klarkxy/hustoj
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity
Files
470b6ad77660655c33534cf005828dc90719a197
hustoj/web/cppreference-zh/chmhelp/cpp-iterator-begin.html
klarkxy 196e706fe4 上传cppreference
2025-08-01 12:57:54 +08:00

376 lines
25 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::begin, std::cbegin</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_iterator_begin 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>begin, <span style="font-size:0.7em; line-height:130%">std::</span>cbegin</h1>
<div id="bodyContent">
<div id="contentSub"><span class="subpages">&lt; <a href="cpp.html">cpp</a>&lrm; | <a href="cpp-iterator.html">iterator</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>&#23450;&#20041;&#20110;&#22836;&#25991;&#20214; <code><a href="cpp-header-array.html">&lt;array&gt;</a></code></div>
</td>
<td></td>
<td></td>
</tr>
<tr class="t-dsc-header">
<td>
<div>&#23450;&#20041;&#20110;&#22836;&#25991;&#20214; <code><a href="cpp-header-deque.html">&lt;deque&gt;</a></code></div>
</td>
<td></td>
<td></td>
</tr>
<tr class="t-dsc-header">
<td>
<div>&#23450;&#20041;&#20110;&#22836;&#25991;&#20214; <code><a href="cpp-header-forward_list.html">&lt;forward_list&gt;</a></code></div>
</td>
<td></td>
<td></td>
</tr>
<tr class="t-dsc-header">
<td>
<div>&#23450;&#20041;&#20110;&#22836;&#25991;&#20214; <code><a href="cpp-header-iterator.html">&lt;iterator&gt;</a></code></div>
</td>
<td></td>
<td></td>
</tr>
<tr class="t-dsc-header">
<td>
<div>&#23450;&#20041;&#20110;&#22836;&#25991;&#20214; <code><a href="cpp-header-list.html">&lt;list&gt;</a></code></div>
</td>
<td></td>
<td></td>
</tr>
<tr class="t-dsc-header">
<td>
<div>&#23450;&#20041;&#20110;&#22836;&#25991;&#20214; <code><a href="cpp-header-map.html">&lt;map&gt;</a></code></div>
</td>
<td></td>
<td></td>
</tr>
<tr class="t-dsc-header">
<td>
<div>&#23450;&#20041;&#20110;&#22836;&#25991;&#20214; <code><a href="cpp-header-regex.html">&lt;regex&gt;</a></code></div>
</td>
<td></td>
<td></td>
</tr>
<tr class="t-dsc-header">
<td>
<div>&#23450;&#20041;&#20110;&#22836;&#25991;&#20214; <code><a href="cpp-header-set.html">&lt;set&gt;</a></code></div>
</td>
<td></td>
<td></td>
</tr>
<tr class="t-dsc-header">
<td>
<div>&#23450;&#20041;&#20110;&#22836;&#25991;&#20214; <code><a href="cpp-header-span.html">&lt;span&gt;</a></code></div>
</td>
<td></td>
<td>
<div><span class="t-mark-rev t-since-cxx20">(C++20 &#36215;)</span></div>
</td>
</tr>
<tr class="t-dsc-header">
<td>
<div>&#23450;&#20041;&#20110;&#22836;&#25991;&#20214; <code><a href="cpp-header-string.html">&lt;string&gt;</a></code></div>
</td>
<td></td>
<td></td>
</tr>
<tr class="t-dsc-header">
<td>
<div>&#23450;&#20041;&#20110;&#22836;&#25991;&#20214; <code><a href="cpp-header-string_view.html">&lt;string_view&gt;</a></code></div>
</td>
<td></td>
<td>
<div><span class="t-mark-rev t-since-cxx17">(C++17 &#36215;)</span></div>
</td>
</tr>
<tr class="t-dsc-header">
<td>
<div>&#23450;&#20041;&#20110;&#22836;&#25991;&#20214; <code><a href="cpp-header-unordered_map.html">&lt;unordered_map&gt;</a></code></div>
</td>
<td></td>
<td></td>
</tr>
<tr class="t-dsc-header">
<td>
<div>&#23450;&#20041;&#20110;&#22836;&#25991;&#20214; <code><a href="cpp-header-unordered_set.html">&lt;unordered_set&gt;</a></code></div>
</td>
<td></td>
<td></td>
</tr>
<tr class="t-dsc-header">
<td>
<div>&#23450;&#20041;&#20110;&#22836;&#25991;&#20214; <code><a href="cpp-header-vector.html">&lt;vector&gt;</a></code></div>
</td>
<td></td>
<td></td>
</tr>
</tbody>
<tbody class="t-dcl-rev t-dcl-rev-num">
<tr class="t-dcl-rev-aux">
<td></td>
<td rowspan="142">(1)</td>
<td></td>
</tr>
<tr class="t-dcl t-since-cxx11 t-until-cxx17">
<td>
<div><span class="mw-geshi cpp source-cpp"><span class="kw1">template</span><span class="sy1">&lt;</span> <span class="kw1">class</span> C <span class="sy1">&gt;</span><br />
