Files
hustoj/web/cppreference-zh/chmhelp/cpp-memory-default_delete.html
2025-08-01 12:57:54 +08:00

232 lines
18 KiB
HTML

<!DOCTYPE html>
<html lang="zh" dir="ltr" class="client-nojs" xmlns="http://www.w3.org/1999/xhtml" xml:lang="zh">
<head><meta http-equiv="x-ua-compatible" content="ie=edge">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>std::default_delete</title>
<link rel="stylesheet" href="ext.css" />
<link rel="stylesheet" href="site_modules.css" />
</head>
<body class="mediawiki ltr sitedir-ltr ns-0 ns-subject page-cpp_memory_default_delete skin-cppreference2 action-view cpp-navbar">
<div id="cpp-content-base">
<div id="content"><a id="top"></a>
<h1 id="firstHeading" class="firstHeading"><span style="font-size:0.7em; line-height:130%">std::</span>default_delete</h1>
<div id="bodyContent">
<div id="contentSub"><span class="subpages">&lt; <a href="cpp.html">cpp</a>&lrm; | <a href="cpp-memory.html">memory</a></span></div>
<div id="mw-content-text" lang="zh" dir="ltr" class="mw-content-ltr" xml:lang="zh">
<table class="t-dcl-begin">
<tbody>
<tr class="t-dsc-header">
<td>
<div>&#23450;&#20041;&#20110;&#22836;&#25991;&#20214; <code><a href="cpp-header-memory.html">&lt;memory&gt;</a></code></div>
</td>
<td></td>
<td></td>
</tr>
<tr class="t-dcl t-since-cxx11">
<td>
<div><span class="mw-geshi cpp source-cpp"><span class="kw1">template</span><span class="sy1">&lt;</span> <span class="kw1">class</span> T <span class="sy1">&gt;</span> <span class="kw1">struct</span> default_delete<span class="sy4">;</span></span></div>
</td>
<td>(1)</td>
<td><span class="t-mark-rev t-since-cxx11">(C++11 &#36215;)</span></td>
</tr>
<tr class="t-dcl t-since-cxx11">
<td>
<div><span class="mw-geshi cpp source-cpp"><span class="kw1">template</span><span class="sy1">&lt;</span> <span class="kw1">class</span> T <span class="sy1">&gt;</span> <span class="kw1">struct</span> default_delete<span class="sy1">&lt;</span>T<span class="br0">[</span><span class="br0">]</span><span class="sy1">&gt;</span><span class="sy4">;</span></span></div>
</td>
<td>(2)</td>
<td><span class="t-mark-rev t-since-cxx11">(C++11 &#36215;)</span></td>
</tr>
<tr class="t-dcl-sep">
<td></td>
<td></td>
<td></td>
</tr>
</tbody>
</table>
<p><code>std::default_delete</code> &#26159;&#19981;&#25351;&#23450;&#21024;&#38500;&#22120;&#26102; <span class="t-lc"><a href="cpp-memory-unique_ptr.html">std::unique_ptr</a></span> &#25152;&#29992;&#30340;&#40664;&#35748;&#21024;&#38500;&#31574;&#30053;&#12290; <code>default_delete</code> &#30340;&#29305;&#21270;&#22312;&#20856;&#22411;&#23454;&#29616;&#19978;&#20026;&#31354;&#31867;&#65292;&#24182;&#19988;&#29992;&#20110;<a href="cpp-language-ebo.html">&#31354;&#22522;&#31867;&#20248;&#21270;</a>&#12290;</p>
<div class="t-li1"><span class="t-li">1)</span> &#38750;&#29305;&#21270;&#30340; <code>default_delete</code> &#29992; <span class="t-c"><span class="mw-geshi cpp source-cpp">delete</span></span> &#35299;&#20998;&#37197;&#21333;&#20010;&#23545;&#35937;&#30340;&#20869;&#23384;&#12290;</div>
<div class="t-li1"><span class="t-li">2)</span> &#20134;&#20026;&#25552;&#20379;&#25968;&#32452;&#31867;&#22411;&#30340;&#20351;&#29992; <span class="t-c"><span class="mw-geshi cpp source-cpp">delete<span class="br0">[</span><span class="br0">]</span></span></span> &#30340;&#37096;&#20998;&#29305;&#21270;&#12290;</div>
<h3><span class="mw-headline" id=".E6.88.90.E5.91.98.E5.87.BD.E6.95.B0">&#25104;&#21592;&#20989;&#25968;</span></h3>
<table class="t-dsc-begin">
<tr class="t-dsc">
<td>
