klarkxy/hustoj
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity
Files
752105e55c6d00f418211a1b9e2299265843c201
hustoj/web/cppreference-zh/chmhelp/cpp-ranges-elements_view-elements_view.html
klarkxy 196e706fe4 上传cppreference
2025-08-01 12:57:54 +08:00

98 lines
8.7 KiB
HTML
Raw Blame History

<!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::ranges::elements_view&lt;V,N&gt;::elements_view</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_ranges_elements_view_elements_view 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::ranges::elements_view&lt;V,N&gt;::</span>elements_view</h1>
<div id="bodyContent">
<div id="contentSub"><span class="subpages">&lt; <a href="cpp.html">cpp</a>&lrm; | <a href="cpp-ranges.html">ranges</a>&lrm; | <a href="cpp-ranges-elements_view.html">elements 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-cxx20">
<td>
<div><span class="mw-geshi cpp source-cpp">elements_view<span class="br0">(</span><span class="br0">)</span> requires std<span class="sy4">::</span><span class="me2">default_initializable</span><span class="sy1">&lt;</span>V<span class="sy1">&gt;</span> <span class="sy1">=</span> <span class="kw1">default</span><span class="sy4">;</span></span></div>
</td>
<td>(1)</td>
<td><span class="t-mark-rev t-since-cxx20">(C++20 &#36215;)</span></td>
</tr>
<tr class="t-dcl t-since-cxx20">
<td>
<div><span class="mw-geshi cpp source-cpp"><span class="kw4">constexpr</span> elements_view<span class="br0">(</span> V base <span class="br0">)</span><span class="sy4">;</span></span></div>
</td>
<td>(2)</td>
<td><span class="t-mark-rev t-since-cxx20">(C++20 &#36215;)</span></td>
</tr>
<tr class="t-dcl-sep">
<td></td>
<td></td>
<td></td>
</tr>
</tbody>
</table>
<p>&#26500;&#36896; <code>elements_view</code> &#12290;</p>
<div class="t-li1"><span class="t-li">1)</span> &#40664;&#35748;&#26500;&#36896;&#20989;&#25968;&#12290;<a href="cpp-language-value_initialization.html">&#20540;&#21021;&#22987;&#21270;</a>&#24213;&#23618;&#35270;&#22270;&#12290;&#26500;&#36896;&#21518; <a href="cpp-ranges-elements_view-base.html"><code>base()</code></a> &#36820;&#22238; <span class="t-c"><span class="mw-geshi cpp source-cpp">V<span class="br0">(</span><span class="br0">)</span></span></span> &#30340;&#21103;&#26412;&#12290;</div>
<div class="t-li1"><span class="t-li">2)</span> &#20197; <span class="t-c"><span class="mw-geshi cpp source-cpp">std<span class="sy4">::</span><span class="me2">move</span><span class="br0">(</span>r<span class="br0">)</span></span></span> &#21021;&#22987;&#21270;&#24213;&#23618;&#35270;&#22270;&#12290;</div>
<h3><span class="mw-headline" id=".E5.8F.82.E6.95.B0">&#21442;&#25968;</span></h3>
<table class="t-par-begin">
<tr class="t-par">
<td>base</td>
<td>-</td>
<td>&#24213;&#23618;&#35270;&#22270;</td>
</tr>
</table>
<h3><span class="mw-headline" id=".E7.A4.BA.E4.BE.8B">&#31034;&#20363;</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 &lt;iostream&gt;</span>
<span class="co2">#include &lt;ranges&gt;</span>
<span class="co2">#include &lt;tuple&gt;</span>
<span class="co2">#include &lt;array&gt;</span>
<span class="kw1">using</span> <span class="kw1">namespace</span> std<span class="sy4">::</span><span class="me2">literals</span><span class="sy4">;</span>
<span class="kw4">int</span> main<span class="br0">(</span><span class="br0">)</span>
<span class="br0">{</span>
<span class="kw4">const</span> <a href="cpp-container-array.html"><span class="kw1268">std::<span class="me2">array</span></span></a><span class="sy1">&lt;</span><a href="cpp-utility-tuple.html"><span class="kw1098">std::<span class="me2">tuple</span></span></a><span class="sy1">&lt;</span><span class="kw4">int</span>, <span class="kw4">char</span>, <a href="cpp-string-basic_string.html"><span class="kw1230">std::<span class="me2">string</span></span></a><span class="sy1">&gt;</span>, <span class="nu0">2</span><span class="sy1">&gt;</span> vt <span class="br0">{</span>
<a href="cpp-utility-tuple.html"><span class="kw1098">std::<span class="me2">tuple</span></span></a><span class="br0">{</span><span class="nu0">1</span>, <span class="st0">&#39;A&#39;</span>, <span class="st0">&quot;&alpha;&quot;</span>s<span class="br0">}</span>,