<span class="kw4">auto</span> begin<span class="br0">(</span> C<span class="sy3">&amp;</span> c <span class="br0">)</span> <span class="sy2">-</span><span class="sy1">&gt;</span> decltype<span class="br0">(</span>c.<span class="me1">begin</span><span class="br0">(</span><span class="br0">)</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-cxx11">(C++11 &#36215;)</span><br />
<span class="t-mark-rev t-until-cxx17">(C++17 &#21069;)</span></td>
</tr>
<tr class="t-dcl t-since-cxx17">
<td>
<div><span class="mw-geshi cpp source-cpp"><span class="kw1">template</span><span class="sy1">&lt;</span> <span class="kw1">class</span> C <span class="sy1">&gt;</span><br />
<span class="kw4">constexpr</span> <span class="kw4">auto</span> begin<span class="br0">(</span> C<span class="sy3">&amp;</span> c <span class="br0">)</span> <span class="sy2">-</span><span class="sy1">&gt;</span> decltype<span class="br0">(</span>c.<span class="me1">begin</span><span class="br0">(</span><span class="br0">)</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-cxx17">(C++17 &#36215;)</span></td>
</tr>
</tbody>
<tbody></tbody>
<tbody class="t-dcl-rev t-dcl-rev-num">
<tr class="t-dcl-rev-aux">
<td></td>
<td rowspan="142">(1)</td>
<td></td>
</tr>
<tr class="t-dcl t-since-cxx11 t-until-cxx17">
<td>
<div><span class="mw-geshi cpp source-cpp"><span class="kw1">template</span><span class="sy1">&lt;</span> <span class="kw1">class</span> C <span class="sy1">&gt;</span><br />
<span class="kw4">auto</span> begin<span class="br0">(</span> <span class="kw4">const</span> C<span class="sy3">&amp;</span> c <span class="br0">)</span> <span class="sy2">-</span><span class="sy1">&gt;</span> decltype<span class="br0">(</span>c.<span class="me1">begin</span><span class="br0">(</span><span class="br0">)</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-cxx11">(C++11 &#36215;)</span><br />
<span class="t-mark-rev t-until-cxx17">(C++17 &#21069;)</span></td>
</tr>
<tr class="t-dcl t-since-cxx17">
<td>
<div><span class="mw-geshi cpp source-cpp"><span class="kw1">template</span><span class="sy1">&lt;</span> <span class="kw1">class</span> C <span class="sy1">&gt;</span><br />
<span class="kw4">constexpr</span> <span class="kw4">auto</span> begin<span class="br0">(</span> <span class="kw4">const</span> C<span class="sy3">&amp;</span> c <span class="br0">)</span> <span class="sy2">-</span><span class="sy1">&gt;</span> decltype<span class="br0">(</span>c.<span class="me1">begin</span><span class="br0">(</span><span class="br0">)</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-cxx17">(C++17 &#36215;)</span></td>
</tr>
</tbody>
<tbody></tbody>
<tbody class="t-dcl-rev t-dcl-rev-num">
<tr class="t-dcl-rev-aux">
<td></td>
<td rowspan="142">(2)</td>
<td></td>
</tr>
<tr class="t-dcl t-since-cxx11 t-until-cxx14">
<td>
<div><span class="mw-geshi cpp source-cpp"><span class="kw1">template</span><span class="sy1">&lt;</span> <span class="kw1">class</span> T, <a href="cpp-types-size_t.html"><span class="kw100">std::<span class="me2">size_t</span></span></a> N <span class="sy1">&gt;</span><br />
T<span class="sy2">*</span> begin<span class="br0">(</span> T <span class="br0">(</span><span class="sy3">&amp;</span>array<span class="br0">)</span><span class="br0">[</span>N<span class="br0">]</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-cxx11">(C++11 &#36215;)</span><br />
<span class="t-mark-rev t-until-cxx14">(C++14 &#21069;)</span></td>
</tr>
<tr class="t-dcl t-since-cxx14">
<td>
<div><span class="mw-geshi cpp source-cpp"><span class="kw1">template</span><span class="sy1">&lt;</span> <span class="kw1">class</span> T, <a href="cpp-types-size_t.html"><span class="kw100">std::<span class="me2">size_t</span></span></a> N <span class="sy1">&gt;</span><br />
<span class="kw4">constexpr</span> T<span class="sy2">*</span> begin<span class="br0">(</span> T <span class="br0">(</span><span class="sy3">&amp;</span>array<span class="br0">)</span><span class="br0">[</span>N<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 &#36215;)</span></td>