<div class="t-dsc-member-div t-dsc-member-nobold-div">
<div><strong class="selflink"><span class="t-lines"><span>(&#26500;&#36896;&#20989;&#25968;)</span></span></strong></div>
</div>
</td>
<td>&#26500;&#36896; <code>default_delete</code> &#23545;&#35937;<br />
<span class="t-mark">(&#20844;&#24320;&#25104;&#21592;&#20989;&#25968;)</span></td>
</tr>
<tr class="t-dsc">
<td>
<div class="t-dsc-member-div">
<div><strong class="selflink"><span class="t-lines"><span>operator()</span></span></strong></div>
</div>
</td>
<td>&#21024;&#38500;&#23545;&#35937;&#25110;&#25968;&#32452;<br />
<span class="t-mark">(&#20844;&#24320;&#25104;&#21592;&#20989;&#25968;)</span></td>
</tr>
</table>
<div class="t-member">
<h2><span class="mw-headline" id="std::default_delete::default_delete"><span style="font-size:0.7em; line-height:130%">std::default_delete::</span>default_delete</span></h2>
<table class="t-dcl-begin">
<tbody>
<tr class="t-dcl">
<td>
<div><span class="mw-geshi cpp source-cpp"><span class="kw4">constexpr</span> default_delete<span class="br0">(</span><span class="br0">)</span> <span class="kw1">noexcept</span> <span class="sy1">=</span> <span class="kw1">default</span><span class="sy4">;</span></span></div>
</td>
<td>(1)</td>
<td class="t-dcl-nopad"></td>
</tr>
<tr class="t-dcl">
<td>
<div><span class="mw-geshi cpp source-cpp"><span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> U<span class="sy1">&gt;</span><br />
default_delete<span class="br0">(</span> <span class="kw4">const</span> default_delete<span class="sy1">&lt;</span>U<span class="sy1">&gt;</span><span class="sy3">&amp;</span> d <span class="br0">)</span> <span class="kw1">noexcept</span><span class="sy4">;</span></span></div>
</td>
<td>(2)</td>
<td><span class="t-mark">(&#20165;&#20026;&#21021;&#31561; <code>default_delete</code> &#27169;&#26495;&#30340;&#25104;&#21592;)</span></td>
</tr>
<tr class="t-dcl">
<td>
<div><span class="mw-geshi cpp source-cpp"><span class="kw1">template</span><span class="sy1">&lt;</span><span class="kw1">class</span> U<span class="sy1">&gt;</span><br />
default_delete<span class="br0">(</span> <span class="kw4">const</span> default_delete<span class="sy1">&lt;</span>U<span class="br0">[</span><span class="br0">]</span><span class="sy1">&gt;</span><span class="sy3">&amp;</span> d <span class="br0">)</span> <span class="kw1">noexcept</span><span class="sy4">;</span></span></div>
</td>
<td>(3)</td>
<td><span class="t-mark">(&#20165;&#20026; <code>default_delete&lt;T[]&gt;</code> &#27169;&#26495;&#29305;&#21270;&#30340;&#25104;&#21592;)</span></td>
</tr>
<tr class="t-dcl-sep">
<td></td>
<td></td>
<td></td>
</tr>
</tbody>
</table>
<div class="t-li1"><span class="t-li">1)</span> &#26500;&#36896; <code>std::default_delete</code> &#23545;&#35937;&#12290;</div>
<div class="t-li1"><span class="t-li">2)</span> &#20174;&#21478;&#19968; <code>std::default_delete</code> &#26500;&#36896; <code>std::default_delete</code> &#23545;&#35937;&#12290;&#27492;&#26500;&#36896;&#20989;&#25968;&#20165;&#33509; <code>U*</code> &#21487;&#38544;&#24335;&#36716;&#25442;&#20026; <code>T*</code> &#25165;&#21442;&#19982;&#37325;&#36733;&#20915;&#35758;&#12290;</div>
<div class="t-li1"><span class="t-li">3)</span> &#20174;&#21478;&#19968; <code>std::default_delete&lt;U[]&gt;</code> &#23545;&#35937;&#26500;&#36896; <code>std::default_delete&lt;T[]&gt;</code> &#23545;&#35937;&#12290;&#27492;&#26500;&#36896;&#20989;&#25968;&#20165;&#33509; <code>U(*)[]</code> &#21487;&#38544;&#24335;&#36716;&#25442;&#20026; <code>T(*)[]</code> &#25165;&#21442;&#19982;&#37325;&#36733;&#20915;&#35758;&#12290;</div>
