156 lines
11 KiB
HTML
156 lines
11 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::owner_less</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_owner_less_void 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>owner_less</h1>
|
|
<div id="bodyContent">
|
|
<div id="contentSub"><span class="subpages">< <a href="cpp.html">cpp</a>‎ | <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>定义于头文件 <code><a href="cpp-header-memory.html"><memory></a></code></div>
|
|
</td>
|
|
<td></td>
|
|
<td></td>
|
|
</tr>
|
|
<tr class="t-dcl t-since-cxx17">
|
|
<td>
|
|
<div><span class="mw-geshi cpp source-cpp"><span class="kw1">template</span><span class="sy1"><></span><br />
|
|
<span class="kw1">struct</span> owner_less<span class="sy1"><</span><span class="kw4">void</span><span class="sy1">></span><span class="sy4">;</span></span></div>
|
|
</td>
|
|
<td class="t-dcl-nopad"></td>
|
|
<td><span class="t-mark-rev t-since-cxx17">(C++17 起)</span></td>
|
|
</tr>
|
|
<tr class="t-dcl-sep">
|
|
<td></td>
|
|
<td></td>
|
|
<td></td>
|
|
</tr>
|
|
</tbody>
|
|
</table>
|
|
<p><span class="t-c"><span class="mw-geshi cpp source-cpp"><a href="cpp-memory-owner_less.html"><span class="kw743">std::<span class="me2">owner_less</span></span></a><span class="sy1"><></span></span></span> 是拥有待推导形参类型的 <span class="t-lc"><a href="cpp-memory-owner_less.html">std::owner_less</a></span> 特化。</p>
|
|
<h3><span class="mw-headline" id=".E6.88.90.E5.91.98.E7.B1.BB.E5.9E.8B">成员类型</span></h3>
|
|
<table class="t-dsc-begin">
|
|
<tr class="t-dsc-hitem">
|
|
<td>成员类型</td>
|
|
<td>定义</td>
|
|
</tr>
|
|
<tr class="t-dsc">
|
|
<td><code>is_transparent</code></td>
|
|
<td>/* 未指定 */</td>
|
|
</tr>
|
|
</table>
|
|
<h3><span class="mw-headline" id=".E6.B3.A8.E6.84.8F">注意</span></h3>
|
|
<p>成员类型 <code>is_transparent</code> 指示调用方，此函数对象是一个<i>通透</i>函数对象：它接受任意类型的参数并使用完美转发，这在将函数对象在多种语境中，或以右值参数使用时，避免不需要的复制和转换。特别是，诸如 <span class="t-lc"><a href="cpp-container-set-find.html">std::set::find</a></span> 和 <span class="t-lc"><a href="cpp-container-set-lower_bound.html">std::set::lower_bound</a></span> 的模板函数在其 <code>Compare</code> 类型上使用此类型。</p>
|
|
<h3><span class="mw-headline" id=".E6.88.90.E5.91.98.E5.87.BD.E6.95.B0">成员函数</span></h3>
|
|
<table class="t-dsc-begin">
|
|
<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>用基于占有者的语义比较其参数<br />
|
|
<span class="t-mark">(函数)</span></td>
|
|
</tr>
|
|
</table>
|
|
<div class="t-member">
|
|
<h2><span class="mw-headline" id="std::owner_less.3Cvoid.3E::operator.28.29"><span style="font-size:0.7em; line-height:130%">std::owner_less<void>::</span>operator()</span></h2>
|
|
<table class="t-dcl-begin">
|
|
<tbody>
|
|
<tr class="t-dcl t-since-cxx17">
|
|
<td>
|
|
<div><span class="mw-geshi cpp source-cpp"><span class="kw1">template</span><span class="sy1"><</span><span class="kw1">class</span> T, <span class="kw1">class</span> U<span class="sy1">></span><br /></span>
|
|
<p><span class="kw4">bool</span> operator<span class="br0">(</span><span class="br0">)</span><span class="br0">(</span> <span class="kw4">const</span> <a href="cpp-memory-shared_ptr.html"><span class="kw734">std::<span class="me2">shared_ptr</span></span></a><span class="sy1"><</span>T<span class="sy1">></span><span class="sy3">&</span> lhs,<br /></p>
|
|
<span class="kw4">const</span> <a href="cpp-memory-shared_ptr.html"><span class="kw734">std::<span class="me2">shared_ptr</span></span></a><span class="sy1"><</span>U<span class="sy1">></span><span class="sy3">&</span> rhs <span class="br0">)</span> <span class="kw4">const</span> <span class="kw1">noexcept</span><span class="sy4">;</span></div>
|
|
</td>
|
|
<td class="t-dcl-nopad"></td>
|
|
<td><span class="t-mark-rev t-since-cxx17">(C++17 起)</span></td>
|
|
</tr>
|
|
<tr class="t-dcl t-since-cxx17">
|
|
<td>
|
|
<div><span class="mw-geshi cpp source-cpp"><span class="kw1">template</span><span class="sy1"><</span><span class="kw1">class</span> T, <span class="kw1">class</span> U<span class="sy1">></span><br /></span>
|
|
<p><span class="kw4">bool</span> operator<span class="br0">(</span><span class="br0">)</span><span class="br0">(</span> <span class="kw4">const</span> <a href="cpp-memory-shared_ptr.html"><span class="kw734">std::<span class="me2">shared_ptr</span></span></a><span class="sy1"><</span>T<span class="sy1">></span><span class="sy3">&</span> lhs,<br /></p>
|
|