</tr>
</tbody>
<tbody>
<tr class="t-dcl t-since-cxx14">
<td>
<div><span class="mw-geshi cpp source-cpp"><span class="kw1">template</span><span class="sy1">&lt;</span> <span class="kw1">class</span> C <span class="sy1">&gt;</span><br /></span>
<p><span class="kw4">constexpr</span> <span class="kw4">auto</span> cbegin<span class="br0">(</span> <span class="kw4">const</span> C<span class="sy3">&amp;</span> c <span class="br0">)</span> <span class="kw1">noexcept</span><span class="br0">(</span><span class="coMULTI">/* see below */</span><span class="br0">)</span><br /></p>
&nbsp; &nbsp; <span class="sy2">-</span><span class="sy1">&gt;</span> decltype<span class="br0">(</span>std<span class="sy4">::</span><span class="me2">begin</span><span class="br0">(</span>c<span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span></div>
</td>
<td>(3)</td>
<td><span class="t-mark-rev t-since-cxx14">(C++14 &#36215;)</span></td>
</tr>
<tr class="t-dcl-sep">
<td></td>
<td></td>
<td></td>
</tr>
</tbody>
</table>
<p>&#36820;&#22238;&#25351;&#21521;&#32473;&#23450;&#33539;&#22260;&#36215;&#22987;&#30340;&#36845;&#20195;&#22120;&#12290;</p>
<div class="t-li1"><span class="t-li">1)</span> &#20934;&#30830;&#36820;&#22238; <span class="t-c"><span class="mw-geshi cpp source-cpp">c.<span class="me1">begin</span><span class="br0">(</span><span class="br0">)</span></span></span> &#65292;&#20856;&#22411;&#22320;&#26159;&#25351;&#21521; <code>c</code> &#25152;&#20195;&#34920;&#30340;&#24207;&#21015;&#36215;&#22987;&#30340;&#36845;&#20195;&#22120;&#12290;&#33509; <code>C</code> &#26159;&#26631;&#20934;<a href="cpp-named_req-Container.html"><span style="font-style:italic">&#23481;&#22120;</span> <span style="font-family: Georgia, &#39;DejaVu Serif&#39;, serif; font-style:italic">(Container)</span></a> &#65292;&#21017;&#22312; <code>c</code> &#19981;&#26159; const &#38480;&#23450;&#26102;&#36820;&#22238; <span class="t-c"><span class="mw-geshi cpp source-cpp">C<span class="sy4">::</span><span class="me2">iterator</span></span></span> &#65292;&#21542;&#21017;&#36820;&#22238; <span class="t-c"><span class="mw-geshi cpp source-cpp">C<span class="sy4">::</span><span class="me2">const_iterator</span></span></span> &#12290;</div>
<div class="t-li1"><span class="t-li">2)</span> &#36820;&#22238;&#25351;&#21521; <code>array</code> &#36215;&#22987;&#30340;&#25351;&#38024;&#12290;</div>
<div class="t-li1"><span class="t-li">3)</span> &#20934;&#30830;&#36820;&#22238; <span class="t-c"><span class="mw-geshi cpp source-cpp">std<span class="sy4">::</span><span class="me2">begin</span><span class="br0">(</span>c<span class="br0">)</span></span></span> &#65292;&#36825;&#37324; <code>c</code> &#22987;&#32456;&#34987;&#35270;&#20026; const &#38480;&#23450;&#12290;&#33509; <code>C</code> &#26159;&#26631;&#20934;<a href="cpp-named_req-Container.html"><span style="font-style:italic">&#23481;&#22120;</span> <span style="font-family: Georgia, &#39;DejaVu Serif&#39;, serif; font-style:italic">(Container)</span></a> &#65292;&#21017;&#22987;&#32456;&#36820;&#22238; <span class="t-c"><span class="mw-geshi cpp source-cpp">C<span class="sy4">::</span><span class="me2">const_iterator</span></span></span> &#12290;</div>
<div class="t-image">
<p><img alt="range-begin-end.svg" src="range-begin-end.svg" width="546" height="157" /></p>
</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>c</td>
<td>-</td>
<td>&#24102; <code>begin</code> &#25104;&#21592;&#20989;&#25968;&#30340;&#23481;&#22120;&#25110;&#35270;&#22270;</td>
</tr>
<tr class="t-par">
<td>array</td>
<td>-</td>
<td>&#20219;&#24847;&#31867;&#22411;&#30340;&#25968;&#32452;</td>
</tr>
</table>
<h3><span class="mw-headline" id=".E8.BF.94.E5.9B.9E.E5.80.BC">&#36820;&#22238;&#20540;</span></h3>
