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| 8 | <title>Copy Constructible</title> |
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| 14 | "86"><br clear="none"> |
| 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"> </td> |
| 96 | </tr> |
| 97 | |
| 98 | <tr> |
| 99 | <td valign="top">Address Operator</td> |
| 100 | |
| 101 | <td valign="top"> |
| 102 | <pre> |
| 103 | &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 | &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 <class T> |
| 138 | struct CopyConstructibleConcept |
| 139 | { |
| 140 | void constraints() { |
| 141 | T a(b); // require copy constructor |
| 142 | T* ptr = &a; // require address of operator |
| 143 | const_constraints(a); |
| 144 | ignore_unused_variable_warning(ptr); |
| 145 | } |
| 146 | void const_constraints(const T& a) { |
| 147 | T c(a); // require const copy constructor |
| 148 | const T* ptr = &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 | |
| 162 | <p><a href="http://validator.w3.org/check?uri=referer"><img border="0" src= |
| 163 | "../../doc/images/valid-html401.png" alt="Valid HTML 4.01 Transitional" |
| 164 | height="31" width="88"></a></p> |
| 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 © 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> |
| 184 | </body> |
| 185 | </html> |