75 lines
4.3 KiB
HTML
75 lines
4.3 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::atomic<T>::is_always_lock_free</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_atomic_atomic_is_always_lock_free 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::atomic<T>::</span>is_always_lock_free</h1>
|
|
<div id="bodyContent">
|
|
<div id="contentSub"><span class="subpages">< <a href="cpp.html">cpp</a>‎ | <a href="cpp-atomic.html">atomic</a>‎ | <a href="cpp-atomic-atomic.html">atomic</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-dcl t-since-cxx17">
|
|
<td>
|
|
<div><span class="mw-geshi cpp source-cpp"><span class="kw4">static</span> <span class="kw4">constexpr</span> <span class="kw4">bool</span> is_always_lock_free <span class="sy1">=</span> <span class="coMULTI">/*implementation-defined*/</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>若此原子类型始终为无锁则为 <code>true</code> ，若它决不或有时为无锁则为 <code>false</code> 。</p>
|
|
<p>此常量的值等于有定义处的宏 <code>ATOMIC_xxx_LOCK_FREE</code> 、成员函数 <span class="t-lc">is_lock_free</span> 和非成员函数 <span class="t-lc"><a href="cpp-atomic-atomic_is_lock_free.html">std::atomic_is_lock_free</a></span> 。</p>
|
|
<h3><span class="mw-headline" id=".E6.B3.A8.E6.84.8F">注意</span></h3>
|
|
<p>无此静态成员常量的非成员函数等价物，因为非成员函数接收指向原子类型的指针，从而在<a href="cpp-language-constant_expression.html">常量表达式</a>中无用。</p>
|
|
<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-atomic-atomic-is_lock_free.html"><span class="t-lines"><span>is_lock_free</span></span></a></div>
|
|
</div>
|
|
</td>
|
|
<td>检查原子对象是否免锁<br />
|
|
<span class="t-mark">(公开成员函数)</span></td>
|
|
</tr>
|
|
<tr class="t-dsc">
|
|
<td>
|
|
<div class="t-dsc-member-div">
|
|
<div><a href="cpp-atomic-atomic_is_lock_free.html"><span class="t-lines"><span>atomic_is_lock_free</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>检查对该原子类型的操作是否是无锁的<br />
|
|
<span class="t-mark">(函数模板)</span></td>
|
|
</tr>
|
|
<tr class="t-dsc">
|
|
<td>
|
|
<div class="t-dsc-member-div">
|
|
<div><strong class="selflink"><span class="t-lines"><span>is_always_lock_free</span></span></strong></div>
|
|
<div><span class="t-lines"><span><span class="t-cmark">[静态]</span> <span class="t-mark-rev t-since-cxx17">(C++17)</span></span></span></div>
|
|
</div>
|
|
</td>
|
|
<td>指示该类型是否始终免锁<br />
|
|
<span class="t-mark">(公开静态成员常量)</span></td>
|
|
</tr>
|
|
</table>
|
|
</div>
|
|
<div class="visualClear"></div>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
</body>
|
|
</html>
|