<h3><span class="mw-headline" id=".E5.8F.82.E6.95.B0">&#21442;&#25968;</span></h3>
<table class="t-par-begin">
<tr class="t-par">
<td>d</td>
<td>-</td>
<td>&#22797;&#21046;&#26469;&#28304;&#30340;&#21024;&#38500;&#22120;</td>
</tr>
</table>
<h3><span class="mw-headline" id=".E6.B3.A8.E8.A7.A3">&#27880;&#35299;</span></h3>
<p><code>std::default_delete</code> &#30340;<a href="cpp-language-converting_constructor.html">&#36716;&#25442;&#26500;&#36896;&#20989;&#25968;</a>&#27169;&#26495;&#20196;&#20174; <span class="t-c"><span class="mw-geshi cpp source-cpp"><a href="cpp-memory-unique_ptr.html"><span class="kw733">std::<span class="me2">unique_ptr</span></span></a><span class="sy1">&lt;</span>Derived<span class="sy1">&gt;</span></span></span> &#21040; <span class="t-c"><span class="mw-geshi cpp source-cpp"><a href="cpp-memory-unique_ptr.html"><span class="kw733">std::<span class="me2">unique_ptr</span></span></a><span class="sy1">&lt;</span>Base<span class="sy1">&gt;</span></span></span> &#30340;&#38544;&#24335;&#36716;&#25442;&#21487;&#34892;&#12290;</p>
</div>
<div class="t-member">
<h2><span class="mw-headline" id="std::default_delete::operator.28.29"><span style="font-size:0.7em; line-height:130%">std::default_delete::</span>operator()</span></h2>
<table class="t-dcl-begin">
<tbody>
<tr class="t-dcl">
<td>
<div><span class="mw-geshi cpp source-cpp"><span class="kw4">void</span> operator<span class="br0">(</span><span class="br0">)</span><span class="br0">(</span>T<span class="sy2">*</span> ptr<span class="br0">)</span> <span class="kw4">const</span><span class="sy4">;</span></span></div>
</td>
<td>(1)</td>
<td><span class="t-mark">(&#20165;&#20026;&#21021;&#31561; <code>default_delete</code> &#27169;&#26495;&#30340;&#25104;&#21592;)</span></td>
</tr>
<tr class="t-dcl">
<td>
<div><span class="mw-geshi cpp source-cpp"><span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> U<span class="sy1">&gt;</span><br />
<span class="kw4">void</span> operator<span class="br0">(</span><span class="br0">)</span><span class="br0">(</span>U<span class="sy2">*</span> ptr<span class="br0">)</span> <span class="kw4">const</span><span class="sy4">;</span></span></div>
</td>
<td>(2)</td>
<td><span class="t-mark">(&#20165;&#20026; <code>default_delete&lt;T[]&gt;</code> &#27169;&#26495;&#29305;&#21270;&#30340;&#25104;&#21592;)</span></td>
</tr>
<tr class="t-dcl-sep">
<td></td>
<td></td>
<td></td>
</tr>
</tbody>
</table>
<div class="t-li1"><span class="t-li">1)</span> &#22312; <code>ptr</code> &#19978;&#35843;&#29992; <code>delete</code> &#12290;</div>
<div class="t-li1"><span class="t-li">2)</span> &#22312; <code>ptr</code> &#19978;&#35843;&#29992; <code>delete[]</code> &#12290;&#27492;&#20989;&#25968;&#20165;&#33509; <span class="t-c"><span class="mw-geshi cpp source-cpp">U<span class="br0">(</span><span class="sy2">*</span><span class="br0">)</span><span class="br0">[</span><span class="br0">]</span></span></span> &#33021;&#38544;&#24335;&#36716;&#25442;&#20026; <span class="t-c"><span class="mw-geshi cpp source-cpp">T<span class="br0">(</span><span class="sy2">*</span><span class="br0">)</span><span class="br0">[</span><span class="br0">]</span></span></span> &#25165;&#21442;&#19982;&#37325;&#36733;&#20915;&#35758;&#12290;</div>
<p>&#20219;&#20309;&#24773;&#20917;&#19979;&#65292;&#33509; U &#26159;&#19981;&#23436;&#25972;&#31867;&#22411;&#65292;&#21017;&#31243;&#24207;&#20026;&#35884;&#26500;&#12290;</p>
<h3><span class="mw-headline" id=".E5.8F.82.E6.95.B0_2">&#21442;&#25968;</span></h3>
