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  24 </div>
  25 <div class="section">
  26 <div class="titlepage"><div><div><h4 class="title">
  27 <a name="boost_test.testing_tools.extended_comparison.strings"></a><a class="link" href="strings.html" title="Strings and C-strings comparison">Strings
  28         and C-strings comparison</a>
  29 </h4></div></div></div>
  30 <p>
  31           In the general case, pointers are compared using their value. However when
  32           type of the the pointers are <code class="computeroutput"><span class="keyword">char</span><span class="special">*</span></code> or <code class="computeroutput"><span class="keyword">wchar_t</span><span class="special">*</span></code>, <a class="link" href="../../utf_reference/testing_tool_ref/assertion_boost_test_universal_macro.html" title="BOOST_TEST"><code class="computeroutput"><span class="identifier">BOOST_TEST</span></code></a> promotes them as null
  33           terminated <code class="computeroutput"><span class="keyword">char</span></code> arrays and
  34           string comparison is used instead. <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span></code>
  35           (or any <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_string</span></code>) and <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">string_view</span></code>
  36           (or any <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_string_view</span></code>) are eligible for string
  37           comparison.
  38         </p>
  39 <p>
  40           String comparison can be used only if the operands to compare in <a class="link" href="../../utf_reference/testing_tool_ref/assertion_boost_test_universal_macro.html" title="BOOST_TEST"><code class="computeroutput"><span class="identifier">BOOST_TEST</span></code></a> can both be considered
  41           as strings type.
  42         </p>
  43 <div class="tip"><table border="0" summary="Tip">
  44 <tr>
  45 <td rowspan="2" align="center" valign="top" width="25"><img alt="[Tip]" src="../../../../../../../doc/src/images/tip.png"></td>
  46 <th align="left">Tip</th>
  47 </tr>
  48 <tr><td align="left" valign="top"><p>
  49             In this form, the comparison method and reporting can be overridden an
  50             additional argument to <a class="link" href="../../utf_reference/testing_tool_ref/assertion_boost_test_universal_macro.html" title="BOOST_TEST"><code class="computeroutput"><span class="identifier">BOOST_TEST</span></code></a>. See the <a class="link" href="collections.html" title="Collections comparison">collection
  51             comparison</a> section for more details, in particular <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">test_tools</span><span class="special">::</span><span class="identifier">per_element</span><span class="special">()</span></code>
  52             and <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">test_tools</span><span class="special">::</span><span class="identifier">lexicographic</span><span class="special">()</span></code>
  53             modifiers.
  54           </p></td></tr>
  55 </table></div>
  56 <h6>
  57 <a name="boost_test.testing_tools.extended_comparison.strings.h0"></a>
  58           <span class="phrase"><a name="boost_test.testing_tools.extended_comparison.strings.example_descr"></a></span><a class="link" href="strings.html#boost_test.testing_tools.extended_comparison.strings.example_descr">Example:
  59           BOOST_TEST string comparison</a>
  60         </h6>
  61 <div class="informaltable"><table class="table">
  62 <colgroup><col></colgroup>
  63 <thead><tr><th>
  64                   <p>
  65                     Code
  66                   </p>
  67                 </th></tr></thead>
  68 <tbody><tr><td>
  69 <pre xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="table-programlisting"><span class="preprocessor">#define</span> <span class="identifier">BOOST_TEST_MODULE</span> <span class="identifier">boost_test_strings</span>
  70 <span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">test</span><span class="special">/</span><span class="identifier">included</span><span class="special">/</span><span class="identifier">unit_test</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
  71
  72 <span class="identifier">BOOST_AUTO_TEST_CASE</span><span class="special">(</span> <span class="identifier">test_pointers</span> <span class="special">)</span>
  73 <span class="special">{</span>
  74   <span class="keyword">float</span> <span class="identifier">a</span><span class="special">(</span><span class="number">0.5f</span><span class="special">),</span> <span class="identifier">b</span><span class="special">(</span><span class="number">0.5f</span><span class="special">);</span>
  75   <span class="keyword">const</span> <span class="keyword">float</span><span class="special">*</span> <span class="identifier">pa</span> <span class="special">=</span> <span class="special">&amp;</span><span class="identifier">a</span><span class="special">,</span> <span class="special">*</span><span class="identifier">pb</span> <span class="special">=</span> <span class="special">&amp;</span><span class="identifier">b</span><span class="special">;</span>
