100 lines
5.6 KiB
HTML
100 lines
5.6 KiB
HTML
<!DOCTYPE html>
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<html lang="zh" dir="ltr" class="client-nojs" xmlns="http://www.w3.org/1999/xhtml" xml:lang="zh">
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<title>std::atomic_flag::atomic_flag</title>
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<body class="mediawiki ltr sitedir-ltr ns-0 ns-subject page-cpp_atomic_atomic_flag_atomic_flag skin-cppreference2 action-view cpp-navbar">
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<div id="cpp-content-base">
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<div id="content"><a id="top"></a>
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<h1 id="firstHeading" class="firstHeading"><span style="font-size:0.7em; line-height:130%">std::atomic_flag::</span>atomic_flag</h1>
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<div id="contentSub"><span class="subpages">< <a href="cpp.html">cpp</a>‎ | <a href="cpp-atomic.html">atomic</a>‎ | <a href="cpp-atomic-atomic_flag.html">atomic flag</a></span></div>
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<div>定义于头文件 <code><a href="cpp-header-atomic.html"><atomic></a></code></div>
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<td></td>
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<td rowspan="142">(1)</td>
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<div><span class="mw-geshi cpp source-cpp">atomic_flag<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>
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<td><span class="t-mark-rev t-since-cxx11">(C++11 起)</span><br />
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<span class="t-mark-rev t-until-cxx20">(C++20 前)</span></td>
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<div><span class="mw-geshi cpp source-cpp"><span class="kw4">constexpr</span> atomic_flag<span class="br0">(</span><span class="br0">)</span> <span class="kw1">noexcept</span><span class="sy4">;</span></span></div>
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<td><span class="t-mark-rev t-since-cxx20">(C++20 起)</span></td>
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<div><span class="mw-geshi cpp source-cpp">atomic_flag<span class="br0">(</span> <span class="kw4">const</span> atomic_flag<span class="sy3">&</span> <span class="br0">)</span> <span class="sy1">=</span> delete<span class="sy4">;</span></span></div>
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</td>
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<td>(2)</td>
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<td><span class="t-mark-rev t-since-cxx11">(C++11 起)</span></td>
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<p>构造新的 <span class="t-lc"><a href="cpp-atomic-atomic_flag.html">std::atomic_flag</a></span> 。</p>
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<div class="t-li1"><span class="t-li">1)</span> 平凡默认构造函数，初始化 <span class="t-lc"><a href="cpp-atomic-atomic_flag.html">std::atomic_flag</a></span> 为未指定状态。</div>
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<td><span class="t-mark-rev t-until-cxx20">(C++20 前)</span></td>
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<div class="t-li1"><span class="t-li">1)</span> 初始化 <span class="t-lc"><a href="cpp-atomic-atomic_flag.html">std::atomic_flag</a></span> 为清除状态。</div>
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<td><span class="t-mark-rev t-since-cxx20">(C++20 起)</span></td>
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<div class="t-li1"><span class="t-li">2)</span> 复制构造函数被删除； <span class="t-lc"><a href="cpp-atomic-atomic_flag.html">std::atomic_flag</a></span> 不可复制。</div>
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<p>另外， <span class="t-lc"><a href="cpp-atomic-atomic_flag.html">std::atomic_flag</a></span> 能以表达式 <span class="t-lc"><a href="cpp-atomic-ATOMIC_FLAG_INIT.html">ATOMIC_FLAG_INIT</a></span> 值初始化。对于拥有静态<a href="cpp-language-storage_duration.html#.E5.AD.98.E5.82.A8.E6.9C.9F">存储期</a>的 <code>atomic_flag</code> ，这保证<a href="cpp-language-initialization.html#.E9.9D.99.E6.80.81.E5.88.9D.E5.A7.8B.E5.8C.96">静态初始化</a>：标志能用于静态对象的构造函数中。<span class="t-rev-inl t-since-cxx20"><span>此宏不再有必要且被弃用。</span> <span><span class="t-mark-rev t-since-cxx20">(C++20 起)</span></span></span></p>
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<h3><span class="mw-headline" id=".E5.8F.82.E9.98.85">参阅</span></h3>
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<div><a href="cpp-atomic-ATOMIC_FLAG_INIT.html"><span class="t-lines"><span>ATOMIC_FLAG_INIT</span></span></a></div>
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<div><span class="t-lines"><span><span class="t-mark-rev t-since-cxx11">(C++11)</span><span class="t-mark-rev t-deprecated-cxx20">(C++20 中弃用)</span></span></span></div>
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<td>将 <span class="t-lc"><a href="cpp-atomic-atomic_flag.html">std::atomic_flag</a></span> 初始化为 <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="kw2">false</span></span></span><br />
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<span class="t-mark">(宏常量)</span></td>
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