108 lines
6.7 KiB
HTML
108 lines
6.7 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::uninitialized_construct_using_allocator</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_uninitialized_construct_using_allocator 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>uninitialized_construct_using_allocator</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-cxx20">
|
|
<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> Alloc, <span class="kw1">class</span>... <span class="me1">Args</span> <span class="sy1">></span><br />
|
|
<span class="kw4">constexpr</span> T<span class="sy2">*</span> uninitialized_construct_using_allocator<span class="br0">(</span> T<span class="sy2">*</span> p, <span class="kw4">const</span> Alloc<span class="sy3">&</span> alloc, Args<span class="sy3">&&</span>... <span class="me1">args</span> <span class="br0">)</span><span class="sy4">;</span></span></div>
|
|
</td>
|
|
<td class="t-dcl-nopad"></td>
|
|
<td><span class="t-mark-rev t-since-cxx20">(C++20 起)</span></td>
|
|
</tr>
|
|
<tr class="t-dcl-sep">
|
|
<td></td>
|
|
<td></td>
|
|
<td></td>
|
|
</tr>
|
|
</tbody>
|
|
</table>
|
|
<p>以<a href="cpp-memory-uses_allocator.html">使用分配器构造</a>的手段在 <span class="t-spar">p</span> 所指示的未初始化内存位置创建给定类型 <code>T</code> 的对象。</p>
|
|
<p>等价于</p>
|
|
<div dir="ltr" class="mw-geshi" style="text-align: left;">
|
|
<div class="cpp source-cpp">
|
|
<pre class="de1"><span class="kw1">return</span> <a href="cpp-utility-apply.html"><span class="kw1103">std::<span class="me2">apply</span></span></a><span class="br0">(</span><span class="br0">[</span><span class="sy3">&</span><span class="br0">]</span><span class="sy1"><</span><span class="kw1">class</span>... <span class="me1">Xs</span><span class="sy1">></span><span class="br0">(</span>Xs<span class="sy3">&&</span>...<span class="me1">xs</span><span class="br0">)</span> <span class="br0">{</span>
|
|
<span class="kw1">return</span> std<span class="sy4">::</span><span class="me2">construct_at</span><span class="br0">(</span>p, <a href="cpp-utility-forward.html"><span class="kw1117">std::<span class="me2">forward</span></span></a><span class="sy1"><</span>Xs<span class="sy1">></span><span class="br0">(</span>xs<span class="br0">)</span>...<span class="br0">)</span><span class="sy4">;</span>
|
|
<span class="br0">}</span>, std<span class="sy4">::</span><span class="me2">uses_allocator_construction_args</span><span class="sy1"><</span>T<span class="sy1">></span><span class="br0">(</span>alloc, <a href="cpp-utility-forward.html"><span class="kw1117">std::<span class="me2">forward</span></span></a><span class="sy1"><</span>Args<span class="sy1">></span><span class="br0">(</span>args<span class="br0">)</span>...<span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span></pre></div>
|
|
</div>
|
|
<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>p</td>
|
|
<td>-</td>
|
|
<td>将要放置对象的内存位置。</td>
|
|
</tr>
|
|
<tr class="t-par">
|
|
<td>alloc</td>
|
|
<td>-</td>
|
|
<td>要使用的分配器。</td>
|
|
</tr>
|
|
<tr class="t-par">
|
|
<td>args</td>
|
|
<td>-</td>
|
|
<td>传递给 <code>T</code> 构造函数的参数。</td>
|
|
</tr>
|
|
</table>
|
|
<h3><span class="mw-headline" id=".E8.BF.94.E5.9B.9E.E5.80.BC">返回值</span></h3>
|
|
<p>指向新创建的 <code>T</code> 类型对象的指针。</p>
|
|
<h3><span class="mw-headline" id=".E5.BC.82.E5.B8.B8">异常</span></h3>
|
|
<p>可能抛出 <code>T</code> 的构造函数所抛的任何异常，常包括 <span class="t-lc"><a href="cpp-memory-new-bad_alloc.html">std::bad_alloc</a></span> 。</p>
|
|
<h3><span class="mw-headline" id=".E7.A4.BA.E4.BE.8B">示例</span></h3>
|
|
<table class="metadata plainlinks ambox mbox-small-left ambox-notice" style="">
|
|
<tr>
|
|
<td class="mbox-empty-cell"></td>
|
|
<td class="mbox-text" style="">本节未完成<br />
|
|
原因：暂无示例</td>
|
|
</tr>
|
|
</table>
|
|
<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-uses_allocator.html"><span class="t-lines"><span>uses_allocator</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>检查指定的类型是否支持使用分配器的构造<br />
|
|
<span class="t-mark">(类模板)</span></td>
|
|
</tr>
|
|
<tr class="t-dsc">
|
|
<td>
|
|
<div class="t-dsc-member-div">
|
|
<div><a href="cpp-memory-make_obj_using_allocator.html"><span class="t-lines"><span>make_obj_using_allocator</span></span></a></div>
|
|
<div><span class="t-lines"><span><span class="t-mark-rev t-since-cxx20">(C++20)</span></span></span></div>
|
|
</div>
|
|
</td>
|
|
<td>以使用分配器构造的手段创建给类型的对象<br />
|
|
<span class="t-mark">(函数模板)</span></td>
|
|
</tr>
|
|
</table>
|
|
</div>
|
|
<div class="visualClear"></div>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
</body>
|
|
</html>
|