literallayout></para>Destruct this object. <para><emphasis role="bold">Throws:</emphasis> This is declared <computeroutput>noexcept</computeroutput> (or <computeroutput>throw()</computeroutput> before C++11). </para></listitem></orderedlist></refsect2></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.from"><refmeta><refentrytitle>Type from</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::from</refname><refpurpose>Indicate the kind of operation where the contract assertion failed. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.exception_hpp">boost/contract/core/exception.hpp</link>>
14922 <phrase role="keyword">enum</phrase> <phrase role="identifier">from</phrase> <phrase role="special">{</phrase> <link linkend="boost.contract.from.from_constructor">from_constructor</link>, <link linkend="boost.contract.from.from_destructor">from_destructor</link>, <link linkend="boost.contract.from.from_function">from_function</link> <phrase role="special">}</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This is passed as a parameter to the assertion failure handler functions. For example, it might be necessary to know in which operation an assertion failed to make sure exceptions are never thrown from destructors, not even when contract failure handlers are programmed by users to throw exceptions instead of terminating the program.</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__"> Throw on Failure</link> </para>
14924 </para><variablelist spacing="compact"><varlistentry><term><computeroutput>from_constructor</computeroutput><anchor id="boost.contract.from.from_constructor"/></term><listitem>Assertion failed when checking contracts for constructors. </listitem></varlistentry><varlistentry><term><computeroutput>from_destructor</computeroutput><anchor id="boost.contract.from.from_destructor"/></term><listitem>Assertion failed when checking contracts for destructors . </listitem></varlistentry><varlistentry><term><computeroutput>from_function</computeroutput><anchor id="boost.contract.from.from_function"/></term><listitem>Assertion failed when checking contracts for functions (members or not, public or not). </listitem></varlistentry></variablelist></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.from_failure_handler"><refmeta><refentrytitle>Type definition from_failure_handler</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>from_failure_handler</refname><refpurpose>Type of assertion failure handler functions (with <computeroutput>from</computeroutput> parameter). </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.exception_hpp">boost/contract/core/exception.hpp</link>>
14927 <phrase role="keyword">typedef</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">function</phrase><phrase role="special"><</phrase> <phrase role="keyword">void</phrase><phrase role="special">(</phrase><phrase role="identifier">from</phrase><phrase role="special">)</phrase><phrase role="special">></phrase> <phrase role="identifier">from_failure_handler</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>Assertion failure handler functions specified by this type must be functors returning <computeroutput>void</computeroutput> and taking a single parameter of type <computeroutput><link linkend="boost.contract.from">boost::contract::from</link></computeroutput>. For example, this is used to specify contract failure handlers for class invariants, preconditions, postconditions, and exception guarantees.</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__"> Throw on Failure</link> </para>
14929 </para></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.failure_handler"><refmeta><refentrytitle>Type definition failure_handler</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>failure_handler</refname><refpurpose>Type of assertion failure handler functions (without <computeroutput>from</computeroutput> parameter). </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.exception_hpp">boost/contract/core/exception.hpp</link>>
14932 <phrase role="keyword">typedef</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">function</phrase><phrase role="special"><</phrase> <phrase role="keyword">void</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">></phrase> <phrase role="identifier">failure_handler</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>Assertion failure handler functions specified by this type must be nullary functors returning <computeroutput>void</computeroutput>. For example, this is used to specify contract failure handlers for implementation checks.</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__"> Throw on Failure</link> </para>
14934 </para></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.set_check_failure"><refmeta><refentrytitle>Function set_check_failure</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::set_check_failure</refname><refpurpose>Set failure handler for implementation checks. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.exception_hpp">boost/contract/core/exception.hpp</link>>
14937 <phrase role="identifier">failure_handler</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase> <phrase role="identifier">set_check_failure</phrase><phrase role="special">(</phrase><phrase role="identifier">failure_handler</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase> f<phrase role="special">)</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>Set a new failure handler and returns it.</para><para><emphasis role="bold">Throws:</emphasis> This is declared <computeroutput>noexcept</computeroutput> (or <computeroutput>throw()</computeroutput> before C++11).</para><para>
14939 <para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__"> Throw on Failure</link>, <link linkend="boost_contract.advanced.implementation_checks"> Implementation Checks</link> </para>
14941 </para><variablelist spacing="compact"><?dbhtml
14942 list-presentation="table"
14943 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
14944 list-presentation="table"
14945 ?><varlistentry><term><computeroutput>f</computeroutput></term><listitem><para>New failure handler functor to set.</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Returns:</term><listitem><para>Same failure handler functor <computeroutput>f</computeroutput> passed as parameter (e.g., for concatenating function calls).</para></listitem></varlistentry></variablelist></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.get_check_failure"><refmeta><refentrytitle>Function get_check_failure</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::get_check_failure</refname><refpurpose>Return failure handler currently set for implementation checks. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.exception_hpp">boost/contract/core/exception.hpp</link>>
14948 <phrase role="identifier">failure_handler</phrase> <phrase role="identifier">get_check_failure</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This is often called only internally by this library.</para><para><emphasis role="bold">Throws:</emphasis> This is declared <computeroutput>noexcept</computeroutput> (or <computeroutput>throw()</computeroutput> before C++11).</para><para>
14949 <para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__"> Throw on Failure</link>, <link linkend="boost_contract.advanced.implementation_checks"> Implementation Checks</link> </para>
14951 </para><variablelist spacing="compact"><?dbhtml
14952 list-presentation="table"
14953 ?><varlistentry><term>Returns:</term><listitem><para>A copy of the failure handler currently set.</para></listitem></varlistentry></variablelist></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.check_failure"><refmeta><refentrytitle>Function check_failure</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::check_failure</refname><refpurpose>Call failure handler for implementation checks. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.exception_hpp">boost/contract/core/exception.hpp</link>>
14956 <phrase role="keyword">void</phrase> <phrase role="identifier">check_failure</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This is often called only internally by this library.</para><para><emphasis role="bold">Throws:</emphasis> This can throw in case programmers specify a failure handler that throws exceptions on implementation check failures (not the default).</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__"> Throw on Failure</link>, <link linkend="boost_contract.advanced.implementation_checks"> Implementation Checks</link> </para>
14958 </para></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.set_precondition_failure"><refmeta><refentrytitle>Function set_precondition_failure</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::set_precondition_failure</refname><refpurpose>Set failure handler for preconditions. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.exception_hpp">boost/contract/core/exception.hpp</link>>
14961 <phrase role="identifier">from_failure_handler</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase>
14962 <phrase role="identifier">set_precondition_failure</phrase><phrase role="special">(</phrase><phrase role="identifier">from_failure_handler</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase> f<phrase role="special">)</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>Set a new failure handler and returns it.</para><para><emphasis role="bold">Throws:</emphasis> This is declared <computeroutput>noexcept</computeroutput> (or <computeroutput>throw()</computeroutput> before C++11).</para><para>
14964 <para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__"> Throw on Failure</link>, <link linkend="boost_contract.tutorial.preconditions"> Preconditions</link> </para>
14966 </para><variablelist spacing="compact"><?dbhtml
14967 list-presentation="table"
14968 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
14969 list-presentation="table"
14970 ?><varlistentry><term><computeroutput>f</computeroutput></term><listitem><para>New failure handler functor to set.</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Returns:</term><listitem><para>Same failure handler functor <computeroutput>f</computeroutput> passed as parameter (e.g., for concatenating function calls).</para></listitem></varlistentry></variablelist></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.get_precondition_failure"><refmeta><refentrytitle>Function get_precondition_failure</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::get_precondition_failure</refname><refpurpose>Return failure handler currently set for preconditions. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.exception_hpp">boost/contract/core/exception.hpp</link>>
14973 <phrase role="identifier">from_failure_handler</phrase> <phrase role="identifier">get_precondition_failure</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This is often called only internally by this library.</para><para><emphasis role="bold">Throws:</emphasis> This is declared <computeroutput>noexcept</computeroutput> (or <computeroutput>throw()</computeroutput> before C++11).</para><para>
14974 <para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__"> Throw on Failure</link>, <link linkend="boost_contract.tutorial.preconditions"> Preconditions</link> </para>
14976 </para><variablelist spacing="compact"><?dbhtml
14977 list-presentation="table"
14978 ?><varlistentry><term>Returns:</term><listitem><para>A copy of the failure handler currently set.</para></listitem></varlistentry></variablelist></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.precondition_failure"><refmeta><refentrytitle>Function precondition_failure</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::precondition_failure</refname><refpurpose>Call failure handler for preconditions. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.exception_hpp">boost/contract/core/exception.hpp</link>>
14981 <phrase role="keyword">void</phrase> <phrase role="identifier">precondition_failure</phrase><phrase role="special">(</phrase><phrase role="identifier">from</phrase> where<phrase role="special">)</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This is often called only internally by this library.</para><para><emphasis role="bold">Throws:</emphasis> This can throw in case programmers specify a failure handler that throws exceptions on contract assertion failures (not the default).</para><para>
14982 <para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__"> Throw on Failure</link>, <link linkend="boost_contract.tutorial.preconditions"> Preconditions</link> </para>
14984 </para><variablelist spacing="compact"><?dbhtml
14985 list-presentation="table"
14986 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
14987 list-presentation="table"
14988 ?><varlistentry><term><computeroutput>where</computeroutput></term><listitem><para>Operation that failed the contract assertion (when this function is called by this library, this parameter will never be <computeroutput>from_destructor</computeroutput> because destructors do not have preconditions).</para></listitem></varlistentry></variablelist></listitem></varlistentry></variablelist></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.set_postcondition_failure"><refmeta><refentrytitle>Function set_postcondition_failure</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::set_postcondition_failure</refname><refpurpose>Set failure handler for postconditions. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.exception_hpp">boost/contract/core/exception.hpp</link>>
14991 <phrase role="identifier">from_failure_handler</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase>
14992 <phrase role="identifier">set_postcondition_failure</phrase><phrase role="special">(</phrase><phrase role="identifier">from_failure_handler</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase> f<phrase role="special">)</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>Set a new failure handler and returns it.</para><para><emphasis role="bold">Throws:</emphasis> This is declared <computeroutput>noexcept</computeroutput> (or <computeroutput>throw()</computeroutput> before C++11).</para><para>
14994 <para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__"> Throw on Failure</link>, <link linkend="boost_contract.tutorial.postconditions"> Postconditions</link> </para>
14996 </para><variablelist spacing="compact"><?dbhtml
14997 list-presentation="table"
14998 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
14999 list-presentation="table"
15000 ?><varlistentry><term><computeroutput>f</computeroutput></term><listitem><para>New failure handler functor to set.</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Returns:</term><listitem><para>Same failure handler functor <computeroutput>f</computeroutput> passed as parameter (e.g., for concatenating function calls).</para></listitem></varlistentry></variablelist></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.get_postcondition_failure"><refmeta><refentrytitle>Function get_postcondition_failure</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::get_postcondition_failure</refname><refpurpose>Return failure handler currently set for postconditions. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.exception_hpp">boost/contract/core/exception.hpp</link>>
15003 <phrase role="identifier">from_failure_handler</phrase> <phrase role="identifier">get_postcondition_failure</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This is often called only internally by this library.</para><para><emphasis role="bold">Throws:</emphasis> This is declared <computeroutput>noexcept</computeroutput> (or <computeroutput>throw()</computeroutput> before C++11).</para><para>
15004 <para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__"> Throw on Failure</link>, <link linkend="boost_contract.tutorial.postconditions"> Postconditions</link> </para>
15006 </para><variablelist spacing="compact"><?dbhtml
15007 list-presentation="table"
15008 ?><varlistentry><term>Returns:</term><listitem><para>A copy of the failure handler currently set.</para></listitem></varlistentry></variablelist></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.postcondition_failure"><refmeta><refentrytitle>Function postcondition_failure</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::postcondition_failure</refname><refpurpose>Call failure handler for postconditions. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.exception_hpp">boost/contract/core/exception.hpp</link>>
15011 <phrase role="keyword">void</phrase> <phrase role="identifier">postcondition_failure</phrase><phrase role="special">(</phrase><phrase role="identifier">from</phrase> where<phrase role="special">)</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This is often called only internally by this library.</para><para><emphasis role="bold">Throws:</emphasis> This can throw in case programmers specify a failure handler that throws exceptions on contract assertion failures (not the default).</para><para>
15012 <para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__"> Throw on Failure</link>, <link linkend="boost_contract.tutorial.postconditions"> Postconditions</link> </para>
15014 </para><variablelist spacing="compact"><?dbhtml
15015 list-presentation="table"
15016 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
15017 list-presentation="table"
15018 ?><varlistentry><term><computeroutput>where</computeroutput></term><listitem><para>Operation that failed the contract assertion (e.g., this might be useful to program failure handler functors that never throw from destructors, not even when they are programmed by users to throw exceptions instead of terminating the program).</para></listitem></varlistentry></variablelist></listitem></varlistentry></variablelist></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.set_except_failure"><refmeta><refentrytitle>Function set_except_failure</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::set_except_failure</refname><refpurpose>Set failure handler for exception guarantees. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.exception_hpp">boost/contract/core/exception.hpp</link>>
15021 <phrase role="identifier">from_failure_handler</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase>
15022 <phrase role="identifier">set_except_failure</phrase><phrase role="special">(</phrase><phrase role="identifier">from_failure_handler</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase> f<phrase role="special">)</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>Set a new failure handler and returns it.</para><para><emphasis role="bold">Throws:</emphasis> This is declared <computeroutput>noexcept</computeroutput> (or <computeroutput>throw()</computeroutput> before C++11).</para><para>
15024 <para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__"> Throw on Failure</link>, <link linkend="boost_contract.tutorial.exception_guarantees"> Exception Guarantees</link> </para>
15026 </para><variablelist spacing="compact"><?dbhtml
15027 list-presentation="table"
15028 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
15029 list-presentation="table"
15030 ?><varlistentry><term><computeroutput>f</computeroutput></term><listitem><para>New failure handler functor to set.</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Returns:</term><listitem><para>Same failure handler functor <computeroutput>f</computeroutput> passed as parameter (e.g., for concatenating function calls).</para></listitem></varlistentry></variablelist></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.get_except_failure"><refmeta><refentrytitle>Function get_except_failure</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::get_except_failure</refname><refpurpose>Return failure handler currently set for exception guarantees. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.exception_hpp">boost/contract/core/exception.hpp</link>>
15033 <phrase role="identifier">from_failure_handler</phrase> <phrase role="identifier">get_except_failure</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This is often called only internally by this library.</para><para><emphasis role="bold">Throws:</emphasis> This is declared <computeroutput>noexcept</computeroutput> (or <computeroutput>throw()</computeroutput> before C++11).</para><para>
15034 <para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__"> Throw on Failure</link>, <link linkend="boost_contract.tutorial.exception_guarantees"> Exception Guarantees</link> </para>
15036 </para><variablelist spacing="compact"><?dbhtml
15037 list-presentation="table"
15038 ?><varlistentry><term>Returns:</term><listitem><para>A copy of the failure handler currently set.</para></listitem></varlistentry></variablelist></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.except_failure"><refmeta><refentrytitle>Function except_failure</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::except_failure</refname><refpurpose>Call failure handler for exception guarantees. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.exception_hpp">boost/contract/core/exception.hpp</link>>
15041 <phrase role="keyword">void</phrase> <phrase role="identifier">except_failure</phrase><phrase role="special">(</phrase><phrase role="identifier">from</phrase> where<phrase role="special">)</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This is often called only internally by this library.</para><para><emphasis role="bold">Throws:</emphasis> This can throw in case programmers specify a failure handler that throws exceptions on contract assertion failures (not the default), however:</para><para><warning><para>When this failure handler is called there is already an active exception (the one that caused the exception guarantees to be checked in the first place). Therefore, programming this failure handler to throw yet another exception will force C++ to automatically terminate the program.</para>
15044 <para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__"> Throw on Failure</link>, <link linkend="boost_contract.tutorial.exception_guarantees"> Exception Guarantees</link> </para>
15046 </para><variablelist spacing="compact"><?dbhtml
15047 list-presentation="table"
15048 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
15049 list-presentation="table"
15050 ?><varlistentry><term><computeroutput>where</computeroutput></term><listitem><para>Operation that failed the contract assertion.</para></listitem></varlistentry></variablelist></listitem></varlistentry></variablelist></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.set_old_failure"><refmeta><refentrytitle>Function set_old_failure</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::set_old_failure</refname><refpurpose>Set failure handler for old values copied at body. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.exception_hpp">boost/contract/core/exception.hpp</link>>
15053 <phrase role="identifier">from_failure_handler</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase> <phrase role="identifier">set_old_failure</phrase><phrase role="special">(</phrase><phrase role="identifier">from_failure_handler</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase> f<phrase role="special">)</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>Set a new failure handler and returns it.</para><para><emphasis role="bold">Throws:</emphasis> This is declared <computeroutput>noexcept</computeroutput> (or <computeroutput>throw()</computeroutput> before C++11).</para><para>
15055 <para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__"> Throw on Failure</link>, <link linkend="boost_contract.advanced.old_values_copied_at_body"> Old Values Copied at Body</link> </para>
15057 </para><variablelist spacing="compact"><?dbhtml
15058 list-presentation="table"
15059 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
15060 list-presentation="table"
15061 ?><varlistentry><term><computeroutput>f</computeroutput></term><listitem><para>New failure handler functor to set.</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Returns:</term><listitem><para>Same failure handler functor <computeroutput>f</computeroutput> passed as parameter (e.g., for concatenating function calls).</para></listitem></varlistentry></variablelist></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.get_old_failure"><refmeta><refentrytitle>Function get_old_failure</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::get_old_failure</refname><refpurpose>Return failure handler currently set for old values copied at body. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.exception_hpp">boost/contract/core/exception.hpp</link>>
15064 <phrase role="identifier">from_failure_handler</phrase> <phrase role="identifier">get_old_failure</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This is often called only internally by this library.</para><para><emphasis role="bold">Throws:</emphasis> This is declared <computeroutput>noexcept</computeroutput> (or <computeroutput>throw()</computeroutput> before C++11).</para><para>
15065 <para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__"> Throw on Failure</link>, <link linkend="boost_contract.advanced.old_values_copied_at_body"> Old Values Copied at Body</link> </para>
15067 </para><variablelist spacing="compact"><?dbhtml
15068 list-presentation="table"
15069 ?><varlistentry><term>Returns:</term><listitem><para>A copy of the failure handler currently set.</para></listitem></varlistentry></variablelist></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.old_failure"><refmeta><refentrytitle>Function old_failure</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::old_failure</refname><refpurpose>Call failure handler for old values copied at body. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.exception_hpp">boost/contract/core/exception.hpp</link>>
15072 <phrase role="keyword">void</phrase> <phrase role="identifier">old_failure</phrase><phrase role="special">(</phrase><phrase role="identifier">from</phrase> where<phrase role="special">)</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This is often called only internally by this library.</para><para><emphasis role="bold">Throws:</emphasis> This can throw in case programmers specify a failure handler that throws exceptions on contract assertion failures (not the default).</para><para>
15073 <para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__"> Throw on Failure</link>, <link linkend="boost_contract.advanced.old_values_copied_at_body"> Old Values Copied at Body</link> </para>
15075 </para><variablelist spacing="compact"><?dbhtml
15076 list-presentation="table"
15077 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
15078 list-presentation="table"
15079 ?><varlistentry><term><computeroutput>where</computeroutput></term><listitem><para>Operation that failed the old value copy (e.g., this might be useful to program failure handler functors that never throw from destructors, not even when they are programmed by users to throw exceptions instead of terminating the program).</para></listitem></varlistentry></variablelist></listitem></varlistentry></variablelist></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.set_entr_idm45394999333872"><refmeta><refentrytitle>Function set_entry_invariant_failure</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::set_entry_invariant_failure</refname><refpurpose>Set failure handler for class invariants at entry. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.exception_hpp">boost/contract/core/exception.hpp</link>>
15082 <phrase role="identifier">from_failure_handler</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase>
15083 <phrase role="identifier">set_entry_invariant_failure</phrase><phrase role="special">(</phrase><phrase role="identifier">from_failure_handler</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase> f<phrase role="special">)</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>Set a new failure handler and returns it.</para><para><emphasis role="bold">Throws:</emphasis> This is declared <computeroutput>noexcept</computeroutput> (or <computeroutput>throw()</computeroutput> before C++11).</para><para>
15085 <para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__"> Throw on Failure</link>, <link linkend="boost_contract.tutorial.class_invariants"> Class Invariants</link>, <link linkend="boost_contract.extras.volatile_public_functions">
15086 Volatile Public Functions</link> </para>
15088 </para><variablelist spacing="compact"><?dbhtml
15089 list-presentation="table"
15090 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
15091 list-presentation="table"
15092 ?><varlistentry><term><computeroutput>f</computeroutput></term><listitem><para>New failure handler functor to set.</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Returns:</term><listitem><para>Same failure handler functor <computeroutput>f</computeroutput> passed as parameter (e.g., for concatenating function calls).</para></listitem></varlistentry></variablelist></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.get_entr_idm45394999324384"><refmeta><refentrytitle>Function get_entry_invariant_failure</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::get_entry_invariant_failure</refname><refpurpose>Return failure handler currently set for class invariants at entry. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.exception_hpp">boost/contract/core/exception.hpp</link>>
15095 <phrase role="identifier">from_failure_handler</phrase> <phrase role="identifier">get_entry_invariant_failure</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This is often called only internally by this library.</para><para><emphasis role="bold">Throws:</emphasis> This is declared <computeroutput>noexcept</computeroutput> (or <computeroutput>throw()</computeroutput> before C++11).</para><para>
15096 <para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__"> Throw on Failure</link>, <link linkend="boost_contract.tutorial.class_invariants"> Class Invariants</link>, <link linkend="boost_contract.extras.volatile_public_functions">
15097 Volatile Public Functions</link> </para>
15099 </para><variablelist spacing="compact"><?dbhtml
15100 list-presentation="table"
15101 ?><varlistentry><term>Returns:</term><listitem><para>A copy of the failure handler currently set.</para></listitem></varlistentry></variablelist></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.entry_invariant_failure"><refmeta><refentrytitle>Function entry_invariant_failure</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::entry_invariant_failure</refname><refpurpose>Call failure handler for class invariants at entry. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.exception_hpp">boost/contract/core/exception.hpp</link>>
15104 <phrase role="keyword">void</phrase> <phrase role="identifier">entry_invariant_failure</phrase><phrase role="special">(</phrase><phrase role="identifier">from</phrase> where<phrase role="special">)</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This is often called only internally by this library.</para><para><emphasis role="bold">Throws:</emphasis> This can throw in case programmers specify a failure handler that throws exceptions on contract assertion failures (not the default).</para><para>
15105 <para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__"> Throw on Failure</link>, <link linkend="boost_contract.tutorial.class_invariants"> Class Invariants</link>, <link linkend="boost_contract.extras.volatile_public_functions">
15106 Volatile Public Functions</link> </para>
15108 </para><variablelist spacing="compact"><?dbhtml
15109 list-presentation="table"
15110 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
15111 list-presentation="table"
15112 ?><varlistentry><term><computeroutput>where</computeroutput></term><listitem><para>Operation that failed the contract assertion (e.g., this might be useful to program failure handler functors that never throw from destructors, not even when they are programmed by users to throw exceptions instead of terminating the program).</para></listitem></varlistentry></variablelist></listitem></varlistentry></variablelist></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.set_exit_invariant_failure"><refmeta><refentrytitle>Function set_exit_invariant_failure</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::set_exit_invariant_failure</refname><refpurpose>Set failure handler for class invariants at exit. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.exception_hpp">boost/contract/core/exception.hpp</link>>
15115 <phrase role="identifier">from_failure_handler</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase>
15116 <phrase role="identifier">set_exit_invariant_failure</phrase><phrase role="special">(</phrase><phrase role="identifier">from_failure_handler</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase> f<phrase role="special">)</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>Set a new failure handler and returns it.</para><para><emphasis role="bold">Throws:</emphasis> This is declared <computeroutput>noexcept</computeroutput> (or <computeroutput>throw()</computeroutput> before C++11).</para><para>
15118 <para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__"> Throw on Failure</link>, <link linkend="boost_contract.tutorial.class_invariants"> Class Invariants</link>, <link linkend="boost_contract.extras.volatile_public_functions">
15119 Volatile Public Functions</link> </para>
15121 </para><variablelist spacing="compact"><?dbhtml
15122 list-presentation="table"
15123 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
15124 list-presentation="table"
15125 ?><varlistentry><term><computeroutput>f</computeroutput></term><listitem><para>New failure handler functor to set.</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Returns:</term><listitem><para>Same failure handler functor <computeroutput>f</computeroutput> passed as parameter (e.g., for concatenating function calls).</para></listitem></varlistentry></variablelist></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.get_exit_invariant_failure"><refmeta><refentrytitle>Function get_exit_invariant_failure</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::get_exit_invariant_failure</refname><refpurpose>Return failure handler currently set for class invariants at exit. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.exception_hpp">boost/contract/core/exception.hpp</link>>
15128 <phrase role="identifier">from_failure_handler</phrase> <phrase role="identifier">get_exit_invariant_failure</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This is often called only internally by this library.</para><para><emphasis role="bold">Throws:</emphasis> This is declared <computeroutput>noexcept</computeroutput> (or <computeroutput>throw()</computeroutput> before C++11).</para><para>
15129 <para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__"> Throw on Failure</link>, <link linkend="boost_contract.tutorial.class_invariants"> Class Invariants</link>, <link linkend="boost_contract.extras.volatile_public_functions">
15130 Volatile Public Functions</link> </para>
15132 </para><variablelist spacing="compact"><?dbhtml
15133 list-presentation="table"
15134 ?><varlistentry><term>Returns:</term><listitem><para>A copy of the failure handler currently set.</para></listitem></varlistentry></variablelist></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.exit_invariant_failure"><refmeta><refentrytitle>Function exit_invariant_failure</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::exit_invariant_failure</refname><refpurpose>Call failure handler for class invariants at exit. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.exception_hpp">boost/contract/core/exception.hpp</link>>
15137 <phrase role="keyword">void</phrase> <phrase role="identifier">exit_invariant_failure</phrase><phrase role="special">(</phrase><phrase role="identifier">from</phrase> where<phrase role="special">)</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This is often called only internally by this library.</para><para><emphasis role="bold">Throws:</emphasis> This can throw in case programmers specify a failure handler that throws exceptions on contract assertion failures (not the default).</para><para>
15138 <para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__"> Throw on Failure</link>, <link linkend="boost_contract.tutorial.class_invariants"> Class Invariants</link>, <link linkend="boost_contract.extras.volatile_public_functions">
15139 Volatile Public Functions</link> </para>
15141 </para><variablelist spacing="compact"><?dbhtml
15142 list-presentation="table"
15143 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
15144 list-presentation="table"
15145 ?><varlistentry><term><computeroutput>where</computeroutput></term><listitem><para>Operation that failed the contract assertion (e.g., this might be useful to program failure handler functors that never throw from destructors, not even when they are programmed by users to throw exceptions instead of terminating the program).</para></listitem></varlistentry></variablelist></listitem></varlistentry></variablelist></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.set_invariant_failure"><refmeta><refentrytitle>Function set_invariant_failure</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::set_invariant_failure</refname><refpurpose>Set failure handler for class invariants (at both entry and exit). </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.exception_hpp">boost/contract/core/exception.hpp</link>>
15148 <phrase role="identifier">from_failure_handler</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase>
15149 <phrase role="identifier">set_invariant_failure</phrase><phrase role="special">(</phrase><phrase role="identifier">from_failure_handler</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase> f<phrase role="special">)</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This is provided for convenience and it is equivalent to call both <computeroutput><computeroutput><link linkend="boost.contract.set_entr_idm45394999333872">boost::contract::set_entry_invariant_failure</link></computeroutput></computeroutput> and <computeroutput><computeroutput><link linkend="boost.contract.set_exit_invariant_failure">boost::contract::set_exit_invariant_failure</link></computeroutput></computeroutput> with the same functor parameter <computeroutput>f</computeroutput>.</para><para><emphasis role="bold">Throws:</emphasis> This is declared <computeroutput>noexcept</computeroutput> (or <computeroutput>throw()</computeroutput> before C++11).</para><para>
15151 <para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__"> Throw on Failure</link>, <link linkend="boost_contract.tutorial.class_invariants"> Class Invariants</link>, <link linkend="boost_contract.extras.volatile_public_functions">
15152 Volatile Public Functions</link> </para>
15154 </para><variablelist spacing="compact"><?dbhtml
15155 list-presentation="table"
15156 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
15157 list-presentation="table"
15158 ?><varlistentry><term><computeroutput>f</computeroutput></term><listitem><para>New failure handler functor to set for both entry and exit invariants.</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Returns:</term><listitem><para>Same failure handler functor <computeroutput>f</computeroutput> passed as parameter (e.g., for concatenating function calls).</para></listitem></varlistentry></variablelist></refsect1></refentry>
15160 <section id="header.boost.contract.core.specify_hpp"><title>Header <<ulink url="../../../../boost/contract/core/specify.hpp">boost/contract/core/specify.hpp</ulink>></title><para>Specify preconditions, old values copied at body, postconditions, and exception guarantees. </para><para>Preconditions, old values copied at body, postconditions, and exception guarantees are all optionals but, when they are specified, they need to be specified in that order. </para><synopsis xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">namespace</phrase> <phrase role="identifier">boost</phrase> <phrase role="special">{</phrase>
15161 <phrase role="keyword">namespace</phrase> <phrase role="identifier">contract</phrase> <phrase role="special">{</phrase>
15162 <phrase role="keyword">class</phrase> <link linkend="boost.contract.specify_except">specify_except</link><phrase role="special">;</phrase>
15163 <phrase role="keyword">class</phrase> <link linkend="boost.contract.specify_nothing">specify_nothing</link><phrase role="special">;</phrase>
15164 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> VirtualResult <phrase role="special">=</phrase> <phrase role="keyword">void</phrase><phrase role="special">></phrase>
15165 <phrase role="keyword">class</phrase> <link linkend="boost.contract.specify__idm45394999245856">specify_old_postcondition_except</link><phrase role="special">;</phrase>
15166 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> VirtualResult <phrase role="special">=</phrase> <phrase role="keyword">void</phrase><phrase role="special">></phrase> <phrase role="keyword">class</phrase> <link linkend="boost.contract.specify__idm45394999207792">specify_postcondition_except</link><phrase role="special">;</phrase>
15167 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> VirtualResult <phrase role="special">=</phrase> <phrase role="keyword">void</phrase><phrase role="special">></phrase>
15168 <phrase role="keyword">class</phrase> <link linkend="boost.contract.specify__idm45394999179040">specify_precondition_old_postcondition_except</link><phrase role="special">;</phrase>
15169 <phrase role="special">}</phrase>
15170 <phrase role="special">}</phrase></synopsis>
15171 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.specify_except"><refmeta><refentrytitle>Class specify_except</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::specify_except</refname><refpurpose>Allow to specify exception guarantees. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.specify_hpp">boost/contract/core/specify.hpp</link>>
15174 <phrase role="keyword">class</phrase> <link linkend="boost.contract.specify_except">specify_except</link> <phrase role="special">{</phrase>
15175 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
15176 <phrase role="comment">// <link linkend="boost.contract.specify_exceptconstruct-copy-destruct">construct/copy/destruct</link></phrase>
15177 <link linkend="idm45394999256816-bb"><phrase role="special">~</phrase><phrase role="identifier">specify_except</phrase></link><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15179 <phrase role="comment">// <link linkend="idm45394999264384-bb">public member functions</link></phrase>
15180 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> F<phrase role="special">></phrase> <link linkend="boost.contract.specify_nothing">specify_nothing</link> <link linkend="idm45394999263824-bb"><phrase role="identifier">except</phrase></link><phrase role="special">(</phrase><phrase role="identifier">F</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15181 <phrase role="special">}</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>Allow to specify the functor this library will call to check exception guarantees. This object is internally constructed by the library when users specify contracts calling <computeroutput><link linkend="boost.contract.function">boost::contract::function</link></computeroutput> and similar functions (that is why this class does not have a public constructor).</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.tutorial.exception_guarantees"> Exception Guarantees</link> </para>
15183 </para><refsect2><title><anchor id="boost.contract.specify_exceptconstruct-copy-destruct"/><computeroutput>specify_except</computeroutput>
15185 construct/copy/destruct</title><orderedlist><listitem><para><literallayout class="monospaced"><anchor id="idm45394999256816-bb"/><phrase role="special">~</phrase><phrase role="identifier">specify_except</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase></literallayout></para>Destruct this object. <para><emphasis role="bold">Throws:</emphasis> This is declared <computeroutput>noexcept(false)</computeroutput> since C++11 to allow users to program failure handlers that throw exceptions on contract assertion failures (not the default, see <link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__">
