libs/contract/doc/html/boost/contract/old_pointer.html

   1 <html>
   2 <head>
   3 <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
   4 <title>Class old_pointer</title>
   5 <link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css">
   6 <meta name="generator" content="DocBook XSL Stylesheets V1.79.1">
   7 <link rel="home" href="../../index.html" title="Chapter&#160;1.&#160;Boost.Contract 1.0.0">
   8 <link rel="up" href="../../reference.html#header.boost.contract.old_hpp" title="Header &lt;boost/contract/old.hpp&gt;">
   9 <link rel="prev" href="is_old_value_copyable.html" title="Struct template is_old_value_copyable">
  10 <link rel="next" href="old_ptr.html" title="Class template old_ptr">
  11 </head>
  12 <body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
  13 <table cellpadding="2" width="100%"><tr>
  14 <td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../boost.png"></td>
  15 <td align="center"><a href="../../../../../../index.html">Home</a></td>
  16 <td align="center"><a href="../../../../../../libs/libraries.htm">Libraries</a></td>
  17 <td align="center"><a href="http://www.boost.org/users/people.html">People</a></td>
  18 <td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td>
  19 <td align="center"><a href="../../../../../../more/index.htm">More</a></td>
  20 </tr></table>
  21 <hr>
  22 <div class="spirit-nav">
  23 <a accesskey="p" href="is_old_value_copyable.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../reference.html#header.boost.contract.old_hpp"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="old_ptr.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
  24 </div>
  25 <div class="refentry">
  26 <a name="boost.contract.old_pointer"></a><div class="titlepage"></div>
  27 <div class="refnamediv">
  28 <h2><span class="refentrytitle">Class old_pointer</span></h2>
  29 <p>boost::contract::old_pointer &#8212; Convert old value copies into old value pointers. </p>
  30 </div>
  31 <h2 xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv-title">Synopsis</h2>
  32 <div xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv"><pre class="synopsis"><span class="comment">// In header: &lt;<a class="link" href="../../reference.html#header.boost.contract.old_hpp" title="Header &lt;boost/contract/old.hpp&gt;">boost/contract/old.hpp</a>&gt;
  33
  34 </span>
  35 <span class="keyword">class</span> <a class="link" href="old_pointer.html" title="Class old_pointer">old_pointer</a> <span class="special">{</span>
  36 <span class="keyword">public</span><span class="special">:</span>
  37
  38   <span class="comment">// <a class="link" href="old_pointer.html#idm45394999074832-bb">public member functions</a></span>
  39   <span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> T<span class="special">&gt;</span> <a class="link" href="old_pointer.html#idm45394999074272-bb"><span class="keyword">operator</span> <span class="identifier">old_ptr_if_copyable</span><span class="special">&lt;</span> <span class="identifier">T</span> <span class="special">&gt;</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span>
  40   <span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> T<span class="special">&gt;</span> <a class="link" href="old_pointer.html#idm45394999068640-bb"><span class="keyword">operator</span> <span class="identifier">old_ptr</span><span class="special">&lt;</span> <span class="identifier">T</span> <span class="special">&gt;</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span>
  41 <span class="special">}</span><span class="special">;</span></pre></div>
  42 <div class="refsect1">
  43 <a name="idm45707994721776"></a><h2>Description</h2>
  44 <p>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.). </p>
  45 <div class="refsect2">
  46 <a name="idm45707994720912"></a><h3>
  47 <a name="idm45394999074832-bb"></a><code class="computeroutput">old_pointer</code> public member functions</h3>
  48 <div class="orderedlist"><ol class="orderedlist" type="1">
  49 <li class="listitem">
