libs/utility/CopyConstructible.html

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   8   <title>Copy Constructible</title>
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  15
  16   <h1>Copy Constructible</h1>
  17
  18   <h3>Description</h3>
  19
  20   <p>A type is Copy Constructible if it is possible to copy objects of that
  21   type.</p>
  22
  23   <h3>Notation</h3>
  24
  25   <table summary="">
  26     <tr>
  27       <td valign="top"><tt>T</tt></td>
  28
  29       <td valign="top">is type that is a model of Copy Constructible</td>
  30     </tr>
  31
  32     <tr>
  33       <td valign="top"><tt>t</tt></td>
  34
  35       <td valign="top">is an object of type <tt>T</tt></td>
  36     </tr>
  37
  38     <tr>
  39       <td valign="top"><tt>u</tt></td>
  40
  41       <td valign="top">is an object of type <tt>const T</tt></td>
  42     </tr>
  43   </table>
  44
  45   <h3>Definitions</h3>
  46
  47   <h3>Valid expressions</h3>
  48
  49   <table border summary="">
  50     <tr>
  51       <th>Name</th>
  52
  53       <th>Expression</th>
  54
  55       <th>Return type</th>
  56
  57       <th>Semantics</th>
  58     </tr>
  59
  60     <tr>
  61       <td valign="top">Copy constructor</td>
  62
  63       <td valign="top"><tt>T(t)</tt></td>
  64
  65       <td valign="top"><tt>T</tt></td>
  66
  67       <td valign="top"><tt>t</tt> is equivalent to <tt>T(t)</tt></td>
  68     </tr>
  69
  70     <tr>
  71       <td valign="top">Copy constructor</td>
  72
  73       <td valign="top">
  74         <pre>
  75 T(u)
  76 </pre>
  77       </td>
  78
  79       <td valign="top"><tt>T</tt></td>
  80
  81       <td valign="top"><tt>u</tt> is equivalent to <tt>T(u)</tt></td>
  82     </tr>
  83
  84     <tr>
  85       <td valign="top">Destructor</td>
  86
  87       <td valign="top">
  88         <pre>
  89 t.~T()
  90 </pre>
  91       </td>
  92
  93       <td valign="top"><tt>T</tt></td>
  94
  95       <td valign="top">&nbsp;</td>
  96     </tr>
  97
  98     <tr>
  99       <td valign="top">Address Operator</td>
 100
 101       <td valign="top">
 102         <pre>
 103 &amp;t
 104 </pre>
 105       </td>
 106
 107       <td valign="top"><tt>T*</tt></td>
 108
 109       <td valign="top">denotes the address of <tt>t</tt></td>
 110     </tr>
 111
 112     <tr>
 113       <td valign="top">Address Operator</td>
 114
 115       <td valign="top">
 116         <pre>
 117 &amp;u
 118 </pre>
 119       </td>
 120
 121       <td valign="top"><tt>T*</tt></td>
 122
 123       <td valign="top">denotes the address of <tt>u</tt></td>
 124     </tr>
 125   </table>
 126
 127   <h3>Models</h3>
 128
 129   <ul>
 130     <li><tt>int</tt></li>
 131
 132     <li><tt>std::pair</tt></li>
 133   </ul>
 134
 135   <h3>Concept Checking Class</h3>
 136   <pre>
 137   template &lt;class T&gt;
 138   struct CopyConstructibleConcept
 139   {
 140     void constraints() {
 141       T a(b);            // require copy constructor
 142       T* ptr = &amp;a;       // require address of operator
 143       const_constraints(a);
 144       ignore_unused_variable_warning(ptr);
 145     }
 146     void const_constraints(const T&amp; a) {
 147       T c(a);            // require const copy constructor
 148       const T* ptr = &amp;a; // require const address of operator
 149       ignore_unused_variable_warning(c);
 150       ignore_unused_variable_warning(ptr);
 151     }
 152     T b;
 153   };
 154 </pre>
 155
 156   <h3>See also</h3>
 157
 158   <p><a href="http://www.sgi.com/tech/stl/DefaultConstructible.html">Default
 159   Constructible</a> and <a href="./Assignable.html">Assignable</a><br></p>
 160   <hr>
 161
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 165
 166   <p>Revised
 167   <!--webbot bot="Timestamp" s-type="EDITED" s-format="%d %B, %Y" startspan -->05
 168   December, 2006<!--webbot bot="Timestamp" endspan i-checksum="38516" --></p>
 169
 170   <table summary="">
 171     <tr valign="top">
 172       <td nowrap><i>Copyright &copy; 2000</i></td>
 173
 174       <td><i><a href="http://www.lsc.nd.edu/~jsiek">Jeremy Siek</a>, Univ.of
 175       Notre Dame (<a href=
 176       "mailto:jsiek@lsc.nd.edu">jsiek@lsc.nd.edu</a>)</i></td>
 177     </tr>
 178   </table>
 179
 180   <p><i>Distributed under the Boost Software License, Version 1.0. (See
 181   accompanying file <a href="../../LICENSE_1_0.txt">LICENSE_1_0.txt</a> or
 182   copy at <a href=
 183   "http://www.boost.org/LICENSE_1_0.txt">http://www.boost.org/LICENSE_1_0.txt</a>)</i></p>
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