1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>checked_delete</title> 5<link rel="stylesheet" href="../../../../../doc/src/boostbook.css" type="text/css"> 6<meta name="generator" content="DocBook XSL Stylesheets V1.79.1"> 7<link rel="home" href="../index.html" title="Chapter 1. Boost.Core"> 8<link rel="up" href="../index.html" title="Chapter 1. Boost.Core"> 9<link rel="prev" href="alloc_construct.html" title="alloc_construct, alloc_destroy"> 10<link rel="next" href="default_allocator.html" title="default_allocator"> 11</head> 12<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> 13<table cellpadding="2" width="100%"><tr> 14<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../boost.png"></td> 15<td align="center"><a href="../../../../../index.html">Home</a></td> 16<td align="center"><a href="../../../../../libs/libraries.htm">Libraries</a></td> 17<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> 18<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> 19<td align="center"><a href="../../../../../more/index.htm">More</a></td> 20</tr></table> 21<hr> 22<div class="spirit-nav"> 23<a accesskey="p" href="alloc_construct.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.html"><img src="../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="default_allocator.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a> 24</div> 25<div class="section"> 26<div class="titlepage"><div><div><h2 class="title" style="clear: both"> 27<a name="core.checked_delete"></a><a class="link" href="checked_delete.html" title="checked_delete">checked_delete</a> 28</h2></div></div></div> 29<div class="toc"><dl class="toc"> 30<dt><span class="section"><a href="checked_delete.html#core.checked_delete.overview">Overview</a></span></dt> 31<dt><span class="section"><a href="checked_delete.html#core.checked_delete.synopsis">Synopsis</a></span></dt> 32<dt><span class="section"><a href="checked_delete.html#core.checked_delete.checked_delete">checked_delete</a></span></dt> 33<dt><span class="section"><a href="checked_delete.html#core.checked_delete.checked_array_delete">checked_array_delete</a></span></dt> 34<dt><span class="section"><a href="checked_delete.html#core.checked_delete.checked_deleter">checked_deleter</a></span></dt> 35<dt><span class="section"><a href="checked_delete.html#core.checked_delete.checked_array_deleter">checked_array_deleter</a></span></dt> 36<dt><span class="section"><a href="checked_delete.html#core.checked_delete.acknowledgements">Acknowledgements</a></span></dt> 37</dl></div> 38<div class="simplesect"> 39<div class="titlepage"><div><div><h3 class="title"> 40<a name="idm45312830251920"></a>Authors</h3></div></div></div> 41<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 42<li class="listitem"> 43 Beman Dawes 44 </li> 45<li class="listitem"> 46 Dave Abrahams 47 </li> 48<li class="listitem"> 49 Vladimir Prus 50 </li> 51<li class="listitem"> 52 Rainer Deyke 53 </li> 54<li class="listitem"> 55 John Maddock 56 </li> 57</ul></div> 58</div> 59<div class="section"> 60<div class="titlepage"><div><div><h3 class="title"> 61<a name="core.checked_delete.overview"></a><a class="link" href="checked_delete.html#core.checked_delete.overview" title="Overview">Overview</a> 62</h3></div></div></div> 63<p> 64 The header <code class="computeroutput"><span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">checked_delete</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span></code> 65 defines two function templates, <code class="computeroutput"><span class="identifier">checked_delete</span></code> 66 and <code class="computeroutput"><span class="identifier">checked_array_delete</span></code>, 67 and two class templates, <code class="computeroutput"><span class="identifier">checked_deleter</span></code> 68 and <code class="computeroutput"><span class="identifier">checked_array_deleter</span></code>. 69 </p> 70<p> 71 The C++ Standard allows, in 5.3.5/5, pointers to incomplete class types to 72 be deleted with a delete-expression. When the class has a non-trivial destructor, 73 or a class-specific operator delete, the behavior is undefined. Some compilers 74 issue a warning when an incomplete type is deleted, but unfortunately, not 75 all do, and programmers sometimes ignore or disable warnings. 76 </p> 77<p> 78 A particularly troublesome case is when a smart pointer's destructor, such 79 as <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">scoped_ptr</span><span class="special"><</span><span class="identifier">T</span><span class="special">>::~</span><span class="identifier">scoped_ptr</span></code>, is instantiated with an incomplete 80 type. This can often lead to silent, hard to track failures. 81 </p> 82<p> 83 The supplied function and class templates can be used to prevent these problems, 84 as they require a complete type, and cause a compilation error otherwise. 