15186 Throw on Failure</link>). </para></listitem></orderedlist></refsect2><refsect2><title><anchor id="idm45394999264384-bb"/><computeroutput>specify_except</computeroutput> public member functions</title><orderedlist><listitem><para><literallayout class="monospaced"><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> F<phrase role="special">></phrase> <link linkend="boost.contract.specify_nothing">specify_nothing</link> <anchor id="idm45394999263824-bb"/><phrase role="identifier">except</phrase><phrase role="special">(</phrase><phrase role="identifier">F</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase> f<phrase role="special">)</phrase><phrase role="special">;</phrase></literallayout></para>Allow to specify exception guarantees. <para>
15188 </para><variablelist spacing="compact"><?dbhtml
15189 list-presentation="table"
15190 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
15191 list-presentation="table"
15192 ?><varlistentry><term><computeroutput>f</computeroutput></term><listitem><para>Nullary functor called by this library to check exception guarantees <computeroutput>f()</computeroutput>. Assertions within this functor are usually programmed using <computeroutput><computeroutput><link linkend="BOOST_CONTRACT_ASSERT">BOOST_CONTRACT_ASSERT</link></computeroutput></computeroutput>, but any exception thrown by a call to this functor indicates a contract assertion failure (and will result in this library calling <computeroutput><computeroutput><link linkend="boost.contract.except_failure">boost::contract::except_failure</link></computeroutput></computeroutput>). This functor should capture variables by (constant) references (to access the values they will have at function exit).</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Returns:</term><listitem><para>After exception guarantees have been specified, the object returned by this function does not allow to specify any additional contract. </para></listitem></varlistentry></variablelist></listitem></orderedlist></refsect2></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.specify_nothing"><refmeta><refentrytitle>Class specify_nothing</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::specify_nothing</refname><refpurpose>Used to prevent setting other contract conditions after exception guarantees. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.specify_hpp">boost/contract/core/specify.hpp</link>>
15195 <phrase role="keyword">class</phrase> <link linkend="boost.contract.specify_nothing">specify_nothing</link> <phrase role="special">{</phrase>
15196 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
15197 <phrase role="comment">// <link linkend="boost.contract.specify_nothingconstruct-copy-destruct">construct/copy/destruct</link></phrase>
15198 <link linkend="idm45394999248752-bb"><phrase role="special">~</phrase><phrase role="identifier">specify_nothing</phrase></link><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15199 <phrase role="special">}</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This class has no member function so it is used to prevent specifying additional functors to check any other contract. This object is internally constructed by the library when users specify contracts calling <computeroutput><link linkend="boost.contract.function">boost::contract::function</link></computeroutput> and similar functions (that is why this class does not have a public constructor).</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.tutorial"> Tutorial</link> </para>
15201 </para><refsect2><title><anchor id="boost.contract.specify_nothingconstruct-copy-destruct"/><computeroutput>specify_nothing</computeroutput>
15203 construct/copy/destruct</title><orderedlist><listitem><para><literallayout class="monospaced"><anchor id="idm45394999248752-bb"/><phrase role="special">~</phrase><phrase role="identifier">specify_nothing</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase></literallayout></para>Destruct this object. <para><emphasis role="bold">Throws:</emphasis> This is declared <computeroutput>noexcept(false)</computeroutput> since C++11 to allow users to program failure handlers that throw exceptions on contract assertion failures (not the default, see <link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__">
15204 Throw on Failure</link>). </para></listitem></orderedlist></refsect2></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.specify__idm45394999245856"><refmeta><refentrytitle>Class template specify_old_postcondition_except</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::specify_old_postcondition_except</refname><refpurpose>Allow to specify old values copied at body, postconditions, and exception guarantees. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.specify_hpp">boost/contract/core/specify.hpp</link>>
15206 </phrase><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> VirtualResult <phrase role="special">=</phrase> <phrase role="keyword">void</phrase><phrase role="special">></phrase>
15207 <phrase role="keyword">class</phrase> <link linkend="boost.contract.specify__idm45394999245856">specify_old_postcondition_except</link> <phrase role="special">{</phrase>
15208 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
15209 <phrase role="comment">// <link linkend="boost.contract.specify__idm45394999245856construct-copy-destruct">construct/copy/destruct</link></phrase>
15210 <link linkend="idm45394999210688-bb"><phrase role="special">~</phrase><phrase role="identifier">specify_old_postcondition_except</phrase></link><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15212 <phrase role="comment">// <link linkend="idm45394999237760-bb">public member functions</link></phrase>
15213 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> F<phrase role="special">></phrase>
15214 <link linkend="boost.contract.specify__idm45394999207792">specify_postcondition_except</link><phrase role="special"><</phrase> <phrase role="identifier">VirtualResult</phrase> <phrase role="special">></phrase> <link linkend="idm45394999237200-bb"><phrase role="identifier">old</phrase></link><phrase role="special">(</phrase><phrase role="identifier">F</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15215 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> F<phrase role="special">></phrase> <link linkend="boost.contract.specify_except">specify_except</link> <link linkend="idm45394999228704-bb"><phrase role="identifier">postcondition</phrase></link><phrase role="special">(</phrase><phrase role="identifier">F</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15216 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> F<phrase role="special">></phrase> <link linkend="boost.contract.specify_nothing">specify_nothing</link> <link linkend="idm45394999217696-bb"><phrase role="identifier">except</phrase></link><phrase role="special">(</phrase><phrase role="identifier">F</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15217 <phrase role="special">}</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>Allow to specify functors this library will call to copy old values at body, check postconditions, and check exception guarantees. This object is internally constructed by the library when users specify contracts calling <computeroutput><link linkend="boost.contract.function">boost::contract::function</link></computeroutput> and similar functions (that is why this class does not have a public constructor).</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.advanced.old_values_copied_at_body"> Old Values Copied at Body</link>, <link linkend="boost_contract.tutorial.postconditions"> Postconditions</link>, <link linkend="boost_contract.tutorial.exception_guarantees"> Exception Guarantees</link></para>
15220 </para><refsect2><title>Template Parameters</title><orderedlist><listitem><para><literallayout class="monospaced"><phrase role="keyword">typename</phrase> VirtualResult <phrase role="special">=</phrase> <phrase role="keyword">void</phrase></literallayout></para><para><para>Return type of the enclosing function declaring the contract if that is either a virtual or an overriding public function, otherwise this is always <computeroutput>void</computeroutput>. (Usually this template parameter is automatically deduced by C++ and it does not need to be explicitly specified by programmers.) </para></para></listitem></orderedlist></refsect2><refsect2><title><anchor id="boost.contract.specify__idm45394999245856construct-copy-destruct"/><computeroutput>specify_old_postcondition_except</computeroutput>
15222 construct/copy/destruct</title><orderedlist><listitem><para><literallayout class="monospaced"><anchor id="idm45394999210688-bb"/><phrase role="special">~</phrase><phrase role="identifier">specify_old_postcondition_except</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase></literallayout></para>Destruct this object. <para><emphasis role="bold">Throws:</emphasis> This is declared <computeroutput>noexcept(false)</computeroutput> since C++11 to allow users to program failure handlers that throw exceptions on contract assertion failures (not the default, see <link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__">
15223 Throw on Failure</link>). </para></listitem></orderedlist></refsect2><refsect2><title><anchor id="idm45394999237760-bb"/><computeroutput>specify_old_postcondition_except</computeroutput> public member functions</title><orderedlist><listitem><para><literallayout class="monospaced"><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> F<phrase role="special">></phrase>
15224 <link linkend="boost.contract.specify__idm45394999207792">specify_postcondition_except</link><phrase role="special"><</phrase> <phrase role="identifier">VirtualResult</phrase> <phrase role="special">></phrase> <anchor id="idm45394999237200-bb"/><phrase role="identifier">old</phrase><phrase role="special">(</phrase><phrase role="identifier">F</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase> f<phrase role="special">)</phrase><phrase role="special">;</phrase></literallayout></para>Allow to specify old values copied at body. <para>It should often be sufficient to initialize old value pointers as soon as they are declared, without using this function (see <link linkend="boost_contract.advanced.old_values_copied_at_body"> Old Values Copied at Body</link>).</para><para>
15226 </para><variablelist spacing="compact"><?dbhtml
15227 list-presentation="table"
15228 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
15229 list-presentation="table"
15230 ?><varlistentry><term><computeroutput>f</computeroutput></term><listitem><para>Nullary functor called by this library <computeroutput>f()</computeroutput> to assign old value copies just before the body is executed but after entry invariants (when they apply) and preconditions are checked. Old value pointers within this functor call are usually assigned using <computeroutput><computeroutput><link linkend="BOOST_CONTRACT_OLDOF">BOOST_CONTRACT_OLDOF</link></computeroutput></computeroutput>. Any exception thrown by a call to this functor will result in this library calling <computeroutput><computeroutput><link linkend="boost.contract.old_failure">boost::contract::old_failure</link></computeroutput></computeroutput> (because old values could not be copied to check postconditions and exception guarantees). This functor should capture old value pointers by references so they can be assigned (all other variables needed to evaluate old value expressions can be captured by (constant) value, or better by (constant) reference to avoid extra copies).</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Returns:</term><listitem><para>After old values copied at body have been specified, the object returned by this function allows to optionally specify postconditions and exception guarantees. </para></listitem></varlistentry></variablelist></listitem><listitem><para><literallayout class="monospaced"><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> F<phrase role="special">></phrase> <link linkend="boost.contract.specify_except">specify_except</link> <anchor id="idm45394999228704-bb"/><phrase role="identifier">postcondition</phrase><phrase role="special">(</phrase><phrase role="identifier">F</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase> f<phrase role="special">)</phrase><phrase role="special">;</phrase></literallayout></para>Allow to specify postconditions. <para>
15232 </para><variablelist spacing="compact"><?dbhtml
15233 list-presentation="table"
15234 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
15235 list-presentation="table"
15236 ?><varlistentry><term><computeroutput>f</computeroutput></term><listitem><para>Functor called by this library to check postconditions <computeroutput>f()</computeroutput> or <computeroutput>f(result)</computeroutput>. Assertions within this functor are usually programmed using <computeroutput><computeroutput><link linkend="BOOST_CONTRACT_ASSERT">BOOST_CONTRACT_ASSERT</link></computeroutput></computeroutput>, but any exception thrown by a call to this functor indicates a contract assertion failure (and will result in this library calling <computeroutput><computeroutput><link linkend="boost.contract.postcondition_failure">boost::contract::postcondition_failure</link></computeroutput></computeroutput>). This functor should capture variables by (constant) references (to access the values they will have at function exit). This functor must be a nullary functor <computeroutput>f()</computeroutput> if <computeroutput>VirtualResult</computeroutput> is <computeroutput>void</computeroutput>, otherwise it must be a unary functor <computeroutput>f(result)</computeroutput> accepting the return value <computeroutput>result</computeroutput> as a parameter of type <computeroutput>VirtualResult const&</computeroutput> (to avoid extra copies of the return value, or of type <computeroutput>VirtualResult</computeroutput> or <computeroutput>VirtualResult const</computeroutput> if extra copies of the return value are irrelevant).</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Returns:</term><listitem><para>After postconditions have been specified, the object returned by this function allows to optionally specify exception guarantees. </para></listitem></varlistentry></variablelist></listitem><listitem><para><literallayout class="monospaced"><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> F<phrase role="special">></phrase> <link linkend="boost.contract.specify_nothing">specify_nothing</link> <anchor id="idm45394999217696-bb"/><phrase role="identifier">except</phrase><phrase role="special">(</phrase><phrase role="identifier">F</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase> f<phrase role="special">)</phrase><phrase role="special">;</phrase></literallayout></para>Allow to specify exception guarantees. <para>
15238 </para><variablelist spacing="compact"><?dbhtml
15239 list-presentation="table"
15240 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
15241 list-presentation="table"
15242 ?><varlistentry><term><computeroutput>f</computeroutput></term><listitem><para>Nullary functor called by this library to check exception guarantees <computeroutput>f()</computeroutput>. Assertions within this functor are usually programmed using <computeroutput><computeroutput><link linkend="BOOST_CONTRACT_ASSERT">BOOST_CONTRACT_ASSERT</link></computeroutput></computeroutput>, but any exception thrown by a call to this functor indicates a contract assertion failure (and will result in this library calling <computeroutput><computeroutput><link linkend="boost.contract.except_failure">boost::contract::except_failure</link></computeroutput></computeroutput>). This functor should capture variables by (constant) references (to access the values they will have at function exit).</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Returns:</term><listitem><para>After exception guarantees have been specified, the object returned by this function does not allow to specify any additional contract. </para></listitem></varlistentry></variablelist></listitem></orderedlist></refsect2></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.specify__idm45394999207792"><refmeta><refentrytitle>Class template specify_postcondition_except</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::specify_postcondition_except</refname><refpurpose>Allow to specify postconditions or exception guarantees. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.specify_hpp">boost/contract/core/specify.hpp</link>>
15244 </phrase><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> VirtualResult <phrase role="special">=</phrase> <phrase role="keyword">void</phrase><phrase role="special">></phrase>
15245 <phrase role="keyword">class</phrase> <link linkend="boost.contract.specify__idm45394999207792">specify_postcondition_except</link> <phrase role="special">{</phrase>
15246 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
15247 <phrase role="comment">// <link linkend="boost.contract.specify__idm45394999207792construct-copy-destruct">construct/copy/destruct</link></phrase>
15248 <link linkend="idm45394999181936-bb"><phrase role="special">~</phrase><phrase role="identifier">specify_postcondition_except</phrase></link><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15250 <phrase role="comment">// <link linkend="idm45394999200512-bb">public member functions</link></phrase>
15251 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> F<phrase role="special">></phrase> <link linkend="boost.contract.specify_except">specify_except</link> <link linkend="idm45394999199952-bb"><phrase role="identifier">postcondition</phrase></link><phrase role="special">(</phrase><phrase role="identifier">F</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15252 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> F<phrase role="special">></phrase> <link linkend="boost.contract.specify_nothing">specify_nothing</link> <link linkend="idm45394999188944-bb"><phrase role="identifier">except</phrase></link><phrase role="special">(</phrase><phrase role="identifier">F</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15253 <phrase role="special">}</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>Allow to specify functors this library will call to check postconditions or exception guarantees. This object is internally constructed by the library when users specify contracts calling <computeroutput><link linkend="boost.contract.function">boost::contract::function</link></computeroutput> and similar functions (that is why this class does not have a public constructor).</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.tutorial.postconditions"> Postconditions</link>, <link linkend="boost_contract.tutorial.exception_guarantees"> Exception Guarantees</link></para>
15256 </para><refsect2><title>Template Parameters</title><orderedlist><listitem><para><literallayout class="monospaced"><phrase role="keyword">typename</phrase> VirtualResult <phrase role="special">=</phrase> <phrase role="keyword">void</phrase></literallayout></para><para><para>Return type of the enclosing function declaring the contract if that is either a virtual or an overriding public function, otherwise this is always <computeroutput>void</computeroutput>. (Usually this template parameter is automatically deduced by C++ and it does not need to be explicitly specified by programmers.) </para></para></listitem></orderedlist></refsect2><refsect2><title><anchor id="boost.contract.specify__idm45394999207792construct-copy-destruct"/><computeroutput>specify_postcondition_except</computeroutput>
15258 construct/copy/destruct</title><orderedlist><listitem><para><literallayout class="monospaced"><anchor id="idm45394999181936-bb"/><phrase role="special">~</phrase><phrase role="identifier">specify_postcondition_except</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase></literallayout></para>Destruct this object. <para><emphasis role="bold">Throws:</emphasis> This is declared <computeroutput>noexcept(false)</computeroutput> since C++11 to allow users to program failure handlers that throw exceptions on contract assertion failures (not the default, see <link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__">
15259 Throw on Failure</link>). </para></listitem></orderedlist></refsect2><refsect2><title><anchor id="idm45394999200512-bb"/><computeroutput>specify_postcondition_except</computeroutput> public member functions</title><orderedlist><listitem><para><literallayout class="monospaced"><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> F<phrase role="special">></phrase> <link linkend="boost.contract.specify_except">specify_except</link> <anchor id="idm45394999199952-bb"/><phrase role="identifier">postcondition</phrase><phrase role="special">(</phrase><phrase role="identifier">F</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase> f<phrase role="special">)</phrase><phrase role="special">;</phrase></literallayout></para>Allow to specify postconditions. <para>
15261 </para><variablelist spacing="compact"><?dbhtml
15262 list-presentation="table"
15263 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
15264 list-presentation="table"
15265 ?><varlistentry><term><computeroutput>f</computeroutput></term><listitem><para>Functor called by this library to check postconditions <computeroutput>f()</computeroutput> or <computeroutput>f(result)</computeroutput>. Assertions within this functor are usually programmed using <computeroutput><computeroutput><link linkend="BOOST_CONTRACT_ASSERT">BOOST_CONTRACT_ASSERT</link></computeroutput></computeroutput>, but any exception thrown by a call to this functor indicates a contract assertion failure (and will result in this library calling <computeroutput><computeroutput><link linkend="boost.contract.postcondition_failure">boost::contract::postcondition_failure</link></computeroutput></computeroutput>). This functor should capture variables by (constant) references (to access the values they will have at function exit). This functor must be a nullary functor <computeroutput>f()</computeroutput> if <computeroutput>VirtualResult</computeroutput> is <computeroutput>void</computeroutput>, otherwise it must be a unary functor <computeroutput>f(result)</computeroutput> accepting the return value <computeroutput>result</computeroutput> as a parameter of type <computeroutput>VirtualResult const&</computeroutput> (to avoid extra copies of the return value, or of type <computeroutput>VirtualResult</computeroutput> or <computeroutput>VirtualResult const</computeroutput> if extra copies of the return value are irrelevant).</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Returns:</term><listitem><para>After postconditions have been specified, the object returned by this function allows to optionally specify exception guarantees. </para></listitem></varlistentry></variablelist></listitem><listitem><para><literallayout class="monospaced"><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> F<phrase role="special">></phrase> <link linkend="boost.contract.specify_nothing">specify_nothing</link> <anchor id="idm45394999188944-bb"/><phrase role="identifier">except</phrase><phrase role="special">(</phrase><phrase role="identifier">F</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase> f<phrase role="special">)</phrase><phrase role="special">;</phrase></literallayout></para>Allow to specify exception guarantees. <para>
15267 </para><variablelist spacing="compact"><?dbhtml
15268 list-presentation="table"
15269 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
15270 list-presentation="table"
15271 ?><varlistentry><term><computeroutput>f</computeroutput></term><listitem><para>Nullary functor called by this library to check exception guarantees <computeroutput>f()</computeroutput>. Assertions within this functor are usually programmed using <computeroutput><computeroutput><link linkend="BOOST_CONTRACT_ASSERT">BOOST_CONTRACT_ASSERT</link></computeroutput></computeroutput>, but any exception thrown by a call to this functor indicates a contract assertion failure (and will result in this library calling <computeroutput><computeroutput><link linkend="boost.contract.except_failure">boost::contract::except_failure</link></computeroutput></computeroutput>). This functor should capture variables by (constant) references (to access the values they will have at function exit).</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Returns:</term><listitem><para>After exception guarantees have been specified, the object returned by this function does not allow to specify any additional contract. </para></listitem></varlistentry></variablelist></listitem></orderedlist></refsect2></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.specify__idm45394999179040"><refmeta><refentrytitle>Class template specify_precondition_old_postcondition_except</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::specify_precondition_old_postcondition_except</refname><refpurpose>Allow to specify preconditions, old values copied at body, postconditions, and exception guarantees. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.specify_hpp">boost/contract/core/specify.hpp</link>>
15273 </phrase><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> VirtualResult <phrase role="special">=</phrase> <phrase role="keyword">void</phrase><phrase role="special">></phrase>
15274 <phrase role="keyword">class</phrase> <link linkend="boost.contract.specify__idm45394999179040">specify_precondition_old_postcondition_except</link> <phrase role="special">{</phrase>
15275 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
15276 <phrase role="comment">// <link linkend="boost.contract.specify__idm45394999179040construct-copy-destruct">construct/copy/destruct</link></phrase>
15277 <link linkend="idm45394999136032-bb"><phrase role="special">~</phrase><phrase role="identifier">specify_precondition_old_postcondition_except</phrase></link><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15279 <phrase role="comment">// <link linkend="idm45394999170160-bb">public member functions</link></phrase>
15280 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> F<phrase role="special">></phrase>
15281 <link linkend="boost.contract.specify__idm45394999245856">specify_old_postcondition_except</link><phrase role="special"><</phrase> <phrase role="identifier">VirtualResult</phrase> <phrase role="special">></phrase> <link linkend="idm45394999169600-bb"><phrase role="identifier">precondition</phrase></link><phrase role="special">(</phrase><phrase role="identifier">F</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15282 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> F<phrase role="special">></phrase>
15283 <link linkend="boost.contract.specify__idm45394999207792">specify_postcondition_except</link><phrase role="special"><</phrase> <phrase role="identifier">VirtualResult</phrase> <phrase role="special">></phrase> <link linkend="idm45394999162544-bb"><phrase role="identifier">old</phrase></link><phrase role="special">(</phrase><phrase role="identifier">F</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15284 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> F<phrase role="special">></phrase> <link linkend="boost.contract.specify_except">specify_except</link> <link linkend="idm45394999154048-bb"><phrase role="identifier">postcondition</phrase></link><phrase role="special">(</phrase><phrase role="identifier">F</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15285 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> F<phrase role="special">></phrase> <link linkend="boost.contract.specify_nothing">specify_nothing</link> <link linkend="idm45394999143040-bb"><phrase role="identifier">except</phrase></link><phrase role="special">(</phrase><phrase role="identifier">F</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15286 <phrase role="special">}</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>Allow to specify functors this library will call to check preconditions, copy old values at body, check postconditions, and check exception guarantees. This object is internally constructed by the library when users specify contracts calling <computeroutput><link linkend="boost.contract.function">boost::contract::function</link></computeroutput> and similar functions (that is why this class does not have a public constructor).</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.tutorial.preconditions"> Preconditions</link>, <link linkend="boost_contract.advanced.old_values_copied_at_body"> Old Values Copied at Body</link>, <link linkend="boost_contract.tutorial.postconditions"> Postconditions</link>, <link linkend="boost_contract.tutorial.exception_guarantees"> Exception Guarantees</link></para>
15289 </para><refsect2><title>Template Parameters</title><orderedlist><listitem><para><literallayout class="monospaced"><phrase role="keyword">typename</phrase> VirtualResult <phrase role="special">=</phrase> <phrase role="keyword">void</phrase></literallayout></para><para><para>Return type of the enclosing function declaring the contract if that is either a virtual or an overriding public function, otherwise this is always <computeroutput>void</computeroutput>. (Usually this template parameter is automatically deduced by C++ and it does not need to be explicitly specified by programmers.) </para></para></listitem></orderedlist></refsect2><refsect2><title><anchor id="boost.contract.specify__idm45394999179040construct-copy-destruct"/><computeroutput>specify_precondition_old_postcondition_except</computeroutput>
15291 construct/copy/destruct</title><orderedlist><listitem><para><literallayout class="monospaced"><anchor id="idm45394999136032-bb"/><phrase role="special">~</phrase><phrase role="identifier">specify_precondition_old_postcondition_except</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase></literallayout></para>Destruct this object. <para><emphasis role="bold">Throws:</emphasis> This is declared <computeroutput>noexcept(false)</computeroutput> since C++11 to allow users to program failure handlers that throw exceptions on contract assertion failures (not the default, see <link linkend="boost_contract.advanced.throw_on_failures__and__noexcept__">
15292 Throw on Failure</link>). </para></listitem></orderedlist></refsect2><refsect2><title><anchor id="idm45394999170160-bb"/><computeroutput>specify_precondition_old_postcondition_except</computeroutput> public member functions</title><orderedlist><listitem><para><literallayout class="monospaced"><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> F<phrase role="special">></phrase>
15293 <link linkend="boost.contract.specify__idm45394999245856">specify_old_postcondition_except</link><phrase role="special"><</phrase> <phrase role="identifier">VirtualResult</phrase> <phrase role="special">></phrase> <anchor id="idm45394999169600-bb"/><phrase role="identifier">precondition</phrase><phrase role="special">(</phrase><phrase role="identifier">F</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase> f<phrase role="special">)</phrase><phrase role="special">;</phrase></literallayout></para>Allow to specify preconditions. <para>
15295 </para><variablelist spacing="compact"><?dbhtml
15296 list-presentation="table"
15297 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
15298 list-presentation="table"
15299 ?><varlistentry><term><computeroutput>f</computeroutput></term><listitem><para>Nullary functor called by this library to check preconditions <computeroutput>f()</computeroutput>. Assertions within this functor are usually programmed using <computeroutput><computeroutput><link linkend="BOOST_CONTRACT_ASSERT">BOOST_CONTRACT_ASSERT</link></computeroutput></computeroutput>, but any exception thrown by a call to this functor indicates a contract assertion failure (and will result in this library calling <computeroutput><computeroutput><link linkend="boost.contract.precondition_failure">boost::contract::precondition_failure</link></computeroutput></computeroutput>). This functor should capture variables by (constant) value, or better by (constant) reference (to avoid extra copies).</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Returns:</term><listitem><para>After preconditions have been specified, the object returned by this function allows to optionally specify old values copied at body, postconditions, and exception guarantees. </para></listitem></varlistentry></variablelist></listitem><listitem><para><literallayout class="monospaced"><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> F<phrase role="special">></phrase>
15300 <link linkend="boost.contract.specify__idm45394999207792">specify_postcondition_except</link><phrase role="special"><</phrase> <phrase role="identifier">VirtualResult</phrase> <phrase role="special">></phrase> <anchor id="idm45394999162544-bb"/><phrase role="identifier">old</phrase><phrase role="special">(</phrase><phrase role="identifier">F</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase> f<phrase role="special">)</phrase><phrase role="special">;</phrase></literallayout></para>Allow to specify old values copied at body. <para>It should often be sufficient to initialize old value pointers as soon as they are declared, without using this function (see <link linkend="boost_contract.advanced.old_values_copied_at_body"> Old Values Copied at Body</link>).</para><para>
15302 </para><variablelist spacing="compact"><?dbhtml
15303 list-presentation="table"
15304 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
15305 list-presentation="table"
15306 ?><varlistentry><term><computeroutput>f</computeroutput></term><listitem><para>Nullary functor called by this library <computeroutput>f()</computeroutput> to assign old value copies just before the body is executed but after entry invariants (when they apply) and preconditions are checked. Old value pointers within this functor call are usually assigned using <computeroutput><computeroutput><link linkend="BOOST_CONTRACT_OLDOF">BOOST_CONTRACT_OLDOF</link></computeroutput></computeroutput>. Any exception thrown by a call to this functor will result in this library calling <computeroutput><computeroutput><link linkend="boost.contract.old_failure">boost::contract::old_failure</link></computeroutput></computeroutput> (because old values could not be copied to check postconditions and exception guarantees). This functor should capture old value pointers by references so they can be assigned (all other variables needed to evaluate old value expressions can be captured by (constant) value, or better by (constant) reference to avoid extra copies).</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Returns:</term><listitem><para>After old values copied at body have been specified, the object returned by this functions allows to optionally specify postconditions and exception guarantees. </para></listitem></varlistentry></variablelist></listitem><listitem><para><literallayout class="monospaced"><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> F<phrase role="special">></phrase> <link linkend="boost.contract.specify_except">specify_except</link> <anchor id="idm45394999154048-bb"/><phrase role="identifier">postcondition</phrase><phrase role="special">(</phrase><phrase role="identifier">F</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase> f<phrase role="special">)</phrase><phrase role="special">;</phrase></literallayout></para>Allow to specify postconditions. <para>
15308 </para><variablelist spacing="compact"><?dbhtml
15309 list-presentation="table"
15310 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
15311 list-presentation="table"
15312 ?><varlistentry><term><computeroutput>f</computeroutput></term><listitem><para>Functor called by this library to check postconditions <computeroutput>f()</computeroutput> or <computeroutput>f(result)</computeroutput>. Assertions within this functor are usually programmed using <computeroutput><computeroutput><link linkend="BOOST_CONTRACT_ASSERT">BOOST_CONTRACT_ASSERT</link></computeroutput></computeroutput>, but any exception thrown by a call to this functor indicates a contract assertion failure (and will result in this library calling <computeroutput><computeroutput><link linkend="boost.contract.postcondition_failure">boost::contract::postcondition_failure</link></computeroutput></computeroutput>). This functor should capture variables by (constant) references (to access the values they will have at function exit). This functor must be a nullary functor <computeroutput>f()</computeroutput> if <computeroutput>VirtualResult</computeroutput> is <computeroutput>void</computeroutput>, otherwise it must be a unary functor <computeroutput>f(result)</computeroutput> accepting the return value <computeroutput>result</computeroutput> as a parameter of type <computeroutput>VirtualResult const&</computeroutput> (to avoid extra copies of the return value, or of type <computeroutput>VirtualResult</computeroutput> or <computeroutput>VirtualResult const</computeroutput> if extra copies of the return value are irrelevant).</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Returns:</term><listitem><para>After postconditions have been specified, the object returned by this function allows to optionally specify exception guarantees. </para></listitem></varlistentry></variablelist></listitem><listitem><para><literallayout class="monospaced"><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> F<phrase role="special">></phrase> <link linkend="boost.contract.specify_nothing">specify_nothing</link> <anchor id="idm45394999143040-bb"/><phrase role="identifier">except</phrase><phrase role="special">(</phrase><phrase role="identifier">F</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase> f<phrase role="special">)</phrase><phrase role="special">;</phrase></literallayout></para>Allow to specify exception guarantees. <para>
15314 </para><variablelist spacing="compact"><?dbhtml
15315 list-presentation="table"
15316 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
15317 list-presentation="table"
15318 ?><varlistentry><term><computeroutput>f</computeroutput></term><listitem><para>Nullary functor called by this library to check exception guarantees <computeroutput>f()</computeroutput>. Assertions within this functor are usually programmed using <computeroutput><computeroutput><link linkend="BOOST_CONTRACT_ASSERT">BOOST_CONTRACT_ASSERT</link></computeroutput></computeroutput>, but any exception thrown by a call to this functor indicates a contract assertion failure (and will result in this library calling <computeroutput><computeroutput><link linkend="boost.contract.except_failure">boost::contract::except_failure</link></computeroutput></computeroutput>). This functor should capture variables by (constant) references (to access the values they will have at function exit).</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Returns:</term><listitem><para>After exception guarantees have been specified, the object returned by this function does not allow to specify any additional contract. </para></listitem></varlistentry></variablelist></listitem></orderedlist></refsect2></refsect1></refentry>
15320 <section id="header.boost.contract.core.virtual_hpp"><title>Header <<ulink url="../../../../boost/contract/core/virtual.hpp">boost/contract/core/virtual.hpp</ulink>></title><para>Handle virtual public functions with contracts (for subcontracting). </para><synopsis xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">namespace</phrase> <phrase role="identifier">boost</phrase> <phrase role="special">{</phrase>
15321 <phrase role="keyword">namespace</phrase> <phrase role="identifier">contract</phrase> <phrase role="special">{</phrase>
15322 <phrase role="keyword">class</phrase> <link linkend="boost.contract.virtual_">virtual_</link><phrase role="special">;</phrase>
15323 <phrase role="special">}</phrase>
15324 <phrase role="special">}</phrase></synopsis>
15325 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.virtual_"><refmeta><refentrytitle>Class virtual_</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::virtual_</refname><refpurpose>Type of extra function parameter to handle contracts for virtual public functions (for subcontracting). </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.core.virtual_hpp">boost/contract/core/virtual.hpp</link>>
15328 <phrase role="keyword">class</phrase> <link linkend="boost.contract.virtual_">virtual_</link> <phrase role="special">{</phrase>
15329 <phrase role="special">}</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>Virtual public functions (and therefore also public function overrides) declaring contracts using this library must specify an extra function parameter at the very end of their parameter list. This parameter must be a pointer to this class and it must have default value <computeroutput>0</computeroutput> or <computeroutput>nullptr</computeroutput> (this extra parameter is often named <computeroutput>v</computeroutput> in this documentation, but any name can be used):</para><para><programlisting><phrase role="keyword">class</phrase> <phrase role="identifier">u</phrase> <phrase role="special">{</phrase>
15330 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
15331 <phrase role="keyword">virtual</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">f</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase> <phrase role="identifier">x</phrase><phrase role="special">,</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Declare `v`.</phrase>
15332 <phrase role="special">...</phrase> <phrase role="comment">// Contract declaration (which will use `v`) and function body.</phrase>
15333 <phrase role="special">}</phrase>
15335 <phrase role="special">...</phrase>
15336 <phrase role="special">}</phrase><phrase role="special">;</phrase>
15337 </programlisting></para><para>In practice this extra parameter does not alter the calling interface of the enclosing function declaring the contract because it is always the very last parameter and it has a default value (so it can always be omitted when users call the function). This extra parameter must be passed to <computeroutput><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput>, <computeroutput><link linkend="BOOST_CONTRACT_OLDOF">BOOST_CONTRACT_OLDOF</link></computeroutput>, and all other operations of this library that accept a pointer to <computeroutput><link linkend="boost.contract.virtual_">boost::contract::virtual_</link></computeroutput>. A part from that, this class is not intended to be directly used by programmers (and that is why this class does not have any public member and it is not copyable).</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.tutorial.virtual_public_functions"> Virtual Public Functions</link>, <link linkend="boost_contract.tutorial.public_function_overrides__subcontracting_">
15338 Public Function Overrides</link> </para>
15340 </para></refsect1></refentry>
15342 <section id="header.boost.contract.destructor_hpp"><title>Header <<ulink url="../../../../boost/contract/destructor.hpp">boost/contract/destructor.hpp</ulink>></title><para>Program contracts for destructors. </para><synopsis xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">namespace</phrase> <phrase role="identifier">boost</phrase> <phrase role="special">{</phrase>
15343 <phrase role="keyword">namespace</phrase> <phrase role="identifier">contract</phrase> <phrase role="special">{</phrase>
15344 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> Class<phrase role="special">></phrase>
15345 <link linkend="boost.contract.specify__idm45394999245856">specify_old_postcondition_except</link> <link linkend="boost.contract.destructor"><phrase role="identifier">destructor</phrase></link><phrase role="special">(</phrase><phrase role="identifier">Class</phrase> <phrase role="special">*</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15346 <phrase role="special">}</phrase>
