上传cppreference
This commit is contained in:
@@ -0,0 +1,91 @@
|
||||
<!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::initializer_list<T>::initializer_list</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_utility_initializer_list_initializer_list 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::initializer_list<T>::</span>initializer_list</h1>
|
||||
<div id="bodyContent">
|
||||
<div id="contentSub"><span class="subpages">< <a href="cpp.html">cpp</a>‎ | <a href="cpp-utility.html">utility</a>‎ | <a href="cpp-utility-initializer_list.html">initializer list</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></tbody>
|
||||
<tbody class="t-dcl-rev">
|
||||
<tr class="t-dcl t-since-cxx11 t-until-cxx14">
|
||||
<td>
|
||||
<div><span class="mw-geshi cpp source-cpp">initializer_list<span class="br0">(</span><span class="br0">)</span> <span class="kw1">noexcept</span><span class="sy4">;</span></span></div>
|
||||
</td>
|
||||
<td class="t-dcl-nopad"></td>
|
||||
<td><span class="t-mark-rev t-since-cxx11">(C++11 起)</span><br />
|
||||
<span class="t-mark-rev t-until-cxx14">(C++14 前)</span></td>
|
||||
</tr>
|
||||
<tr class="t-dcl t-since-cxx14">
|
||||
<td>
|
||||
<div><span class="mw-geshi cpp source-cpp"><span class="kw4">constexpr</span> initializer_list<span class="br0">(</span><span class="br0">)</span> <span class="kw1">noexcept</span><span class="sy4">;</span></span></div>
|
||||
</td>
|
||||
<td class="t-dcl-nopad"></td>
|
||||
<td><span class="t-mark-rev t-since-cxx14">(C++14 起)</span></td>
|
||||
</tr>
|
||||
</tbody>
|
||||
<tbody>
|
||||
<tr class="t-dcl-sep">
|
||||
<td></td>
|
||||
<td></td>
|
||||
<td></td>
|
||||
</tr>
|
||||
</tbody>
|
||||
</table>
|
||||
<p>构造空的 initializer_list 。</p>
|
||||
<h3><span class="mw-headline" id=".E5.8F.82.E6.95.B0">参数</span></h3>
|
||||
<p>（无）</p>
|
||||
<h3><span class="mw-headline" id=".E5.A4.8D.E6.9D.82.E5.BA.A6">复杂度</span></h3>
|
||||
<p>常数</p>
|
||||
<h3><span class="mw-headline" id=".E7.A4.BA.E4.BE.8B">示例</span></h3>
|
||||
<div class="t-example">
|
||||
<div class="t-example-live-link"></div>
|
||||
<div dir="ltr" class="mw-geshi" style="text-align: left;">
|
||||
<div class="cpp source-cpp">
|
||||
<pre class="de1"><span class="co2">#include <iostream></span>
|
||||
<span class="co2">#include <initializer_list></span>
|
||||
|
||||
<span class="kw4">int</span> main<span class="br0">(</span><span class="br0">)</span>
|
||||
<span class="br0">{</span>
|
||||
<a href="cpp-utility-initializer_list.html"><span class="kw960">std::<span class="me2">initializer_list</span></span></a><span class="sy1"><</span><span class="kw4">int</span><span class="sy1">></span> empty_list<span class="sy4">;</span>
|
||||
<a href="cpp-io-cout.html"><span class="kw1758">std::<span class="me2">cout</span></span></a> <span class="sy1"><<</span> <span class="st0">"empty_list.size(): "</span> <span class="sy1"><<</span> empty_list.<span class="me1">size</span><span class="br0">(</span><span class="br0">)</span> <span class="sy1"><<</span> <span class="st0">'<span class="es1">\n</span>'</span><span class="sy4">;</span>
|
||||
|
||||
<span class="co1">// 用列表初始化创建初始化器列表</span>
|
||||
<a href="cpp-utility-initializer_list.html"><span class="kw960">std::<span class="me2">initializer_list</span></span></a><span class="sy1"><</span><span class="kw4">int</span><span class="sy1">></span> digits <span class="br0">{</span><span class="nu0">1</span>, <span class="nu0">2</span>, <span class="nu0">3</span>, <span class="nu0">4</span>, <span class="nu0">5</span><span class="br0">}</span><span class="sy4">;</span>
|
||||
<a href="cpp-io-cout.html"><span class="kw1758">std::<span class="me2">cout</span></span></a> <span class="sy1"><<</span> <span class="st0">"digits.size(): "</span> <span class="sy1"><<</span> digits.<span class="me1">size</span><span class="br0">(</span><span class="br0">)</span> <span class="sy1"><<</span> <span class="st0">'<span class="es1">\n</span>'</span><span class="sy4">;</span>
|
||||
|
||||
<span class="co1">// auto 的特殊规则表示‘ fraction ’拥有类型</span>
|
||||
<span class="co1">// type std::initializer_list<double></span>
|
||||
<span class="kw4">auto</span> fractions <span class="sy1">=</span> <span class="br0">{</span><span class="nu16">3.14159</span>, <span class="nu16">2.71828</span><span class="br0">}</span><span class="sy4">;</span>
|
||||
<a href="cpp-io-cout.html"><span class="kw1758">std::<span class="me2">cout</span></span></a> <span class="sy1"><<</span> <span class="st0">"fractions.size(): "</span> <span class="sy1"><<</span> fractions.<span class="me1">size</span><span class="br0">(</span><span class="br0">)</span> <span class="sy1"><<</span> <span class="st0">'<span class="es1">\n</span>'</span><span class="sy4">;</span>
|
||||
<span class="br0">}</span></pre></div>
|
||||
</div>
|
||||
<p>输出：</p>
|
||||
<div dir="ltr" class="mw-geshi" style="text-align: left;">
|
||||
<div class="text source-text">
|
||||
<pre class="de1">empty_list.size(): 0
|
||||
digits.size(): 5
|
||||
fractions.size(): 2</pre></div>
|
||||
</div>
|
||||
</div>
|
||||
<h3><span class="mw-headline" id=".E6.B3.A8.E6.84.8F">注意</span></h3>
|
||||
<p>尽管缺少构造函数，创建非空初始化器列表亦是可能的。在这些时候隐式构造 <code>std::initializer_list</code> 实例：</p>
|
||||
<ul>
|
||||
<li><i>花括号初始化列表</i>用于<a href="cpp-language-list_initialization.html">列表初始化</a>时，包括函数调用列表初始化和赋值表达式</li>
|
||||
<li><i>花括号初始化列表</i>被绑定到 <a href="cpp-language-auto.html"><tt>auto</tt></a> 时，包括在<a href="cpp-language-range-for.html">有范围 for 循环</a>中</li>
|
||||
</ul>
|
||||
</div>
|
||||
<div class="visualClear"></div>
|
||||
</div>
|
||||
</div>
|
||||
</div>
|
||||
</body>
|
||||
</html>
|
||||
Reference in New Issue
Block a user