<a href="cpp-utility-tuple.html"><span class="kw1098">std::<span class="me2">tuple</span></span></a><span class="br0">{</span><span class="nu0">2</span>, <span class="st0">&#39;B&#39;</span>, <span class="st0">&quot;&beta;&quot;</span>s<span class="br0">}</span>,
<span class="br0">}</span><span class="sy4">;</span>
<span class="br0">[</span><span class="br0">[</span>maybe_unused<span class="br0">]</span><span class="br0">]</span>
<span class="kw4">auto</span> empty <span class="sy1">=</span> std<span class="sy4">::</span><span class="me2">views</span><span class="sy4">::</span><span class="me2">elements</span><span class="sy1">&lt;</span><span class="nu0">0</span><span class="sy1">&gt;</span><span class="sy4">;</span>
<span class="kw4">auto</span> ev0 <span class="sy1">=</span> std<span class="sy4">::</span><span class="me2">views</span><span class="sy4">::</span><span class="me2">elements</span><span class="sy1">&lt;</span><span class="nu0">0</span><span class="sy1">&gt;</span><span class="br0">(</span>vt<span class="br0">)</span><span class="sy4">;</span>
<span class="kw4">auto</span> ev1 <span class="sy1">=</span> std<span class="sy4">::</span><span class="me2">views</span><span class="sy4">::</span><span class="me2">elements</span><span class="sy1">&lt;</span><span class="nu0">1</span><span class="sy1">&gt;</span><span class="br0">(</span>vt<span class="br0">)</span><span class="sy4">;</span>
<span class="kw4">auto</span> ev2 <span class="sy1">=</span> std<span class="sy4">::</span><span class="me2">views</span><span class="sy4">::</span><span class="me2">elements</span><span class="sy1">&lt;</span><span class="nu0">2</span><span class="sy1">&gt;</span><span class="br0">(</span>vt<span class="br0">)</span><span class="sy4">;</span>
<span class="kw1">for</span> <span class="br0">(</span><span class="kw4">auto</span> <span class="kw4">const</span><span class="sy3">&amp;</span> e<span class="sy4">:</span> ev0<span class="br0">)</span> <span class="br0">{</span> <a href="cpp-io-cout.html"><span class="kw1758">std::<span class="me2">cout</span></span></a> <span class="sy1">&lt;&lt;</span> e <span class="sy1">&lt;&lt;</span> <span class="st0">&#39; &#39;</span><span class="sy4">;</span> <span class="br0">}</span>
<a href="cpp-io-cout.html"><span class="kw1758">std::<span class="me2">cout</span></span></a> <span class="sy1">&lt;&lt;</span> <span class="st0">&#39;<span class="es1">\n</span>&#39;</span><span class="sy4">;</span>
<span class="kw1">for</span> <span class="br0">(</span><span class="kw4">auto</span> <span class="kw4">const</span><span class="sy3">&amp;</span> e<span class="sy4">:</span> ev1<span class="br0">)</span> <span class="br0">{</span> <a href="cpp-io-cout.html"><span class="kw1758">std::<span class="me2">cout</span></span></a> <span class="sy1">&lt;&lt;</span> e <span class="sy1">&lt;&lt;</span> <span class="st0">&#39; &#39;</span><span class="sy4">;</span> <span class="br0">}</span>
<a href="cpp-io-cout.html"><span class="kw1758">std::<span class="me2">cout</span></span></a> <span class="sy1">&lt;&lt;</span> <span class="st0">&#39;<span class="es1">\n</span>&#39;</span><span class="sy4">;</span>
<span class="kw1">for</span> <span class="br0">(</span><span class="kw4">auto</span> <span class="kw4">const</span><span class="sy3">&amp;</span> e<span class="sy4">:</span> ev2<span class="br0">)</span> <span class="br0">{</span> <a href="cpp-io-cout.html"><span class="kw1758">std::<span class="me2">cout</span></span></a> <span class="sy1">&lt;&lt;</span> e <span class="sy1">&lt;&lt;</span> <span class="st0">&#39; &#39;</span><span class="sy4">;</span> <span class="br0">}</span>
<a href="cpp-io-cout.html"><span class="kw1758">std::<span class="me2">cout</span></span></a> <span class="sy1">&lt;&lt;</span> <span class="st0">&#39;<span class="es1">\n</span>&#39;</span><span class="sy4">;</span>
<span class="br0">}</span></pre></div>
</div>
<p>&#36755;&#20986;&#65306;</p>
<div dir="ltr" class="mw-geshi" style="text-align: left;">
<div class="text source-text">
<pre class="de1">1 2
A B
&alpha; &beta;</pre></div>
</div>
</div>
</div>
<div class="visualClear"></div>
</div>
</div>
</div>
</body>
</html>
Reference in New Issue View Git Blame Copy Permalink