15347 <phrase role="special">}</phrase></synopsis>
15348 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.destructor"><refmeta><refentrytitle>Function template destructor</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::destructor</refname><refpurpose>Program contracts for destructors. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.destructor_hpp">boost/contract/destructor.hpp</link>>
15351 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> Class<phrase role="special">></phrase>
15352 <link linkend="boost.contract.specify__idm45394999245856">specify_old_postcondition_except</link> <phrase role="identifier">destructor</phrase><phrase role="special">(</phrase><phrase role="identifier">Class</phrase> <phrase role="special">*</phrase> obj<phrase role="special">)</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This is used to specify postconditions, exception guarantees, old value copies at body, and check class invariants for destructors (destructors cannot have preconditions, see <link linkend="boost_contract.contract_programming_overview.destructor_calls"> Destructor Calls</link>):</para><para><programlisting><phrase role="keyword">class</phrase> <phrase role="identifier">u</phrase> <phrase role="special">{</phrase>
15353 <phrase role="keyword">friend</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">access</phrase><phrase role="special">;</phrase>
15355 <phrase role="keyword">void</phrase> <phrase role="identifier">invariant</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional (as for static and volatile).</phrase>
15356 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15357 <phrase role="special">...</phrase>
15358 <phrase role="special">}</phrase>
15360 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
15361 <phrase role="special">~</phrase><phrase role="identifier">u</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
15362 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="identifier">old_type</phrase><phrase role="special">></phrase> <phrase role="identifier">old_var</phrase><phrase role="special">;</phrase>
15363 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">destructor</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
15364 <phrase role="comment">// No `.precondition` (destructors have no preconditions).</phrase>
15365 <phrase role="special">.</phrase><phrase role="identifier">old</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
15366 <phrase role="identifier">old_var</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">old_expr</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15367 <phrase role="special">...</phrase>
15368 <phrase role="special">}</phrase><phrase role="special">)</phrase>
15369 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
15370 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15371 <phrase role="special">...</phrase>
15372 <phrase role="special">}</phrase><phrase role="special">)</phrase>
15373 <phrase role="special">.</phrase><phrase role="identifier">except</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
15374 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15375 <phrase role="special">...</phrase>
15376 <phrase role="special">}</phrase><phrase role="special">)</phrase>
15377 <phrase role="special">;</phrase>
15379 <phrase role="special">...</phrase> <phrase role="comment">// Destructor body.</phrase>
15380 <phrase role="special">}</phrase>
15382 <phrase role="special">...</phrase>
15383 <phrase role="special">}</phrase><phrase role="special">;</phrase>
15384 </programlisting></para><para>For optimization, this can be omitted for destructors that do not have postconditions and exception guarantees, within classes that have no invariants.</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.tutorial.destructors"> Destructors</link></para>
15389 </para><variablelist spacing="compact"><?dbhtml
15390 list-presentation="table"
15391 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
15392 list-presentation="table"
15393 ?><varlistentry><term><computeroutput>obj</computeroutput></term><listitem><para>The object <computeroutput>this</computeroutput> from the scope of the enclosing destructor declaring the contract. (Destructors check all class invariants, including static and volatile invariants, see <link linkend="boost_contract.tutorial.class_invariants">
15394 Class Invariants</link> and <link linkend="boost_contract.extras.volatile_public_functions">
15395 Volatile Public Functions</link>).</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Template Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
15396 list-presentation="table"
15397 ?><varlistentry><term><computeroutput>Class</computeroutput></term><listitem><para>The type of the class containing the destructor declaring the contract. (Usually this template parameter is automatically deduced by C++ and it does not need to be explicitly specified by programmers.)</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Returns:</term><listitem><para>The result of this function must be assigned to a variable of type <computeroutput><link linkend="boost.contract.check">boost::contract::check</link></computeroutput> declared explicitly (i.e., without using C++11 <computeroutput>auto</computeroutput> declarations) and locally just before the code of the destructor body (otherwise this library will generate a run-time error, see <computeroutput><link linkend="BOOST_CO_idm45394999694064">BOOST_CONTRACT_ON_MISSING_CHECK_DECL</link></computeroutput>). </para></listitem></varlistentry></variablelist></refsect1></refentry>
15399 <section id="header.boost.contract.function_hpp"><title>Header <<ulink url="../../../../boost/contract/function.hpp">boost/contract/function.hpp</ulink>></title><para>Program contracts for (non-public) functions. </para><synopsis xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">namespace</phrase> <phrase role="identifier">boost</phrase> <phrase role="special">{</phrase>
15400 <phrase role="keyword">namespace</phrase> <phrase role="identifier">contract</phrase> <phrase role="special">{</phrase>
15401 <link linkend="boost.contract.specify__idm45394999179040">specify_precondition_old_postcondition_except</link> <link linkend="boost.contract.function"><phrase role="identifier">function</phrase></link><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15402 <phrase role="special">}</phrase>
15403 <phrase role="special">}</phrase></synopsis>
15404 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.function"><refmeta><refentrytitle>Function function</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::function</refname><refpurpose>Program contracts for non-member, private and protected functions. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.function_hpp">boost/contract/function.hpp</link>>
15407 <link linkend="boost.contract.specify__idm45394999179040">specify_precondition_old_postcondition_except</link> <phrase role="identifier">function</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This is used to specify preconditions, postconditions, exception guarantees, and old value copies at body for non-member, private and protected functions (these functions never check class invariants, see <link linkend="boost_contract.contract_programming_overview.function_calls"> Function Calls</link>):</para><para><programlisting><phrase role="keyword">void</phrase> <phrase role="identifier">f</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
15408 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="identifier">old_type</phrase><phrase role="special">></phrase> <phrase role="identifier">old_var</phrase><phrase role="special">;</phrase>
15409 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">function</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase>
15410 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
15411 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15412 <phrase role="special">...</phrase>
15413 <phrase role="special">}</phrase><phrase role="special">)</phrase>
15414 <phrase role="special">.</phrase><phrase role="identifier">old</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
15415 <phrase role="identifier">old_var</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">old_expr</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15416 <phrase role="special">...</phrase>
15417 <phrase role="special">}</phrase><phrase role="special">)</phrase>
15418 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
15419 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15420 <phrase role="special">...</phrase>
15421 <phrase role="special">}</phrase><phrase role="special">)</phrase>
15422 <phrase role="special">.</phrase><phrase role="identifier">except</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
15423 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15424 <phrase role="special">...</phrase>
15425 <phrase role="special">}</phrase><phrase role="special">)</phrase>
15426 <phrase role="special">;</phrase>
15428 <phrase role="special">...</phrase> <phrase role="comment">// Function body.</phrase>
15429 <phrase role="special">}</phrase>
15430 </programlisting></para><para>This can be used also to program contracts in implementation code for lambda functions, loops, and arbitrary blocks of code. For optimization, this can be omitted for code that does not have preconditions, postconditions, and exception guarantees.</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.tutorial.non_member_functions"> Non-Member Functions</link>, <link linkend="boost_contract.advanced.private_and_protected_functions">
15431 Private and Protected Functions</link>, <link linkend="boost_contract.advanced.lambdas__loops__code_blocks__and__constexpr__">
15432 Lambdas, Loops, Code Blocks</link></para>
15435 </para><variablelist spacing="compact"><?dbhtml
15436 list-presentation="table"
15437 ?><varlistentry><term>Returns:</term><listitem><para>The result of this function must be assigned to a variable of type <computeroutput><link linkend="boost.contract.check">boost::contract::check</link></computeroutput> declared explicitly (i.e., without using C++11 <computeroutput>auto</computeroutput> declarations) and locally just before the code of the function body (otherwise this library will generate a run-time error, see <computeroutput><link linkend="BOOST_CO_idm45394999694064">BOOST_CONTRACT_ON_MISSING_CHECK_DECL</link></computeroutput>). </para></listitem></varlistentry></variablelist></refsect1></refentry>
15439 <section id="header.boost.contract.old_hpp"><title>Header <<ulink url="../../../../boost/contract/old.hpp">boost/contract/old.hpp</ulink>></title><para>Handle old values. </para><synopsis xmlns:xi="http://www.w3.org/2001/XInclude">
15441 <link linkend="BOOST_CONTRACT_OLDOF">BOOST_CONTRACT_OLDOF</link>(...)</synopsis><synopsis xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">namespace</phrase> <phrase role="identifier">boost</phrase> <phrase role="special">{</phrase>
15442 <phrase role="keyword">namespace</phrase> <phrase role="identifier">contract</phrase> <phrase role="special">{</phrase>
15443 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> T<phrase role="special">></phrase> <phrase role="keyword">struct</phrase> <link linkend="boost.contract.is_old_value_copyable">is_old_value_copyable</link><phrase role="special">;</phrase>
15445 <phrase role="keyword">class</phrase> <link linkend="boost.contract.old_pointer">old_pointer</link><phrase role="special">;</phrase>
15446 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> T<phrase role="special">></phrase> <phrase role="keyword">class</phrase> <link linkend="boost.contract.old_ptr">old_ptr</link><phrase role="special">;</phrase>
15447 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> T<phrase role="special">></phrase> <phrase role="keyword">class</phrase> <link linkend="boost.contract.old_ptr_if_copyable">old_ptr_if_copyable</link><phrase role="special">;</phrase>
15448 <phrase role="keyword">class</phrase> <link linkend="boost.contract.old_value">old_value</link><phrase role="special">;</phrase>
15450 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> T<phrase role="special">></phrase> <phrase role="keyword">struct</phrase> <link linkend="boost.contract.old_value_copy">old_value_copy</link><phrase role="special">;</phrase>
15451 <link linkend="boost.contract.old_value">old_value</link> <link linkend="boost.contract.null_old"><phrase role="identifier">null_old</phrase></link><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15452 <link linkend="boost.contract.old_pointer">old_pointer</link> <link linkend="boost.contract.make_old_idm45394998968720"><phrase role="identifier">make_old</phrase></link><phrase role="special">(</phrase><link linkend="boost.contract.old_value">old_value</link> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15453 <link linkend="boost.contract.old_pointer">old_pointer</link> <link linkend="boost.contract.make_old_idm45394998958240"><phrase role="identifier">make_old</phrase></link><phrase role="special">(</phrase><link linkend="boost.contract.virtual_">virtual_</link> <phrase role="special">*</phrase><phrase role="special">,</phrase> <link linkend="boost.contract.old_value">old_value</link> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15454 <phrase role="keyword">bool</phrase> <link linkend="boost.contract.copy_old_idm45394998944672"><phrase role="identifier">copy_old</phrase></link><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15455 <phrase role="keyword">bool</phrase> <link linkend="boost.contract.copy_old_idm45394998938528"><phrase role="identifier">copy_old</phrase></link><phrase role="special">(</phrase><link linkend="boost.contract.virtual_">virtual_</link> <phrase role="special">*</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15456 <phrase role="special">}</phrase>
15457 <phrase role="special">}</phrase></synopsis>
15458 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.is_old_value_copyable"><refmeta><refentrytitle>Struct template is_old_value_copyable</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::is_old_value_copyable</refname><refpurpose>Trait to check if an old value type can be copied or not. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.old_hpp">boost/contract/old.hpp</link>>
15460 </phrase><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> T<phrase role="special">></phrase>
15461 <phrase role="keyword">struct</phrase> <link linkend="boost.contract.is_old_value_copyable">is_old_value_copyable</link> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">is_copy_constructible</phrase><phrase role="special"><</phrase> <phrase role="identifier">T</phrase> <phrase role="special">></phrase> <phrase role="special">{</phrase>
15462 <phrase role="special">}</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>By default, this unary boolean meta-function is equivalent to <computeroutput>boost::is_copy_constructible<T></computeroutput> but programmers can chose to specialize it for user-defined types (in general some kind of specialization is also needed on compilers that do not support C++11, see <ulink url="http://www.boost.org/doc/libs/release/libs/type_traits/doc/html/boost_typetraits/reference/is_copy_constructible.html"><computeroutput>boost::is_copy_constructible</computeroutput></ulink>):</para><para><programlisting><phrase role="keyword">class</phrase> <phrase role="identifier">u</phrase><phrase role="special">;</phrase> <phrase role="comment">// Some user-defined type for which old values shall not be copied.</phrase>
15464 <phrase role="keyword">namespace</phrase> <phrase role="identifier">boost</phrase> <phrase role="special">{</phrase> <phrase role="keyword">namespace</phrase> <phrase role="identifier">contract</phrase> <phrase role="special">{</phrase>
15465 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="special">></phrase> <phrase role="comment">// Specialization to not copy old values of type `u`.</phrase>
15466 <phrase role="keyword">struct</phrase> <phrase role="identifier">is_old_value_copyable</phrase><phrase role="special"><</phrase><phrase role="identifier">u</phrase><phrase role="special">></phrase> <phrase role="special">:</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">false_type</phrase> <phrase role="special">{</phrase><phrase role="special">}</phrase><phrase role="special">;</phrase>
15467 <phrase role="special">}</phrase> <phrase role="special">}</phrase> <phrase role="comment">// namespace</phrase>
15468 </programlisting></para><para>A given old value type <computeroutput>T</computeroutput> is copied only if <computeroutput>boost::contract::is_old_value_copyable<T>::value</computeroutput> is <computeroutput>true</computeroutput>. A copyable old value type <computeroutput>V</computeroutput> is always copied using <computeroutput>boost::contract::old_value_copy<V></computeroutput>. A non-copyable old value type <computeroutput>W</computeroutput> generates a compile-time error when <computeroutput>boost::contract::old_ptr<W></computeroutput> is dereferenced, but instead leaves <computeroutput>boost::contract::old_ptr_if_copyable<W></computeroutput> always null (without generating compile-time errors).</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.extras.old_value_requirements__templates_">
15469 Old Value Requirements</link> </para>
15471 </para></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.old_pointer"><refmeta><refentrytitle>Class old_pointer</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::old_pointer</refname><refpurpose>Convert old value copies into old value pointers. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.old_hpp">boost/contract/old.hpp</link>>
15474 <phrase role="keyword">class</phrase> <link linkend="boost.contract.old_pointer">old_pointer</link> <phrase role="special">{</phrase>
15475 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
15477 <phrase role="comment">// <link linkend="idm45394999074832-bb">public member functions</link></phrase>
15478 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> T<phrase role="special">></phrase> <link linkend="idm45394999074272-bb"><phrase role="keyword">operator</phrase> <phrase role="identifier">old_ptr_if_copyable</phrase><phrase role="special"><</phrase> <phrase role="identifier">T</phrase> <phrase role="special">></phrase></link><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15479 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> T<phrase role="special">></phrase> <link linkend="idm45394999068640-bb"><phrase role="keyword">operator</phrase> <phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase> <phrase role="identifier">T</phrase> <phrase role="special">></phrase></link><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15480 <phrase role="special">}</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This class is usually only implicitly used by this library and it does not explicitly appear in user code (that is why this class does not have public constructors, etc.). </para><refsect2><title><anchor id="idm45394999074832-bb"/><computeroutput>old_pointer</computeroutput> public member functions</title><orderedlist><listitem><para><literallayout class="monospaced"><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> T<phrase role="special">></phrase> <anchor id="idm45394999074272-bb"/><phrase role="keyword">operator</phrase> <phrase role="identifier">old_ptr_if_copyable</phrase><phrase role="special"><</phrase> <phrase role="identifier">T</phrase> <phrase role="special">></phrase><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase></literallayout></para>Convert this object to an actual old value pointer for which the old value type <computeroutput>T</computeroutput> might or not be copyable. <para>For example, this is implicitly called when assigning or initializing old value pointers of type <computeroutput><computeroutput><link linkend="boost.contract.old_ptr_if_copyable">boost::contract::old_ptr_if_copyable</link></computeroutput></computeroutput>.</para><para>
15481 </para><variablelist spacing="compact"><?dbhtml
15482 list-presentation="table"
15483 ?><varlistentry><term>Template Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
15484 list-presentation="table"
15485 ?><varlistentry><term><computeroutput>T</computeroutput></term><listitem><para>Type of the pointed old value. The old value pointer will always be null if this type is not copyable (see <computeroutput><computeroutput><link linkend="boost.contract.is_old_value_copyable">boost::contract::is_old_value_copyable</link></computeroutput></computeroutput>), but this library will not generate a compile-time error. </para></listitem></varlistentry></variablelist></listitem></varlistentry></variablelist></listitem><listitem><para><literallayout class="monospaced"><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> T<phrase role="special">></phrase> <anchor id="idm45394999068640-bb"/><phrase role="keyword">operator</phrase> <phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase> <phrase role="identifier">T</phrase> <phrase role="special">></phrase><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase></literallayout></para>Convert this object to an actual old value pointer for which the old value type <computeroutput>T</computeroutput> must be copyable. <para>For example, this is implicitly called when assigning or initializing old value pointers of type <computeroutput><computeroutput><link linkend="boost.contract.old_ptr">boost::contract::old_ptr</link></computeroutput></computeroutput>.</para><para>
15486 </para><variablelist spacing="compact"><?dbhtml
15487 list-presentation="table"
15488 ?><varlistentry><term>Template Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
15489 list-presentation="table"
15490 ?><varlistentry><term><computeroutput>T</computeroutput></term><listitem><para>Type of the pointed old value. This type must be copyable (see <computeroutput><computeroutput><link linkend="boost.contract.is_old_value_copyable">boost::contract::is_old_value_copyable</link></computeroutput></computeroutput>), otherwise this library will generate a compile-time error when the old value pointer is dereferenced. </para></listitem></varlistentry></variablelist></listitem></varlistentry></variablelist></listitem></orderedlist></refsect2></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.old_ptr"><refmeta><refentrytitle>Class template old_ptr</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::old_ptr</refname><refpurpose>Old value pointer that requires the pointed old value type to be copyable. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.old_hpp">boost/contract/old.hpp</link>>
15492 </phrase><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> T<phrase role="special">></phrase>
15493 <phrase role="keyword">class</phrase> <link linkend="boost.contract.old_ptr">old_ptr</link> <phrase role="special">{</phrase>
15494 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
15495 <phrase role="comment">// types</phrase>
15496 <phrase role="keyword">typedef</phrase> <phrase role="identifier">T</phrase> <anchor id="boost.contract.old_ptr.element_type"/><phrase role="identifier">element_type</phrase><phrase role="special">;</phrase> <phrase role="comment">// Pointed old value type. </phrase>
15498 <phrase role="comment">// <link linkend="boost.contract.old_ptrconstruct-copy-destruct">construct/copy/destruct</link></phrase>
15499 <link linkend="idm45394999038400-bb"><phrase role="identifier">old_ptr</phrase></link><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15501 <phrase role="comment">// <link linkend="idm45394999053440-bb">public member functions</link></phrase>
15502 <phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase> <link linkend="idm45394999052880-bb"><phrase role="keyword">operator</phrase> <phrase role="special">*</phrase></link><phrase role="special">(</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase><phrase role="special">;</phrase>
15503 <phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase> <phrase role="special">*</phrase> <link linkend="idm45394999047296-bb"><phrase role="keyword">operator</phrase><phrase role="special">-></phrase></link><phrase role="special">(</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase><phrase role="special">;</phrase>
15504 <phrase role="keyword">explicit</phrase> <link linkend="idm45394999041712-bb"><phrase role="keyword">operator</phrase> <phrase role="keyword">bool</phrase></link><phrase role="special">(</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase><phrase role="special">;</phrase>
15505 <phrase role="special">}</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This pointer can be set to point an actual old value copy using either <computeroutput><link linkend="BOOST_CONTRACT_OLDOF">BOOST_CONTRACT_OLDOF</link></computeroutput> or <computeroutput><link linkend="boost.contract.make_old_idm45394998968720">boost::contract::make_old</link></computeroutput> (that is why this class does not have public non-default constructors):</para><para><programlisting><phrase role="keyword">class</phrase> <phrase role="identifier">u</phrase> <phrase role="special">{</phrase>
15506 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
15507 <phrase role="keyword">virtual</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">f</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">,</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
15508 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="identifier">old_type</phrase><phrase role="special">></phrase> <phrase role="identifier">old_var</phrase> <phrase role="special">=</phrase> <phrase role="comment">// For copyable `old_type`.</phrase>
15509 <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">old_expr</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15510 <phrase role="special">...</phrase>
15511 <phrase role="special">}</phrase>
15513 <phrase role="special">...</phrase>
15514 <phrase role="special">}</phrase><phrase role="special">;</phrase>
15515 </programlisting></para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.tutorial.old_values"> Old Values</link></para>
15518 </para><refsect2><title>Template Parameters</title><orderedlist><listitem><para><literallayout class="monospaced"><phrase role="keyword">typename</phrase> T</literallayout></para><para><para>Type of the pointed old value. This type must be copyable (i.e., <computeroutput>boost::contract::is_old_value_copyable<T>::value</computeroutput> must be <computeroutput>true</computeroutput>), otherwise this pointer will always be null and this library will generate a compile-time error when the pointer is dereferenced. </para></para></listitem></orderedlist></refsect2><refsect2><title><anchor id="boost.contract.old_ptrconstruct-copy-destruct"/><computeroutput>old_ptr</computeroutput>
15520 construct/copy/destruct</title><orderedlist><listitem><para><literallayout class="monospaced"><anchor id="idm45394999038400-bb"/><phrase role="identifier">old_ptr</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase></literallayout></para>Construct this old value pointer as null. </listitem></orderedlist></refsect2><refsect2><title><anchor id="idm45394999053440-bb"/><computeroutput>old_ptr</computeroutput> public member functions</title><orderedlist><listitem><para><literallayout class="monospaced"><phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase> <anchor id="idm45394999052880-bb"/><phrase role="keyword">operator</phrase> <phrase role="special">*</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase><phrase role="special">;</phrase></literallayout></para>Dereference this old value pointer. <para>This will generate a run-time error if this pointer is null and a compile-time error if the pointed type <computeroutput>T</computeroutput> is not copyable (i.e., if <computeroutput>boost::contract::is_old_value_copyable<T>::value</computeroutput> is <computeroutput>false</computeroutput>).</para><para>
15521 </para><variablelist spacing="compact"><?dbhtml
15522 list-presentation="table"
15523 ?><varlistentry><term>Returns:</term><listitem><para>The pointed old value. Contract assertions should not change the state of the program so this member function is <computeroutput>const</computeroutput> and it returns the old value as a reference to a constant object (see <link linkend="boost_contract.contract_programming_overview.constant_correctness">
15524 Constant Correctness</link>). </para></listitem></varlistentry></variablelist></listitem><listitem><para><literallayout class="monospaced"><phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase> <phrase role="special">*</phrase> <anchor id="idm45394999047296-bb"/><phrase role="keyword">operator</phrase><phrase role="special">-></phrase><phrase role="special">(</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase><phrase role="special">;</phrase></literallayout></para>Structure-dereference this old value pointer. <para>This will generate a compile-time error if the pointed type <computeroutput>T</computeroutput> is not copyable (i.e., if <computeroutput>boost::contract::is_old_value_copyable<T>::value</computeroutput> is <computeroutput>false</computeroutput>).</para><para>
15525 </para><variablelist spacing="compact"><?dbhtml
15526 list-presentation="table"
15527 ?><varlistentry><term>Returns:</term><listitem><para>A pointer to the old value (null if this old value pointer is null). Contract assertions should not change the state of the program so this member function is <computeroutput>const</computeroutput> and it returns the old value as a pointer to a constant object (see <link linkend="boost_contract.contract_programming_overview.constant_correctness">
15528 Constant Correctness</link>). </para></listitem></varlistentry></variablelist></listitem><listitem><para><literallayout class="monospaced"><phrase role="keyword">explicit</phrase> <anchor id="idm45394999041712-bb"/><phrase role="keyword">operator</phrase> <phrase role="keyword">bool</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase><phrase role="special">;</phrase></literallayout></para>Query if this old value pointer is null or not (safe-bool operator). <para>(This is implemented using safe-bool emulation on compilers that do not support C++11 explicit type conversion operators.)</para><para>
15529 </para><variablelist spacing="compact"><?dbhtml
15530 list-presentation="table"
15531 ?><varlistentry><term>Returns:</term><listitem><para>True if this pointer is not null, false otherwise. </para></listitem></varlistentry></variablelist></listitem></orderedlist></refsect2></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.old_ptr_if_copyable"><refmeta><refentrytitle>Class template old_ptr_if_copyable</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::old_ptr_if_copyable</refname><refpurpose>Old value pointer that does not require the pointed old value type to be copyable. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.old_hpp">boost/contract/old.hpp</link>>
15533 </phrase><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> T<phrase role="special">></phrase>
15534 <phrase role="keyword">class</phrase> <link linkend="boost.contract.old_ptr_if_copyable">old_ptr_if_copyable</link> <phrase role="special">{</phrase>
15535 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
15536 <phrase role="comment">// types</phrase>
15537 <phrase role="keyword">typedef</phrase> <phrase role="identifier">T</phrase> <anchor id="boost.contract.old_ptr_if_copyable.element_type"/><phrase role="identifier">element_type</phrase><phrase role="special">;</phrase> <phrase role="comment">// Pointed old value type. </phrase>
15539 <phrase role="comment">// <link linkend="boost.contract.old_ptr_if_copyableconstruct-copy-destruct">construct/copy/destruct</link></phrase>
15540 <link linkend="idm45394999013184-bb"><phrase role="identifier">old_ptr_if_copyable</phrase></link><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15541 <link linkend="idm45394999012576-bb"><phrase role="identifier">old_ptr_if_copyable</phrase></link><phrase role="special">(</phrase><link linkend="boost.contract.old_ptr">old_ptr</link><phrase role="special"><</phrase> <phrase role="identifier">T</phrase> <phrase role="special">></phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15543 <phrase role="comment">// <link linkend="idm45394999028256-bb">public member functions</link></phrase>
15544 <phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase> <link linkend="idm45394999027696-bb"><phrase role="keyword">operator</phrase> <phrase role="special">*</phrase></link><phrase role="special">(</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase><phrase role="special">;</phrase>
15545 <phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase> <phrase role="special">*</phrase> <link linkend="idm45394999022096-bb"><phrase role="keyword">operator</phrase><phrase role="special">-></phrase></link><phrase role="special">(</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase><phrase role="special">;</phrase>
15546 <phrase role="keyword">explicit</phrase> <link linkend="idm45394999016496-bb"><phrase role="keyword">operator</phrase> <phrase role="keyword">bool</phrase></link><phrase role="special">(</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase><phrase role="special">;</phrase>
15547 <phrase role="special">}</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This pointer can be set to point to an actual old value copy using either <computeroutput><link linkend="BOOST_CONTRACT_OLDOF">BOOST_CONTRACT_OLDOF</link></computeroutput> or <computeroutput><link linkend="boost.contract.make_old_idm45394998968720">boost::contract::make_old</link></computeroutput>:</para><para><programlisting><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">></phrase> <phrase role="comment">// Type `T` might or not be copyable.</phrase>
15548 <phrase role="keyword">class</phrase> <phrase role="identifier">u</phrase> <phrase role="special">{</phrase>
15549 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
15550 <phrase role="keyword">virtual</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">f</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">,</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
15551 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr_if_copyable</phrase><phrase role="special"><</phrase><phrase role="identifier">T</phrase><phrase role="special">></phrase> <phrase role="identifier">old_var</phrase> <phrase role="special">=</phrase>
15552 <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">old_expr</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15553 <phrase role="special">...</phrase>
15554 <phrase role="keyword">if</phrase><phrase role="special">(</phrase><phrase role="identifier">old_var</phrase><phrase role="special">)</phrase> <phrase role="special">...</phrase> <phrase role="comment">// Always null for non-copyable types.</phrase>
15555 <phrase role="special">...</phrase>
15556 <phrase role="special">}</phrase>
15558 <phrase role="special">...</phrase>
15559 <phrase role="special">}</phrase><phrase role="special">;</phrase>
15560 </programlisting></para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.extras.old_value_requirements__templates_">
15561 Old Value Requirements</link></para>
15564 </para><refsect2><title>Template Parameters</title><orderedlist><listitem><para><literallayout class="monospaced"><phrase role="keyword">typename</phrase> T</literallayout></para><para><para>Type of the pointed old value. If this type is not copyable (i.e., <computeroutput>boost::contract::is_old_value_copyable<T>::value</computeroutput> is <computeroutput>false</computeroutput>), this pointer will always be null (but this library will not generate a compile-time error when this pointer is dereferenced). </para></para></listitem></orderedlist></refsect2><refsect2><title><anchor id="boost.contract.old_ptr_if_copyableconstruct-copy-destruct"/><computeroutput>old_ptr_if_copyable</computeroutput>
15566 construct/copy/destruct</title><orderedlist><listitem><para><literallayout class="monospaced"><anchor id="idm45394999013184-bb"/><phrase role="identifier">old_ptr_if_copyable</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase></literallayout></para>Construct this old value pointer as null. </listitem><listitem><para><literallayout class="monospaced"><anchor id="idm45394999012576-bb"/><phrase role="identifier">old_ptr_if_copyable</phrase><phrase role="special">(</phrase><link linkend="boost.contract.old_ptr">old_ptr</link><phrase role="special"><</phrase> <phrase role="identifier">T</phrase> <phrase role="special">></phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase> other<phrase role="special">)</phrase><phrase role="special">;</phrase></literallayout></para>Construct this old value pointer from an old value pointer that requires the old value type to be copyable. <para>Ownership of the pointed value object is transferred to this pointer. This constructor is implicitly called by this library when assigning an object of this type using <computeroutput><computeroutput><link linkend="BOOST_CONTRACT_OLDOF">BOOST_CONTRACT_OLDOF</link></computeroutput></computeroutput> (this constructor is usually not explicitly called by user code).</para><para>
15567 </para><variablelist spacing="compact"><?dbhtml
15568 list-presentation="table"
15569 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
15570 list-presentation="table"
15571 ?><varlistentry><term><computeroutput>other</computeroutput></term><listitem><para>Old value pointer that requires the old value type to be copyable. </para></listitem></varlistentry></variablelist></listitem></varlistentry></variablelist></listitem></orderedlist></refsect2><refsect2><title><anchor id="idm45394999028256-bb"/><computeroutput>old_ptr_if_copyable</computeroutput> public member functions</title><orderedlist><listitem><para><literallayout class="monospaced"><phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase> <anchor id="idm45394999027696-bb"/><phrase role="keyword">operator</phrase> <phrase role="special">*</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase><phrase role="special">;</phrase></literallayout></para>Dereference this old value pointer. <para>This will generate a run-time error if this pointer is null, but no compile-time error is generated if the pointed type <computeroutput>T</computeroutput> is not copyable (i.e., if <computeroutput>boost::contract::is_old_value_copyable<T>::value</computeroutput> is <computeroutput>false</computeroutput>).</para><para>
15572 </para><variablelist spacing="compact"><?dbhtml
15573 list-presentation="table"
15574 ?><varlistentry><term>Returns:</term><listitem><para>The pointed old value. Contract assertions should not change the state of the program so this member function is <computeroutput>const</computeroutput> and it returns the old value as a reference to a constant object (see <link linkend="boost_contract.contract_programming_overview.constant_correctness">
15575 Constant Correctness</link>). </para></listitem></varlistentry></variablelist></listitem><listitem><para><literallayout class="monospaced"><phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase> <phrase role="special">*</phrase> <anchor id="idm45394999022096-bb"/><phrase role="keyword">operator</phrase><phrase role="special">-></phrase><phrase role="special">(</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase><phrase role="special">;</phrase></literallayout></para>Structure-dereference this old value pointer. <para>This will return null but will not generate a compile-time error if the pointed type <computeroutput>T</computeroutput> is not copyable (i.e., if <computeroutput>boost::contract::is_old_value_copyable<T>::value</computeroutput> is <computeroutput>false</computeroutput>).</para><para>
15576 </para><variablelist spacing="compact"><?dbhtml
15577 list-presentation="table"
15578 ?><varlistentry><term>Returns:</term><listitem><para>A pointer to the old value (null if this old value pointer is null). Contract assertions should not change the state of the program so this member function is <computeroutput>const</computeroutput> and it returns the old value as a pointer to a constant object (see <link linkend="boost_contract.contract_programming_overview.constant_correctness">
15579 Constant Correctness</link>). </para></listitem></varlistentry></variablelist></listitem><listitem><para><literallayout class="monospaced"><phrase role="keyword">explicit</phrase> <anchor id="idm45394999016496-bb"/><phrase role="keyword">operator</phrase> <phrase role="keyword">bool</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase><phrase role="special">;</phrase></literallayout></para>Query if this old value pointer is null or not (safe-bool operator). <para>(This is implemented using safe-bool emulation on compilers that do not support C++11 explicit type conversion operators.)</para><para>
15580 </para><variablelist spacing="compact"><?dbhtml
15581 list-presentation="table"
15582 ?><varlistentry><term>Returns:</term><listitem><para>True if this pointer is not null, false otherwise. </para></listitem></varlistentry></variablelist></listitem></orderedlist></refsect2></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.old_value"><refmeta><refentrytitle>Class old_value</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::old_value</refname><refpurpose>Convert user-specified expressions to old values. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.old_hpp">boost/contract/old.hpp</link>>
15585 <phrase role="keyword">class</phrase> <link linkend="boost.contract.old_value">old_value</link> <phrase role="special">{</phrase>
15586 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
15587 <phrase role="comment">// <link linkend="boost.contract.old_valueconstruct-copy-destruct">construct/copy/destruct</link></phrase>
15588 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> T<phrase role="special">></phrase>
15589 <link linkend="idm45394999003184-bb"><phrase role="identifier">old_value</phrase></link><phrase role="special">(</phrase><phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase><phrase role="special">,</phrase>
15590 <phrase role="keyword">typename</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">enable_if</phrase><phrase role="special"><</phrase> <link linkend="boost.contract.is_old_value_copyable">boost::contract::is_old_value_copyable</link><phrase role="special"><</phrase> <phrase role="identifier">T</phrase> <phrase role="special">></phrase> <phrase role="special">></phrase><phrase role="special">::</phrase><phrase role="identifier">type</phrase> <phrase role="special">*</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15591 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> T<phrase role="special">></phrase>
15592 <link linkend="idm45394998995648-bb"><phrase role="identifier">old_value</phrase></link><phrase role="special">(</phrase><phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase><phrase role="special">,</phrase>
15593 <phrase role="keyword">typename</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">disable_if</phrase><phrase role="special"><</phrase> <link linkend="boost.contract.is_old_value_copyable">boost::contract::is_old_value_copyable</link><phrase role="special"><</phrase> <phrase role="identifier">T</phrase> <phrase role="special">></phrase> <phrase role="special">></phrase><phrase role="special">::</phrase><phrase role="identifier">type</phrase> <phrase role="special">*</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15594 <phrase role="special">}</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This class is usually only implicitly used by this library and it does not explicitly appear in user code.</para><para>On older compilers that cannot correctly deduce the <computeroutput><link linkend="boost.contract.is_old_value_copyable">boost::contract::is_old_value_copyable</link></computeroutput> trait used in the declaration of this class, programmers can manually specialize that trait to make sure that only old value types that are copyable are actually copied.</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.extras.old_value_requirements__templates_">