<span class="kw4">const</span> <a href="cpp-memory-weak_ptr.html"><span class="kw741">std::<span class="me2">weak_ptr</span></span></a><span class="sy1"><</span>U<span class="sy1">></span><span class="sy3">&</span> rhs <span class="br0">)</span> <span class="kw4">const</span> <span class="kw1">noexcept</span><span class="sy4">;</span></div>
|
|
</td>
|
|
<td class="t-dcl-nopad"></td>
|
|
<td><span class="t-mark-rev t-since-cxx17">(C++17 起)</span></td>
|
|
</tr>
|
|
<tr class="t-dcl t-since-cxx17">
|
|
<td>
|
|
<div><span class="mw-geshi cpp source-cpp"><span class="kw1">template</span><span class="sy1"><</span><span class="kw1">class</span> T, <span class="kw1">class</span> U<span class="sy1">></span><br /></span>
|
|
<p><span class="kw4">bool</span> operator<span class="br0">(</span><span class="br0">)</span><span class="br0">(</span> <span class="kw4">const</span> <a href="cpp-memory-weak_ptr.html"><span class="kw741">std::<span class="me2">weak_ptr</span></span></a><span class="sy1"><</span>T<span class="sy1">></span><span class="sy3">&</span> lhs,<br /></p>
|
|
<span class="kw4">const</span> <a href="cpp-memory-shared_ptr.html"><span class="kw734">std::<span class="me2">shared_ptr</span></span></a><span class="sy1"><</span>U<span class="sy1">></span><span class="sy3">&</span> rhs <span class="br0">)</span> <span class="kw4">const</span> <span class="kw1">noexcept</span><span class="sy4">;</span></div>
|
|
</td>
|
|
<td class="t-dcl-nopad"></td>
|
|
<td><span class="t-mark-rev t-since-cxx17">(C++17 起)</span></td>
|
|
</tr>
|
|
<tr class="t-dcl t-since-cxx17">
|
|
<td>
|
|
<div><span class="mw-geshi cpp source-cpp"><span class="kw1">template</span><span class="sy1"><</span><span class="kw1">class</span> T, <span class="kw1">class</span> U<span class="sy1">></span><br /></span>
|
|
<p><span class="kw4">bool</span> operator<span class="br0">(</span><span class="br0">)</span><span class="br0">(</span> <span class="kw4">const</span> <a href="cpp-memory-weak_ptr.html"><span class="kw741">std::<span class="me2">weak_ptr</span></span></a><span class="sy1"><</span>T<span class="sy1">></span><span class="sy3">&</span> lhs,<br /></p>
|
|
<span class="kw4">const</span> <a href="cpp-memory-weak_ptr.html"><span class="kw741">std::<span class="me2">weak_ptr</span></span></a><span class="sy1"><</span>U<span class="sy1">></span><span class="sy3">&</span> rhs <span class="br0">)</span> <span class="kw4">const</span> <span class="kw1">noexcept</span><span class="sy4">;</span></div>
|
|
</td>
|
|
<td class="t-dcl-nopad"></td>
|
|
<td><span class="t-mark-rev t-since-cxx17">(C++17 起)</span></td>
|
|
</tr>
|
|
<tr class="t-dcl-sep">
|
|
<td></td>
|
|
<td></td>
|
|
<td></td>
|
|
</tr>
|
|
</tbody>
|
|
</table>
|
|
<p>用基于占有者的语义比较 <code>lhs</code> 与 <code>rhs</code> 。等效地调用 <span class="t-c"><span class="mw-geshi cpp source-cpp">lhs.<span class="me1">owner_before</span><span class="br0">(</span>rhs<span class="br0">)</span></span></span> 。</p>
|
|
<p>顺序是严格弱序关系。</p>
|
|
<p><code>lhs</code> 与 <code>rhs</code> 仅若均为空或共享所有权才等价。</p>
|
|
<h3><span class="mw-headline" id=".E5.8F.82.E6.95.B0">参数</span></h3>
|
|
<table class="t-par-begin">
|
|
<tr class="t-par">
|
|
<td>lhs, rhs</td>
|
|
<td>-</td>
|
|
<td>要比较的共享所有权指针</td>
|
|
</tr>
|
|
</table>
|
|
<h3><span class="mw-headline" id=".E8.BF.94.E5.9B.9E.E5.80.BC">返回值</span></h3>
|
|
<p>若以基于占有者的顺序确定 <code>lhs</code> <i>小于</i> <code>rhs</code> 则为 <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="kw2">true</span></span></span> 。</p>
|
|
<p><br /></p>
|
|
</div>
|
|
<h3><span class="mw-headline" id=".E5.8F.82.E9.98.85">参阅</span></h3>
|
|
<table class="t-dsc-begin">
|
|
<tr class="t-dsc">
|
|
<td>
|
|
<div class="t-dsc-member-div">
|
|
<div><a href="cpp-memory-shared_ptr-owner_before.html"><span class="t-lines"><span>owner_before</span></span></a></div>
|
|
</div>
|
|
</td>
|
|
<td>提供基于拥有者的共享指针排序<br />
|
|
<span class="t-mark">(<code>std::shared_ptr<T></code> 的公开成员函数)</span></td>
|
|
</tr>
|
|
<tr class="t-dsc">
|
|
<td>
|
|
<div class="t-dsc-member-div">
|
|
<div><a href="cpp-memory-weak_ptr-owner_before.html"><span class="t-lines"><span>owner_before</span></span></a></div>
|
|
</div>
|
|
</td>
|
|
<td>提供弱指针的基于拥有者顺序<br />
|
|
<span class="t-mark">(<code>std::weak_ptr<T></code> 的公开成员函数)</span></td>
|
|
</tr>
|
|
</table>
|
|
</div>
|
|
<div class="visualClear"></div>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
</body>
|
|
</html>
|