上传cppreference
This commit is contained in:
@@ -0,0 +1,92 @@
|
||||
<!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::basic_string_view<CharT,Traits>::operator[]</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_string_basic_string_view_operator_at 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::basic_string_view<CharT,Traits>::</span>operator[]</h1>
|
||||
<div id="bodyContent">
|
||||
<div id="contentSub"><span class="subpages">< <a href="cpp.html">cpp</a>‎ | <a href="cpp-string.html">string</a>‎ | <a href="cpp-string-basic_string_view.html">basic string view</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-dcl t-since-cxx17">
|
||||
<td>
|
||||
<div><span class="mw-geshi cpp source-cpp"><span class="kw4">constexpr</span> const_reference operator<span class="br0">[</span><span class="br0">]</span><span class="br0">(</span>size_type pos<span class="br0">)</span> <span class="kw4">const</span><span class="sy4">;</span></span></div>
|
||||
</td>
|
||||
<td class="t-dcl-nopad"></td>
|
||||
<td><span class="t-mark-rev t-since-cxx17">(C++17 起)</span></td>
|
||||
</tr>
|
||||
<tr class="t-dcl-sep">
|
||||
<td></td>
|
||||
<td></td>
|
||||
<td></td>
|
||||
</tr>
|
||||
</tbody>
|
||||
</table>
|
||||
<p>返回到位于指定位置 <code>pos</code> 的字符的 const 引用。</p>
|
||||
<p>不进行边界检查：若 <span class="t-c"><span class="mw-geshi cpp source-cpp">pos <span class="sy1">>=</span> size<span class="br0">(</span><span class="br0">)</span></span></span> 则行为未定义。</p>
|
||||
<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>pos</td>
|
||||
<td>-</td>
|
||||
<td>要返回的字符位置</td>
|
||||
</tr>
|
||||
</table>
|
||||
<h3><span class="mw-headline" id=".E8.BF.94.E5.9B.9E.E5.80.BC">返回值</span></h3>
|
||||
<p>到所请求字符的 const 引用。</p>
|
||||
<h3><span class="mw-headline" id=".E5.BC.82.E5.B8.B8">异常</span></h3>
|
||||
<p>不抛出。</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=".E6.B3.A8.E8.A7.A3">注解</span></h3>
|
||||
<p>不同于 <span class="t-lc"><a href="cpp-string-basic_string-operator_at.html">std::basic_string::operator[]</a></span> ， <code>std::basic_string_view::operator[](size())</code> 拥有未定义行为，而非返回 <code>CharT()</code> 。</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 <string_view></span>
|
||||
<span class="kw4">int</span> main<span class="br0">(</span><span class="br0">)</span>
|
||||
<span class="br0">{</span>
|
||||
<a href="cpp-string-basic_string.html"><span class="kw1230">std::<span class="me2">string</span></span></a> str <span class="sy1">=</span> <span class="st0">"Exemplar"</span><span class="sy4">;</span>
|
||||
<a href="cpp-string-basic_string_view.html"><span class="kw1248">std::<span class="me2">string_view</span></span></a> v <span class="sy1">=</span> str<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> v<span class="br0">[</span><span class="nu0">2</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">// v[2] = 'y'; // 错误：不能通过字符串视图修改</span>
|
||||
str<span class="br0">[</span><span class="nu0">2</span><span class="br0">]</span> <span class="sy1">=</span> <span class="st0">'y'</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> v<span class="br0">[</span><span class="nu0">2</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">e
|
||||
y</pre></div>
|
||||
</div>
|
||||
</div>
|
||||
<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-string-basic_string_view-at.html"><span class="t-lines"><span>at</span></span></a></div>
|
||||
</div>
|
||||
</td>
|
||||
<td>访问指定字符，带有边界检查<br />
|
||||
<span class="t-mark">(公开成员函数)</span></td>
|
||||
</tr>
|
||||
</table>
|
||||
</div>
|
||||
<div class="visualClear"></div>
|
||||
</div>
|
||||
</div>
|
||||
</div>
|
||||
</body>
|
||||
</html>
|
||||
Reference in New Issue
Block a user