<table class="t-par-begin">
<tr class="t-par">
<td>ptr</td>
<td>-</td>
<td>&#35201;&#21024;&#38500;&#30340;&#23545;&#35937;&#25110;&#25968;&#32452;</td>
</tr>
</table>
<h3><span class="mw-headline" id=".E5.BC.82.E5.B8.B8">&#24322;&#24120;</span></h3>
<p>&#26080;&#24322;&#24120;&#20445;&#35777;&#12290;</p>
</div>
<h3><span class="mw-headline" id=".E5.9C.A8.E4.B8.8D.E5.AE.8C.E6.95.B4.E7.B1.BB.E5.9E.8B.E4.B8.8A.E8.B0.83.E7.94.A8">&#22312;&#19981;&#23436;&#25972;&#31867;&#22411;&#19978;&#35843;&#29992;</span></h3>
<p>&#20110;&#20195;&#30721;&#20013;&#35843;&#29992; operator() &#28857;&#65292;&#31867;&#22411;&#24517;&#39035;&#23436;&#25972;&#12290;&#19968;&#20123;&#23454;&#29616;&#20013;&#29992; <code>static_assert</code> &#30830;&#20445;&#22914;&#27492;&#12290;&#27492;&#35201;&#27714;&#30340;&#21407;&#22240;&#65292;&#26159; C++ &#20013;&#33509;&#23436;&#25972;&#31867;&#31867;&#22411;&#25317;&#26377;&#38750;&#24179;&#20961;&#26512;&#26500;&#20989;&#25968;&#25110;&#35299;&#20998;&#37197;&#20989;&#25968;&#65292;&#21017;&#22312;&#19981;&#23436;&#25972;&#31867;&#22411;&#19978;&#35843;&#29992; <a href="cpp-language-delete.html"><tt>delete</tt></a> &#26159;&#26410;&#23450;&#20041;&#34892;&#20026;&#65292;&#22240;&#20026;&#32534;&#35793;&#22120;&#26080;&#27861;&#24471;&#30693;&#36825;&#31181;&#20989;&#25968;&#26159;&#21542;&#23384;&#22312;&#19988;&#24517;&#39035;&#34987;&#35843;&#29992;&#12290;</p>
<h3><span class="mw-headline" id=".E7.A4.BA.E4.BE.8B">&#31034;&#20363;</span></h3>
<div class="t-example">
<div class="t-example-live-link"></div>
<div dir="ltr" class="mw-geshi" style="text-align: left;">
<div class="cpp source-cpp">
<pre class="de1"><span class="co2">#include &lt;memory&gt;</span>
<span class="co2">#include &lt;vector&gt;</span>
<span class="co2">#include &lt;algorithm&gt;</span>
<span class="kw4">int</span> main<span class="br0">(</span><span class="br0">)</span>
<span class="br0">{</span>
<span class="co1">// {</span>
<span class="co1">// std::shared_ptr&lt;int&gt; shared_bad(new int[10]);</span>
<span class="co1">// } // &#26512;&#26500;&#20989;&#25968;&#35843;&#29992; delete &#65292;&#26410;&#23450;&#20041;&#34892;&#20026;</span>
<span class="br0">{</span>
<a href="cpp-memory-shared_ptr.html"><span class="kw734">std::<span class="me2">shared_ptr</span></span></a><span class="sy1">&lt;</span><span class="kw4">int</span><span class="sy1">&gt;</span> shared_good<span class="br0">(</span>new <span class="kw4">int</span><span class="br0">[</span><span class="nu0">10</span><span class="br0">]</span>, std<span class="sy4">::</span><span class="me2">default_delete</span><span class="sy1">&lt;</span><span class="kw4">int</span><span class="br0">[</span><span class="br0">]</span><span class="sy1">&gt;</span>
<span class="br0">(</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
<span class="br0">}</span> <span class="co1">// &#26512;&#26500;&#20989;&#25968;&#35843;&#29992; delete[] &#65292; ok</span>
<span class="br0">{</span>
<a href="cpp-memory-unique_ptr.html"><span class="kw733">std::<span class="me2">unique_ptr</span></span></a><span class="sy1">&lt;</span><span class="kw4">int</span><span class="sy1">&gt;</span> ptr<span class="br0">(</span>new <span class="kw4">int</span><span class="br0">(</span><span class="nu0">5</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
<span class="br0">}</span> <span class="co1">// unique_ptr&lt;int&gt; &#20351;&#29992; default_delete&lt;int&gt;</span>
<span class="br0">{</span>