85 </p> 86</div> 87<div class="section"> 88<div class="titlepage"><div><div><h3 class="title"> 89<a name="core.checked_delete.synopsis"></a><a class="link" href="checked_delete.html#core.checked_delete.synopsis" title="Synopsis">Synopsis</a> 90</h3></div></div></div> 91<pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">boost</span> 92<span class="special">{</span> 93 <span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span> <span class="keyword">void</span> <span class="identifier">checked_delete</span><span class="special">(</span><span class="identifier">T</span> <span class="special">*</span> <span class="identifier">p</span><span class="special">);</span> 94 <span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span> <span class="keyword">void</span> <span class="identifier">checked_array_delete</span><span class="special">(</span><span class="identifier">T</span> <span class="special">*</span> <span class="identifier">p</span><span class="special">);</span> 95 <span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span> <span class="keyword">struct</span> <span class="identifier">checked_deleter</span><span class="special">;</span> 96 <span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span> <span class="keyword">struct</span> <span class="identifier">checked_array_deleter</span><span class="special">;</span> 97<span class="special">}</span> 98</pre> 99</div> 100<div class="section"> 101<div class="titlepage"><div><div><h3 class="title"> 102<a name="core.checked_delete.checked_delete"></a><a class="link" href="checked_delete.html#core.checked_delete.checked_delete" title="checked_delete">checked_delete</a> 103</h3></div></div></div> 104<div class="section"> 105<div class="titlepage"><div><div><h4 class="title"> 106<a name="core.checked_delete.checked_delete.template_class_t_void_checked_de"></a><a class="link" href="checked_delete.html#core.checked_delete.checked_delete.template_class_t_void_checked_de" title="template<class T> void checked_delete(T * p);">template<class 107 T> void checked_delete(T * p);</a> 108</h4></div></div></div> 109<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 110<li class="listitem"> 111 <span class="bold"><strong>Requires:</strong></span> <code class="computeroutput"><span class="identifier">T</span></code> 112 must be a complete type. The expression <code class="computeroutput"><span class="keyword">delete</span> 113 <span class="identifier">p</span></code> must be well-formed. 114 </li> 115<li class="listitem"> 116 <span class="bold"><strong>Effects:</strong></span> <code class="computeroutput"><span class="keyword">delete</span> 117 <span class="identifier">p</span><span class="special">;</span></code> 118 </li> 119</ul></div> 120</div> 121</div> 122<div class="section"> 123<div class="titlepage"><div><div><h3 class="title"> 124<a name="core.checked_delete.checked_array_delete"></a><a class="link" href="checked_delete.html#core.checked_delete.checked_array_delete" title="checked_array_delete">checked_array_delete</a> 125</h3></div></div></div> 126<div class="section"> 127<div class="titlepage"><div><div><h4 class="title"> 128<a name="core.checked_delete.checked_array_delete.template_class_t_void_checked_ar"></a><a class="link" href="checked_delete.html#core.checked_delete.checked_array_delete.template_class_t_void_checked_ar" title="template<class T> void checked_array_delete(T * p);">template<class 129 T> void checked_array_delete(T * p);</a> 130</h4></div></div></div> 131<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 132<li class="listitem"> 133 <span class="bold"><strong>Requires:</strong></span> <code class="computeroutput"><span class="identifier">T</span></code> 134 must be a complete type. The expression <code class="computeroutput"><span class="keyword">delete</span> 135 <span class="special">[]</span> <span class="identifier">p</span></code> 136 must be well-formed. 137 </li> 138<li class="listitem"> 139 <span class="bold"><strong>Effects:</strong></span> <code class="computeroutput"><span class="keyword">delete</span> 140 <span class="special">[]</span> <span class="identifier">p</span><span class="special">;</span></code> 141 </li> 142</ul></div> 143</div> 144</div> 145<div class="section"> 146<div class="titlepage"><div><div><h3 class="title"> 147<a name="core.checked_delete.checked_deleter"></a><a class="link" href="checked_delete.html#core.checked_delete.checked_deleter" title="checked_deleter">checked_deleter</a> 148</h3></div></div></div> 149<pre class="programlisting"><span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span> <span class="keyword">struct</span> <span class="identifier">checked_deleter</span> 150<span class="special">{</span> 151 <span class="keyword">typedef</span> <span class="keyword">void</span> <span class="identifier">result_type</span><span class="special">;</span> 152 <span class="keyword">typedef</span> <span class="identifier">T</span> <span class="special">*</span> <span class="identifier">argument_type</span><span class="special">;</span> 153 <span class="keyword">void</span> <span class="keyword">operator</span><span class="special">()(</span><span class="identifier">T</span> <span class="special">*</span> <span class="identifier">p</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span> 