  76   <span class="identifier">BOOST_TEST</span><span class="special">(</span><span class="identifier">a</span> <span class="special">==</span> <span class="identifier">b</span><span class="special">);</span>
  77   <span class="identifier">BOOST_TEST</span><span class="special">(</span><span class="identifier">pa</span> <span class="special">==</span> <span class="identifier">pb</span><span class="special">);</span>
  78 <span class="special">}</span>
  79
  80 <span class="identifier">BOOST_AUTO_TEST_CASE</span><span class="special">(</span> <span class="identifier">test_strings</span> <span class="special">)</span>
  81 <span class="special">{</span>
  82   <span class="keyword">const</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">a</span> <span class="special">=</span> <span class="string">"test1"</span><span class="special">;</span>
  83   <span class="keyword">const</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">b</span> <span class="special">=</span> <span class="string">"test2"</span><span class="special">;</span>
  84   <span class="keyword">const</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">c</span> <span class="special">=</span> <span class="string">"test1"</span><span class="special">;</span>
  85   <span class="identifier">BOOST_TEST</span><span class="special">(</span><span class="identifier">a</span> <span class="special">==</span> <span class="identifier">b</span><span class="special">);</span>
  86   <span class="identifier">BOOST_TEST</span><span class="special">(</span><span class="identifier">a</span> <span class="special">==</span> <span class="identifier">c</span><span class="special">);</span>
  87   <span class="identifier">BOOST_TEST</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">(</span><span class="string">"test1"</span><span class="special">)</span> <span class="special">==</span> <span class="identifier">b</span><span class="special">);</span>
  88   <span class="identifier">BOOST_TEST</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">(</span><span class="string">"test1"</span><span class="special">)</span> <span class="special">&lt;</span> <span class="identifier">a</span><span class="special">,</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">test_tools</span><span class="special">::</span><span class="identifier">per_element</span><span class="special">());</span>
  89   <span class="identifier">BOOST_TEST</span><span class="special">(</span><span class="identifier">b</span> <span class="special">&lt;</span> <span class="identifier">a</span><span class="special">,</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">test_tools</span><span class="special">::</span><span class="identifier">lexicographic</span><span class="special">());</span>
  90 <span class="special">}</span>
  91 </pre>
  92                 </td></tr></tbody>
  93 </table></div>
  94 <div class="informaltable"><table class="table">
  95 <colgroup><col></colgroup>
  96 <thead><tr><th>
  97                   <p>
  98                     Output
  99                   </p>
 100                 </th></tr></thead>
 101 <tbody><tr><td>
 102 <pre xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="table-programlisting"><span class="special">&gt;</span> <span class="special">./</span><span class="identifier">boost_test_strings</span>
 103 <span class="identifier">Running</span> <span class="number">2</span> <span class="identifier">test</span> <span class="identifier">cases</span><span class="special">...</span>
 104 <span class="identifier">test</span><span class="special">.</span><span class="identifier">cpp</span><span class="special">:</span><span class="number">17</span><span class="special">:</span> <span class="identifier">error</span><span class="special">:</span> <span class="identifier">in</span> <span class="string">"test_pointers"</span><span class="special">:</span> <span class="identifier">check</span> <span class="identifier">pa</span> <span class="special">==</span> <span class="identifier">pb</span> <span class="identifier">has</span> <span class="identifier">failed</span> <span class="special">[</span><span class="number">0</span><span class="identifier">x7fff54f9dea4</span> <span class="special">!=</span> <span class="number">0</span><span class="identifier">x7fff54f9dea0</span><span class="special">]</span>
 105 <span class="identifier">test</span><span class="special">.</span><span class="identifier">cpp</span><span class="special">:</span><span class="number">25</span><span class="special">:</span> <span class="identifier">error</span><span class="special">:</span> <span class="identifier">in</span> <span class="string">"test_strings"</span><span class="special">:</span> <span class="identifier">check</span> <span class="identifier">a</span> <span class="special">==</span> <span class="identifier">b</span> <span class="identifier">has</span> <span class="identifier">failed</span> <span class="special">[</span><span class="identifier">test1</span> <span class="special">!=</span> <span class="identifier">test2</span><span class="special">]</span>