15595 Old Value Requirements</link> </para>
15597 </para><refsect2><title><anchor id="boost.contract.old_valueconstruct-copy-destruct"/><computeroutput>old_value</computeroutput>
15599 construct/copy/destruct</title><orderedlist><listitem><para><literallayout class="monospaced"><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> T<phrase role="special">></phrase>
15600 <anchor id="idm45394999003184-bb"/><phrase role="identifier">old_value</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase> old<phrase role="special">,</phrase>
15601 <phrase role="keyword">typename</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">enable_if</phrase><phrase role="special"><</phrase> <link linkend="boost.contract.is_old_value_copyable">boost::contract::is_old_value_copyable</link><phrase role="special"><</phrase> <phrase role="identifier">T</phrase> <phrase role="special">></phrase> <phrase role="special">></phrase><phrase role="special">::</phrase><phrase role="identifier">type</phrase> <phrase role="special">*</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase></literallayout></para>Construct this object from the specified old value when the old value type is copy constructible. <para>The specified old value <computeroutput>old</computeroutput> is copied (one time only) using <computeroutput><computeroutput><link linkend="boost.contract.old_value_copy">boost::contract::old_value_copy</link></computeroutput></computeroutput>, in which case the related old value pointer will not be null (but no copy is made if postconditions and exception guarantees are not being checked, see <computeroutput><computeroutput><link linkend="BOOST_CONTRACT_NO_OLDS">BOOST_CONTRACT_NO_OLDS</link></computeroutput></computeroutput>).</para><para>
15603 </para><variablelist spacing="compact"><?dbhtml
15604 list-presentation="table"
15605 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
15606 list-presentation="table"
15607 ?><varlistentry><term><computeroutput>old</computeroutput></term><listitem><para>Old value to be copied.</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Template Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
15608 list-presentation="table"
15609 ?><varlistentry><term><computeroutput>T</computeroutput></term><listitem><para>Old value type. </para></listitem></varlistentry></variablelist></listitem></varlistentry></variablelist></listitem><listitem><para><literallayout class="monospaced"><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> T<phrase role="special">></phrase>
15610 <anchor id="idm45394998995648-bb"/><phrase role="identifier">old_value</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase> old<phrase role="special">,</phrase>
15611 <phrase role="keyword">typename</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">disable_if</phrase><phrase role="special"><</phrase> <link linkend="boost.contract.is_old_value_copyable">boost::contract::is_old_value_copyable</link><phrase role="special"><</phrase> <phrase role="identifier">T</phrase> <phrase role="special">></phrase> <phrase role="special">></phrase><phrase role="special">::</phrase><phrase role="identifier">type</phrase> <phrase role="special">*</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase></literallayout></para>Construct this object from the specified old value when the old value type is not copyable. <para>The specified old value <computeroutput>old</computeroutput> cannot be copied in this case so it is not copied and the related old value pointer will always be null (thus calls to this constructor have no effect and they will likely be optimized away by most compilers).</para><para>
15613 </para><variablelist spacing="compact"><?dbhtml
15614 list-presentation="table"
15615 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
15616 list-presentation="table"
15617 ?><varlistentry><term><computeroutput>old</computeroutput></term><listitem><para>Old value (that will not be copied in this case).</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Template Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
15618 list-presentation="table"
15619 ?><varlistentry><term><computeroutput>T</computeroutput></term><listitem><para>Old value type. </para></listitem></varlistentry></variablelist></listitem></varlistentry></variablelist></listitem></orderedlist></refsect2></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.old_value_copy"><refmeta><refentrytitle>Struct template old_value_copy</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::old_value_copy</refname><refpurpose>Trait to copy an old value. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.old_hpp">boost/contract/old.hpp</link>>
15621 </phrase><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> T<phrase role="special">></phrase>
15622 <phrase role="keyword">struct</phrase> <link linkend="boost.contract.old_value_copy">old_value_copy</link> <phrase role="special">{</phrase>
15623 <phrase role="comment">// <link linkend="boost.contract.old_value_copyconstruct-copy-destruct">construct/copy/destruct</link></phrase>
15624 <phrase role="keyword">explicit</phrase> <link linkend="idm45394998977872-bb"><phrase role="identifier">old_value_copy</phrase></link><phrase role="special">(</phrase><phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15626 <phrase role="comment">// <link linkend="idm45394998981760-bb">public member functions</link></phrase>
15627 <phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase> <link linkend="idm45394998981200-bb"><phrase role="identifier">old</phrase></link><phrase role="special">(</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase><phrase role="special">;</phrase>
15628 <phrase role="special">}</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>By default, the implementation of this trait uses <computeroutput>T's</computeroutput> copy constructor to make one single copy of the specified value. However, programmers can specialize this trait to copy old values using user-specific operations different from <computeroutput>T's</computeroutput> copy constructor. The default implementation of this trait is equivalent to:</para><para><programlisting><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">></phrase>
15629 <phrase role="keyword">class</phrase> <phrase role="identifier">old_value_copy</phrase> <phrase role="special">{</phrase>
15630 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
15631 <phrase role="keyword">explicit</phrase> <phrase role="identifier">old_value_copy</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">old</phrase><phrase role="special">)</phrase> <phrase role="special">:</phrase>
15632 <phrase role="identifier">old_</phrase><phrase role="special">(</phrase><phrase role="identifier">old</phrase><phrase role="special">)</phrase> <phrase role="comment">// One single copy of value using T's copy constructor.</phrase>
15633 <phrase role="special">{</phrase><phrase role="special">}</phrase>
15635 <phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">old</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase> <phrase role="keyword">return</phrase> <phrase role="identifier">old_</phrase><phrase role="special">;</phrase> <phrase role="special">}</phrase>
15637 <phrase role="keyword">private</phrase><phrase role="special">:</phrase>
15638 <phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">old_</phrase><phrase role="special">;</phrase> <phrase role="comment">// The old value copy.</phrase>
15639 <phrase role="special">}</phrase><phrase role="special">;</phrase>
15640 </programlisting></para><para>This library will instantiate and use this trait only on old value types <computeroutput>T</computeroutput> that are copyable (i.e., for which <computeroutput>boost::contract::is_old_value_copyable<T>::value</computeroutput> is <computeroutput>true</computeroutput>).</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.extras.old_value_requirements__templates_">
15641 Old Value Requirements</link> </para>
15643 </para><refsect2><title><anchor id="boost.contract.old_value_copyconstruct-copy-destruct"/><computeroutput>old_value_copy</computeroutput>
15645 construct/copy/destruct</title><orderedlist><listitem><para><literallayout class="monospaced"><phrase role="keyword">explicit</phrase> <anchor id="idm45394998977872-bb"/><phrase role="identifier">old_value_copy</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase> old<phrase role="special">)</phrase><phrase role="special">;</phrase></literallayout></para>Construct this object by making one single copy of the specified old value. <para>This is the only operation within this library that actually copies old values. This ensures this library makes one and only one copy of an old value (if they actually need to be copied, see <computeroutput><computeroutput><link linkend="BOOST_CONTRACT_NO_OLDS">BOOST_CONTRACT_NO_OLDS</link></computeroutput></computeroutput>).</para><para>
15646 </para><variablelist spacing="compact"><?dbhtml
15647 list-presentation="table"
15648 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
15649 list-presentation="table"
15650 ?><varlistentry><term><computeroutput>old</computeroutput></term><listitem><para>The old value to copy. </para></listitem></varlistentry></variablelist></listitem></varlistentry></variablelist></listitem></orderedlist></refsect2><refsect2><title><anchor id="idm45394998981760-bb"/><computeroutput>old_value_copy</computeroutput> public member functions</title><orderedlist><listitem><para><literallayout class="monospaced"><phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase> <anchor id="idm45394998981200-bb"/><phrase role="identifier">old</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase><phrase role="special">;</phrase></literallayout></para>Return a (constant) reference to the old value that was copied. <para>Contract assertions should not change the state of the program so the old value copy is returned as <computeroutput>const</computeroutput> (see <link linkend="boost_contract.contract_programming_overview.constant_correctness">
15651 Constant Correctness</link>). </para></listitem></orderedlist></refsect2></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.null_old"><refmeta><refentrytitle>Function null_old</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::null_old</refname><refpurpose>Return a "null" old value. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.old_hpp">boost/contract/old.hpp</link>>
15654 <link linkend="boost.contract.old_value">old_value</link> <phrase role="identifier">null_old</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>The related old value pointer will also be null. This function is usually only called by the code expanded by <computeroutput><computeroutput><link linkend="BOOST_CONTRACT_OLDOF">BOOST_CONTRACT_OLDOF</link></computeroutput></computeroutput>.</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.extras.no_macros__and_no_variadic_macros_"> No Macros</link></para>
15657 </para><variablelist spacing="compact"><?dbhtml
15658 list-presentation="table"
15659 ?><varlistentry><term>Returns:</term><listitem><para>Null old value. </para></listitem></varlistentry></variablelist></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.make_old_idm45394998968720"><refmeta><refentrytitle>Function make_old</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::make_old</refname><refpurpose>Make an old value pointer (but not for virtual public functions and public functions overrides). </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.old_hpp">boost/contract/old.hpp</link>>
15662 <link linkend="boost.contract.old_pointer">old_pointer</link> <phrase role="identifier">make_old</phrase><phrase role="special">(</phrase><link linkend="boost.contract.old_value">old_value</link> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase> old<phrase role="special">)</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>The related old value pointer will not be null if the specified old value was actually copied. This function is usually only called by code expanded by <computeroutput>BOOST_CONTRACT_OLDOF(old_expr)</computeroutput> as in:</para><para><programlisting><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">make_old</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">copy_old</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase> <phrase role="special">?</phrase> <phrase role="identifier">old_expr</phrase> <phrase role="special">:</phrase>
15663 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">null_old</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">)</phrase>
15664 </programlisting></para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.extras.no_macros__and_no_variadic_macros_"> No Macros</link></para>
15668 </para><variablelist spacing="compact"><?dbhtml
15669 list-presentation="table"
15670 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
15671 list-presentation="table"
15672 ?><varlistentry><term><computeroutput>old</computeroutput></term><listitem><para>Old value which is usually implicitly constructed from the user old value expression to be copied (use the ternary operator <computeroutput>?:</computeroutput> to completely avoid to evaluate the old value expression when <computeroutput>boost::contract::copy_old()</computeroutput> is <computeroutput>false</computeroutput>).</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Returns:</term><listitem><para>Old value pointer (usually implicitly converted to either <computeroutput><link linkend="boost.contract.old_ptr">boost::contract::old_ptr</link></computeroutput> or <computeroutput><link linkend="boost.contract.old_ptr_if_copyable">boost::contract::old_ptr_if_copyable</link></computeroutput> in user code). </para></listitem></varlistentry></variablelist></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.make_old_idm45394998958240"><refmeta><refentrytitle>Function make_old</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::make_old</refname><refpurpose>Make an old value pointer (for virtual public functions and public functions overrides). </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.old_hpp">boost/contract/old.hpp</link>>
15675 <link linkend="boost.contract.old_pointer">old_pointer</link> <phrase role="identifier">make_old</phrase><phrase role="special">(</phrase><link linkend="boost.contract.virtual_">virtual_</link> <phrase role="special">*</phrase> v<phrase role="special">,</phrase> <link linkend="boost.contract.old_value">old_value</link> <phrase role="keyword">const</phrase> <phrase role="special">&</phrase> old<phrase role="special">)</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>The related old value pointer will not be null if the specified old value was actually copied. This function is usually only called by code expanded by <computeroutput>BOOST_CONTRACT_OLDOF(v, old_expr)</computeroutput> as in:</para><para><programlisting><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">make_old</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">copy_old</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">)</phrase> <phrase role="special">?</phrase> <phrase role="identifier">old_expr</phrase> <phrase role="special">:</phrase>
15676 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">null_old</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">)</phrase>
15677 </programlisting></para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.extras.no_macros__and_no_variadic_macros_"> No Macros</link></para>
15681 </para><variablelist spacing="compact"><?dbhtml
15682 list-presentation="table"
15683 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
15684 list-presentation="table"
15685 ?><varlistentry><term><computeroutput>old</computeroutput></term><listitem><para>Old value which is usually implicitly constructed from the user old value expression to be copied (use the ternary operator <computeroutput>?:</computeroutput> to completely avoid to evaluate the old value expression when <computeroutput>boost::contract::copy_old(v)</computeroutput> is <computeroutput>false</computeroutput>).</para></listitem></varlistentry><varlistentry><term><computeroutput>v</computeroutput></term><listitem><para>The trailing parameter of type <computeroutput><computeroutput><link linkend="boost.contract.virtual_">boost::contract::virtual_</link></computeroutput></computeroutput><computeroutput>*</computeroutput> and default value <computeroutput>0</computeroutput> from the enclosing virtual or overriding public function declaring the contract. </para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Returns:</term><listitem><para>Old value pointer (usually implicitly converted to either <computeroutput><link linkend="boost.contract.old_ptr">boost::contract::old_ptr</link></computeroutput> or <computeroutput><link linkend="boost.contract.old_ptr_if_copyable">boost::contract::old_ptr_if_copyable</link></computeroutput> in user code). </para></listitem></varlistentry></variablelist></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.copy_old_idm45394998944672"><refmeta><refentrytitle>Function copy_old</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::copy_old</refname><refpurpose>Query if old values need to be copied (but not for virtual public functions and public function overrides). </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.old_hpp">boost/contract/old.hpp</link>>
15688 <phrase role="keyword">bool</phrase> <phrase role="identifier">copy_old</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>For example, this function always returns false when both postconditions and exception guarantees are not being checked (see <computeroutput><computeroutput><link linkend="BOOST_CONTRACT_NO_OLDS">BOOST_CONTRACT_NO_OLDS</link></computeroutput></computeroutput>). This function is usually only called by the code expanded by <computeroutput><computeroutput><link linkend="BOOST_CONTRACT_OLDOF">BOOST_CONTRACT_OLDOF</link></computeroutput></computeroutput>.</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.extras.no_macros__and_no_variadic_macros_"> No Macros</link></para>
15691 </para><variablelist spacing="compact"><?dbhtml
15692 list-presentation="table"
15693 ?><varlistentry><term>Returns:</term><listitem><para>True if old values need to be copied, false otherwise. </para></listitem></varlistentry></variablelist></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.copy_old_idm45394998938528"><refmeta><refentrytitle>Function copy_old</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::copy_old</refname><refpurpose>Query if old values need to be copied (for virtual public functions and public function overrides). </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.old_hpp">boost/contract/old.hpp</link>>
15696 <phrase role="keyword">bool</phrase> <phrase role="identifier">copy_old</phrase><phrase role="special">(</phrase><link linkend="boost.contract.virtual_">virtual_</link> <phrase role="special">*</phrase> v<phrase role="special">)</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>For example, this function always returns false when both postconditions and exception guarantees are not being checked (see <computeroutput><computeroutput><link linkend="BOOST_CONTRACT_NO_OLDS">BOOST_CONTRACT_NO_OLDS</link></computeroutput></computeroutput>). In addition, this function returns false when overridden functions are being called subsequent times by this library to support subcontracting. This function is usually only called by the code expanded by <computeroutput><computeroutput><link linkend="BOOST_CONTRACT_OLDOF">BOOST_CONTRACT_OLDOF</link></computeroutput></computeroutput>.</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.extras.no_macros__and_no_variadic_macros_"> No Macros</link></para>
15700 </para><variablelist spacing="compact"><?dbhtml
15701 list-presentation="table"
15702 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
15703 list-presentation="table"
15704 ?><varlistentry><term><computeroutput>v</computeroutput></term><listitem><para>The trailing parameter of type <computeroutput><computeroutput><link linkend="boost.contract.virtual_">boost::contract::virtual_</link></computeroutput></computeroutput><computeroutput>*</computeroutput> and default value <computeroutput>0</computeroutput> from the enclosing virtual or overriding public function declaring the contract.</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Returns:</term><listitem><para>True if old values need to be copied, false otherwise. </para></listitem></varlistentry></variablelist></refsect1></refentry>
15705 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CONTRACT_OLDOF"><refmeta><refentrytitle>Macro BOOST_CONTRACT_OLDOF</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_OLDOF</refname><refpurpose>Macro typically used to copy an old value expression and assign it to an old value pointer. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.old_hpp">boost/contract/old.hpp</link>>
15707 </phrase>BOOST_CONTRACT_OLDOF(...)</synopsis></refsynopsisdiv><refsect1><title>Description</title><para>The expression expanded by this macro should be assigned to an old value pointer of type <computeroutput><link linkend="boost.contract.old_ptr">boost::contract::old_ptr</link></computeroutput> or <computeroutput><link linkend="boost.contract.old_ptr_if_copyable">boost::contract::old_ptr_if_copyable</link></computeroutput>. This is an overloaded variadic macro and it can be used in the following different ways.</para><para>1. From within virtual public functions and public functions overrides:</para><para><programlisting><phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">old_expr</phrase><phrase role="special">)</phrase>
15708 </programlisting></para><para>2. From all other operations:</para><para><programlisting><phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">old_expr</phrase><phrase role="special">)</phrase>
15709 </programlisting></para><para>Where:</para><para><itemizedlist>
15710 <listitem><para><computeroutput><emphasis role="bold">v</emphasis></computeroutput> is the extra parameter of type <computeroutput><link linkend="boost.contract.virtual_">boost::contract::virtual_</link></computeroutput><computeroutput>*</computeroutput> and default value <computeroutput>0</computeroutput> from the enclosing virtual public function or public function overrides declaring the contract. </para>
15712 <listitem><para><computeroutput><emphasis role="bold">old_expr</emphasis></computeroutput> is the expression to be evaluated and copied into the old value pointer. (This is not a variadic macro parameter so any comma it might contain must be protected by round parenthesis and <computeroutput>BOOST_CONTRACT_OLDOF(v, (old_expr))</computeroutput> will always work.)</para>
15715 On compilers that do not support variadic macros, programmers can manually copy old value expressions without using this macro (see <link linkend="boost_contract.extras.no_macros__and_no_variadic_macros_"> No Macros</link>).</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.tutorial.old_values"> Old Values</link> </para>
15717 </para></refsect1></refentry>
15719 <section id="header.boost.contract.override_hpp"><title>Header <<ulink url="../../../../boost/contract/override.hpp">boost/contract/override.hpp</ulink>></title><para>Handle public function overrides (for subcontracting). </para><synopsis xmlns:xi="http://www.w3.org/2001/XInclude">
15721 <link linkend="BOOST_CO_idm45394998912688">BOOST_CONTRACT_NAMED_OVERRIDE</link>(type_name, func_name)
15722 <link linkend="BOOST_CONTRACT_OVERRIDE">BOOST_CONTRACT_OVERRIDE</link>(func_name)
15723 <link linkend="BOOST_CONTRACT_OVERRIDES">BOOST_CONTRACT_OVERRIDES</link>(...)</synopsis>
15724 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CO_idm45394998912688"><refmeta><refentrytitle>Macro BOOST_CONTRACT_NAMED_OVERRIDE</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_NAMED_OVERRIDE</refname><refpurpose>Declare an override type trait with an arbitrary name. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.override_hpp">boost/contract/override.hpp</link>>
15726 </phrase>BOOST_CONTRACT_NAMED_OVERRIDE(type_name, func_name)</synopsis></refsynopsisdiv><refsect1><title>Description</title><para>Declare the override type trait named <computeroutput>type_name</computeroutput> to pass as an explicit template parameter to <computeroutput><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput> for public function overrides.</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.advanced.named_overrides"> Named Overrides</link></para>
15729 </para><variablelist spacing="compact"><?dbhtml
15730 list-presentation="table"
15731 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
15732 list-presentation="table"
15733 ?><varlistentry><term><computeroutput>func_name</computeroutput></term><listitem><para>Function name of the public function override. This macro is called just once even if the function name is overloaded (the same override type trait is used for all overloaded functions with the same name, see <link linkend="boost_contract.advanced.function_overloads">
15734 Function Overloads</link>). (This is not a variadic macro parameter but it should never contain commas because it is an identifier.) </para></listitem></varlistentry><varlistentry><term><computeroutput>type_name</computeroutput></term><listitem><para>Name of the override type trait this macro will declare. (This is not a variadic macro parameter but it should never contain commas because it is an identifier.) </para></listitem></varlistentry></variablelist></listitem></varlistentry></variablelist></refsect1></refentry>
15735 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CONTRACT_OVERRIDE"><refmeta><refentrytitle>Macro BOOST_CONTRACT_OVERRIDE</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_OVERRIDE</refname><refpurpose>Declare an override type trait named <computeroutput>override_<emphasis>func_name</emphasis></computeroutput>. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.override_hpp">boost/contract/override.hpp</link>>
15737 </phrase>BOOST_CONTRACT_OVERRIDE(func_name)</synopsis></refsynopsisdiv><refsect1><title>Description</title><para>Declare the override type trait named <computeroutput>override_<emphasis>func_name</emphasis></computeroutput> to pass as an explicit template parameter to <computeroutput><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput> for public function overrides. Use <computeroutput><link linkend="BOOST_CO_idm45394998912688">BOOST_CONTRACT_NAMED_OVERRIDE</link></computeroutput> to generate an override type trait with a name different than <computeroutput>override_<emphasis>func_name</emphasis></computeroutput> (usually not needed).</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.tutorial.public_function_overrides__subcontracting_">
15738 Public Function Overrides</link></para>
15741 </para><variablelist spacing="compact"><?dbhtml
15742 list-presentation="table"
15743 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
15744 list-presentation="table"
15745 ?><varlistentry><term><computeroutput>func_name</computeroutput></term><listitem><para>Function name of the public function override. This macro is called just once even if the function name is overloaded (the same override type trait is used for all overloaded functions with the same name, see <link linkend="boost_contract.advanced.function_overloads"> Function Overloads</link>). (This is not a variadic macro parameter but it should never contain any comma because it is an identifier.) </para></listitem></varlistentry></variablelist></listitem></varlistentry></variablelist></refsect1></refentry>
15746 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CONTRACT_OVERRIDES"><refmeta><refentrytitle>Macro BOOST_CONTRACT_OVERRIDES</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_OVERRIDES</refname><refpurpose>Declare multiple override type traits at once naming them <computeroutput>override_...</computeroutput> (for convenience). </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.override_hpp">boost/contract/override.hpp</link>>
15748 </phrase>BOOST_CONTRACT_OVERRIDES(...)</synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This variadic macro is provided for convenience as <computeroutput>BOOST_CONTRACT_OVERRIDES(f_1, f_2, ..., f_n)</computeroutput> expands to code equivalent to:</para><para><programlisting><phrase role="identifier">BOOST_CONTRACT_OVERRIDE</phrase><phrase role="special">(</phrase><phrase role="identifier">f_1</phrase><phrase role="special">)</phrase>
15749 <phrase role="identifier">BOOST_CONTRACT_OVERRIDE</phrase><phrase role="special">(</phrase><phrase role="identifier">f_2</phrase><phrase role="special">)</phrase>
15750 <phrase role="special">...</phrase>
15751 <phrase role="identifier">BOOST_CONTRACT_OVERRIDE</phrase><phrase role="special">(</phrase><phrase role="identifier">f_n</phrase><phrase role="special">)</phrase>
15752 </programlisting></para><para>On compilers that do not support variadic macros, the override type traits can be equivalently programmed one-by-one calling <computeroutput><link linkend="BOOST_CONTRACT_OVERRIDE">BOOST_CONTRACT_OVERRIDE</link></computeroutput> for each function name as shown above.</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.tutorial.public_function_overrides__subcontracting_">
15753 Public Function Overrides</link></para>
15756 </para><variablelist spacing="compact"><?dbhtml
15757 list-presentation="table"
15758 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
15759 list-presentation="table"
15760 ?><varlistentry><term><computeroutput>...</computeroutput></term><listitem><para>A comma separated list of one or more function names of public function overrides. (Each function name should never contain commas because it is an identifier.) </para></listitem></varlistentry></variablelist></listitem></varlistentry></variablelist></refsect1></refentry>
15762 <section id="header.boost.contract.public_function_hpp"><title>Header <<ulink url="../../../../boost/contract/public_function.hpp">boost/contract/public_function.hpp</ulink>></title><para>Program contracts for public functions (including subcontracting). </para><para>The different overloads handle public functions that are static, virtual void, virtual non-void, overriding void, and overriding non-void. </para><synopsis xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">namespace</phrase> <phrase role="identifier">boost</phrase> <phrase role="special">{</phrase>
15763 <phrase role="keyword">namespace</phrase> <phrase role="identifier">contract</phrase> <phrase role="special">{</phrase>
15764 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> Class<phrase role="special">></phrase>
15765 <link linkend="boost.contract.specify__idm45394999179040">specify_precondition_old_postcondition_except</link> <link linkend="boost.contract.public_f_idm45394998885120"><phrase role="identifier">public_function</phrase></link><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15766 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> Class<phrase role="special">></phrase>
15767 <link linkend="boost.contract.specify__idm45394999179040">specify_precondition_old_postcondition_except</link> <link linkend="boost.contract.public_f_idm45394998874224"><phrase role="identifier">public_function</phrase></link><phrase role="special">(</phrase><phrase role="identifier">Class</phrase> <phrase role="special">*</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15768 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> Class<phrase role="special">></phrase>
15769 <link linkend="boost.contract.specify__idm45394999179040">specify_precondition_old_postcondition_except</link>
15770 <link linkend="boost.contract.public_f_idm45394998859936"><phrase role="identifier">public_function</phrase></link><phrase role="special">(</phrase><link linkend="boost.contract.virtual_">virtual_</link> <phrase role="special">*</phrase><phrase role="special">,</phrase> <phrase role="identifier">Class</phrase> <phrase role="special">*</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15771 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> VirtualResult<phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> Class<phrase role="special">></phrase>
15772 <link linkend="boost.contract.specify__idm45394999179040">specify_precondition_old_postcondition_except</link><phrase role="special"><</phrase> <phrase role="identifier">VirtualResult</phrase> <phrase role="special">></phrase>
15773 <link linkend="boost.contract.public_f_idm45394998841296"><phrase role="identifier">public_function</phrase></link><phrase role="special">(</phrase><link linkend="boost.contract.virtual_">virtual_</link> <phrase role="special">*</phrase><phrase role="special">,</phrase> <phrase role="identifier">VirtualResult</phrase> <phrase role="special">&</phrase><phrase role="special">,</phrase> <phrase role="identifier">Class</phrase> <phrase role="special">*</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15774 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> Override<phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> F<phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> Class<phrase role="special">,</phrase> <phrase role="keyword">typename</phrase><phrase role="special">...</phrase> Args<phrase role="special">></phrase>
15775 <link linkend="boost.contract.specify__idm45394999179040">specify_precondition_old_postcondition_except</link>
15776 <link linkend="boost.contract.public_f_idm45394998817488"><phrase role="identifier">public_function</phrase></link><phrase role="special">(</phrase><link linkend="boost.contract.virtual_">virtual_</link> <phrase role="special">*</phrase><phrase role="special">,</phrase> <phrase role="identifier">F</phrase><phrase role="special">,</phrase> <phrase role="identifier">Class</phrase> <phrase role="special">*</phrase><phrase role="special">,</phrase> <phrase role="identifier">Args</phrase> <phrase role="special">&</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15777 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> Override<phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> VirtualResult<phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> F<phrase role="special">,</phrase>
15778 <phrase role="keyword">typename</phrase> Class<phrase role="special">,</phrase> <phrase role="keyword">typename</phrase><phrase role="special">...</phrase> Args<phrase role="special">></phrase>
15779 <link linkend="boost.contract.specify__idm45394999179040">specify_precondition_old_postcondition_except</link><phrase role="special"><</phrase> <phrase role="identifier">VirtualResult</phrase> <phrase role="special">></phrase>
15780 <link linkend="boost.contract.public_f_idm45394998787360"><phrase role="identifier">public_function</phrase></link><phrase role="special">(</phrase><link linkend="boost.contract.virtual_">virtual_</link> <phrase role="special">*</phrase><phrase role="special">,</phrase> <phrase role="identifier">VirtualResult</phrase> <phrase role="special">&</phrase><phrase role="special">,</phrase> <phrase role="identifier">F</phrase><phrase role="special">,</phrase> <phrase role="identifier">Class</phrase> <phrase role="special">*</phrase><phrase role="special">,</phrase> <phrase role="identifier">Args</phrase> <phrase role="special">&</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15781 <phrase role="special">}</phrase>
15782 <phrase role="special">}</phrase></synopsis>
15783 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.public_f_idm45394998885120"><refmeta><refentrytitle>Function template public_function</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::public_function</refname><refpurpose>Program contracts for static public functions. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.public_function_hpp">boost/contract/public_function.hpp</link>>
15786 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> Class<phrase role="special">></phrase>
15787 <link linkend="boost.contract.specify__idm45394999179040">specify_precondition_old_postcondition_except</link> <phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This is used to specify preconditions, postconditions, exception guarantees, old value copies at body, and check static class invariants for static public functions:</para><para><programlisting><phrase role="keyword">class</phrase> <phrase role="identifier">u</phrase> <phrase role="special">{</phrase>
15788 <phrase role="keyword">friend</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">access</phrase><phrase role="special">;</phrase>
15790 <phrase role="keyword">static</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">static_invariant</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional (as for non-static).</phrase>
15791 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15792 <phrase role="special">...</phrase>
15793 <phrase role="special">}</phrase>
15795 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
15796 <phrase role="keyword">static</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">f</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
15797 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="identifier">old_type</phrase><phrase role="special">></phrase> <phrase role="identifier">old_var</phrase><phrase role="special">;</phrase>
15798 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special"><</phrase><phrase role="identifier">u</phrase><phrase role="special">></phrase><phrase role="special">(</phrase><phrase role="special">)</phrase>
15799 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
15800 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15801 <phrase role="special">...</phrase>
15802 <phrase role="special">}</phrase><phrase role="special">)</phrase>
15803 <phrase role="special">.</phrase><phrase role="identifier">old</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
15804 <phrase role="identifier">old_var</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">old_expr</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15805 <phrase role="special">...</phrase>
15806 <phrase role="special">}</phrase><phrase role="special">)</phrase>
15807 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
15808 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15809 <phrase role="special">...</phrase>
15810 <phrase role="special">}</phrase><phrase role="special">)</phrase>
15811 <phrase role="special">.</phrase><phrase role="identifier">except</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
15812 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15813 <phrase role="special">...</phrase>
15814 <phrase role="special">}</phrase><phrase role="special">)</phrase>
15815 <phrase role="special">;</phrase>
15817 <phrase role="special">...</phrase> <phrase role="comment">// Function body.</phrase>
15818 <phrase role="special">}</phrase>
15820 <phrase role="special">...</phrase>
15821 <phrase role="special">}</phrase><phrase role="special">;</phrase>
15822 </programlisting></para><para>For optimization, this can be omitted for static public functions that do not have preconditions, postconditions and exception guarantees, within classes that have no static invariants.</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.tutorial.static_public_functions"> Static Public Functions</link></para>
15826 </para><variablelist spacing="compact"><?dbhtml
15827 list-presentation="table"
15828 ?><varlistentry><term>Template Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
15829 list-presentation="table"
15830 ?><varlistentry><term><computeroutput>Class</computeroutput></term><listitem><para>The type of the class containing the static public function declaring the contract. This template parameter must be explicitly specified for static public functions (because they have no object <computeroutput>this</computeroutput> so there is no function argument from which this type template parameter can be automatically deduced by C++).</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Returns:</term><listitem><para>The result of this function must be assigned to a variable of type <computeroutput><link linkend="boost.contract.check">boost::contract::check</link></computeroutput> declared explicitly (i.e., without using C++11 <computeroutput>auto</computeroutput> declarations) and locally just before the code of the static public function body (otherwise this library will generate a run-time error, see <computeroutput><link linkend="BOOST_CO_idm45394999694064">BOOST_CONTRACT_ON_MISSING_CHECK_DECL</link></computeroutput>). </para></listitem></varlistentry></variablelist></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.public_f_idm45394998874224"><refmeta><refentrytitle>Function template public_function</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::public_function</refname><refpurpose>Program contracts for public functions that are not static, not virtual, and do not not override. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.public_function_hpp">boost/contract/public_function.hpp</link>>
15833 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> Class<phrase role="special">></phrase>
15834 <link linkend="boost.contract.specify__idm45394999179040">specify_precondition_old_postcondition_except</link> <phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="identifier">Class</phrase> <phrase role="special">*</phrase> obj<phrase role="special">)</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This is used to specify preconditions, postconditions, exception guarantees, old value copies at body, and check class invariants for public functions that are not static, not virtual, and do not override:</para><para><programlisting><phrase role="keyword">class</phrase> <phrase role="identifier">u</phrase> <phrase role="special">{</phrase>
15835 <phrase role="keyword">friend</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">access</phrase><phrase role="special">;</phrase>
15837 <phrase role="keyword">void</phrase> <phrase role="identifier">invariant</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional (as for static and volatile).</phrase>
15838 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15839 <phrase role="special">...</phrase>
15840 <phrase role="special">}</phrase>
15842 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
15843 <phrase role="keyword">void</phrase> <phrase role="identifier">f</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
15844 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="identifier">old_type</phrase><phrase role="special">></phrase> <phrase role="identifier">old_var</phrase><phrase role="special">;</phrase>
15845 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
15846 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
15847 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15848 <phrase role="special">...</phrase>
15849 <phrase role="special">}</phrase><phrase role="special">)</phrase>
15850 <phrase role="special">.</phrase><phrase role="identifier">old</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
15851 <phrase role="identifier">old_var</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">old_expr</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15852 <phrase role="special">...</phrase>
15853 <phrase role="special">}</phrase><phrase role="special">)</phrase>
15854 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
15855 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15856 <phrase role="special">...</phrase>
15857 <phrase role="special">}</phrase><phrase role="special">)</phrase>
15858 <phrase role="special">.</phrase><phrase role="identifier">except</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
15859 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15860 <phrase role="special">...</phrase>
15861 <phrase role="special">}</phrase><phrase role="special">)</phrase>
15862 <phrase role="special">;</phrase>
15864 <phrase role="special">...</phrase> <phrase role="comment">// Function body.</phrase>
15865 <phrase role="special">}</phrase>
15867 <phrase role="special">...</phrase>