154<span class="special">};</span> 155</pre> 156<div class="section"> 157<div class="titlepage"><div><div><h4 class="title"> 158<a name="core.checked_delete.checked_deleter.void_checked_deleter_t_operator_"></a><a class="link" href="checked_delete.html#core.checked_delete.checked_deleter.void_checked_deleter_t_operator_" title="void checked_deleter<T>::operator()(T * p) const;">void 159 checked_deleter<T>::operator()(T * p) const;</a> 160</h4></div></div></div> 161<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 162<li class="listitem"> 163 <span class="bold"><strong>Requires:</strong></span> <code class="computeroutput"><span class="identifier">T</span></code> 164 must be a complete type. The expression <code class="computeroutput"><span class="keyword">delete</span> 165 <span class="identifier">p</span></code> must be well-formed. 166 </li> 167<li class="listitem"> 168 <span class="bold"><strong>Effects:</strong></span> <code class="computeroutput"><span class="keyword">delete</span> 169 <span class="identifier">p</span><span class="special">;</span></code> 170 </li> 171</ul></div> 172</div> 173</div> 174<div class="section"> 175<div class="titlepage"><div><div><h3 class="title"> 176<a name="core.checked_delete.checked_array_deleter"></a><a class="link" href="checked_delete.html#core.checked_delete.checked_array_deleter" title="checked_array_deleter">checked_array_deleter</a> 177</h3></div></div></div> 178<pre class="programlisting"><span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span> <span class="keyword">struct</span> <span class="identifier">checked_array_deleter</span> 179<span class="special">{</span> 180 <span class="keyword">typedef</span> <span class="keyword">void</span> <span class="identifier">result_type</span><span class="special">;</span> 181 <span class="keyword">typedef</span> <span class="identifier">T</span> <span class="special">*</span> <span class="identifier">argument_type</span><span class="special">;</span> 182 <span class="keyword">void</span> <span class="keyword">operator</span><span class="special">()(</span><span class="identifier">T</span> <span class="special">*</span> <span class="identifier">p</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span> 183<span class="special">};</span> 184</pre> 185<div class="section"> 186<div class="titlepage"><div><div><h4 class="title"> 187<a name="core.checked_delete.checked_array_deleter.void_checked_array_deleter_t_ope"></a><a class="link" href="checked_delete.html#core.checked_delete.checked_array_deleter.void_checked_array_deleter_t_ope" title="void checked_array_deleter<T>::operator()(T * p) const;">void 188 checked_array_deleter<T>::operator()(T * p) const;</a> 189</h4></div></div></div> 190<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 191<li class="listitem"> 192 <span class="bold"><strong>Requires:</strong></span> <code class="computeroutput"><span class="identifier">T</span></code> 193 must be a complete type. The expression <code class="computeroutput"><span class="keyword">delete</span> 194 <span class="special">[]</span> <span class="identifier">p</span></code> 195 must be well-formed. 196 </li> 197<li class="listitem"> 198 <span class="bold"><strong>Effects:</strong></span> <code class="computeroutput"><span class="keyword">delete</span> 199 <span class="special">[]</span> <span class="identifier">p</span><span class="special">;</span></code> 200 </li> 201</ul></div> 202</div> 203</div> 204<div class="section"> 205<div class="titlepage"><div><div><h3 class="title"> 206<a name="core.checked_delete.acknowledgements"></a><a class="link" href="checked_delete.html#core.checked_delete.acknowledgements" title="Acknowledgements">Acknowledgements</a> 207</h3></div></div></div> 208<p> 209 The function templates <code class="computeroutput"><span class="identifier">checked_delete</span></code> 210 and <code class="computeroutput"><span class="identifier">checked_array_delete</span></code> 211 were originally part of <code class="computeroutput"><span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">utility</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span></code>, 212 and the documentation acknowledged Beman Dawes, Dave Abrahams, Vladimir Prus, 213 Rainer Deyke, John Maddock, and others as contributors. 214 </p> 215</div> 216</div> 217<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 218<td align="left"></td> 219<td align="right"><div class="copyright-footer">Copyright © 2014 Peter Dimov<br>Copyright © 2014 Glen Fernandes<br>Copyright © 2014 Andrey Semashev<p> 220 Distributed under the <a href="http://boost.org/LICENSE_1_0.txt" target="_top">Boost 221 Software License, Version 1.0</a>. 222 </p> 223</div></td> 224</tr></table> 225<hr> 226<div class="spirit-nav"> 227<a accesskey="p" href="alloc_construct.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.html"><img src="../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="default_allocator.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a> 228</div> 229</body> 230</html> 231
