1<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 2 3<html> 4<head> 5 <meta http-equiv="Content-Language" content="en-us"> 6 <meta http-equiv="Content-Type" content="text/html; charset=us-ascii"> 7 8 <title>Copy Constructible</title> 9</head> 10 11<body bgcolor="#FFFFFF" link="#0000EE" text="#000000" vlink="#551A8B" alink= 12"#FF0000"> 13 <img src="../../boost.png" alt="C++ Boost" width="277" height= 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> 75T(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> 89t.~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> 186