15868 <phrase role="special">}</phrase><phrase role="special">;</phrase>
15869 </programlisting></para><para>For optimization, this can be omitted for public functions that do not have preconditions, postconditions and exception guarantees, within classes that have no invariants.</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.tutorial.public_functions"> Public Functions</link></para>
15874 </para><variablelist spacing="compact"><?dbhtml
15875 list-presentation="table"
15876 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
15877 list-presentation="table"
15878 ?><varlistentry><term><computeroutput>obj</computeroutput></term><listitem><para>The object <computeroutput>this</computeroutput> from the scope of the enclosing public function declaring the contract. This object might be mutable, <computeroutput>const</computeroutput>, <computeroutput>volatile</computeroutput>, or <computeroutput>const volatile</computeroutput> depending on the cv-qualifier of the enclosing function (volatile public functions will check volatile class invariants, see <link linkend="boost_contract.extras.volatile_public_functions">
15879 Volatile Public Functions</link>).</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Template Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
15880 list-presentation="table"
15881 ?><varlistentry><term><computeroutput>Class</computeroutput></term><listitem><para>The type of the class containing the public function declaring the contract. (Usually this template parameter is automatically deduced by C++ and it does not need to be explicitly specified by programmers.)</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Returns:</term><listitem><para>The result of this function must be assigned to a variable of type <computeroutput><link linkend="boost.contract.check">boost::contract::check</link></computeroutput> declared explicitly (i.e., without using C++11 <computeroutput>auto</computeroutput> declarations) and locally just before the code of the public function body (otherwise this library will generate a run-time error, see <computeroutput><link linkend="BOOST_CO_idm45394999694064">BOOST_CONTRACT_ON_MISSING_CHECK_DECL</link></computeroutput>). </para></listitem></varlistentry></variablelist></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.public_f_idm45394998859936"><refmeta><refentrytitle>Function template public_function</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::public_function</refname><refpurpose>Program contracts for void virtual public functions that do not override. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.public_function_hpp">boost/contract/public_function.hpp</link>>
15884 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> Class<phrase role="special">></phrase>
15885 <link linkend="boost.contract.specify__idm45394999179040">specify_precondition_old_postcondition_except</link>
15886 <phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><link linkend="boost.contract.virtual_">virtual_</link> <phrase role="special">*</phrase> v<phrase role="special">,</phrase> <phrase role="identifier">Class</phrase> <phrase role="special">*</phrase> obj<phrase role="special">)</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This is used to specify preconditions, postconditions, exception guarantees, old value copies at body, and check class invariants for public functions that are virtual, do not override, and return <computeroutput>void:</computeroutput> </para><para><programlisting><phrase role="keyword">class</phrase> <phrase role="identifier">u</phrase> <phrase role="special">{</phrase>
15887 <phrase role="keyword">friend</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">access</phrase><phrase role="special">;</phrase>
15889 <phrase role="keyword">void</phrase> <phrase role="identifier">invariant</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional (as for static and volatile).</phrase>
15890 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15891 <phrase role="special">...</phrase>
15892 <phrase role="special">}</phrase>
15894 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
15895 <phrase role="keyword">void</phrase> <phrase role="identifier">f</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">,</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
15896 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="identifier">old_type</phrase><phrase role="special">></phrase> <phrase role="identifier">old_var</phrase><phrase role="special">;</phrase>
15897 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">)</phrase>
15898 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
15899 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15900 <phrase role="special">...</phrase>
15901 <phrase role="special">}</phrase><phrase role="special">)</phrase>
15902 <phrase role="special">.</phrase><phrase role="identifier">old</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
15903 <phrase role="identifier">old_var</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">old_expr</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15904 <phrase role="special">...</phrase>
15905 <phrase role="special">}</phrase><phrase role="special">)</phrase>
15906 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
15907 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15908 <phrase role="special">...</phrase>
15909 <phrase role="special">}</phrase><phrase role="special">)</phrase>
15910 <phrase role="special">.</phrase><phrase role="identifier">except</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
15911 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15912 <phrase role="special">...</phrase>
15913 <phrase role="special">}</phrase><phrase role="special">)</phrase>
15914 <phrase role="special">;</phrase>
15916 <phrase role="special">...</phrase> <phrase role="comment">// Function body.</phrase>
15917 <phrase role="special">}</phrase>
15919 <phrase role="special">...</phrase>
15920 <phrase role="special">}</phrase><phrase role="special">;</phrase>
15921 </programlisting></para><para>A virtual public function should always call <computeroutput><computeroutput><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput></computeroutput> otherwise this library will not be able to correctly use it for subcontracting.</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.tutorial.virtual_public_functions"> Virtual Public Functions</link></para>
15926 </para><variablelist spacing="compact"><?dbhtml
15927 list-presentation="table"
15928 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
15929 list-presentation="table"
15930 ?><varlistentry><term><computeroutput>obj</computeroutput></term><listitem><para>The object <computeroutput>this</computeroutput> from the scope of the enclosing virtual public function declaring the contract. This object might be mutable, <computeroutput>const</computeroutput>, <computeroutput>volatile</computeroutput>, or <computeroutput>const volatile</computeroutput> depending on the cv-qualifier of the enclosing function (volatile public functions will check volatile class invariants, see <link linkend="boost_contract.extras.volatile_public_functions">
15931 Volatile Public Functions</link>).</para></listitem></varlistentry><varlistentry><term><computeroutput>v</computeroutput></term><listitem><para>The trailing parameter of type <computeroutput><computeroutput><link linkend="boost.contract.virtual_">boost::contract::virtual_</link></computeroutput></computeroutput><computeroutput>*</computeroutput> and default value <computeroutput>0</computeroutput> from the enclosing virtual public function. </para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Template Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
15932 list-presentation="table"
15933 ?><varlistentry><term><computeroutput>Class</computeroutput></term><listitem><para>The type of the class containing the virtual public function declaring the contract. (Usually this template parameter is automatically deduced by C++ and it does not need to be explicitly specified by programmers.)</para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Returns:</term><listitem><para>The result of this function must be assigned to a variable of type <computeroutput><link linkend="boost.contract.check">boost::contract::check</link></computeroutput> declared explicitly (i.e., without using C++11 <computeroutput>auto</computeroutput> declarations) and locally just before the code of the public function body (otherwise this library will generate a run-time error, see <computeroutput><link linkend="BOOST_CO_idm45394999694064">BOOST_CONTRACT_ON_MISSING_CHECK_DECL</link></computeroutput>). </para></listitem></varlistentry></variablelist></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.public_f_idm45394998841296"><refmeta><refentrytitle>Function template public_function</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::public_function</refname><refpurpose>Program contracts for non-void virtual public functions that do not override. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.public_function_hpp">boost/contract/public_function.hpp</link>>
15936 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> VirtualResult<phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> Class<phrase role="special">></phrase>
15937 <link linkend="boost.contract.specify__idm45394999179040">specify_precondition_old_postcondition_except</link><phrase role="special"><</phrase> <phrase role="identifier">VirtualResult</phrase> <phrase role="special">></phrase>
15938 <phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><link linkend="boost.contract.virtual_">virtual_</link> <phrase role="special">*</phrase> v<phrase role="special">,</phrase> <phrase role="identifier">VirtualResult</phrase> <phrase role="special">&</phrase> r<phrase role="special">,</phrase> <phrase role="identifier">Class</phrase> <phrase role="special">*</phrase> obj<phrase role="special">)</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This is used to specify preconditions, postconditions, exception guarantees, old value copies at body, and check class invariants for public functions that are virtual, do not override, and do not return <computeroutput>void:</computeroutput> </para><para><programlisting><phrase role="keyword">class</phrase> <phrase role="identifier">u</phrase> <phrase role="special">{</phrase>
15939 <phrase role="keyword">friend</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">access</phrase><phrase role="special">;</phrase>
15941 <phrase role="keyword">void</phrase> <phrase role="identifier">invariant</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional (as for static and volatile).</phrase>
15942 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15943 <phrase role="special">...</phrase>
15944 <phrase role="special">}</phrase>
15946 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
15947 <phrase role="identifier">t</phrase> <phrase role="identifier">f</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">,</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
15948 <phrase role="identifier">t</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
15949 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="identifier">old_type</phrase><phrase role="special">></phrase> <phrase role="identifier">old_var</phrase><phrase role="special">;</phrase>
15950 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase>
15951 <phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">result</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">)</phrase>
15952 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
15953 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15954 <phrase role="special">...</phrase>
15955 <phrase role="special">}</phrase><phrase role="special">)</phrase>
15956 <phrase role="special">.</phrase><phrase role="identifier">old</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
15957 <phrase role="identifier">old_var</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">old_expr</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15958 <phrase role="special">...</phrase>
15959 <phrase role="special">}</phrase><phrase role="special">)</phrase>
15960 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">(</phrase><phrase role="identifier">t</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">result</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
15961 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15962 <phrase role="special">...</phrase>
15963 <phrase role="special">}</phrase><phrase role="special">)</phrase>
15964 <phrase role="special">.</phrase><phrase role="identifier">except</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
15965 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
15966 <phrase role="special">...</phrase>
15967 <phrase role="special">}</phrase><phrase role="special">)</phrase>
15968 <phrase role="special">;</phrase>
15970 <phrase role="special">...</phrase> <phrase role="comment">// Function body (use `return result = return_expr`).</phrase>
15971 <phrase role="special">}</phrase>
15973 <phrase role="special">...</phrase>
15974 <phrase role="special">}</phrase><phrase role="special">;</phrase>
15975 </programlisting></para><para>A virtual public function should always call <computeroutput><computeroutput><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput></computeroutput> otherwise this library will not be able to correctly use it for subcontracting.</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.tutorial.virtual_public_functions"> Virtual Public Functions</link></para>
15980 </para><variablelist spacing="compact"><?dbhtml
15981 list-presentation="table"
15982 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
15983 list-presentation="table"
15984 ?><varlistentry><term><computeroutput>obj</computeroutput></term><listitem><para>The object <computeroutput>this</computeroutput> from the scope of the enclosing virtual public function declaring the contract. This object might be mutable, <computeroutput>const</computeroutput>, <computeroutput>volatile</computeroutput>, or <computeroutput>const volatile</computeroutput> depending on the cv-qualifier of the enclosing function (volatile public functions will check volatile class invariants, see <link linkend="boost_contract.extras.volatile_public_functions">
15985 Volatile Public Functions</link>).</para></listitem></varlistentry><varlistentry><term><computeroutput>r</computeroutput></term><listitem><para>A reference to the return value of the enclosing virtual public function declaring the contract. This is usually a local variable declared by the enclosing virtual public function just before the contract, but programmers must set it to the actual value being returned by the function at each <computeroutput>return</computeroutput> statement. </para></listitem></varlistentry><varlistentry><term><computeroutput>v</computeroutput></term><listitem><para>The trailing parameter of type <computeroutput><computeroutput><link linkend="boost.contract.virtual_">boost::contract::virtual_</link></computeroutput></computeroutput><computeroutput>*</computeroutput> and default value <computeroutput>0</computeroutput> from the enclosing virtual public function. </para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Template Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
15986 list-presentation="table"
15987 ?><varlistentry><term><computeroutput>Class</computeroutput></term><listitem><para>The type of the class containing the virtual public function declaring the contract. (Usually this template parameter is automatically deduced by C++ and it does not need to be explicitly specified by programmers.)</para></listitem></varlistentry><varlistentry><term><computeroutput>VirtualResult</computeroutput></term><listitem><para>This type must be the same as, or compatible with, the return type of the enclosing virtual public function declaring the contract (this library might not be able to generate a compile-time error if these types mismatch, but in general that will cause run-time errors or undefined behaviour). Alternatively, <computeroutput>boost::optional<<emphasis>return-type</emphasis>></computeroutput> can also be used (see <link linkend="boost_contract.advanced.optional_return_values">
15988 Optional Return Values</link>). (Usually this template parameter is automatically deduced by C++ and it does not need to be explicitly specified by programmers.) </para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Returns:</term><listitem><para>The result of this function must be assigned to a variable of type <computeroutput><link linkend="boost.contract.check">boost::contract::check</link></computeroutput> declared explicitly (i.e., without using C++11 <computeroutput>auto</computeroutput> declarations) and locally just before the code of the public function body (otherwise this library will generate a run-time error, see <computeroutput><link linkend="BOOST_CO_idm45394999694064">BOOST_CONTRACT_ON_MISSING_CHECK_DECL</link></computeroutput>). </para></listitem></varlistentry></variablelist></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.public_f_idm45394998817488"><refmeta><refentrytitle>Function template public_function</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::public_function</refname><refpurpose>Program contracts for void public functions overrides (virtual or not). </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.public_function_hpp">boost/contract/public_function.hpp</link>>
15991 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> Override<phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> F<phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> Class<phrase role="special">,</phrase> <phrase role="keyword">typename</phrase><phrase role="special">...</phrase> Args<phrase role="special">></phrase>
15992 <link linkend="boost.contract.specify__idm45394999179040">specify_precondition_old_postcondition_except</link>
15993 <phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><link linkend="boost.contract.virtual_">virtual_</link> <phrase role="special">*</phrase> v<phrase role="special">,</phrase> <phrase role="identifier">F</phrase> f<phrase role="special">,</phrase> <phrase role="identifier">Class</phrase> <phrase role="special">*</phrase> obj<phrase role="special">,</phrase> <phrase role="identifier">Args</phrase> <phrase role="special">&</phrase><phrase role="special">...</phrase> args<phrase role="special">)</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This is used to specify preconditions, postconditions, exception guarantees, old value copies at body, and check class invariants for public function overrides (virtual or not) that return <computeroutput>void:</computeroutput> </para><para><programlisting><phrase role="keyword">class</phrase> <phrase role="identifier">u</phrase>
15994 <phrase role="preprocessor">#define</phrase> <phrase role="identifier">BASES</phrase> <phrase role="keyword">private</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor_precondition</phrase><phrase role="special"><</phrase><phrase role="identifier">u</phrase><phrase role="special">></phrase><phrase role="special">,</phrase> \
15995 <phrase role="keyword">public</phrase> <phrase role="identifier">b</phrase><phrase role="special">,</phrase> <phrase role="keyword">private</phrase> <phrase role="identifier">w</phrase>
15996 <phrase role="special">:</phrase> <phrase role="identifier">BASES</phrase>
15997 <phrase role="special">{</phrase>
15998 <phrase role="keyword">friend</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">access</phrase><phrase role="special">;</phrase>
16000 <phrase role="keyword">typedef</phrase> <phrase role="identifier">BOOST_CONTRACT_BASE_TYPES</phrase><phrase role="special">(</phrase><phrase role="identifier">BASES</phrase><phrase role="special">)</phrase> <phrase role="identifier">base_types</phrase><phrase role="special">;</phrase>
16001 <phrase role="preprocessor">#undef</phrase> <phrase role="identifier">BASES</phrase>
16003 <phrase role="keyword">void</phrase> <phrase role="identifier">invariant</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional (as for static and volatile).</phrase>
16004 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16005 <phrase role="special">...</phrase>
16006 <phrase role="special">}</phrase>
16008 <phrase role="identifier">BOOST_CONTRACT_OVERRIDES</phrase><phrase role="special">(</phrase><phrase role="identifier">f</phrase><phrase role="special">)</phrase>
16010 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
16011 <phrase role="comment">// Override from `b::f`.</phrase>
16012 <phrase role="keyword">void</phrase> <phrase role="identifier">f</phrase><phrase role="special">(</phrase><phrase role="identifier">t_1</phrase> <phrase role="identifier">a_1</phrase><phrase role="special">,</phrase> <phrase role="special">...</phrase><phrase role="special">,</phrase> <phrase role="identifier">t_n</phrase> <phrase role="identifier">a_n</phrase><phrase role="special">,</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
16013 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="identifier">old_type</phrase><phrase role="special">></phrase> <phrase role="identifier">old_var</phrase><phrase role="special">;</phrase>
16014 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special"><</phrase>
16015 <phrase role="identifier">override_f</phrase><phrase role="special">></phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="special">&</phrase><phrase role="identifier">u</phrase><phrase role="special">::</phrase><phrase role="identifier">f</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">,</phrase> <phrase role="identifier">a_1</phrase><phrase role="special">,</phrase> <phrase role="special">...</phrase><phrase role="special">,</phrase> <phrase role="identifier">a_n</phrase><phrase role="special">)</phrase>
16016 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
16017 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16018 <phrase role="special">...</phrase>
16019 <phrase role="special">}</phrase><phrase role="special">)</phrase>
16020 <phrase role="special">.</phrase><phrase role="identifier">old</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
16021 <phrase role="identifier">old_var</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">old_expr</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16022 <phrase role="special">...</phrase>
16023 <phrase role="special">}</phrase><phrase role="special">)</phrase>
16024 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
16025 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16026 <phrase role="special">...</phrase>
16027 <phrase role="special">}</phrase><phrase role="special">)</phrase>
16028 <phrase role="special">.</phrase><phrase role="identifier">except</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
16029 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16030 <phrase role="special">...</phrase>
16031 <phrase role="special">}</phrase><phrase role="special">)</phrase>
16032 <phrase role="special">;</phrase>
16034 <phrase role="special">...</phrase> <phrase role="comment">// Function body.</phrase>
16035 <phrase role="special">}</phrase>
16037 <phrase role="special">...</phrase>
16038 <phrase role="special">}</phrase><phrase role="special">;</phrase>
16039 </programlisting></para><para>A public function override should always call <computeroutput><computeroutput><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput></computeroutput> otherwise this library will not be able to correctly use it for subcontracting.</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.tutorial.public_function_overrides__subcontracting_">
16040 Public Function Overrides</link></para>
16045 </para><variablelist spacing="compact"><?dbhtml
16046 list-presentation="table"
16047 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
16048 list-presentation="table"
16049 ?><varlistentry><term><computeroutput>args</computeroutput></term><listitem><para>All arguments passed to the enclosing public function override declaring the contract (by reference and in the order they appear in the enclosing function declaration), but excluding the trailing argument <computeroutput>v</computeroutput>.</para></listitem></varlistentry><varlistentry><term><computeroutput>f</computeroutput></term><listitem><para>A pointer to the enclosing public function override declaring the contract (but see <link linkend="boost_contract.advanced.function_overloads">
16050 Function Overloads</link>). </para></listitem></varlistentry><varlistentry><term><computeroutput>obj</computeroutput></term><listitem><para>The object <computeroutput>this</computeroutput> from the scope of the enclosing public function override declaring the contract. This object might be mutable, <computeroutput>const</computeroutput>, <computeroutput>volatile</computeroutput>, or <computeroutput>const volatile</computeroutput> depending on the cv-qualifier of the enclosing function (volatile public functions will check volatile class invariants, see <link linkend="boost_contract.extras.volatile_public_functions">
16051 Volatile Public Functions</link>). </para></listitem></varlistentry><varlistentry><term><computeroutput>v</computeroutput></term><listitem><para>The trailing parameter of type <computeroutput><computeroutput><link linkend="boost.contract.virtual_">boost::contract::virtual_</link></computeroutput></computeroutput><computeroutput>*</computeroutput> and default value <computeroutput>0</computeroutput> from the enclosing public function override. </para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Template Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
16052 list-presentation="table"
16053 ?><varlistentry><term><computeroutput>Args</computeroutput></term><listitem><para>The types of all parameters passed to the enclosing public function override declaring the contract, but excluding the trailing parameter type <computeroutput><computeroutput><link linkend="boost.contract.virtual_">boost::contract::virtual_</link></computeroutput>*</computeroutput>. On compilers that do not support variadic templates, this library internally implements this function using preprocessor meta-programming (in this case, the maximum number of supported arguments is defined by <computeroutput><computeroutput><link linkend="BOOST_CONTRACT_MAX_ARGS">BOOST_CONTRACT_MAX_ARGS</link></computeroutput></computeroutput>). (Usually these template parameters are automatically deduced by C++ and they do not need to be explicitly specified by programmers.)</para></listitem></varlistentry><varlistentry><term><computeroutput>Class</computeroutput></term><listitem><para>The type of the class containing the virtual public function declaring the contract. (Usually this template parameter is automatically deduced by C++ and it does not need to be explicitly specified by programmers.) </para></listitem></varlistentry><varlistentry><term><computeroutput>F</computeroutput></term><listitem><para>The function pointer type of the enclosing public function override declaring the contract. (Usually this template parameter is automatically deduced by C++ and it does not need to be explicitly specified by programmers.) </para></listitem></varlistentry><varlistentry><term><computeroutput>Override</computeroutput></term><listitem><para>The type trait <computeroutput>override_<emphasis>function-name</emphasis></computeroutput> declared using the <computeroutput><computeroutput><link linkend="BOOST_CONTRACT_OVERRIDE">BOOST_CONTRACT_OVERRIDE</link></computeroutput></computeroutput> or related macros. This template parameter must be explicitly specified (because there is no function argument from which it can be automatically deduced by C++). </para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Returns:</term><listitem><para>The result of this function must be assigned to a variable of type <computeroutput><link linkend="boost.contract.check">boost::contract::check</link></computeroutput> declared explicitly (i.e., without using C++11 <computeroutput>auto</computeroutput> declarations) and locally just before the code of the public function body (otherwise this library will generate a run-time error, see <computeroutput><link linkend="BOOST_CO_idm45394999694064">BOOST_CONTRACT_ON_MISSING_CHECK_DECL</link></computeroutput>). </para></listitem></varlistentry></variablelist></refsect1></refentry><refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="boost.contract.public_f_idm45394998787360"><refmeta><refentrytitle>Function template public_function</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>boost::contract::public_function</refname><refpurpose>Program contracts for non-void public functions overrides (virtual or not). </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract.public_function_hpp">boost/contract/public_function.hpp</link>>
16056 <phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> Override<phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> VirtualResult<phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> F<phrase role="special">,</phrase>
16057 <phrase role="keyword">typename</phrase> Class<phrase role="special">,</phrase> <phrase role="keyword">typename</phrase><phrase role="special">...</phrase> Args<phrase role="special">></phrase>
16058 <link linkend="boost.contract.specify__idm45394999179040">specify_precondition_old_postcondition_except</link><phrase role="special"><</phrase> <phrase role="identifier">VirtualResult</phrase> <phrase role="special">></phrase>
16059 <phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><link linkend="boost.contract.virtual_">virtual_</link> <phrase role="special">*</phrase> v<phrase role="special">,</phrase> <phrase role="identifier">VirtualResult</phrase> <phrase role="special">&</phrase> r<phrase role="special">,</phrase> <phrase role="identifier">F</phrase> f<phrase role="special">,</phrase> <phrase role="identifier">Class</phrase> <phrase role="special">*</phrase> obj<phrase role="special">,</phrase>
16060 <phrase role="identifier">Args</phrase> <phrase role="special">&</phrase><phrase role="special">...</phrase> args<phrase role="special">)</phrase><phrase role="special">;</phrase></synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This is used to specify preconditions, postconditions, exception guarantees, old value copies at body, and check class invariants for public function overrides (virtual or not) that do not return <computeroutput>void:</computeroutput> </para><para><programlisting><phrase role="keyword">class</phrase> <phrase role="identifier">u</phrase>
16061 <phrase role="preprocessor">#define</phrase> <phrase role="identifier">BASES</phrase> <phrase role="keyword">private</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor_precondition</phrase><phrase role="special"><</phrase><phrase role="identifier">u</phrase><phrase role="special">></phrase><phrase role="special">,</phrase> \
16062 <phrase role="keyword">public</phrase> <phrase role="identifier">b</phrase><phrase role="special">,</phrase> <phrase role="keyword">private</phrase> <phrase role="identifier">w</phrase>
16063 <phrase role="special">:</phrase> <phrase role="identifier">BASES</phrase>
16064 <phrase role="special">{</phrase>
16065 <phrase role="keyword">friend</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">access</phrase><phrase role="special">;</phrase>
16067 <phrase role="keyword">typedef</phrase> <phrase role="identifier">BOOST_CONTRACT_BASE_TYPES</phrase><phrase role="special">(</phrase><phrase role="identifier">BASES</phrase><phrase role="special">)</phrase> <phrase role="identifier">base_types</phrase><phrase role="special">;</phrase>
16068 <phrase role="preprocessor">#undef</phrase> <phrase role="identifier">BASES</phrase>
16070 <phrase role="keyword">void</phrase> <phrase role="identifier">invariant</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional (as for static and volatile).</phrase>
16071 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16072 <phrase role="special">...</phrase>
16073 <phrase role="special">}</phrase>
16075 <phrase role="identifier">BOOST_CONTRACT_OVERRIDES</phrase><phrase role="special">(</phrase><phrase role="identifier">f</phrase><phrase role="special">)</phrase>
16077 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
16078 <phrase role="comment">// Override from `b::f`.</phrase>
16079 <phrase role="identifier">t</phrase> <phrase role="identifier">f</phrase><phrase role="special">(</phrase><phrase role="identifier">t_1</phrase> <phrase role="identifier">a_1</phrase><phrase role="special">,</phrase> <phrase role="special">...</phrase><phrase role="special">,</phrase> <phrase role="identifier">t_n</phrase> <phrase role="identifier">a_n</phrase><phrase role="special">,</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
16080 <phrase role="identifier">t</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
16081 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="identifier">old_type</phrase><phrase role="special">></phrase> <phrase role="identifier">old_var</phrase><phrase role="special">;</phrase>
16082 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">c</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special"><</phrase>
16083 <phrase role="identifier">override_f</phrase><phrase role="special">></phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">result</phrase><phrase role="special">,</phrase> <phrase role="special">&</phrase><phrase role="identifier">u</phrase><phrase role="special">::</phrase><phrase role="identifier">f</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">,</phrase> <phrase role="identifier">a_1</phrase><phrase role="special">,</phrase> <phrase role="special">...</phrase><phrase role="special">,</phrase> <phrase role="identifier">a_n</phrase><phrase role="special">)</phrase>
16084 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
16085 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16086 <phrase role="special">...</phrase>
16087 <phrase role="special">}</phrase><phrase role="special">)</phrase>
16088 <phrase role="special">.</phrase><phrase role="identifier">old</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
16089 <phrase role="identifier">old_var</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">old_expr</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16090 <phrase role="special">...</phrase>
16091 <phrase role="special">}</phrase><phrase role="special">)</phrase>
16092 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">(</phrase><phrase role="identifier">t</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">result</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
16093 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16094 <phrase role="special">...</phrase>
16095 <phrase role="special">}</phrase><phrase role="special">)</phrase>
16096 <phrase role="special">.</phrase><phrase role="identifier">except</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
16097 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16098 <phrase role="special">...</phrase>
16099 <phrase role="special">}</phrase><phrase role="special">)</phrase>
16100 <phrase role="special">;</phrase>
16102 <phrase role="special">...</phrase> <phrase role="comment">// Function body (use `return result = return_expr`).</phrase>
16103 <phrase role="special">}</phrase>
16105 <phrase role="special">...</phrase>
16106 <phrase role="special">}</phrase><phrase role="special">;</phrase>
16107 </programlisting></para><para>A public function override should always call <computeroutput><computeroutput><link linkend="boost.contract.public_f_idm45394998885120">boost::contract::public_function</link></computeroutput></computeroutput> otherwise this library will not be able to correctly use it for subcontracting.</para><para><para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.tutorial.public_function_overrides__subcontracting_">
16108 Public Function Overrides</link></para>
16113 </para><variablelist spacing="compact"><?dbhtml
16114 list-presentation="table"
16115 ?><varlistentry><term>Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
16116 list-presentation="table"
16117 ?><varlistentry><term><computeroutput>args</computeroutput></term><listitem><para>All arguments passed to the enclosing public function override declaring the contract (by reference and in the order they appear in the enclosing function declaration), but excluding the trailing argument <computeroutput>v</computeroutput>.</para></listitem></varlistentry><varlistentry><term><computeroutput>f</computeroutput></term><listitem><para>A pointer to the enclosing public function override declaring the contract (but see <link linkend="boost_contract.advanced.function_overloads">
16118 Function Overloads</link>). </para></listitem></varlistentry><varlistentry><term><computeroutput>obj</computeroutput></term><listitem><para>The object <computeroutput>this</computeroutput> from the scope of the enclosing public function override declaring the contract. This object might be mutable, <computeroutput>const</computeroutput>, <computeroutput>volatile</computeroutput>, or <computeroutput>const volatile</computeroutput> depending on the cv-qualifier of the enclosing function (volatile public functions will check volatile class invariants, see <link linkend="boost_contract.extras.volatile_public_functions">
16119 Volatile Public Functions</link>). </para></listitem></varlistentry><varlistentry><term><computeroutput>r</computeroutput></term><listitem><para>A reference to the return value of the enclosing public function override declaring the contract. This is usually a local variable declared by the enclosing public function override just before the contract, but programmers must set it to the actual value being returned by the function at each <computeroutput>return</computeroutput> statement. </para></listitem></varlistentry><varlistentry><term><computeroutput>v</computeroutput></term><listitem><para>The trailing parameter of type <computeroutput><computeroutput><link linkend="boost.contract.virtual_">boost::contract::virtual_</link></computeroutput></computeroutput><computeroutput>*</computeroutput> and default value <computeroutput>0</computeroutput> from the enclosing public function override. </para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Template Parameters:</term><listitem><variablelist spacing="compact"><?dbhtml
16120 list-presentation="table"
16121 ?><varlistentry><term><computeroutput>Args</computeroutput></term><listitem><para>The types of all parameters passed to the enclosing public function override declaring the contract, but excluding the trailing parameter type <computeroutput><computeroutput><link linkend="boost.contract.virtual_">boost::contract::virtual_</link></computeroutput>*</computeroutput>. On compilers that do not support variadic templates, this library internally implements this function using preprocessor meta-programming (in this case, the maximum number of supported arguments is defined by <computeroutput><computeroutput><link linkend="BOOST_CONTRACT_MAX_ARGS">BOOST_CONTRACT_MAX_ARGS</link></computeroutput></computeroutput>). (Usually these template parameters are automatically deduced by C++ and they do not need to be explicitly specified by programmers.)</para></listitem></varlistentry><varlistentry><term><computeroutput>Class</computeroutput></term><listitem><para>The type of the class containing the virtual public function declaring the contract. (Usually this template parameter is automatically deduced by C++ and it does not need to be explicitly specified by programmers.) </para></listitem></varlistentry><varlistentry><term><computeroutput>F</computeroutput></term><listitem><para>The function pointer type of the enclosing public function override declaring the contract. (Usually this template parameter is automatically deduced by C++ and it does not need to be explicitly specified by programmers.) </para></listitem></varlistentry><varlistentry><term><computeroutput>Override</computeroutput></term><listitem><para>The type trait <computeroutput>override_<emphasis>function-name</emphasis></computeroutput> declared using the <computeroutput><computeroutput><link linkend="BOOST_CONTRACT_OVERRIDE">BOOST_CONTRACT_OVERRIDE</link></computeroutput></computeroutput> or related macros. This template parameter must be explicitly specified (because there is no function argument from which it can be automatically deduced by C++). </para></listitem></varlistentry><varlistentry><term><computeroutput>VirtualResult</computeroutput></term><listitem><para>This type must be the same as, or compatible with, the return type of the enclosing public function override declaring the contract (this library might not be able to generate a compile-time error if these types mismatch, but in general that will cause run-time errors or undefined behaviour). Alternatively, <computeroutput>boost::optional<<emphasis>return-type</emphasis>></computeroutput> can also be used (see <link linkend="boost_contract.advanced.optional_return_values">
16122 Optional Return Values</link>). (Usually this template parameter is automatically deduced by C++ and it does not need to be explicitly specified by programmers.) </para></listitem></varlistentry></variablelist></listitem></varlistentry><varlistentry><term>Returns:</term><listitem><para>The result of this function must be assigned to a variable of type <computeroutput><link linkend="boost.contract.check">boost::contract::check</link></computeroutput> declared explicitly (i.e., without using C++11 <computeroutput>auto</computeroutput> declarations) and locally just before the code of the public function body (otherwise this library will generate a run-time error, see <computeroutput><link linkend="BOOST_CO_idm45394999694064">BOOST_CONTRACT_ON_MISSING_CHECK_DECL</link></computeroutput>). </para></listitem></varlistentry></variablelist></refsect1></refentry>
16124 <section id="header.boost.contract_macro_hpp"><title>Header <<ulink url="../../../../boost/contract_macro.hpp">boost/contract_macro.hpp</ulink>></title><para>Allow to disable contracts to completely remove their compile-time and run-time overhead. </para><para>This header automatically includes all header files <computeroutput>boost/contract/*.hpp</computeroutput> necessary to use its macros.</para><para>Almost all the macros defined in this header file are variadic macros. On compilers that do not support variadic macros, programmers can manually code <computeroutput>#ifndef BOOST_CONTRACT_NO_...</computeroutput> statements instead (see <link linkend="boost_contract.extras.disable_contract_compilation__macro_interface_">
16125 Disable Contract Compilation</link>). </para><synopsis xmlns:xi="http://www.w3.org/2001/XInclude">
16127 <link linkend="BOOST_CO_idm45394998748208">BOOST_CONTRACT_PRECONDITION</link>(...)
16128 <link linkend="BOOST_CO_idm45394998736528">BOOST_CONTRACT_POSTCONDITION</link>(...)
16129 <link linkend="BOOST_CONTRACT_EXCEPT">BOOST_CONTRACT_EXCEPT</link>(...)
16130 <link linkend="BOOST_CONTRACT_OLD">BOOST_CONTRACT_OLD</link>(...)
16131 <link linkend="BOOST_CONTRACT_OLD_PTR">BOOST_CONTRACT_OLD_PTR</link>(...)
16132 <link linkend="BOOST_CO_idm45394998674080">BOOST_CONTRACT_OLD_PTR_IF_COPYABLE</link>(...)
16133 <link linkend="BOOST_CONTRACT_INVARIANT">BOOST_CONTRACT_INVARIANT</link>(...)
16134 <link linkend="BOOST_CO_idm45394998635328">BOOST_CONTRACT_INVARIANT_VOLATILE</link>(...)
16135 <link linkend="BOOST_CO_idm45394998621472">BOOST_CONTRACT_STATIC_INVARIANT</link>(...)
16136 <link linkend="BOOST_CONTRACT_CONSTRUCTOR">BOOST_CONTRACT_CONSTRUCTOR</link>(...)
16137 <link linkend="BOOST_CO_idm45394998587680">BOOST_CONTRACT_CONSTRUCTOR_PRECONDITION</link>(...)
16138 <link linkend="BOOST_CONTRACT_DESTRUCTOR">BOOST_CONTRACT_DESTRUCTOR</link>(...)
16139 <link linkend="BOOST_CONTRACT_FUNCTION">BOOST_CONTRACT_FUNCTION</link>()
16140 <link linkend="BOOST_CO_idm45394998534992">BOOST_CONTRACT_STATIC_PUBLIC_FUNCTION</link>(...)
16141 <link linkend="BOOST_CO_idm45394998517984">BOOST_CONTRACT_PUBLIC_FUNCTION</link>(...)
