63 lines
3.6 KiB
HTML
63 lines
3.6 KiB
HTML
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<title>std::experimental::void_t</title>
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<body class="mediawiki ltr sitedir-ltr ns-0 ns-subject page-cpp_experimental_void_t skin-cppreference2 action-view cpp-navbar">
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<h1 id="firstHeading" class="firstHeading"><span style="font-size:0.7em; line-height:130%">std::experimental::</span>void_t</h1>
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<div id="contentSub"><span class="subpages">< <a href="cpp.html">cpp</a>‎ | <a href="cpp-experimental.html">experimental</a></span></div>
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<div>定义于头文件 <code><a href="https://zh.cppreference.com/mwiki/index.php?title=cpp/header/experimental/type_traits&action=edit&redlink=1" class="new" title="cpp/header/experimental/type traits（页面不存在）"><experimental/type_traits></a></code></div>
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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>... <span class="sy1">></span><br />
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<span class="kw1">using</span> void_t <span class="sy1">=</span> <span class="kw4">void</span><span class="sy4">;</span></span></div>
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<td><span class="t-mark-rev t-since-libfund-ts-2 t-mark-ts">(库基础 TS v2)</span></td>
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<p>工具元函数，映射任何类型序列到类型 <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="kw4">void</span></span></span> 。</p>
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<h3><span class="mw-headline" id=".E6.B3.A8.E8.A7.A3">注解</span></h3>
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<p>此工具原函数用于在 <a href="cpp-language-sfinae.html">SFINAE</a> 语境中检测非良构的类型。它首先作为 <span class="t-lc"><a href="cpp-types-void_t.html">std::void_t</a></span> 被投票选入 C++17 ，然后才同样作为 <code>std::experimental::void_t</code> 加入库基础 TS ，因为<a href="cpp-experimental-is_detected.html">检测手法</a>依赖它，而 LFTS v2 基于 C++14 。</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-types-void_t.html"><span class="t-lines"><span>void_t</span></span></a></div>
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<div><span class="t-lines"><span><span class="t-mark-rev t-since-cxx17">(C++17)</span></span></span></div>
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<td><code>void</code> 变参别名模板<br />
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<span class="t-mark">(别名模板)</span></td>
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