  50 <pre class="literallayout"><span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> T<span class="special">&gt;</span> <a name="idm45394999074272-bb"></a><span class="keyword">operator</span> <span class="identifier">old_ptr_if_copyable</span><span class="special">&lt;</span> <span class="identifier">T</span> <span class="special">&gt;</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre>Convert this object to an actual old value pointer for which the old value type <code class="computeroutput">T</code> might or not be copyable. <p>For example, this is implicitly called when assigning or initializing old value pointers of type <code class="computeroutput"><code class="computeroutput"><a class="link" href="old_ptr_if_copyable.html" title="Class template old_ptr_if_copyable">boost::contract::old_ptr_if_copyable</a></code></code>.</p>
  51 <p>
  52 </p>
  53 <div class="variablelist"><table border="0" class="variablelist compact">
  54 <colgroup>
  55 <col align="left" valign="top">
  56 <col>
  57 </colgroup>
  58 <tbody><tr>
  59 <td><p><span class="term">Template Parameters:</span></p></td>
  60 <td><div class="variablelist"><table border="0" class="variablelist compact">
  61 <colgroup>
  62 <col align="left" valign="top">
  63 <col>
  64 </colgroup>
  65 <tbody><tr>
  66 <td><p><span class="term"><code class="computeroutput">T</code></span></p></td>
  67 <td><p>Type of the pointed old value. The old value pointer will always be null if this type is not copyable (see <code class="computeroutput"><code class="computeroutput"><a class="link" href="is_old_value_copyable.html" title="Struct template is_old_value_copyable">boost::contract::is_old_value_copyable</a></code></code>), but this library will not generate a compile-time error. </p></td>
  68 </tr></tbody>
  69 </table></div></td>
  70 </tr></tbody>
  71 </table></div>
  72 </li>
  73 <li class="listitem">
  74 <pre class="literallayout"><span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> T<span class="special">&gt;</span> <a name="idm45394999068640-bb"></a><span class="keyword">operator</span> <span class="identifier">old_ptr</span><span class="special">&lt;</span> <span class="identifier">T</span> <span class="special">&gt;</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre>Convert this object to an actual old value pointer for which the old value type <code class="computeroutput">T</code> must be copyable. <p>For example, this is implicitly called when assigning or initializing old value pointers of type <code class="computeroutput"><code class="computeroutput"><a class="link" href="old_ptr.html" title="Class template old_ptr">boost::contract::old_ptr</a></code></code>.</p>
  75 <p>
  76 </p>
  77 <div class="variablelist"><table border="0" class="variablelist compact">
  78 <colgroup>
  79 <col align="left" valign="top">
  80 <col>
  81 </colgroup>
  82 <tbody><tr>
  83 <td><p><span class="term">Template Parameters:</span></p></td>
  84 <td><div class="variablelist"><table border="0" class="variablelist compact">
  85 <colgroup>
  86 <col align="left" valign="top">
  87 <col>
  88 </colgroup>
  89 <tbody><tr>
  90 <td><p><span class="term"><code class="computeroutput">T</code></span></p></td>
  91 <td><p>Type of the pointed old value. This type must be copyable (see <code class="computeroutput"><code class="computeroutput"><a class="link" href="is_old_value_copyable.html" title="Struct template is_old_value_copyable">boost::contract::is_old_value_copyable</a></code></code>), otherwise this library will generate a compile-time error when the old value pointer is dereferenced. </p></td>
  92 </tr></tbody>
  93 </table></div></td>
  94 </tr></tbody>
  95 </table></div>
  96 </li>
  97 </ol></div>
  98 </div>
  99 </div>
 100 </div>
 101 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 102 <td align="left"></td>
 103 <td align="right"><div class="copyright-footer">Copyright &#169; 2008-2019 Lorenzo Caminiti<p>
 104         Distributed under the Boost Software License, Version 1.0 (see accompanying
 105         file LICENSE_1_0.txt or a copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
 106       </p>
 107 </div></td>
 108 </tr></table>
 109 <hr>
 110 <div class="spirit-nav">
 111 <a accesskey="p" href="is_old_value_copyable.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../reference.html#header.boost.contract.old_hpp"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="old_ptr.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
 112 </div>
 113 </body>
 114 </html>