16142 <link linkend="BOOST_CO_idm45394998486064">BOOST_CONTRACT_PUBLIC_FUNCTION_OVERRIDE</link>(...)</synopsis>
16143 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CO_idm45394998748208"><refmeta><refentrytitle>Macro BOOST_CONTRACT_PRECONDITION</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_PRECONDITION</refname><refpurpose>Program preconditions that can be completely disabled at compile-time. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract_macro_hpp">boost/contract_macro.hpp</link>>
16145 </phrase>BOOST_CONTRACT_PRECONDITION(...)</synopsis></refsynopsisdiv><refsect1><title>Description</title><para><computeroutput>BOOST_CONTRACT_PRECONDITION(f)</computeroutput> expands to code equivalent to the following (note that no code is generated when <computeroutput><link linkend="BOOST_CO_idm45394999662416">BOOST_CONTRACT_NO_PRECONDITIONS</link></computeroutput> is defined):</para><para><programlisting><phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_PRECONDITIONS</phrase>
16146 <phrase role="special">.</phrase><phrase role="identifier">precondition</phrase><phrase role="special">(</phrase><phrase role="identifier">f</phrase><phrase role="special">)</phrase>
16147 <phrase role="preprocessor">#endif</phrase>
16148 </programlisting></para><para>Where:</para><para><itemizedlist>
16149 <listitem><para><computeroutput><emphasis role="bold">f</emphasis></computeroutput> is the nullay functor called by this library to check preconditions <computeroutput>f()</computeroutput>. Assertions within this functor are usually programmed using <computeroutput><link linkend="BOOST_CONTRACT_ASSERT">BOOST_CONTRACT_ASSERT</link></computeroutput>, but any exception thrown by a call to this functor indicates a contract assertion failure (and will result in this library calling <computeroutput><link linkend="boost.contract.precondition_failure">boost::contract::precondition_failure</link></computeroutput>). This functor should capture variables by (constant) value, or better by (constant) reference (to avoid extra copies). (This is a variadic macro parameter so it can contain commas not protected by round parenthesis.)</para>
16152 <para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.extras.disable_contract_compilation__macro_interface_">
16153 Disable Contract Compilation</link>, <link linkend="boost_contract.tutorial.preconditions"> Preconditions</link> </para>
16155 </para></refsect1></refentry>
16156 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CO_idm45394998736528"><refmeta><refentrytitle>Macro BOOST_CONTRACT_POSTCONDITION</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_POSTCONDITION</refname><refpurpose>Program postconditions that can be completely disabled at compile-time. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract_macro_hpp">boost/contract_macro.hpp</link>>
16158 </phrase>BOOST_CONTRACT_POSTCONDITION(...)</synopsis></refsynopsisdiv><refsect1><title>Description</title><para><computeroutput>BOOST_CONTRACT_POSTCONDITION(f)</computeroutput> expands to code equivalent to the following (note that no code is generated when <computeroutput><link linkend="BOOST_CO_idm45394999656032">BOOST_CONTRACT_NO_POSTCONDITIONS</link></computeroutput> is defined):</para><para><programlisting><phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_POSTCONDITIONS</phrase>
16159 <phrase role="special">.</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">(</phrase><phrase role="identifier">f</phrase><phrase role="special">)</phrase>
16160 <phrase role="preprocessor">#endif</phrase>
16161 </programlisting></para><para>Where:</para><para><itemizedlist>
16162 <listitem><para><computeroutput><emphasis role="bold">f</emphasis></computeroutput> is the functor called by this library to check postconditions <computeroutput>f()</computeroutput> or <computeroutput>f(result)</computeroutput>. Assertions within this functor are usually programmed using <computeroutput><link linkend="BOOST_CONTRACT_ASSERT">BOOST_CONTRACT_ASSERT</link></computeroutput>, but any exception thrown by a call to this functor indicates a contract assertion failure (and will result in this library calling <computeroutput><link linkend="boost.contract.postcondition_failure">boost::contract::postcondition_failure</link></computeroutput>). This functor should capture variables by (constant) references (to access the values they will have at function exit). This functor takes the return value (preferably by <computeroutput>const&</computeroutput>) <computeroutput>result</computeroutput> as its one single parameter <computeroutput>f(result)</computeroutput> but only for virtual public functions and public functions overrides, otherwise it takes no parameter <computeroutput>f()</computeroutput>. (This is a variadic macro parameter so it can contain commas not protected by round parenthesis.)</para>
16165 <para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.extras.disable_contract_compilation__macro_interface_">
16166 Disable Contract Compilation</link>, <link linkend="boost_contract.tutorial.postconditions"> Postconditions</link> </para>
16168 </para></refsect1></refentry>
16169 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CONTRACT_EXCEPT"><refmeta><refentrytitle>Macro BOOST_CONTRACT_EXCEPT</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_EXCEPT</refname><refpurpose>Program exception guarantees that can be completely disabled at compile-time. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract_macro_hpp">boost/contract_macro.hpp</link>>
16171 </phrase>BOOST_CONTRACT_EXCEPT(...)</synopsis></refsynopsisdiv><refsect1><title>Description</title><para><computeroutput>BOOST_CONTRACT_EXCEPT(f)</computeroutput> expands to code equivalent to the following (note that no code is generated when <computeroutput><link linkend="BOOST_CONTRACT_NO_EXCEPTS">BOOST_CONTRACT_NO_EXCEPTS</link></computeroutput> is defined):</para><para><programlisting><phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_EXCEPTS</phrase>
16172 <phrase role="special">.</phrase><phrase role="identifier">except</phrase><phrase role="special">(</phrase><phrase role="identifier">f</phrase><phrase role="special">)</phrase>
16173 <phrase role="preprocessor">#endif</phrase>
16174 </programlisting></para><para>Where:</para><para><itemizedlist>
16175 <listitem><para><computeroutput><emphasis role="bold">f</emphasis></computeroutput> is the nullary functor called by this library to check exception guarantees <computeroutput>f()</computeroutput>. Assertions within this functor are usually programmed using <computeroutput><link linkend="BOOST_CONTRACT_ASSERT">BOOST_CONTRACT_ASSERT</link></computeroutput>, but any exception thrown by a call to this functor indicates a contract assertion failure (and will result in this library calling <computeroutput><link linkend="boost.contract.except_failure">boost::contract::except_failure</link></computeroutput>). This functor should capture variables by (constant) references (to access the values they will have at function exit). (This is a variadic macro parameter so it can contain commas not protected by round parenthesis.)</para>
16178 <para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.extras.disable_contract_compilation__macro_interface_">
16179 Disable Contract Compilation</link>, <link linkend="boost_contract.tutorial.exception_guarantees"> Exception Guarantees</link> </para>
16181 </para></refsect1></refentry>
16182 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CONTRACT_OLD"><refmeta><refentrytitle>Macro BOOST_CONTRACT_OLD</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_OLD</refname><refpurpose>Program old value copies at body that can be completely disabled at compile-time. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract_macro_hpp">boost/contract_macro.hpp</link>>
16184 </phrase>BOOST_CONTRACT_OLD(...)</synopsis></refsynopsisdiv><refsect1><title>Description</title><para><computeroutput>BOOST_CONTRACT_OLD(f)</computeroutput> expands to code equivalent to the following (note that no code is generated when <computeroutput><link linkend="BOOST_CONTRACT_NO_OLDS">BOOST_CONTRACT_NO_OLDS</link></computeroutput> is defined):</para><para><programlisting><phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_OLDS</phrase>
16185 <phrase role="special">.</phrase><phrase role="identifier">old</phrase><phrase role="special">(</phrase><phrase role="identifier">f</phrase><phrase role="special">)</phrase>
16186 <phrase role="preprocessor">#endif</phrase>
16187 </programlisting></para><para>Where:</para><para><itemizedlist>
16188 <listitem><para><computeroutput><emphasis role="bold">f</emphasis></computeroutput> is the nullary functor called by this library <computeroutput>f()</computeroutput> to assign old value copies just before the body is execute but after entry invariants (when they apply) and preconditions are checked. Old value pointers within this functor call are usually assigned using <computeroutput><link linkend="BOOST_CONTRACT_OLDOF">BOOST_CONTRACT_OLDOF</link></computeroutput>. Any exception thrown by a call to this functor will result in this library calling <computeroutput><link linkend="boost.contract.old_failure">boost::contract::old_failure</link></computeroutput> (because old values could not be copied to check postconditions and exception guarantees). This functor should capture old value pointers by references so they can be assigned (all other variables needed to evaluate old value expressions can be captured by (constant) value, or better by (constant) reference to avoid extra copies). (This is a variadic macro parameter so it can contain commas not protected by round parenthesis.)</para>
16191 <para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.extras.disable_contract_compilation__macro_interface_">
16192 Disable Contract Compilation</link>, <link linkend="boost_contract.advanced.old_values_copied_at_body">
16193 Old Values Copied at Body</link> </para>
16195 </para></refsect1></refentry>
16196 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CONTRACT_OLD_PTR"><refmeta><refentrytitle>Macro BOOST_CONTRACT_OLD_PTR</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_OLD_PTR</refname><refpurpose>Program old values that can be completely disabled at compile-time for old value types that are required to be copyable. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract_macro_hpp">boost/contract_macro.hpp</link>>
16198 </phrase>BOOST_CONTRACT_OLD_PTR(...)</synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This is used to program old value copies for copyable types:</para><para><programlisting><phrase role="keyword">class</phrase> <phrase role="identifier">u</phrase> <phrase role="special">{</phrase>
16199 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
16200 <phrase role="keyword">void</phrase> <phrase role="identifier">f</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
16201 <phrase role="identifier">BOOST_CONTRACT_OLD_PTR</phrase><phrase role="special">(</phrase><phrase role="identifier">old_type_a</phrase><phrase role="special">)</phrase><phrase role="special">(</phrase><phrase role="identifier">old_var_a</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase> <phrase role="comment">// Null...</phrase>
16202 <phrase role="identifier">BOOST_CONTRACT_OLD_PTR</phrase><phrase role="special">(</phrase><phrase role="identifier">old_type_b</phrase><phrase role="special">)</phrase><phrase role="special">(</phrase><phrase role="identifier">old_var_b</phrase><phrase role="special">,</phrase> <phrase role="identifier">old_expr_b</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase> <phrase role="comment">// Set.</phrase>
16203 <phrase role="identifier">BOOST_CONTRACT_PUBLIC_FUNCTION</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
16204 <phrase role="special">...</phrase>
16205 <phrase role="identifier">BOOST_CONTRACT_OLD</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase>
16206 <phrase role="identifier">old_var_a</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">old_expr_a</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase> <phrase role="comment">// ...set.</phrase>
16207 <phrase role="special">...</phrase>
16208 <phrase role="special">}</phrase><phrase role="special">)</phrase>
16209 <phrase role="special">...</phrase>
16210 <phrase role="special">;</phrase>
16212 <phrase role="special">...</phrase> <phrase role="comment">// Function body.</phrase>
16213 <phrase role="special">}</phrase>
16215 <phrase role="keyword">virtual</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">g</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">,</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
16216 <phrase role="identifier">BOOST_CONTRACT_OLD_PTR</phrase><phrase role="special">(</phrase><phrase role="identifier">old_type_a</phrase><phrase role="special">)</phrase><phrase role="special">(</phrase><phrase role="identifier">old_var_a</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase> <phrase role="comment">// No `v`</phrase>
16217 <phrase role="identifier">BOOST_CONTRACT_OLD_PTR</phrase><phrase role="special">(</phrase><phrase role="identifier">old_type_b</phrase><phrase role="special">)</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">old_var_b</phrase><phrase role="special">,</phrase> <phrase role="identifier">old_expr_b</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase> <phrase role="comment">// `v`</phrase>
16218 <phrase role="identifier">BOOST_CONTRACT_PUBLIC_FUNCTION</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">)</phrase>
16219 <phrase role="special">...</phrase>
16220 <phrase role="identifier">BOOST_CONTRACT_OLD</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase>
16221 <phrase role="identifier">old_var_a</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">old_expr_a</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase> <phrase role="comment">// `v`</phrase>
16222 <phrase role="special">...</phrase>
16223 <phrase role="special">}</phrase><phrase role="special">)</phrase>
16224 <phrase role="special">...</phrase>
16225 <phrase role="special">;</phrase>
16227 <phrase role="special">...</phrase> <phrase role="comment">// Function body.</phrase>
16228 <phrase role="special">}</phrase>
16230 <phrase role="special">...</phrase>
16231 <phrase role="special">}</phrase><phrase role="special">;</phrase>
16232 </programlisting></para><para>This is an overloaded variadic macro and it can be used in the following different ways (note that no code is generated when <computeroutput><link linkend="BOOST_CONTRACT_NO_OLDS">BOOST_CONTRACT_NO_OLDS</link></computeroutput> is defined).</para><para>1. <computeroutput>BOOST_CONTRACT_OLD_PTR(old_type)(old_var)</computeroutput> expands to code equivalent to the following (this leaves the old value pointer null):</para><para><programlisting><phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_OLDS</phrase>
16233 <phrase role="comment">// This declaration does not need to use `v`.</phrase>
16234 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="identifier">old_type</phrase><phrase role="special">></phrase> <phrase role="identifier">old_var</phrase>
16235 <phrase role="preprocessor">#endif</phrase>
16236 </programlisting></para><para>2. <computeroutput>BOOST_CONTRACT_OLD_PTR(old_type)(old_var, old_expr)</computeroutput> expands to code equivalent to the following (this initializes the pointer to the old value copy, but not to be used for virtual public functions and public function overrides):</para><para><programlisting><phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_OLDS</phrase>
16237 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="identifier">old_type</phrase><phrase role="special">></phrase> <phrase role="identifier">old_var</phrase> <phrase role="special">=</phrase>
16238 <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">old_expr</phrase><phrase role="special">)</phrase>
16239 <phrase role="preprocessor">#endif</phrase>
16240 </programlisting></para><para>3. <computeroutput>BOOST_CONTRACT_OLD_PTR(old_type)(v, old_var, old_expr)</computeroutput> expands to code equivalent to the following (this initializes the pointer to the old value copy for virtual public functions and public function overrides):</para><para><programlisting><phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_OLDS</phrase>
16241 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr</phrase><phrase role="special"><</phrase><phrase role="identifier">old_type</phrase><phrase role="special">></phrase> <phrase role="identifier">old_var</phrase> <phrase role="special">=</phrase>
16242 <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">old_expr</phrase><phrase role="special">)</phrase>
16243 <phrase role="preprocessor">#endif</phrase>
16244 </programlisting></para><para>Where:</para><para><itemizedlist>
16245 <listitem><para><computeroutput><emphasis role="bold">old_type</emphasis></computeroutput> is the type of the pointed old value. This type must be copyable (i.e., <computeroutput>boost::contract::is_old_value_copyable<old_type>::value</computeroutput> is <computeroutput>true</computeroutput>), otherwise this pointer will always be null and this library will generate a compile-time error when the pointer is dereferenced (see <computeroutput><link linkend="BOOST_CO_idm45394998674080">BOOST_CONTRACT_OLD_PTR_IF_COPYABLE</link></computeroutput>). (This is a variadic macro parameter so it can contain commas not protected by round parenthesis.) (Rationale: Template parameters like this one are specified to this library macro interface using their own set of parenthesis <computeroutput>SOME_MACRO(template_params)(other_params)</computeroutput>.) </para>
16247 <listitem><para><computeroutput><emphasis role="bold">v</emphasis></computeroutput> is the extra training parameter of type <computeroutput><link linkend="boost.contract.virtual_">boost::contract::virtual_</link></computeroutput><computeroutput>*</computeroutput> and default value <computeroutput>0</computeroutput> from the enclosing virtual public function or public function override declaring the contract. (This is not a variadic macro parameter but it should never contain commas because it is an identifier.) </para>
16249 <listitem><para><computeroutput><emphasis role="bold">old_var</emphasis></computeroutput> is the name of the old value pointer variable. (This is not a variadic macro parameter but it should never contain commas because it is an identifier.) </para>
16251 <listitem><para><computeroutput><emphasis role="bold">old_expr</emphasis></computeroutput> is the expression to be evaluated and copied in the old value pointer. (This is not a variadic macro parameter so any comma it might contain must be protected by round parenthesis and <computeroutput>BOOST_CONTRACT_OLD_PTR(old_type)(v, old_var, (old_expr))</computeroutput> will always work.)</para>
16254 <para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.extras.disable_contract_compilation__macro_interface_">
16255 Disable Contract Compilation</link>, <link linkend="boost_contract.tutorial.old_values"> Old Values</link> </para>
16257 </para></refsect1></refentry>
16258 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CO_idm45394998674080"><refmeta><refentrytitle>Macro BOOST_CONTRACT_OLD_PTR_IF_COPYABLE</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_OLD_PTR_IF_COPYABLE</refname><refpurpose>Program old values that can be completely disabled at compile-time for old value types that are not required to be copyable. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract_macro_hpp">boost/contract_macro.hpp</link>>
16260 </phrase>BOOST_CONTRACT_OLD_PTR_IF_COPYABLE(...)</synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This is used to program old value copies for types that might or might not be copyable:</para><para><programlisting><phrase role="keyword">template</phrase><phrase role="special"><</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">></phrase> <phrase role="comment">// Type `T` might or not be copyable.</phrase>
16261 <phrase role="keyword">class</phrase> <phrase role="identifier">u</phrase> <phrase role="special">{</phrase>
16262 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
16263 <phrase role="keyword">void</phrase> <phrase role="identifier">f</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
16264 <phrase role="identifier">BOOST_CONTRACT_OLD_PTR_IF_COPYABLE</phrase><phrase role="special">(</phrase><phrase role="identifier">old_type_a</phrase><phrase role="special">)</phrase><phrase role="special">(</phrase><phrase role="identifier">old_var_a</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16265 <phrase role="identifier">BOOST_CONTRACT_OLD_PTR_IF_COPYABLE</phrase><phrase role="special">(</phrase><phrase role="identifier">old_type_b</phrase><phrase role="special">)</phrase><phrase role="special">(</phrase><phrase role="identifier">old_var_b</phrase><phrase role="special">,</phrase>
16266 <phrase role="identifier">old_expr_b</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16267 <phrase role="identifier">BOOST_CONTRACT_PUBLIC_FUNCTION</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
16268 <phrase role="special">...</phrase>
16269 <phrase role="identifier">BOOST_CONTRACT_OLD</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase>
16270 <phrase role="identifier">old_var_a</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">old_expr_a</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16271 <phrase role="special">...</phrase>
16272 <phrase role="special">}</phrase><phrase role="special">)</phrase>
16273 <phrase role="special">...</phrase> <phrase role="comment">// In postconditions or exception guarantees:</phrase>
16274 <phrase role="keyword">if</phrase><phrase role="special">(</phrase><phrase role="identifier">old_var_a</phrase><phrase role="special">)</phrase> <phrase role="special">...</phrase> <phrase role="comment">// Always null for non-copyable types.</phrase>
16275 <phrase role="keyword">if</phrase><phrase role="special">(</phrase><phrase role="identifier">old_var_b</phrase><phrase role="special">)</phrase> <phrase role="special">...</phrase> <phrase role="comment">// Always null for non-copyable types.</phrase>
16276 <phrase role="special">...</phrase>
16277 <phrase role="special">;</phrase>
16279 <phrase role="special">...</phrase> <phrase role="comment">// Function body.</phrase>
16280 <phrase role="special">}</phrase>
16282 <phrase role="keyword">virtual</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">g</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">,</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
16283 <phrase role="identifier">BOOST_CONTRACT_OLD_PTR_IF_COPYABLE</phrase><phrase role="special">(</phrase><phrase role="identifier">old_type_a</phrase><phrase role="special">)</phrase><phrase role="special">(</phrase><phrase role="identifier">old_var_a</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16284 <phrase role="identifier">BOOST_CONTRACT_OLD_PTR_IF_COPYABLE</phrase><phrase role="special">(</phrase><phrase role="identifier">old_type_b</phrase><phrase role="special">)</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">old_var_b</phrase><phrase role="special">,</phrase>
16285 <phrase role="identifier">old_expr_b</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16286 <phrase role="identifier">BOOST_CONTRACT_PUBLIC_FUNCTION</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">)</phrase>
16287 <phrase role="special">...</phrase>
16288 <phrase role="identifier">BOOST_CONTRACT_OLD</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase>
16289 <phrase role="identifier">old_var_a</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">old_expr_a</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16290 <phrase role="special">...</phrase>
16291 <phrase role="special">}</phrase><phrase role="special">)</phrase>
16292 <phrase role="special">...</phrase> <phrase role="comment">// In postconditions or exception guarantees:</phrase>
16293 <phrase role="keyword">if</phrase><phrase role="special">(</phrase><phrase role="identifier">old_var_a</phrase><phrase role="special">)</phrase> <phrase role="special">...</phrase> <phrase role="comment">// Always null for non-copyable types.</phrase>
16294 <phrase role="keyword">if</phrase><phrase role="special">(</phrase><phrase role="identifier">old_var_b</phrase><phrase role="special">)</phrase> <phrase role="special">...</phrase> <phrase role="comment">// Always null for non-copyable types.</phrase>
16295 <phrase role="special">...</phrase>
16296 <phrase role="special">;</phrase>
16298 <phrase role="special">...</phrase> <phrase role="comment">// Function body.</phrase>
16299 <phrase role="special">}</phrase>
16301 <phrase role="special">...</phrase>
16302 <phrase role="special">}</phrase><phrase role="special">;</phrase>
16303 </programlisting></para><para>This is an overloaded variadic macro and it can be used in the following different ways (note that no code is generated when <computeroutput><link linkend="BOOST_CONTRACT_NO_OLDS">BOOST_CONTRACT_NO_OLDS</link></computeroutput> is defined).</para><para>1. <computeroutput>BOOST_CONTRACT_OLD_PTR_IF_COPYABLE(old_type)(old_var)</computeroutput> expands to code equivalent to the following (this leaves the old value pointer null):</para><para><programlisting><phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_OLDS</phrase>
16304 <phrase role="comment">// This declaration does not need to use `v`.</phrase>
16305 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr_if_copyable</phrase><phrase role="special"><</phrase><phrase role="identifier">old_type</phrase><phrase role="special">></phrase> <phrase role="identifier">old_var</phrase>
16306 <phrase role="preprocessor">#endif</phrase>
16307 </programlisting></para><para>2. <computeroutput>BOOST_CONTRACT_OLD_PTR_IF_COPYABLE(old_type)(old_var, old_expr)</computeroutput> expands to code equivalent to the following (this initializes the pointer to the old value copy, but not to be used for virtual public functions and public function overrides):</para><para><programlisting><phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_OLDS</phrase>
16308 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr_if_copyable</phrase><phrase role="special"><</phrase><phrase role="identifier">old_type</phrase><phrase role="special">></phrase> <phrase role="identifier">old_var</phrase> <phrase role="special">=</phrase>
16309 <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">old_expr</phrase><phrase role="special">)</phrase>
16310 <phrase role="preprocessor">#endif</phrase>
16311 </programlisting></para><para>3. <computeroutput>BOOST_CONTRACT_OLD_PTR_IF_COPYABLE(old_type)(v, old_var, old_expr)</computeroutput> expands to code equivalent to the following (this initializes the pointer to the old value copy for virtual public functions and public function overrides):</para><para><programlisting><phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_OLDS</phrase>
16312 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">old_ptr_if_copyable</phrase><phrase role="special"><</phrase><phrase role="identifier">old_type</phrase><phrase role="special">></phrase> <phrase role="identifier">old_var</phrase> <phrase role="special">=</phrase>
16313 <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">old_expr</phrase><phrase role="special">)</phrase>
16314 <phrase role="preprocessor">#endif</phrase>
16315 </programlisting></para><para>Where:</para><para><itemizedlist>
16316 <listitem><para><computeroutput><emphasis role="bold">old_type</emphasis></computeroutput> is the type of the pointed old value. If this type is not copyable (i.e., <computeroutput>boost::contract::is_old_value_copyable<old_type>::value</computeroutput> is <computeroutput>false</computeroutput>), this pointer will always be null, but this library will not generate a compile-time error when this pointer is dereferenced (see <computeroutput><link linkend="BOOST_CONTRACT_OLD_PTR">BOOST_CONTRACT_OLD_PTR</link></computeroutput>). (This is a variadic macro parameter so it can contain commas not protected by round parenthesis.) </para>
16318 <listitem><para><computeroutput><emphasis role="bold">v</emphasis></computeroutput> is the extra trailing parameter of type <computeroutput><link linkend="boost.contract.virtual_">boost::contract::virtual_</link></computeroutput><computeroutput>*</computeroutput> and default value <computeroutput>0</computeroutput> from the enclosing virtual public function or public function override declaring the contract. (This is not a variadic macro parameter but it should never contain commas because it is an identifier.) </para>
16320 <listitem><para><computeroutput><emphasis role="bold">old_var</emphasis></computeroutput> is the name of the old value pointer variable. (This is not a variadic macro parameter but it should never contain commas because it is an identifier.) </para>
16322 <listitem><para><computeroutput><emphasis role="bold">old_expr</emphasis></computeroutput> is the expression to be evaluated and copied in the old value pointer. (This is not a variadic macro parameter so any comma it might contain must be protected by round parenthesis and <computeroutput>BOOST_CONTRACT_OLD_PTR_IF_COPYABLE(old_type)(v, old_var, (old_expr))</computeroutput> will always work.)</para>
16325 <para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.extras.disable_contract_compilation__macro_interface_">
16326 Disable Contract Compilation</link>, <link linkend="boost_contract.extras.old_value_requirements__templates_">
16327 Old Value Requirements</link> </para>
16329 </para></refsect1></refentry>
16330 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CONTRACT_INVARIANT"><refmeta><refentrytitle>Macro BOOST_CONTRACT_INVARIANT</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_INVARIANT</refname><refpurpose>Program (constant) class invariants that can be completely disabled at compile-time. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract_macro_hpp">boost/contract_macro.hpp</link>>
16332 </phrase>BOOST_CONTRACT_INVARIANT(...)</synopsis></refsynopsisdiv><refsect1><title>Description</title><para><computeroutput>BOOST_CONTRACT_INVARIANT</computeroutput>({ ... }) expands to code equivalent to the following (note that no code is generated when <computeroutput><link linkend="BOOST_CO_idm45394999622032">BOOST_CONTRACT_NO_INVARIANTS</link></computeroutput> is defined):</para><para><programlisting><phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_INVARIANTS</phrase>
16333 <phrase role="keyword">void</phrase> <phrase role="identifier">BOOST_CONTRACT_INVARIANT_FUNC</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase> <phrase role="special">{</phrase>
16334 <phrase role="special">...</phrase>
16335 <phrase role="special">}</phrase>
16336 <phrase role="preprocessor">#endif</phrase>
16337 </programlisting></para><para>Where:</para><para><itemizedlist>
16338 <listitem><para><emphasis role="bold">{ ... }</emphasis> is the definition of the function that checks class invariants for public functions that are not static and not volatile (see <computeroutput><link linkend="BOOST_CO_idm45394998621472">BOOST_CONTRACT_STATIC_INVARIANT</link></computeroutput> and <computeroutput><link linkend="BOOST_CO_idm45394998635328">BOOST_CONTRACT_INVARIANT_VOLATILE</link></computeroutput>). The curly parenthesis are mandatory (rationale: this is so the syntax of this macro resembles mote the syntax of the lambda functions usually used to specify preconditions, etc.). Assertions within this function are usually programmed using <computeroutput><link linkend="BOOST_CONTRACT_ASSERT">BOOST_CONTRACT_ASSERT</link></computeroutput>, but any exception thrown by a call to this function indicates a contract assertion failure (and will result in this library calling either <computeroutput><link linkend="boost.contract.entry_invariant_failure">boost::contract::entry_invariant_failure</link></computeroutput> or <computeroutput><link linkend="boost.contract.exit_invariant_failure">boost::contract::exit_invariant_failure</link></computeroutput>). (This is a variadic macro parameter so it can contain commas not protected by round parenthesis.)</para>
16341 <para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.extras.disable_contract_compilation__macro_interface_">
16342 Disable Contract Compilation</link>, <link linkend="boost_contract.tutorial.class_invariants"> Class Invariants</link> </para>
16344 </para></refsect1></refentry>
16345 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CO_idm45394998635328"><refmeta><refentrytitle>Macro BOOST_CONTRACT_INVARIANT_VOLATILE</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_INVARIANT_VOLATILE</refname><refpurpose>Program volatile class invariants that can be completely disabled at compile-time. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract_macro_hpp">boost/contract_macro.hpp</link>>
16347 </phrase>BOOST_CONTRACT_INVARIANT_VOLATILE(...)</synopsis></refsynopsisdiv><refsect1><title>Description</title><para><computeroutput>BOOST_CONTRACT_INVARIANT_VOLATILE</computeroutput>({ ... }) expands to code equivalent to the following (note that no code is generated when <computeroutput><link linkend="BOOST_CO_idm45394999622032">BOOST_CONTRACT_NO_INVARIANTS</link></computeroutput> is defined):</para><para><programlisting><phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_INVARIANTS</phrase>
16348 <phrase role="keyword">void</phrase> <phrase role="identifier">BOOST_CONTRACT_INVARIANT_FUNC</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase> <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase> <phrase role="special">{</phrase>
16349 <phrase role="special">...</phrase>
16350 <phrase role="special">}</phrase>
16351 <phrase role="preprocessor">#endif</phrase>
16352 </programlisting></para><para>Where:</para><para><itemizedlist>
16353 <listitem><para><emphasis role="bold">{ ... }</emphasis> is the definition of the function that checks class invariants for volatile public functions (see <computeroutput><link linkend="BOOST_CONTRACT_INVARIANT">BOOST_CONTRACT_INVARIANT</link></computeroutput> and <computeroutput><link linkend="BOOST_CO_idm45394998621472">BOOST_CONTRACT_STATIC_INVARIANT</link></computeroutput>). The curly parenthesis are mandatory. Assertions within this function are usually programmed using <computeroutput><link linkend="BOOST_CONTRACT_ASSERT">BOOST_CONTRACT_ASSERT</link></computeroutput>, but any exception thrown by a call to this function indicates a contract assertion failure (and will result in this library calling either <computeroutput><link linkend="boost.contract.entry_invariant_failure">boost::contract::entry_invariant_failure</link></computeroutput> or <computeroutput><link linkend="boost.contract.exit_invariant_failure">boost::contract::exit_invariant_failure</link></computeroutput>). (This is a variadic macro parameter so it can contain commas not protected by round parenthesis.)</para>
16356 <para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.extras.disable_contract_compilation__macro_interface_">
16357 Disable Contract Compilation</link>, <link linkend="boost_contract.extras.volatile_public_functions">
16358 Volatile Public Functions</link> </para>
16360 </para></refsect1></refentry>
16361 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CO_idm45394998621472"><refmeta><refentrytitle>Macro BOOST_CONTRACT_STATIC_INVARIANT</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_STATIC_INVARIANT</refname><refpurpose>Program static class invariants that can be completely disabled at compile-time. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract_macro_hpp">boost/contract_macro.hpp</link>>
16363 </phrase>BOOST_CONTRACT_STATIC_INVARIANT(...)</synopsis></refsynopsisdiv><refsect1><title>Description</title><para><computeroutput>BOOST_CONTRACT_STATIC_INVARIANT</computeroutput>({ ... }) expands to code equivalent to the following (note that no code is generated when <computeroutput><link linkend="BOOST_CO_idm45394999622032">BOOST_CONTRACT_NO_INVARIANTS</link></computeroutput> is defined):</para><para><programlisting><phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_INVARIANTS</phrase>
16364 <phrase role="keyword">static</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">BOOST_CONTRACT_STATIC_INVARIANT_FUNC</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
16365 <phrase role="special">...</phrase>
16366 <phrase role="special">}</phrase>
16367 <phrase role="preprocessor">#endif</phrase>
16368 </programlisting></para><para>Where:</para><para><itemizedlist>
16369 <listitem><para><emphasis role="bold">{ ... }</emphasis> is the definition of the function that checks class invariants for static public functions (see <computeroutput><link linkend="BOOST_CONTRACT_INVARIANT">BOOST_CONTRACT_INVARIANT</link></computeroutput> and <computeroutput><link linkend="BOOST_CO_idm45394998635328">BOOST_CONTRACT_INVARIANT_VOLATILE</link></computeroutput>). The curly parenthesis are mandatory. Assertions within this function are usually programmed using <computeroutput><link linkend="BOOST_CONTRACT_ASSERT">BOOST_CONTRACT_ASSERT</link></computeroutput>, but any exception thrown by a call to this function indicates a contract assertion failure (and will result in this library calling either <computeroutput><link linkend="boost.contract.entry_invariant_failure">boost::contract::entry_invariant_failure</link></computeroutput> or <computeroutput><link linkend="boost.contract.exit_invariant_failure">boost::contract::exit_invariant_failure</link></computeroutput>). (This is a variadic macro parameter so it can contain commas not protected by round parenthesis.)</para>
16372 <para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.extras.disable_contract_compilation__macro_interface_">
16373 Disable Contract Compilation</link>, <link linkend="boost_contract.tutorial.class_invariants"> Class Invariants</link> </para>
16375 </para></refsect1></refentry>
16376 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CONTRACT_CONSTRUCTOR"><refmeta><refentrytitle>Macro BOOST_CONTRACT_CONSTRUCTOR</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_CONSTRUCTOR</refname><refpurpose>Program contracts that can be completely disabled at compile-time for constructors. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract_macro_hpp">boost/contract_macro.hpp</link>>
16378 </phrase>BOOST_CONTRACT_CONSTRUCTOR(...)</synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This is used together with <computeroutput><link linkend="BOOST_CO_idm45394998736528">BOOST_CONTRACT_POSTCONDITION</link></computeroutput>, <computeroutput><link linkend="BOOST_CONTRACT_EXCEPT">BOOST_CONTRACT_EXCEPT</link></computeroutput>, and <computeroutput><link linkend="BOOST_CONTRACT_OLD">BOOST_CONTRACT_OLD</link></computeroutput> to specify postconditions, exception guarantees, and old value copies at body that can be completely disabled at compile-time for constructors (see <computeroutput><link linkend="BOOST_CO_idm45394998587680">BOOST_CONTRACT_CONSTRUCTOR_PRECONDITION</link></computeroutput> to specify preconditions for constructors):</para><para><programlisting><phrase role="keyword">class</phrase> <phrase role="identifier">u</phrase> <phrase role="special">{</phrase>
16379 <phrase role="keyword">friend</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">access</phrase><phrase role="special">;</phrase>
16381 <phrase role="identifier">BOOST_CONTRACT_INVARIANT</phrase><phrase role="special">(</phrase><phrase role="special">{</phrase> <phrase role="comment">// Optional (as for static and volatile).</phrase>
16382 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16383 <phrase role="special">...</phrase>
16384 <phrase role="special">}</phrase><phrase role="special">)</phrase>
16386 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
16387 <phrase role="identifier">u</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
