74 lines
4.1 KiB
HTML
74 lines
4.1 KiB
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::visit_format_arg</title>
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<body class="mediawiki ltr sitedir-ltr ns-0 ns-subject page-cpp_utility_format_visit_format_arg skin-cppreference2 action-view cpp-navbar">
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<div id="cpp-content-base">
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<h1 id="firstHeading" class="firstHeading"><span style="font-size:0.7em; line-height:130%">std::</span>visit_format_arg</h1>
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<div id="contentSub"><span class="subpages">< <a href="cpp.html">cpp</a>‎ | <a href="cpp-utility.html">utility</a>‎ | <a href="cpp-utility-format.html">format</a></span></div>
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<div id="mw-content-text" lang="zh" dir="ltr" class="mw-content-ltr" xml:lang="zh">
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<div>定义于头文件 <code><a href="cpp-header-format.html"><format></a></code></div>
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<td></td>
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<div><span class="mw-geshi cpp source-cpp"><span class="kw1">template</span><span class="sy1"><</span><span class="kw1">class</span> Visitor, <span class="kw1">class</span> Context<span class="sy1">></span><br />
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<span class="coMULTI">/*see below*/</span> visit_format_arg<span class="br0">(</span>Visitor<span class="sy3">&&</span> vis, std<span class="sy4">::</span><span class="me2">basic_format_arg</span><span class="sy1"><</span>Context<span class="sy1">></span> arg<span class="br0">)</span><span class="sy4">;</span></span></div>
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<td class="t-dcl-nopad"></td>
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<td><span class="t-mark-rev t-since-cxx20">(C++20 起)</span></td>
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<p>应用 <code>vis</code> 到 <code>arg</code> 中含有的对象。等价于</p>
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<p><span class="t-cc"><span class="mw-geshi cpp source-cpp"><a href="cpp-utility-variant-visit.html"><span class="kw1086">std::<span class="me2">visit</span></span></a><span class="br0">(</span><a href="cpp-utility-forward.html"><span class="kw1117">std::<span class="me2">forward</span></span></a><span class="sy1"><</span>Visitor<span class="sy1">></span><span class="br0">(</span>vis<span class="br0">)</span>, value<span class="br0">)</span></span></span></p>
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<p>其中 <code>value</code> 是存储于 <code>arg</code> 的 <span class="t-lc"><a href="cpp-utility-variant.html">std::variant</a></span> 。</p>
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<h3><span class="mw-headline" id=".E5.8F.82.E6.95.B0">参数</span></h3>
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<table class="t-par-begin">
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<td>vis</td>
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<td>-</td>
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<td>接受来自 <code>arg</code> 的每个可能可选项的<a href="cpp-named_req-Callable.html"><span style="font-style:italic">可调用</span> <span style="font-family: Georgia, 'DejaVu Serif', serif; font-style:italic">(Callable)</span></a></td>
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<tr class="t-par">
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<td>arg</td>
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<td>-</td>
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<td>要观览的 <span class="t-lc">std::basic_format_arg</span></td>
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<h3><span class="mw-headline" id=".E8.BF.94.E5.9B.9E.E5.80.BC">返回值</span></h3>
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<p>选择的观览器调用所返回的值。</p>
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<h3><span class="mw-headline" id=".E7.A4.BA.E4.BE.8B">示例</span></h3>
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<td class="mbox-text" style="">本节未完成<br />
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原因：暂无示例</td>
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<h3><span class="mw-headline" id=".E5.8F.82.E9.98.85">参阅</span></h3>
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