<a href="cpp-memory-unique_ptr.html"><span class="kw733">std::<span class="me2">unique_ptr</span></span></a><span class="sy1">&lt;</span><span class="kw4">int</span><span class="br0">[</span><span class="br0">]</span><span class="sy1">&gt;</span> ptr<span class="br0">(</span>new <span class="kw4">int</span><span class="br0">[</span><span class="nu0">10</span><span class="br0">]</span><span class="br0">)</span><span class="sy4">;</span>
<span class="br0">}</span> <span class="co1">// unique_ptr&lt;int[]&gt; &#20351;&#29992; default_delete&lt;int[]&gt;</span>
<span class="co1">// default_delete &#33021;&#29992;&#20110;&#38656;&#35201;&#21024;&#38500;&#29992;&#20989;&#25968;&#23545;&#35937;&#30340;&#20219;&#20309;&#22330;&#25152;</span>
<a href="cpp-container-vector.html"><span class="kw1268">std::<span class="me2">vector</span></span></a><span class="sy1">&lt;</span><span class="kw4">int</span><span class="sy2">*</span><span class="sy1">&gt;</span> v<span class="sy4">;</span>
<span class="kw1">for</span><span class="br0">(</span><span class="kw4">int</span> n <span class="sy1">=</span> <span class="nu0">0</span><span class="sy4">;</span> n <span class="sy1">&lt;</span> <span class="nu0">100</span><span class="sy4">;</span> <span class="sy2">++</span>n<span class="br0">)</span>
v.<span class="me1">push_back</span><span class="br0">(</span>new <span class="kw4">int</span><span class="br0">(</span>n<span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
<a href="cpp-algorithm-for_each.html"><span class="kw1567">std::<span class="me2">for_each</span></span></a><span class="br0">(</span>v.<span class="me1">begin</span><span class="br0">(</span><span class="br0">)</span>, v.<span class="me1">end</span><span class="br0">(</span><span class="br0">)</span>, std<span class="sy4">::</span><span class="me2">default_delete</span><span class="sy1">&lt;</span><span class="kw4">int</span><span class="sy1">&gt;</span><span class="br0">(</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
<span class="br0">}</span></pre></div>
</div>
</div>
<h3><span class="mw-headline" id=".E7.BC.BA.E9.99.B7.E6.8A.A5.E5.91.8A">&#32570;&#38519;&#25253;&#21578;</span></h3>
<p>&#19979;&#21015;&#26356;&#25913;&#34892;&#20026;&#30340;&#32570;&#38519;&#25253;&#21578;&#36861;&#28335;&#22320;&#24212;&#29992;&#20110;&#20197;&#21069;&#20986;&#29256;&#30340; C++ &#26631;&#20934;&#12290;</p>
<table class="dsctable" style="font-size:0.8em">
<tr>
<th>DR</th>
<th>&#24212;&#29992;&#20110;</th>
<th>&#20986;&#29256;&#26102;&#30340;&#34892;&#20026;</th>
<th>&#27491;&#30830;&#34892;&#20026;</th>
</tr>
<tr>
<td><a rel="nofollow" class="external text" href="https://cplusplus.github.io/LWG/issue2118">LWG 2118</a></td>
<td>C++11</td>
<td><code>default_delete&lt;T[]&gt;</code> &#30340;&#25104;&#21592;&#20989;&#25968;&#25298;&#32477;&#38480;&#23450;&#36716;&#25442;</td>
<td>&#25509;&#21463;</td>
</tr>
</table>
<h3><span class="mw-headline" id=".E5.8F.82.E9.98.85">&#21442;&#38405;</span></h3>
<table class="t-dsc-begin">
<tr class="t-dsc">
<td>
<div class="t-dsc-member-div">
<div><a href="cpp-memory-unique_ptr.html"><span class="t-lines"><span>unique_ptr</span></span></a></div>
<div><span class="t-lines"><span><span class="t-mark-rev t-since-cxx11">(C++11)</span></span></span></div>
</div>
</td>
<td>&#25317;&#26377;&#29420;&#26377;&#23545;&#35937;&#25152;&#26377;&#26435;&#35821;&#20041;&#30340;&#26234;&#33021;&#25351;&#38024;<br />
<span class="t-mark">(&#31867;&#27169;&#26495;)</span></td>
</tr>
</table>
</div>
<div class="visualClear"></div>
</div>
</div>
</div>
</body>
</html>