16388 <phrase role="identifier">BOOST_CONTRACT_OLD_PTR</phrase><phrase role="special">(</phrase><phrase role="identifier">old_type</phrase><phrase role="special">)</phrase><phrase role="special">(</phrase><phrase role="identifier">old_var</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16389 <phrase role="identifier">BOOST_CONTRACT_CONSTRUCTOR</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
16390 <phrase role="comment">// No `PRECONDITION` (use `CONSTRUCTOR_PRECONDITION` if needed).</phrase>
16391 <phrase role="identifier">BOOST_CONTRACT_OLD</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
16392 <phrase role="identifier">old_var</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">old_epxr</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16393 <phrase role="special">...</phrase>
16394 <phrase role="special">}</phrase><phrase role="special">)</phrase>
16395 <phrase role="identifier">BOOST_CONTRACT_POSTCONDITION</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
16396 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16397 <phrase role="special">...</phrase>
16398 <phrase role="special">}</phrase><phrase role="special">)</phrase>
16399 <phrase role="identifier">BOOST_CONTRACT_EXCEPT</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
16400 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16401 <phrase role="special">...</phrase>
16402 <phrase role="special">}</phrase><phrase role="special">)</phrase>
16403 <phrase role="special">;</phrase> <phrase role="comment">// Trailing `;` is required.</phrase>
16405 <phrase role="special">...</phrase> <phrase role="comment">// Constructor body.</phrase>
16406 <phrase role="special">}</phrase>
16408 <phrase role="special">...</phrase>
16409 <phrase role="special">}</phrase><phrase role="special">;</phrase>
16410 </programlisting></para><para>For optimization, this can be omitted for constructors that do not have postconditions and exception guarantees, within classes that have no invariants.</para><para><computeroutput>BOOST_CONTRACT_CONSTRUCTOR(obj)</computeroutput> expands to code equivalent to the following (note that no code is generated when <computeroutput><link linkend="BOOST_CO_idm45394999605408">BOOST_CONTRACT_NO_CONSTRUCTORS</link></computeroutput> is defined):</para><para><programlisting><phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_CONSTRUCTORS</phrase>
16411 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">internal_var</phrase> <phrase role="special">=</phrase>
16412 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor</phrase><phrase role="special">(</phrase><phrase role="identifier">obj</phrase><phrase role="special">)</phrase>
16413 <phrase role="preprocessor">#endif</phrase>
16414 </programlisting></para><para>Where:</para><para><itemizedlist>
16415 <listitem><para><computeroutput><emphasis role="bold">obj</emphasis></computeroutput> is the object <computeroutput>this</computeroutput> from the scope of the enclosing constructor declaring the contract. Constructors check all class invariants, including static and volatile invariants (see <computeroutput><link linkend="BOOST_CONTRACT_INVARIANT">BOOST_CONTRACT_INVARIANT</link></computeroutput>, <computeroutput><link linkend="BOOST_CO_idm45394998621472">BOOST_CONTRACT_STATIC_INVARIANT</link></computeroutput>, and <computeroutput><link linkend="BOOST_CO_idm45394998635328">BOOST_CONTRACT_INVARIANT_VOLATILE</link></computeroutput>). (This is a variadic macro parameter so it can contain commas not protected by round parenthesis.) </para>
16417 <listitem><para><computeroutput><emphasis role="bold">internal_var</emphasis></computeroutput> is a variable name internally generated by this library (this name is unique but only on different line numbers so this macro cannot be expanded multiple times on the same line).</para>
16420 <para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.extras.disable_contract_compilation__macro_interface_">
16421 Disable Contract Compilation</link>, <link linkend="boost_contract.tutorial.constructors"> Constructors</link> </para>
16423 </para></refsect1></refentry>
16424 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CO_idm45394998587680"><refmeta><refentrytitle>Macro BOOST_CONTRACT_CONSTRUCTOR_PRECONDITION</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_CONSTRUCTOR_PRECONDITION</refname><refpurpose>Program preconditions that can be disabled at compile-time for constructors. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract_macro_hpp">boost/contract_macro.hpp</link>>
16426 </phrase>BOOST_CONTRACT_CONSTRUCTOR_PRECONDITION(...)</synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This is used together with <computeroutput><link linkend="BOOST_CONTRACT_CONSTRUCTOR">BOOST_CONTRACT_CONSTRUCTOR</link></computeroutput> to specify contracts for constructors. Constructors that do not have preconditions do not use this macro. When at least one of the class constructors uses this macro, <computeroutput><link linkend="boost.contract.constructor_precondition">boost::contract::constructor_precondition</link></computeroutput> must be the first and private base of the class declaring the constructor for which preconditions are programmed:</para><para><programlisting><phrase role="keyword">class</phrase> <phrase role="identifier">u</phrase>
16427 <phrase role="preprocessor">#define</phrase> <phrase role="identifier">BASES</phrase> <phrase role="keyword">private</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor_precondition</phrase><phrase role="special"><</phrase><phrase role="identifier">u</phrase><phrase role="special">></phrase><phrase role="special">,</phrase> \
16428 <phrase role="keyword">public</phrase> <phrase role="identifier">b</phrase>
16429 <phrase role="special">:</phrase> <phrase role="identifier">BASES</phrase>
16430 <phrase role="special">{</phrase>
16431 <phrase role="keyword">friend</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">access</phrase><phrase role="special">;</phrase>
16433 <phrase role="keyword">typedef</phrase> <phrase role="identifier">BOOST_CONTRACT_BASE_TYPES</phrase><phrase role="special">(</phrase><phrase role="identifier">BASES</phrase><phrase role="special">)</phrase> <phrase role="identifier">base_types</phrase><phrase role="special">;</phrase>
16434 <phrase role="preprocessor">#undef</phrase> <phrase role="identifier">BASES</phrase>
16436 <phrase role="special">...</phrase>
16438 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
16439 <phrase role="keyword">explicit</phrase> <phrase role="identifier">u</phrase><phrase role="special">(</phrase><phrase role="keyword">unsigned</phrase> <phrase role="identifier">x</phrase><phrase role="special">)</phrase> <phrase role="special">:</phrase>
16440 <phrase role="identifier">BOOST_CONTRACT_CONSTRUCTOR_PRECONDITION</phrase><phrase role="special">(</phrase><phrase role="identifier">u</phrase><phrase role="special">)</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase>
16441 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="identifier">x</phrase> <phrase role="special">!=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16442 <phrase role="special">}</phrase><phrase role="special">)</phrase><phrase role="special">,</phrase>
16443 <phrase role="identifier">b</phrase><phrase role="special">(</phrase><phrase role="number">1</phrase> <phrase role="special">/</phrase> <phrase role="identifier">x</phrase><phrase role="special">)</phrase>
16444 <phrase role="special">{</phrase>
16445 <phrase role="special">...</phrase>
16446 <phrase role="special">}</phrase>
16448 <phrase role="special">...</phrase>
16449 <phrase role="special">}</phrase><phrase role="special">;</phrase>
16450 </programlisting></para><para><computeroutput>BOOST_CONTRACT_CONSTRUCTOR_PRECONDITION(class_type)(f)</computeroutput> expands to code equivalent to the following (note that when <computeroutput><link linkend="BOOST_CO_idm45394999662416">BOOST_CONTRACT_NO_PRECONDITIONS</link></computeroutput> is defined, this macro trivially expands to a default constructor call that is internally implemented to do nothing so this should have minimal to no overhead):</para><para><programlisting><phrase role="comment">// Guarded only by NO_PRECONDITIONS (and not also by NO_CONSTRUCTORS)</phrase>
16451 <phrase role="comment">// because for constructor's preconditions (not for postconditions, etc.).</phrase>
16452 <phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_PRECONDITIONS</phrase>
16453 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor_precondition</phrase><phrase role="special"><</phrase><phrase role="identifier">class_type</phrase><phrase role="special">></phrase><phrase role="special">(</phrase><phrase role="identifier">f</phrase><phrase role="special">)</phrase>
16454 <phrase role="preprocessor">#else</phrase> <phrase role="comment">// No-op call (likely optimized away, minimal to no overhead).</phrase>
16455 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor_precondition</phrase><phrase role="special"><</phrase><phrase role="identifier">class_type</phrase><phrase role="special">></phrase><phrase role="special">(</phrase><phrase role="special">)</phrase>
16456 <phrase role="preprocessor">#endif</phrase>
16457 </programlisting></para><para>Where:</para><para><itemizedlist>
16458 <listitem><para><computeroutput><emphasis role="bold">class_type</emphasis></computeroutput> is the type of the class containing the constructor for which preconditions are being programmed. (This is a variadic macro parameter so it can contain commas not protected by round parenthesis.) </para>
16460 <listitem><para><computeroutput><emphasis role="bold">f</emphasis></computeroutput> is the nullary functor called by this library to check constructor preconditions <computeroutput>f()</computeroutput>. Assertions within this functor call are usually programmed using <computeroutput><link linkend="BOOST_CONTRACT_ASSERT">BOOST_CONTRACT_ASSERT</link></computeroutput>, but any exception thrown by a call to this functor indicates a contract failure (and will result in this library calling <computeroutput><link linkend="boost.contract.precondition_failure">boost::contract::precondition_failure</link></computeroutput>). This functor should capture variables by (constant) value, or better by (constant) reference to avoid extra copies. (This is a variadic macro parameter so it can contain commas not protected by round parenthesis.)</para>
16463 <para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.extras.disable_contract_compilation__macro_interface_">
16464 Disable Contract Compilation</link>, <link linkend="boost_contract.tutorial.constructors"> Constructors</link> </para>
16466 </para></refsect1></refentry>
16467 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CONTRACT_DESTRUCTOR"><refmeta><refentrytitle>Macro BOOST_CONTRACT_DESTRUCTOR</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_DESTRUCTOR</refname><refpurpose>Program contracts that can be completely disabled at compile-time for destructors. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract_macro_hpp">boost/contract_macro.hpp</link>>
16469 </phrase>BOOST_CONTRACT_DESTRUCTOR(...)</synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This is used together with <computeroutput><link linkend="BOOST_CO_idm45394998736528">BOOST_CONTRACT_POSTCONDITION</link></computeroutput>, <computeroutput><link linkend="BOOST_CONTRACT_EXCEPT">BOOST_CONTRACT_EXCEPT</link></computeroutput>, and <computeroutput><link linkend="BOOST_CONTRACT_OLD">BOOST_CONTRACT_OLD</link></computeroutput> to specify postconditions, exception guarantees, and old value copies at body that can be completely disabled at compile-time for destructors (destructors cannot have preconditions, see <link linkend="boost_contract.contract_programming_overview.destructor_calls"> Destructor Calls</link>):</para><para><programlisting><phrase role="keyword">class</phrase> <phrase role="identifier">u</phrase> <phrase role="special">{</phrase>
16470 <phrase role="keyword">friend</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">access</phrase><phrase role="special">;</phrase>
16472 <phrase role="identifier">BOOST_CONTRACT_INVARIANT</phrase><phrase role="special">(</phrase><phrase role="special">{</phrase> <phrase role="comment">// Optional (as for static and volatile).</phrase>
16473 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16474 <phrase role="special">...</phrase>
16475 <phrase role="special">}</phrase><phrase role="special">)</phrase>
16477 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
16478 <phrase role="special">~</phrase><phrase role="identifier">u</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
16479 <phrase role="identifier">BOOST_CONTRACT_OLD_PTR</phrase><phrase role="special">(</phrase><phrase role="identifier">old_type</phrase><phrase role="special">)</phrase><phrase role="special">(</phrase><phrase role="identifier">old_var</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16480 <phrase role="identifier">BOOST_CONTRACT_DESTRUCTOR</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
16481 <phrase role="comment">// No `PRECONDITION` (destructors have no preconditions).</phrase>
16482 <phrase role="identifier">BOOST_CONTRACT_OLD</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
16483 <phrase role="identifier">old_var</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">old_expr</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16484 <phrase role="special">...</phrase>
16485 <phrase role="special">}</phrase><phrase role="special">)</phrase>
16486 <phrase role="identifier">BOOST_CONTRACT_POSTCONDITION</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
16487 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16488 <phrase role="special">...</phrase>
16489 <phrase role="special">}</phrase><phrase role="special">)</phrase>
16490 <phrase role="identifier">BOOST_CONTRACT_EXCEPT</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
16491 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16492 <phrase role="special">...</phrase>
16493 <phrase role="special">}</phrase><phrase role="special">)</phrase>
16494 <phrase role="special">;</phrase> <phrase role="comment">// Trailing `;` is required.</phrase>
16496 <phrase role="special">...</phrase> <phrase role="comment">// Destructor body.</phrase>
16497 <phrase role="special">}</phrase>
16499 <phrase role="special">...</phrase>
16500 <phrase role="special">}</phrase><phrase role="special">;</phrase>
16501 </programlisting></para><para>For optimization, this can be omitted for destructors that do not have postconditions and exception guarantees, within classes that have no invariants.</para><para><computeroutput>BOOST_CONTRACT_DESTRUCTOR(obj)</computeroutput> expands to code equivalent to the following (note that no code is generated when <computeroutput><link linkend="BOOST_CO_idm45394999594544">BOOST_CONTRACT_NO_DESTRUCTORS</link></computeroutput> is defined):</para><para><programlisting><phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_DESTRUCTORS</phrase>
16502 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">internal_var</phrase> <phrase role="special">=</phrase>
16503 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">destructor</phrase><phrase role="special">(</phrase><phrase role="identifier">obj</phrase><phrase role="special">)</phrase>
16504 <phrase role="preprocessor">#endif</phrase>
16505 </programlisting></para><para>Where:</para><para><itemizedlist>
16506 <listitem><para><computeroutput><emphasis role="bold">obj</emphasis></computeroutput> is the object <computeroutput>this</computeroutput> from the scope of the enclosing destructor declaring the contract. Destructors check all class invariants, including static and volatile invariants (see <link linkend="boost_contract.tutorial.class_invariants">
16507 Class Invariants</link> and <link linkend="boost_contract.extras.volatile_public_functions">
16508 Volatile Public Functions</link>). (This is a variadic macro parameter so it can contain commas not protected by round parenthesis.) </para>
16510 <listitem><para><computeroutput><emphasis role="bold">internal_var</emphasis></computeroutput> is a variable name internally generated by this library (this name is unique but only on different line numbers so this macro cannot be expanded multiple times on the same line).</para>
16513 <para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.extras.disable_contract_compilation__macro_interface_">
16514 Disable Contract Compilation</link>, <link linkend="boost_contract.tutorial.destructors"> Destructors</link> </para>
16516 </para></refsect1></refentry>
16517 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CONTRACT_FUNCTION"><refmeta><refentrytitle>Macro BOOST_CONTRACT_FUNCTION</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_FUNCTION</refname><refpurpose>Program contracts that can be completely disabled at compile-time for (non-public) functions. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract_macro_hpp">boost/contract_macro.hpp</link>>
16519 </phrase>BOOST_CONTRACT_FUNCTION()</synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This is used together with <computeroutput><link linkend="BOOST_CO_idm45394998748208">BOOST_CONTRACT_PRECONDITION</link></computeroutput>, <computeroutput><link linkend="BOOST_CO_idm45394998736528">BOOST_CONTRACT_POSTCONDITION</link></computeroutput>, <computeroutput><link linkend="BOOST_CONTRACT_EXCEPT">BOOST_CONTRACT_EXCEPT</link></computeroutput>, and <computeroutput><link linkend="BOOST_CONTRACT_OLD">BOOST_CONTRACT_OLD</link></computeroutput> to specify preconditions, postconditions, exception guarantees, and old value copies at body that can be completely disabled at compile-time for (non-public) functions:</para><para><programlisting><phrase role="keyword">void</phrase> <phrase role="identifier">f</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
16520 <phrase role="identifier">BOOST_CONTRACT_OLD_PTR</phrase><phrase role="special">(</phrase><phrase role="identifier">old_type</phrase><phrase role="special">)</phrase><phrase role="special">(</phrase><phrase role="identifier">old_var</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16521 <phrase role="identifier">BOOST_CONTRACT_FUNCTION</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase>
16522 <phrase role="identifier">BOOST_CONTRACT_PRECONDITION</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
16523 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16524 <phrase role="special">...</phrase>
16525 <phrase role="special">}</phrase><phrase role="special">)</phrase>
16526 <phrase role="identifier">BOOST_CONTRACT_OLD</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
16527 <phrase role="identifier">old_var</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">old_expr</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16528 <phrase role="special">...</phrase>
16529 <phrase role="special">}</phrase><phrase role="special">)</phrase>
16530 <phrase role="identifier">BOOST_CONTRACT_POSTCONDITION</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
16531 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16532 <phrase role="special">...</phrase>
16533 <phrase role="special">}</phrase><phrase role="special">)</phrase>
16534 <phrase role="identifier">BOOST_CONTRACT_EXCEPT</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
16535 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16536 <phrase role="special">...</phrase>
16537 <phrase role="special">}</phrase><phrase role="special">)</phrase>
16538 <phrase role="special">;</phrase> <phrase role="comment">// Trailing `;` is required.</phrase>
16540 <phrase role="special">...</phrase> <phrase role="comment">// Function body.</phrase>
16541 <phrase role="special">}</phrase>
16542 </programlisting></para><para>This can be used to program contracts for non-member functions but also for private and protected functions, lambda functions, loops, arbitrary blocks of code, etc. For optimization, this can be omitted for code that does not have preconditions, postconditions, and exception guarantees.</para><para><computeroutput>BOOST_CONTRACT_FUNCTION()</computeroutput> expands to code equivalent to the following (note that no code is generated when <computeroutput><link linkend="BOOST_CO_idm45394999577072">BOOST_CONTRACT_NO_FUNCTIONS</link></computeroutput> is defined):</para><para><programlisting><phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_FUNCTIONS</phrase>
16543 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">internal_var</phrase> <phrase role="special">=</phrase>
16544 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">function</phrase><phrase role="special">(</phrase><phrase role="special">)</phrase>
16545 <phrase role="preprocessor">#endif</phrase>
16546 </programlisting></para><para>Where:</para><para><itemizedlist>
16547 <listitem><para><computeroutput><emphasis role="bold">internal_var</emphasis></computeroutput> is a variable name internally generated by this library (this name is unique but only on different line numbers so this macro cannot be expanded multiple times on the same line).</para>
16550 <para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.extras.disable_contract_compilation__macro_interface_">
16551 Disable Contract Compilation</link>, <link linkend="boost_contract.tutorial.non_member_functions"> Non-Member Functions</link>, <link linkend="boost_contract.advanced.private_and_protected_functions">
16552 Private and Protected Functions</link>, <link linkend="boost_contract.advanced.lambdas__loops__code_blocks__and__constexpr__">
16553 Lambdas, Loops, Code Blocks</link> </para>
16555 </para></refsect1></refentry>
16556 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CO_idm45394998534992"><refmeta><refentrytitle>Macro BOOST_CONTRACT_STATIC_PUBLIC_FUNCTION</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_STATIC_PUBLIC_FUNCTION</refname><refpurpose>Program contracts that can be completely disabled at compile-time for static public functions. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract_macro_hpp">boost/contract_macro.hpp</link>>
16558 </phrase>BOOST_CONTRACT_STATIC_PUBLIC_FUNCTION(...)</synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This is used together with <computeroutput><link linkend="BOOST_CO_idm45394998748208">BOOST_CONTRACT_PRECONDITION</link></computeroutput>, <computeroutput><link linkend="BOOST_CO_idm45394998736528">BOOST_CONTRACT_POSTCONDITION</link></computeroutput>, <computeroutput><link linkend="BOOST_CONTRACT_EXCEPT">BOOST_CONTRACT_EXCEPT</link></computeroutput>, and <computeroutput><link linkend="BOOST_CONTRACT_OLD">BOOST_CONTRACT_OLD</link></computeroutput> to specify preconditions, postconditions, exception guarantees, and old value copies at body that can be completely disabled at compile-time for static public functions:</para><para><programlisting><phrase role="keyword">class</phrase> <phrase role="identifier">u</phrase> <phrase role="special">{</phrase>
16559 <phrase role="keyword">friend</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">access</phrase><phrase role="special">;</phrase>
16561 <phrase role="identifier">BOOST_CONTRACT_STATIC_INVARIANT</phrase><phrase role="special">(</phrase><phrase role="special">{</phrase> <phrase role="comment">// Optional (as for non-static).</phrase>
16562 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16563 <phrase role="special">...</phrase>
16564 <phrase role="special">}</phrase><phrase role="special">)</phrase>
16566 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
16567 <phrase role="keyword">static</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">f</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
16568 <phrase role="identifier">BOOST_CONTRACT_OLD_PTR</phrase><phrase role="special">(</phrase><phrase role="identifier">old_type</phrase><phrase role="special">)</phrase><phrase role="special">(</phrase><phrase role="identifier">old_var</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16569 <phrase role="identifier">BOOST_CONTRACT_PUBLIC_FUNCTION</phrase><phrase role="special">(</phrase><phrase role="identifier">u</phrase><phrase role="special">)</phrase>
16570 <phrase role="identifier">BOOST_CONTRACT_PRECONDITION</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
16571 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16572 <phrase role="special">...</phrase>
16573 <phrase role="special">}</phrase><phrase role="special">)</phrase>
16574 <phrase role="identifier">BOOST_CONTRACT_OLD</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
16575 <phrase role="identifier">old_var</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">old_expr</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16576 <phrase role="special">...</phrase>
16577 <phrase role="special">}</phrase><phrase role="special">)</phrase>
16578 <phrase role="identifier">BOOST_CONTRACT_POSTCONDITION</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
16579 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16580 <phrase role="special">...</phrase>
16581 <phrase role="special">}</phrase><phrase role="special">)</phrase>
16582 <phrase role="identifier">BOOST_CONTRACT_EXCEPT</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
16583 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16584 <phrase role="special">...</phrase>
16585 <phrase role="special">}</phrase><phrase role="special">)</phrase>
16586 <phrase role="special">;</phrase> <phrase role="comment">// Trailing `;` is required.</phrase>
16588 <phrase role="special">...</phrase> <phrase role="comment">// Function body.</phrase>
16589 <phrase role="special">}</phrase>
16591 <phrase role="special">...</phrase>
16592 <phrase role="special">}</phrase><phrase role="special">;</phrase>
16593 </programlisting></para><para>For optimization, this can be omitted for static public functions that do not have preconditions, postconditions and exception guarantees, within classes that have no static invariants.</para><para><computeroutput>BOOST_CONTRACT_STATIC_PUBLIC_FUNCTION(class_type)</computeroutput> expands to code equivalent to the following (note that no code is generated when <computeroutput><link linkend="BOOST_CO_idm45394999586272">BOOST_CONTRACT_NO_PUBLIC_FUNCTIONS</link></computeroutput> is defined):</para><para><programlisting><phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_PUBLIC_FUNCTIONS</phrase>
16594 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">internal_var</phrase> <phrase role="special">=</phrase>
16595 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special"><</phrase><phrase role="identifier">class_type</phrase><phrase role="special">></phrase><phrase role="special">(</phrase><phrase role="special">)</phrase>
16596 <phrase role="preprocessor">#endif</phrase>
16597 </programlisting></para><para>Where:</para><para><itemizedlist>
16598 <listitem><para><computeroutput><emphasis role="bold">class_type</emphasis></computeroutput> is the type of the class containing the static public function declaring the contract. (This is a variadic macro parameter so it can contain commas not protected by round parenthesis.) </para>
16600 <listitem><para><computeroutput><emphasis role="bold">internal_var</emphasis></computeroutput> is a variable name internally generated by this library (this name is unique but only on different line numbers so this macro cannot be expanded multiple times on the same line).</para>
16603 <para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.extras.disable_contract_compilation__macro_interface_">
16604 Disable Contract Compilation</link>, <link linkend="boost_contract.tutorial.static_public_functions"> Static Public Functions</link> </para>
16606 </para></refsect1></refentry>
16607 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CO_idm45394998517984"><refmeta><refentrytitle>Macro BOOST_CONTRACT_PUBLIC_FUNCTION</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_PUBLIC_FUNCTION</refname><refpurpose>Program contracts that can be completely disabled at compile-time for non-static public functions that do not override. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract_macro_hpp">boost/contract_macro.hpp</link>>
16609 </phrase>BOOST_CONTRACT_PUBLIC_FUNCTION(...)</synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This is used together with <computeroutput><link linkend="BOOST_CO_idm45394998748208">BOOST_CONTRACT_PRECONDITION</link></computeroutput>, <computeroutput><link linkend="BOOST_CO_idm45394998736528">BOOST_CONTRACT_POSTCONDITION</link></computeroutput>, <computeroutput><link linkend="BOOST_CONTRACT_EXCEPT">BOOST_CONTRACT_EXCEPT</link></computeroutput>, and <computeroutput><link linkend="BOOST_CONTRACT_OLD">BOOST_CONTRACT_OLD</link></computeroutput> to specify preconditions, postconditions, exception guarantees, and old value copies at body that can be completely disabled at compile-time for non-static public functions (virtual or not, void or not) that do not override:</para><para><programlisting><phrase role="keyword">class</phrase> <phrase role="identifier">u</phrase> <phrase role="special">{</phrase>
16610 <phrase role="keyword">friend</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">access</phrase><phrase role="special">;</phrase>
16612 <phrase role="identifier">BOOST_CONTRACT_INVARIANT</phrase><phrase role="special">(</phrase><phrase role="special">{</phrase> <phrase role="comment">// Optional (as for static and volatile).</phrase>
16613 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16614 <phrase role="special">...</phrase>
16615 <phrase role="special">}</phrase><phrase role="special">)</phrase>
16617 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
16618 <phrase role="comment">// Non-virtual (same if void).</phrase>
16619 <phrase role="identifier">t</phrase> <phrase role="identifier">f</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
16620 <phrase role="identifier">t</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
16621 <phrase role="identifier">BOOST_CONTRACT_OLD_PTR</phrase><phrase role="special">(</phrase><phrase role="identifier">old_type</phrase><phrase role="special">)</phrase><phrase role="special">(</phrase><phrase role="identifier">old_var</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16622 <phrase role="identifier">BOOST_CONTRACT_PUBLIC_FUNCTION</phrase><phrase role="special">(</phrase><phrase role="keyword">this</phrase><phrase role="special">)</phrase>
16623 <phrase role="identifier">BOOST_CONTRACT_PRECONDITION</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
16624 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16625 <phrase role="special">...</phrase>
16626 <phrase role="special">}</phrase><phrase role="special">)</phrase>
16627 <phrase role="identifier">BOOST_CONTRACT_OLD</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
16628 <phrase role="identifier">old_var</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">old_expr</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16629 <phrase role="special">...</phrase>
16630 <phrase role="special">}</phrase><phrase role="special">)</phrase>
16631 <phrase role="identifier">BOOST_CONTRACT_POSTCONDITION</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
16632 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16633 <phrase role="special">...</phrase>
16634 <phrase role="special">}</phrase><phrase role="special">)</phrase>
16635 <phrase role="identifier">BOOST_CONTRACT_EXCEPT</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
16636 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16637 <phrase role="special">...</phrase>
16638 <phrase role="special">}</phrase><phrase role="special">)</phrase>
16639 <phrase role="special">;</phrase> <phrase role="comment">// Trailing `;` is required.</phrase>
16641 <phrase role="special">...</phrase> <phrase role="comment">// Function body (use `return result = return_expr`).</phrase>
16642 <phrase role="special">}</phrase>
16644 <phrase role="comment">// Virtual and void.</phrase>
16645 <phrase role="keyword">virtual</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">g</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">,</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
16646 <phrase role="identifier">BOOST_CONTRACT_OLD_PTR</phrase><phrase role="special">(</phrase><phrase role="identifier">old_type</phrase><phrase role="special">)</phrase><phrase role="special">(</phrase><phrase role="identifier">old_var</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16647 <phrase role="identifier">BOOST_CONTRACT_PUBLIC_FUNCTION</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">)</phrase>
16648 <phrase role="special">...</phrase>
16649 <phrase role="identifier">BOOST_CONTRACT_OLD</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
16650 <phrase role="identifier">old_var</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">old_expr</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16651 <phrase role="special">...</phrase>
16652 <phrase role="special">}</phrase><phrase role="special">)</phrase>
16653 <phrase role="special">...</phrase>
16654 <phrase role="special">;</phrase> <phrase role="comment">// Trailing `;` is required.</phrase>
16656 <phrase role="special">...</phrase> <phrase role="comment">// Function body.</phrase>
16657 <phrase role="special">}</phrase>
16659 <phrase role="comment">// Virtual and non-void.</phrase>
16660 <phrase role="keyword">virtual</phrase> <phrase role="identifier">t</phrase> <phrase role="identifier">h</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">,</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
16661 <phrase role="identifier">t</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
16662 <phrase role="identifier">BOOST_CONTRACT_OLD_PTR</phrase><phrase role="special">(</phrase><phrase role="identifier">old_type</phrase><phrase role="special">)</phrase><phrase role="special">(</phrase><phrase role="identifier">old_var</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16663 <phrase role="identifier">BOOST_CONTRACT_PUBLIC_FUNCTION</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">result</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">)</phrase>
16664 <phrase role="special">...</phrase>
16665 <phrase role="identifier">BOOST_CONTRACT_OLD</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
16666 <phrase role="identifier">old_var</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">old_expr</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16667 <phrase role="special">...</phrase>
16668 <phrase role="special">}</phrase><phrase role="special">)</phrase>
16669 <phrase role="identifier">BOOST_CONTRACT_POSTCONDITION</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">(</phrase><phrase role="identifier">t</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">result</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional</phrase>
16670 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16671 <phrase role="special">...</phrase>
16672 <phrase role="special">}</phrase><phrase role="special">)</phrase>
16673 <phrase role="special">...</phrase>
16674 <phrase role="special">;</phrase> <phrase role="comment">// Trailing `;` is required.</phrase>
16676 <phrase role="special">...</phrase> <phrase role="comment">// Function body (use `return result = return_expr`).</phrase>
16677 <phrase role="special">}</phrase>
16679 <phrase role="special">...</phrase>
16680 <phrase role="special">}</phrase><phrase role="special">;</phrase>
16681 </programlisting></para><para>For optimization, this can be omitted for non-virtual public functions that do not have preconditions, postconditions and exception guarantees, within classes that have no invariants. Virtual public functions should always use <computeroutput><link linkend="BOOST_CO_idm45394998517984">BOOST_CONTRACT_PUBLIC_FUNCTION</link></computeroutput> otherwise this library will not be able to correctly use them for subcontracting.</para><para>This is an overloaded variadic macro and it can be used in the following different ways (note that no code is generated when <computeroutput><link linkend="BOOST_CO_idm45394999586272">BOOST_CONTRACT_NO_PUBLIC_FUNCTIONS</link></computeroutput> is defined).</para><para>1. <computeroutput>BOOST_CONTRACT_PUBLIC_FUNCTION(obj)</computeroutput> expands to code equivalent to the following (for non-virtual public functions that are not static and do not override, returning void or not):</para><para><programlisting><phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_PUBLIC_FUNCTIONS</phrase>
16682 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">internal_var</phrase> <phrase role="special">=</phrase>
16683 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="identifier">obj</phrase><phrase role="special">)</phrase>
16684 <phrase role="preprocessor">#endif</phrase>
16685 </programlisting></para><para>2. <computeroutput>BOOST_CONTRACT_PUBLIC_FUNCTION(v, obj)</computeroutput> expands to code equivalent to the following (for virtual public functions that do not override, returning void):</para><para><programlisting><phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_PUBLIC_FUNCTIONS</phrase>
16686 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">internal_var</phrase> <phrase role="special">=</phrase>
16687 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">obj</phrase><phrase role="special">)</phrase>
16688 <phrase role="preprocessor">#endif</phrase>
16689 </programlisting></para><para>3. <computeroutput>BOOST_CONTRACT_PUBLIC_FUNCTION(v, r, obj)</computeroutput> expands to code equivalent to the following (for virtual public functions that do not override, not returning void):</para><para><programlisting><phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_PUBLIC_FUNCTIONS</phrase>
16690 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">internal_var</phrase> <phrase role="special">=</phrase>
16691 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">public_function</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">r</phrase><phrase role="special">,</phrase> <phrase role="identifier">obj</phrase><phrase role="special">)</phrase>
16692 <phrase role="preprocessor">#endif</phrase>
16693 </programlisting></para><para>Where (these are all variadic macro parameters so they can contain commas not protected by round parenthesis):</para><para><itemizedlist>
16694 <listitem><para><computeroutput><emphasis role="bold">v</emphasis></computeroutput> is the extra parameter of type <computeroutput><link linkend="boost.contract.virtual_">boost::contract::virtual_</link></computeroutput><computeroutput>*</computeroutput> and default value <computeroutput>0</computeroutput> from the enclosing virtual public function declaring the contract. </para>
16696 <listitem><para><computeroutput><emphasis role="bold">r</emphasis></computeroutput> is a reference to the return value of the enclosing virtual public function declaring the contract. This is usually a local variable declared by the enclosing virtual public function just before the contract, but programmers must set it to the actual value being returned by the function at each <computeroutput>return</computeroutput> statement. </para>
16698 <listitem><para><computeroutput><emphasis role="bold">obj</emphasis></computeroutput> is the object <computeroutput>this</computeroutput> from the scope of the enclosing public function declaring the contract. This object might be mutable, <computeroutput>const</computeroutput>, <computeroutput>volatile</computeroutput>, or <computeroutput>const volatile</computeroutput> depending on the cv-qualifier of the enclosing function (volatile public functions will check volatile class invariants, see <link linkend="boost_contract.extras.volatile_public_functions">
16699 Volatile Public Functions</link>). </para>
16701 <listitem><para><computeroutput><emphasis role="bold">internal_var</emphasis></computeroutput> is a variable name internally generated by this library (this name is unique but only on different line numbers so this macro cannot be expanded multiple times on the same line).</para>