 106 <span class="identifier">test</span><span class="special">.</span><span class="identifier">cpp</span><span class="special">:</span><span class="number">27</span><span class="special">:</span> <span class="identifier">error</span><span class="special">:</span> <span class="identifier">in</span> <span class="string">"test_strings"</span><span class="special">:</span> <span class="identifier">check</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">(</span><span class="string">"test1"</span><span class="special">)</span> <span class="special">==</span> <span class="identifier">b</span> <span class="identifier">has</span> <span class="identifier">failed</span> <span class="special">[</span><span class="identifier">test1</span> <span class="special">!=</span> <span class="identifier">test2</span><span class="special">]</span>
 107 <span class="identifier">test</span><span class="special">.</span><span class="identifier">cpp</span><span class="special">:</span><span class="number">28</span><span class="special">:</span> <span class="identifier">error</span><span class="special">:</span> <span class="identifier">in</span> <span class="string">"test_strings"</span><span class="special">:</span> <span class="identifier">check</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">(</span><span class="string">"test1"</span><span class="special">)</span> <span class="special">&lt;</span> <span class="identifier">a</span> <span class="identifier">has</span> <span class="identifier">failed</span>
 108 <span class="identifier">Mismatch</span> <span class="identifier">at</span> <span class="identifier">position</span> <span class="number">0</span><span class="special">:</span> <span class="char">'t'</span> <span class="special">&gt;=</span> <span class="char">'t'</span><span class="special">.</span>
 109 <span class="identifier">Mismatch</span> <span class="identifier">at</span> <span class="identifier">position</span> <span class="number">1</span><span class="special">:</span> <span class="char">'e'</span> <span class="special">&gt;=</span> <span class="char">'e'</span><span class="special">.</span>
 110 <span class="identifier">Mismatch</span> <span class="identifier">at</span> <span class="identifier">position</span> <span class="number">2</span><span class="special">:</span> <span class="char">'s'</span> <span class="special">&gt;=</span> <span class="char">'s'</span><span class="special">.</span>
 111 <span class="identifier">Mismatch</span> <span class="identifier">at</span> <span class="identifier">position</span> <span class="number">3</span><span class="special">:</span> <span class="char">'t'</span> <span class="special">&gt;=</span> <span class="char">'t'</span><span class="special">.</span>
 112 <span class="identifier">Mismatch</span> <span class="identifier">at</span> <span class="identifier">position</span> <span class="number">4</span><span class="special">:</span> <span class="char">'1'</span> <span class="special">&gt;=</span> <span class="char">'1'</span><span class="special">.</span>
 113 <span class="identifier">test</span><span class="special">.</span><span class="identifier">cpp</span><span class="special">:</span><span class="number">29</span><span class="special">:</span> <span class="identifier">error</span><span class="special">:</span> <span class="identifier">in</span> <span class="string">"test_strings"</span><span class="special">:</span> <span class="identifier">check</span> <span class="identifier">b</span> <span class="special">&lt;</span> <span class="identifier">a</span> <span class="identifier">has</span> <span class="identifier">failed</span>
 114 <span class="identifier">Failure</span> <span class="identifier">at</span> <span class="identifier">position</span> <span class="number">4</span><span class="special">:</span> <span class="char">'2'</span> <span class="special">&gt;=</span> <span class="char">'1'</span><span class="special">.</span>
 115
 116 <span class="special">***</span> <span class="number">5</span> <span class="identifier">failures</span> <span class="identifier">are</span> <span class="identifier">detected</span> <span class="identifier">in</span> <span class="identifier">the</span> <span class="identifier">test</span> <span class="identifier">module</span> <span class="string">"boost_test_strings"</span>
 117 </pre>
 118                 </td></tr></tbody>
 119 </table></div>
 120 <div class="note"><table border="0" summary="Note">
 121 <tr>
 122 <td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../../../../../../../doc/src/images/note.png"></td>
 123 <th align="left">Note</th>
 124 </tr>
 125 <tr><td align="left" valign="top"><p>
 126             <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">string_view</span></code> support added in Boost.Test
 127             <a class="link" href="../../change_log.html#ref_CHANGE_LOG_3_12">Boost 1.72</a>.
 128           </p></td></tr>
 129 </table></div>
 130 </div>
 131 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
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 133 <td align="right"><div class="copyright-footer">Copyright &#169; 2001-2019 Boost.Test
 134       contributors<p>
 135         Distributed under the Boost Software License, Version 1.0. (See accompanying
 136         file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
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