<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <meta http-equiv="Content-Language" content="en-us"> <meta http-equiv="Content-Type" content="text/html; charset=us-ascii"> <title>Copy Constructible</title> </head> <body bgcolor="#FFFFFF" link="#0000EE" text="#000000" vlink="#551A8B" alink= "#FF0000"> <img src="../../boost.png" alt="C++ Boost" width="277" height= "86"><br clear="none"> <h1>Copy Constructible</h1> <h3>Description</h3> <p>A type is Copy Constructible if it is possible to copy objects of that type.</p> <h3>Notation</h3> <table summary=""> <tr> <td valign="top"><tt>T</tt></td> <td valign="top">is type that is a model of Copy Constructible</td> </tr> <tr> <td valign="top"><tt>t</tt></td> <td valign="top">is an object of type <tt>T</tt></td> </tr> <tr> <td valign="top"><tt>u</tt></td> <td valign="top">is an object of type <tt>const T</tt></td> </tr> </table> <h3>Definitions</h3> <h3>Valid expressions</h3> <table border summary=""> <tr> <th>Name</th> <th>Expression</th> <th>Return type</th> <th>Semantics</th> </tr> <tr> <td valign="top">Copy constructor</td> <td valign="top"><tt>T(t)</tt></td> <td valign="top"><tt>T</tt></td> <td valign="top"><tt>t</tt> is equivalent to <tt>T(t)</tt></td> </tr> <tr> <td valign="top">Copy constructor</td> <td valign="top"> <pre> T(u) </pre> </td> <td valign="top"><tt>T</tt></td> <td valign="top"><tt>u</tt> is equivalent to <tt>T(u)</tt></td> </tr> <tr> <td valign="top">Destructor</td> <td valign="top"> <pre> t.~T() </pre> </td> <td valign="top"><tt>T</tt></td> <td valign="top"> </td> </tr> <tr> <td valign="top">Address Operator</td> <td valign="top"> <pre> &t </pre> </td> <td valign="top"><tt>T*</tt></td> <td valign="top">denotes the address of <tt>t</tt></td> </tr> <tr> <td valign="top">Address Operator</td> <td valign="top"> <pre> &u </pre> </td> <td valign="top"><tt>T*</tt></td> <td valign="top">denotes the address of <tt>u</tt></td> </tr> </table> <h3>Models</h3> <ul> <li><tt>int</tt></li> <li><tt>std::pair</tt></li> </ul> <h3>Concept Checking Class</h3> <pre> template <class T> struct CopyConstructibleConcept { void constraints() { T a(b); // require copy constructor T* ptr = &a; // require address of operator const_constraints(a); ignore_unused_variable_warning(ptr); } void const_constraints(const T& a) { T c(a); // require const copy constructor const T* ptr = &a; // require const address of operator ignore_unused_variable_warning(c); ignore_unused_variable_warning(ptr); } T b; }; </pre> <h3>See also</h3> <p><a href="http://www.sgi.com/tech/stl/DefaultConstructible.html">Default Constructible</a> and <a href="./Assignable.html">Assignable</a><br></p> <hr> <p><a href="http://validator.w3.org/check?uri=referer"><img border="0" src= "../../doc/images/valid-html401.png" alt="Valid HTML 4.01 Transitional" height="31" width="88"></a></p> <p>Revised <!--webbot bot="Timestamp" s-type="EDITED" s-format="%d %B, %Y" startspan -->05 December, 2006<!--webbot bot="Timestamp" endspan i-checksum="38516" --></p> <table summary=""> <tr valign="top"> <td nowrap><i>Copyright © 2000</i></td> <td><i><a href="http://www.lsc.nd.edu/~jsiek">Jeremy Siek</a>, Univ.of Notre Dame (<a href= "mailto:jsiek@lsc.nd.edu">jsiek@lsc.nd.edu</a>)</i></td> </tr> </table> <p><i>Distributed under the Boost Software License, Version 1.0. (See accompanying file <a href="../../LICENSE_1_0.txt">LICENSE_1_0.txt</a> or copy at <a href= "http://www.boost.org/LICENSE_1_0.txt">http://www.boost.org/LICENSE_1_0.txt</a>)</i></p> </body> </html>