16704 <para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.extras.disable_contract_compilation__macro_interface_">
16705 Disable Contract Compilation</link>, <link linkend="boost_contract.tutorial.public_functions"> Public Functions</link>, <link linkend="boost_contract.tutorial.virtual_public_functions">
16706 Virtual Public Functions</link> </para>
16708 </para></refsect1></refentry>
16709 <refentry xmlns:xi="http://www.w3.org/2001/XInclude" id="BOOST_CO_idm45394998486064"><refmeta><refentrytitle>Macro BOOST_CONTRACT_PUBLIC_FUNCTION_OVERRIDE</refentrytitle><manvolnum>3</manvolnum></refmeta><refnamediv><refname>BOOST_CONTRACT_PUBLIC_FUNCTION_OVERRIDE</refname><refpurpose>Program contracts that can be completely disabled at compile-time for public function overrides. </refpurpose></refnamediv><refsynopsisdiv><synopsis><phrase role="comment">// In header: <<link linkend="header.boost.contract_macro_hpp">boost/contract_macro.hpp</link>>
16711 </phrase>BOOST_CONTRACT_PUBLIC_FUNCTION_OVERRIDE(...)</synopsis></refsynopsisdiv><refsect1><title>Description</title><para>This is used together with <computeroutput><link linkend="BOOST_CO_idm45394998748208">BOOST_CONTRACT_PRECONDITION</link></computeroutput>, <computeroutput><link linkend="BOOST_CO_idm45394998736528">BOOST_CONTRACT_POSTCONDITION</link></computeroutput>, <computeroutput><link linkend="BOOST_CONTRACT_EXCEPT">BOOST_CONTRACT_EXCEPT</link></computeroutput>, and <computeroutput><link linkend="BOOST_CONTRACT_OLD">BOOST_CONTRACT_OLD</link></computeroutput> to specify preconditions, postconditions, exception guarantees, and old value copies at body that can be completely disabled at compile-time for public function overrides (virtual or not):</para><para><programlisting><phrase role="keyword">class</phrase> <phrase role="identifier">u</phrase>
16712 <phrase role="preprocessor">#define</phrase> <phrase role="identifier">BASES</phrase> <phrase role="keyword">private</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">constructor_precondition</phrase><phrase role="special"><</phrase><phrase role="identifier">u</phrase><phrase role="special">></phrase><phrase role="special">,</phrase> \
16713 <phrase role="keyword">public</phrase> <phrase role="identifier">b</phrase><phrase role="special">,</phrase> <phrase role="keyword">private</phrase> <phrase role="identifier">w</phrase>
16714 <phrase role="special">:</phrase> <phrase role="identifier">BASES</phrase>
16715 <phrase role="special">{</phrase>
16716 <phrase role="keyword">friend</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">access</phrase><phrase role="special">;</phrase>
16718 <phrase role="keyword">typedef</phrase> <phrase role="identifier">BOOST_CONTRACT_BASE_TYPES</phrase><phrase role="special">(</phrase><phrase role="identifier">BASES</phrase><phrase role="special">)</phrase> <phrase role="identifier">base_types</phrase><phrase role="special">;</phrase>
16719 <phrase role="preprocessor">#undef</phrase> <phrase role="identifier">BASES</phrase>
16721 <phrase role="identifier">BOOST_CONTRACT_INVARIANT</phrase><phrase role="special">(</phrase><phrase role="special">{</phrase> <phrase role="comment">// Optional (as for static and volatile).</phrase>
16722 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16723 <phrase role="special">...</phrase>
16724 <phrase role="special">}</phrase><phrase role="special">)</phrase>
16726 <phrase role="identifier">BOOST_CONTRACT_OVERRIDES</phrase><phrase role="special">(</phrase><phrase role="identifier">f</phrase><phrase role="special">,</phrase> <phrase role="identifier">g</phrase><phrase role="special">)</phrase>
16728 <phrase role="keyword">public</phrase><phrase role="special">:</phrase>
16729 <phrase role="comment">// Override from `b::f`, and void.</phrase>
16730 <phrase role="keyword">void</phrase> <phrase role="identifier">f</phrase><phrase role="special">(</phrase><phrase role="identifier">t_1</phrase> <phrase role="identifier">a_1</phrase><phrase role="special">,</phrase> <phrase role="special">...</phrase><phrase role="special">,</phrase> <phrase role="identifier">t_n</phrase> <phrase role="identifier">a_n</phrase><phrase role="special">,</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
16731 <phrase role="identifier">BOOST_CONTRACT_OLD_PTR</phrase><phrase role="special">(</phrase><phrase role="identifier">old_type</phrase><phrase role="special">)</phrase><phrase role="special">(</phrase><phrase role="identifier">old_var</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16732 <phrase role="identifier">BOOST_CONTRACT_PUBLIC_FUNCTION_OVERRIDE</phrase><phrase role="special">(</phrase><phrase role="identifier">override_f</phrase><phrase role="special">)</phrase><phrase role="special">(</phrase>
16733 <phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="special">&</phrase><phrase role="identifier">u</phrase><phrase role="special">::</phrase><phrase role="identifier">f</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">,</phrase> <phrase role="identifier">a_1</phrase><phrase role="special">,</phrase> <phrase role="special">...</phrase><phrase role="special">,</phrase> <phrase role="identifier">a_n</phrase><phrase role="special">)</phrase>
16734 <phrase role="identifier">BOOST_CONTRACT_PRECONDITION</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
16735 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16736 <phrase role="special">...</phrase>
16737 <phrase role="special">}</phrase><phrase role="special">)</phrase>
16738 <phrase role="identifier">BOOST_CONTRACT_OLD</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
16739 <phrase role="identifier">old_var</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">old_expr</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16740 <phrase role="special">...</phrase>
16741 <phrase role="special">}</phrase><phrase role="special">)</phrase>
16742 <phrase role="identifier">BOOST_CONTRACT_POSTCONDITION</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
16743 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16744 <phrase role="special">...</phrase>
16745 <phrase role="special">}</phrase><phrase role="special">)</phrase>
16746 <phrase role="identifier">BOOST_CONTRACT_EXCEPT</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
16747 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16748 <phrase role="special">...</phrase>
16749 <phrase role="special">}</phrase><phrase role="special">)</phrase>
16750 <phrase role="special">;</phrase> <phrase role="comment">// Trailing `;` is required.</phrase>
16752 <phrase role="special">...</phrase> <phrase role="comment">// Function body.</phrase>
16753 <phrase role="special">}</phrase>
16755 <phrase role="comment">// Override from `b::g`, and void.</phrase>
16756 <phrase role="identifier">t</phrase> <phrase role="identifier">g</phrase><phrase role="special">(</phrase><phrase role="identifier">t_1</phrase> <phrase role="identifier">a_1</phrase><phrase role="special">,</phrase> <phrase role="special">...</phrase><phrase role="special">,</phrase> <phrase role="identifier">t_n</phrase> <phrase role="identifier">a_n</phrase><phrase role="special">,</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">virtual_</phrase><phrase role="special">*</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase>
16757 <phrase role="identifier">t</phrase> <phrase role="identifier">result</phrase><phrase role="special">;</phrase>
16758 <phrase role="identifier">BOOST_CONTRACT_OLD_PTR</phrase><phrase role="special">(</phrase><phrase role="identifier">old_type</phrase><phrase role="special">)</phrase><phrase role="special">(</phrase><phrase role="identifier">old_var</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16759 <phrase role="identifier">BOOST_CONTRACT_PUBLIC_FUNCTION_OVERRIDE</phrase><phrase role="special">(</phrase><phrase role="identifier">override_g</phrase><phrase role="special">)</phrase><phrase role="special">(</phrase>
16760 <phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">result</phrase><phrase role="special">,</phrase> <phrase role="special">&</phrase><phrase role="identifier">u</phrase><phrase role="special">::</phrase><phrase role="identifier">g</phrase><phrase role="special">,</phrase> <phrase role="keyword">this</phrase><phrase role="special">,</phrase> <phrase role="identifier">a_1</phrase><phrase role="special">,</phrase> <phrase role="special">...</phrase><phrase role="special">,</phrase> <phrase role="identifier">a_n</phrase><phrase role="special">)</phrase>
16761 <phrase role="special">...</phrase>
16762 <phrase role="identifier">BOOST_CONTRACT_OLD</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional.</phrase>
16763 <phrase role="identifier">old_var</phrase> <phrase role="special">=</phrase> <phrase role="identifier">BOOST_CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">old_expr</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16764 <phrase role="special">...</phrase>
16765 <phrase role="special">}</phrase><phrase role="special">)</phrase>
16766 <phrase role="identifier">BOOST_CONTRACT_POSTCONDITION</phrase><phrase role="special">(</phrase><phrase role="special">[</phrase><phrase role="special">&</phrase><phrase role="special">]</phrase> <phrase role="special">(</phrase><phrase role="identifier">t</phrase> <phrase role="keyword">const</phrase><phrase role="special">&</phrase> <phrase role="identifier">result</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase> <phrase role="comment">// Optional</phrase>
16767 <phrase role="identifier">BOOST_CONTRACT_ASSERT</phrase><phrase role="special">(</phrase><phrase role="special">...</phrase><phrase role="special">)</phrase><phrase role="special">;</phrase>
16768 <phrase role="special">...</phrase>
16769 <phrase role="special">}</phrase><phrase role="special">)</phrase>
16770 <phrase role="special">...</phrase>
16771 <phrase role="special">;</phrase> <phrase role="comment">// Trailing `;` is required.</phrase>
16773 <phrase role="special">...</phrase> <phrase role="comment">// Function body (use `return result = return_expr`).</phrase>
16774 <phrase role="special">}</phrase>
16776 <phrase role="special">...</phrase>
16777 <phrase role="special">}</phrase><phrase role="special">;</phrase>
16778 </programlisting></para><para>Public function overrides should always use <computeroutput><link linkend="BOOST_CO_idm45394998486064">BOOST_CONTRACT_PUBLIC_FUNCTION_OVERRIDE</link></computeroutput> otherwise this library will not be able to correctly use it for subcontracting.</para><para>This is an overloaded variadic macro and it can be used in the following different ways (note that no code is generated when <computeroutput><link linkend="BOOST_CO_idm45394999586272">BOOST_CONTRACT_NO_PUBLIC_FUNCTIONS</link></computeroutput> is defined).</para><para>1. <computeroutput>BOOST_CONTRACT_PUBLIC_FUNCTION_OVERRIDE(override_type)(v, f, obj, ...)</computeroutput> expands to code equivalent to the following (for public function overrides that return void):</para><para><programlisting><phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_PUBLIC_FUNCTIONS</phrase>
16779 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">internal_var</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase>
16780 <phrase role="identifier">public_function</phrase><phrase role="special"><</phrase><phrase role="identifier">override_type</phrase><phrase role="special">></phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">f</phrase><phrase role="special">,</phrase> <phrase role="identifier">obj</phrase><phrase role="special">,</phrase> <phrase role="special">...</phrase><phrase role="special">)</phrase>
16781 <phrase role="preprocessor">#endif</phrase>
16782 </programlisting></para><para>2. <computeroutput>BOOST_CONTRACT_PUBLIC_FUNCTION_OVERRIDE(override_type)(v, r, f, obj, ...)</computeroutput> expands to code equivalent to the following (for public function overrides that do not return void):</para><para><programlisting><phrase role="preprocessor">#ifndef</phrase> <phrase role="identifier">BOOST_CONTRACT_NO_PUBLIC_FUNCTIONS</phrase>
16783 <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase><phrase role="identifier">check</phrase> <phrase role="identifier">internal_var</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">contract</phrase><phrase role="special">::</phrase>
16784 <phrase role="identifier">public_function</phrase><phrase role="special"><</phrase><phrase role="identifier">override_type</phrase><phrase role="special">></phrase><phrase role="special">(</phrase><phrase role="identifier">v</phrase><phrase role="special">,</phrase> <phrase role="identifier">r</phrase><phrase role="special">,</phrase> <phrase role="identifier">f</phrase><phrase role="special">,</phrase> <phrase role="identifier">obj</phrase><phrase role="special">,</phrase> <phrase role="special">...</phrase><phrase role="special">)</phrase>
16785 <phrase role="preprocessor">#endif</phrase>
16786 </programlisting></para><para>Where (these are all variadic macro parameters so they can contain commas not protected by round parenthesis):</para><para><itemizedlist>
16787 <listitem><para><computeroutput><emphasis role="bold">override_type</emphasis></computeroutput> is the type <computeroutput>override_<emphasis>function-name</emphasis></computeroutput> declared using the <computeroutput><link linkend="BOOST_CONTRACT_OVERRIDE">BOOST_CONTRACT_OVERRIDE</link></computeroutput> or related macros. </para>
16789 <listitem><para><computeroutput><emphasis role="bold">v</emphasis></computeroutput> is the extra parameter of type <computeroutput><link linkend="boost.contract.virtual_">boost::contract::virtual_</link></computeroutput><computeroutput>*</computeroutput> and default value <computeroutput>0</computeroutput> from the enclosing virtual public function declaring the contract. </para>
16791 <listitem><para><computeroutput><emphasis role="bold">r</emphasis></computeroutput> is a reference to the return value of the enclosing virtual public function declaring the contract. This is usually a local variable declared by the enclosing virtual public function just before the contract, but programmers must set it to the actual value being returned by the function at each <computeroutput>return</computeroutput> statement. </para>
16793 <listitem><para><computeroutput><emphasis role="bold">f</emphasis></computeroutput> is a pointer to the enclosing public function override declaring the contract. </para>
16795 <listitem><para><computeroutput><emphasis role="bold">obj</emphasis></computeroutput> is the object <computeroutput>this</computeroutput> from the scope of the enclosing public function declaring the contract. This object might be mutable, <computeroutput>const</computeroutput>, <computeroutput>volatile</computeroutput>, or <computeroutput>const volatile</computeroutput> depending on the cv-qualifier of the enclosing function (volatile public functions will check volatile class invariants, see <link linkend="boost_contract.extras.volatile_public_functions">
16796 Volatile Public Functions</link>). </para>
16798 <listitem><para><computeroutput><emphasis role="bold">...</emphasis></computeroutput> is a variadic macro parameter listing all the arguments passed to the enclosing public function override declaring the contract (by reference and in the order they appear in the enclosing function declaration), but excluding the trailing argument <computeroutput>v</computeroutput>. </para>
16800 <listitem><para><computeroutput><emphasis role="bold">internal_var</emphasis></computeroutput> is a variable name internally generated by this library (this name is unique but only on different line numbers so this macro cannot be expanded multiple times on the same line).</para>
16803 <para><emphasis role="bold">See Also:</emphasis><para> <link linkend="boost_contract.extras.disable_contract_compilation__macro_interface_">
16804 Disable Contract Compilation</link>, <link linkend="boost_contract.tutorial.public_function_overrides__subcontracting_">
16805 Public Function Overrides</link> </para>
16807 </para></refsect1></refentry>
16810 <section id="boost_contract.release_notes">
16811 <title><link linkend="boost_contract.release_notes">Release Notes</link></title>
16813 This section contains notes on all releases of this library (from the latest
16816 <section id="boost_contract.release_notes.release_1_0_1">
16817 <title><link linkend="boost_contract.release_notes.release_1_0_1">Release 1.0.1</link></title>
16822 Cleanups and small fixes:
16824 <orderedlist inheritnum="ignore" continuation="restarts">
16827 Using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">uncaught_exceptions</phrase></computeroutput> on C++17 compilers
16828 onward (instead of the now obsolete <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">uncaught_exception</phrase></computeroutput>).
16833 Fixed a few warnings.
16838 Removed linking to Boost.System (Boost.System is now a header-only library).
16843 Added this library to Boost's Continuous Integration (CI).
16848 Fixed documentation typos.
16853 Released files are part of <ulink url="https://www.boost.org/users/history/">Boost
16857 <section id="boost_contract.release_notes.release_1_0_0">
16858 <title><link linkend="boost_contract.release_notes.release_1_0_0">Release 1.0.0</link></title>
16860 January 6, 2018 (Il Giorno della Befana)
16863 First Boost release:
16865 <orderedlist inheritnum="ignore" continuation="restarts">
16868 Fixed all tests to pass as Boost regression tests (and marked those that
16869 are expected to fail on some specific compiler/platform versions).
16874 Adjusted build scripts to work within Boost libraries.
16879 Updated documentation to fit as a Boost library.
16884 Released files are part of <ulink url="https://www.boost.org/users/history/">Boost
16888 <section id="boost_contract.release_notes.release_0_5_0">
16889 <title><link linkend="boost_contract.release_notes.release_0_5_0">Release 0.5.0</link></title>
16894 Contracts without the macros:
16896 <orderedlist inheritnum="ignore" continuation="restarts">
16899 Using plain C++ code instead of macros to program contracts.
16900 <orderedlist inheritnum="ignore" continuation="restarts">
16903 The removed macros very hard to use because they required programmers
16904 to learn a domain-specific embedded language that replaced the
16905 usual C++ syntax for declaring functions and classes.
16910 The removed macros also made the code less readable, increased
16911 compilation time (because of extensive preprocessor meta-programming),
16912 and gave cryptic compiler errors.
16917 However, the removed macros more correctly specified contracts
16918 in code declarations instead of definitions, and they completely
16919 removed extra code when contracts were disabled (both of those
16920 can be done by the current version of this library but at the cost
16921 of manually writing some boiler-plate code which was previous automatically
16922 handled by the macros instead, see <link linkend="boost_contract.extras.separate_body_implementation">Separate
16923 Body Implementation</link> and <link linkend="boost_contract.extras.disable_contract_compilation__macro_interface_">Disable
16924 Contract Compilation</link>).
16932 Simplified the library by removing some extra features that were not
16933 directly related to contract programming, specifically:
16934 <orderedlist inheritnum="ignore" continuation="restarts">
16937 Removed loop variants (because these are rarely if ever used).
16942 Removed named and deduced parameters (because these can be programmed
16943 directly using <ulink url="http://www.boost.org/doc/libs/release/libs/parameter/doc/html/index.html">Boost.Parameter</ulink>).
16948 Removed concepts (because these can be programmed directly using
16949 <ulink url="http://www.boost.org/doc/libs/1_65_0/libs/concept_check/concept_check.htm">Boost.ConceptCheck</ulink>).
16954 Removed emulation of virtual specifiers <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">override</phrase></computeroutput>,
16955 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">final</phrase></computeroutput>, and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">new</phrase></computeroutput> (because <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">override</phrase></computeroutput>
16956 can be programmed directly using C++11, while <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">final</phrase></computeroutput>
16957 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">new</phrase></computeroutput> are rarely
16963 Removed <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">static_assert</phrase></computeroutput>
16964 emulation (because this can be programmed directly using C++11,
16965 or using <ulink url="http://www.boost.org/doc/libs/1_65_0/doc/html/boost_staticassert.html">Boost.StaticAssert</ulink>).
16973 Ensuring that old values and return values are copied only once even
16974 when subcontracting is used with multiple inheritance.
16979 Improved template meta-programming algorithm that searches the inheritance
16980 tree for subcontracting when multiple inheritance is used.
16985 Exception specifications and function-try blocks apply also to exceptions
16986 thrown by the contracts, and not just to exceptions thrown by the body.
16991 Added contracts for exception guarantees (using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase><phrase role="identifier">except</phrase><phrase role="special">(...)</phrase></computeroutput>,
16997 Added predefined assertion levels for "audit" and "axiom".
17002 Added <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">call_if</phrase></computeroutput> and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">condition_if</phrase></computeroutput> (assertions requirements
17003 were supported also by previous revisions of this library but they were
17004 handled by internal code generated by the contract macros).
17009 Released <ulink url="https://github.com/boostorg/contract/releases/tag/v0.5.0">files</ulink>.
17012 <section id="boost_contract.release_notes.release_0_4_1">
17013 <title><link linkend="boost_contract.release_notes.release_0_4_1">Release 0.4.1</link></title>
17016 This revision of the library passed Boost formal review and it was accepted
17017 into the Boost libraries (see <ulink url="https://groups.google.com/forum/?fromgroups=#!topic/boost-list/jQ7OjAmos_Y">https://groups.google.com/forum/?fromgroups=#!topic/boost-list/jQ7OjAmos_Y</ulink>).
17024 Accepted into Boost:
17026 <orderedlist inheritnum="ignore" continuation="restarts">
17029 Using non-fix-spaced font in Full Table of Contents section.
17034 Added a couple of notes to the documentation.
17039 Changed <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">CONTRACT_MEMBER_BODY</phrase><phrase role="special">(</phrase><phrase role="identifier">class_type</phrase><phrase role="special">,</phrase> <phrase role="identifier">function_name</phrase><phrase role="special">)</phrase></computeroutput> to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">class_type</phrase><phrase role="special">::</phrase><phrase role="identifier">CONTRACT_MEMBER_BODY</phrase><phrase role="special">(</phrase><phrase role="identifier">function_name</phrase><phrase role="special">)</phrase></computeroutput> so the macro can also be used to declare
17040 derived classes avoiding using the library syntax even when the base
17041 class has contracts.
17046 Released <ulink url="https://github.com/boostorg/contract/releases/tag/v0.4.1">files</ulink>.
17049 <section id="boost_contract.release_notes.release_0_4_0">
17050 <title><link linkend="boost_contract.release_notes.release_0_4_0">Release 0.4.0</link></title>
17055 Simplified syntax, added named parameters and concepts:
17057 <orderedlist inheritnum="ignore" continuation="restarts">
17060 Simplified syntax by reducing extra parenthesis to the bare necessary
17061 minimum (using some of the preprocessor parsing techniques originally
17062 introduced by Boost.LocalFunction).
17067 Postcondition old values only copy the old-of expression (e.g., copy
17068 just vector size instead of entire vector). This improves performance
17069 and introduces the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">ConstantCopyConstructible</phrase></computeroutput>
17070 requirement just for the old value expression type (e.g., a vector might
17071 not be copyable while its size always is because it is an integral type).
17072 Removed the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">copyable</phrase></computeroutput>
17078 Body defined outside the macros (so compiler-errors for definitions retain
17079 their usual meaning).
17084 Added <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">CONTRACT_CLASS</phrase></computeroutput>
17085 macro and removed the need to duplicate declaration elements (do not
17086 repeat function declaration, do not repeat class name in function declaration,
17092 Using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">_TPL</phrase></computeroutput> macros so
17093 to reduce compile-time (instead of internally making all templates contract
17094 functions so to use <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">typename</phrase></computeroutput>
17100 Overloading no longer requires unique parameter names.
17105 Added C++11-like virtual specifiers.
17110 Added constant assertions plus constant-expressions for select assertion
17111 if-conditions and for loop variants.
17116 Added named and deduced parameters.
17121 Added concept checking.
17126 Removed the interface to use the library without the macro (programmers
17127 were required to write too much boiler-plate code for the non-macro interface
17128 to be actually usable, plus supporting both the macro and non-macro interfaces
17129 limited what the macros could do).
17134 Released <ulink url="https://github.com/boostorg/contract/releases/tag/v0.4.0">files</ulink>.
17137 <section id="boost_contract.release_notes.release_0_3_490">
17138 <title><link linkend="boost_contract.release_notes.release_0_3_490">Release
17139 0.3.490</link></title>
17144 Support for most/all C++ constructs:
17146 <orderedlist inheritnum="ignore" continuation="restarts">
17149 Added support and examples for <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">volatile</phrase></computeroutput>,
17150 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">auto</phrase></computeroutput>, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">explicit</phrase></computeroutput>,
17151 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">export</phrase></computeroutput>, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">extern</phrase></computeroutput>,
17152 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">friend</phrase></computeroutput>, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">inline</phrase></computeroutput>,
17153 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">struct</phrase></computeroutput>, and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">throw</phrase></computeroutput> (for exception specifications).
17158 Documented that <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">union</phrase></computeroutput> cannot
17164 Released <ulink url="https://github.com/boostorg/contract/releases/tag/v0.3.490">files</ulink>.
17167 <section id="boost_contract.release_notes.release_0_3_469">
17168 <title><link linkend="boost_contract.release_notes.release_0_3_469">Release
17169 0.3.469</link></title>
17174 Support for most/all contract programming features:
17176 <orderedlist inheritnum="ignore" continuation="restarts">
17179 Removed use of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">self</phrase></computeroutput>,
17180 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">variable</phrase><phrase role="special">.</phrase><phrase role="identifier">now</phrase></computeroutput>, and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">variable</phrase><phrase role="special">.</phrase><phrase role="identifier">old</phrase></computeroutput>
17181 in writing contracts. Object <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">this</phrase></computeroutput>
17182 and variables are now accessed as usual in member functions. <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">CONTRACT_OLDOF</phrase><phrase role="special">(</phrase><phrase role="identifier">variable</phrase><phrase role="special">)</phrase></computeroutput>
17183 is used to access old values in postconditions.
17188 Added <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">(</phrase><phrase role="identifier">precondition</phrase><phrase role="special">)</phrase></computeroutput>, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">(</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">)</phrase></computeroutput>,
17189 and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">(</phrase><phrase role="identifier">body</phrase><phrase role="special">)</phrase></computeroutput> to specify contracts within the function
17190 signature sequence. If no preconditions then <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">(</phrase><phrase role="identifier">precondition</phrase><phrase role="special">)</phrase>
17191 <phrase role="special">({...})</phrase></computeroutput> is simply omitted from
17192 the sequence (same for postconditions, body is mandatory instead). For
17193 non-void functions, users can name the result argument with <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">(</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">)</phrase> <phrase role="special">(</phrase><phrase role="identifier">result</phrase><phrase role="special">-</phrase><phrase role="identifier">name</phrase><phrase role="special">)</phrase> <phrase role="special">({...})</phrase></computeroutput>.
17198 Changed contract class template to use same syntax as Boost.Function
17199 (i.e., <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">F</phrase></computeroutput> function type).
17204 Added support for free functions and static member functions.
17209 Added support for subcontracting with multiple inheritance.
17214 Added static class invariants which are always checked (also at constructors
17215 entry, destructor exit, and by static member functions).
17220 Added block invariants and Eiffel-like loop variants.
17225 Added handlers to customize action on contract failure (default to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">terminate</phrase><phrase role="special">()</phrase></computeroutput>).
17230 Removed feature for automatic contract documentation using Doxygen (this
17231 is not compatible with added <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">(</phrase><phrase role="identifier">precondition</phrase><phrase role="special">)</phrase></computeroutput>,
17232 <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">(</phrase><phrase role="identifier">postcondition</phrase><phrase role="special">)</phrase></computeroutput>, and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">(</phrase><phrase role="identifier">body</phrase><phrase role="special">)</phrase></computeroutput>
17233 because Doxygen preprocessor is not capable to handle Boost.Preprocessor
17239 Rewritten entire documentation (now using Boost.QuickBook instead of
17245 Released <ulink url="https://github.com/boostorg/contract/releases/tag/v0.3.469">files</ulink>.
17248 <section id="boost_contract.release_notes.release_0_2_190">
17249 <title><link linkend="boost_contract.release_notes.release_0_2_190">Release
17250 0.2.190</link></title>
17255 Compiled on both GCC and MSVC:
17257 <orderedlist inheritnum="ignore" continuation="restarts">
17260 Compiled using both GCC (Linux and Cygwin) and MSVC (Windows XP).
17265 Required to use void to specify empty function argument list. This is
17266 to comply with C++03 standard that does not allow to pass empty macro
17267 parameters so it does not support empty preprocessor sequences <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">()</phrase></computeroutput>.
17272 Released <ulink url="https://github.com/boostorg/contract/releases/tag/v0.2.190">files</ulink>.
17275 <section id="boost_contract.release_notes.release_0_1_126">
17276 <title><link linkend="boost_contract.release_notes.release_0_1_126">Release
17277 0.1.126</link></title>
17282 Added documentation:
17284 <orderedlist inheritnum="ignore" continuation="restarts">
17287 Completed first documentation draft.
17292 Released <ulink url="https://github.com/boostorg/contract/releases/tag/v0.1.126">files</ulink>.
17295 <section id="boost_contract.release_notes.release_0_1_55">
17296 <title><link linkend="boost_contract.release_notes.release_0_1_55">Release
17297 0.1.55</link></title>
17302 Cleaned-up first release:
17304 <orderedlist inheritnum="ignore" continuation="restarts">
17307 Reorganized files to cleanup root directory.
17312 Added installation program.
17317 Released <ulink url="https://github.com/boostorg/contract/releases/tag/v0.1.55">files</ulink>.
17320 <section id="boost_contract.release_notes.release_0_1_50">
17321 <title><link linkend="boost_contract.release_notes.release_0_1_50">Release
17322 0.1.50</link></title>
17329 <orderedlist inheritnum="ignore" continuation="restarts">
17332 First public release.
17337 Released <ulink url="https://github.com/boostorg/contract/releases/tag/v0.1.50">files</ulink>.
17341 <section id="boost_contract.bibliography">
17342 <title><link linkend="boost_contract.bibliography">Bibliography</link></title>
17344 This section lists all references consulted while designing and developing
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17441 Widman. <ulink url="http://www.open-std.org/JTC1/SC22/WG21/docs/papers/2005/n1773.html"><emphasis>Proposal
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17446 <anchor id="N1866_anchor"/>[N1866] L. Crowl and T. Ottosen. <ulink url="http://www.open-std.org/JTC1/SC22/WG21/docs/papers/2005/n1866.html"><emphasis>Proposal
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17451 <anchor id="N1895_anchor"/>[N1895] H. Sutter and F. Glassborow. <ulink url="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2005/n1895.pdf"><emphasis>Delegating
17452 Constructors (revision 2)</emphasis></ulink>. C++ Standards Committee, N1895,
17456 <anchor id="N1962_anchor"/>[N1962] L. Crowl and T. Ottosen. <ulink url="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2006/n1962.html"><emphasis>Proposal
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17461 <anchor id="N2081_anchor"/>[N2081] D. Gregor and B. Stroustrup. <ulink url="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2006/n2081.pdf"><emphasis>Concepts
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17465 <anchor id="N2887_anchor"/>[N2887] G. Dos Reis, B. Stroustrup, and A. Meredith.
17466 <ulink url="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2887.pdf"><emphasis>Axioms:
17467 Semantics Aspects of C++ Concepts</emphasis></ulink>. The C++ Standards Committee,
17471 <anchor id="N2914_anchor"/>[N2914] P. Becker. <ulink url="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2914.pdf"><emphasis>Working
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17473 Committee, N2914, 2009.
17476 <anchor id="N2906_anchor"/>[N2906] B. Stroustrup. <ulink url="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2906.pdf"><emphasis>Simplifying
17477 the sue of concepts</emphasis></ulink>. The C++ Standards Committee, N2906,
17481 <anchor id="N3248_anchor"/>[N3248] J. Lakos. <ulink url="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2011/n3248.pdf"><emphasis><literal moreinfo="none">noexcept</literal>
17482 Prevents Library Validation</emphasis></ulink>. The C++ Standards Committee,
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17491 <anchor id="N4160_anchor"/>[N4160] A. Krzemienski. <ulink url="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4160.html"><emphasis>Value
17492 constraints</emphasis></ulink>. The C++ Standards Committee, N4160, 2014.
17495 <anchor id="N4248_anchor"/>[N4248] A. Meredith. <ulink url="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4248.html"><emphasis>Library
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17497 Committee, N4248, 2014.
17500 <anchor id="N4293_anchor"/>[N4293] J. D. Garcia. <ulink url="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4293.pdf"><emphasis>C++
17501 language support for contract programming</emphasis></ulink>. The C++ Standards
17502 Committee, N4293, 2014.
17505 <anchor id="N4378_anchor"/>[N4378] J. Lakos, N. Myers, A. Zakharov, and A.
17506 Beels. <ulink url="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4378.pdf"><emphasis>Language
17507 Support for Contract Assertions (Revision 10)</emphasis></ulink>. The C++ Standards
17508 Committee, N4378, 2015.
17511 <anchor id="Nana_anchor"/>[Nana] P. J. Maker. <ulink url="https://github.com/pjmaker/nana"><emphasis>GNU
17512 Nana</emphasis></ulink>. 2014.
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17516 about Contract Assertions</emphasis></ulink>. The C++ Standards Committee,
17520 <anchor id="N4435_anchor"/>[N4435] W. E. Brown. <ulink url="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4435.pdf"><emphasis>Proposing
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17547 N. Myers, and B. Stroustrup. <ulink url="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0380r1.pdf"><emphasis>A
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17553 for contract based programming in C++</emphasis></ulink>. The C++ Standards
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17575 C++ Programming Language</emphasis>. Addison Wesley, 4th Edition, 2013.
17578 <anchor id="Tandin04_anchor"/>[Tandin04] A. Tandin. <ulink url="http://www.codeproject.com/KB/macros/DbC_and_Doxygen.aspx"><emphasis>Design
17579 by Contract macros for C++ and link to Doxygen</emphasis></ulink>. 2004.
17582 <anchor id="Wilson06_anchor"/>[Wilson06] M. Wilson. <ulink url="http://www.artima.com/cppsource/deepspace.html"><emphasis>Contract
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17587 <section id="boost_contract.acknowledgments">
17588 <title><link linkend="boost_contract.acknowledgments">Acknowledgments</link></title>
17590 This section tries to recognize the contributions of all the different people
17591 that participated directly or indirectly to the design and development of this
17595 Sincere thanks to my parents for their support with my education and my studies
17596 in computer science.
17599 Many thanks to Andrzej Krzemienski for reviewing early versions of this library
17600 providing valuable insights and exchanging early ideas on assertion requirements.
17603 Many thanks to Vicente J. Botet Escriba for reviewing earlier versions of this
17604 library providing valuable insights and for suggesting to use a dedicated trait
17605 to copy old values.
17608 Thanks to Steven Watanabe for providing valuable insights on C++, SFINAE, and
17612 Thanks to Dave Abrahams for moderating the Boost review of this library.
17615 Thanks to Daniel James for his help with incorporating this library files into
17616 the Boost Git repository.
17619 Thanks to James E. King III for integrating this library with Boost's Continuous
17623 Thanks to David Maley for sharing source code form his inspiring work on emulating
17624 contract programming and subcontracting in C++ in <link linkend="Maley99_anchor">[Maley99]</link>.
17627 Many thanks to Thorsten Ottosen for his work on the <link linkend="N1962_anchor">[N1962]</link>
17628 proposal (and its previous revisions) and for clarifying the proposal requirements
17629 directly with the library authors when needed.
17632 Many thanks to Bertrand Meyer for his pioneering and thorough work on contract
17633 programming in <link linkend="Meyer97_anchor">[Meyer97]</link>.
17636 Finally, many thanks to the entire Boost community and <ulink url="http://lists.boost.org">mailing
17637 list</ulink> for providing valuable comments on this library and great insights
17638 on the C++ programming language.