<p>&#25351;&#21521;&#33539;&#22260;&#36215;&#22987;&#30340;&#36845;&#20195;&#22120;</p>
<h3><span class="mw-headline" id=".E5.BC.82.E5.B8.B8">&#24322;&#24120;</span></h3>
<div class="t-li1"><span class="t-li">3)</span>
<div class="t-noexcept-full"><a href="cpp-language-noexcept_spec.html"><tt>noexcept</tt></a> &#35828;&#26126;&#65306;&nbsp;&nbsp;
<div class="t-noexcept-box"><span class="t-cc"><span class="mw-geshi cpp source-cpp"><span class="kw1">noexcept</span><span class="br0">(</span><span class="kw1">noexcept</span><span class="br0">(</span>std<span class="sy4">::</span><span class="me2">begin</span><span class="br0">(</span>c<span class="br0">)</span><span class="br0">)</span><span class="br0">)</span></span></span></div>
</div>
</div>
<h3><span class="mw-headline" id=".E9.87.8D.E8.BD.BD">&#37325;&#36733;</span></h3>
<p>&#21487;&#20197;&#20026;&#19981;&#26292;&#38706;&#36866;&#21512;&#30340; <code>begin()</code> &#25104;&#21592;&#20989;&#25968;&#30340;&#31867;&#25110;&#26522;&#20030;&#25552;&#20379; <code>begin</code> &#30340;&#33258;&#23450;&#20041;&#37325;&#36733;&#65292;&#20174;&#32780;&#33021;&#36845;&#20195;&#23427;&#12290;&#26631;&#20934;&#24211;&#24050;&#25552;&#20379;&#19979;&#21015;&#37325;&#36733;&#65306;</p>
<table class="t-dsc-begin">
<tr class="t-dsc">
<td>
<div class="t-dsc-member-div">
<div><a href="cpp-utility-initializer_list-begin2.html"><span class="t-lines"><span>std::begin<span class="t-dsc-small">(std::initializer_list)</span></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>&#29305;&#21270; <span class="t-lc"><strong class="selflink">std::begin</strong></span><br />
<span class="t-mark">(&#20989;&#25968;&#27169;&#26495;)</span></td>
</tr>
<tr class="t-dsc">
<td>
<div class="t-dsc-member-div">
<div><a href="cpp-numeric-valarray-begin2.html"><span class="t-lines"><span>std::begin<span class="t-dsc-small">(std::valarray)</span></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>&#29305;&#21270;&#30340; <span class="t-lc"><strong class="selflink">std::begin</strong></span><br />
<span class="t-mark">(&#20989;&#25968;&#27169;&#26495;)</span></td>
</tr>
<tr class="t-dsc">
<td>
<div class="t-dsc-member-div">
<div><a href="cpp-filesystem-directory_iterator-begin.html"><span class="t-lines"><span>begin<span class="t-dsc-small">(std::filesystem::directory_iterator)</span></span><span>end<span class="t-dsc-small">(std::filesystem::directory_iterator)</span></span></span></a></div>
</div>
</td>
<td>&#22522;&#20110;&#33539;&#22260;&#30340; for &#24490;&#29615;&#25903;&#25345;<br />
<span class="t-mark">(&#20989;&#25968;)</span></td>
</tr>
<tr class="t-dsc">
<td>
<div class="t-dsc-member-div">
<div><a href="cpp-filesystem-recursive_directory_iterator-begin.html"><span class="t-lines"><span>begin<span class="t-dsc-small">(std::filesystem::recursive_directory_iterator)</span></span><span>end<span class="t-dsc-small">(std::filesystem::recursive_directory_iterator)</span></span></span></a></div>
</div>
</td>
<td>&#22522;&#20110;&#33539;&#22260;&#30340; for &#24490;&#29615;&#25903;&#25345;<br />
<span class="t-mark">(&#20989;&#25968;)</span></td>
</tr>
</table>
<p>&#21516; <code>swap</code> &#30340;&#20351;&#29992;&#65288;&#20110;<a href="cpp-named_req-Swappable.html"><span style="font-style:italic">&#21487;&#20132;&#25442;</span> <span style="font-family: Georgia, &#39;DejaVu Serif&#39;, serif; font-style:italic">(Swappable)</span></a> &#25551;&#36848;&#65289;&#65292; <code>begin</code> &#20989;&#25968;&#22312;&#27867;&#22411;&#35821;&#22659;&#20013;&#30340;&#20351;&#29992;&#31561;&#20215;&#20110; <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="kw1">using</span> std<span class="sy4">::</span><span class="me2">begin</span><span class="sy4">;</span> begin<span class="br0">(</span>arg<span class="br0">)</span><span class="sy4">;</span></span></span>&#65292;&#36825;&#20801;&#35768; <a href="cpp-language-adl.html">ADL</a> &#20026;&#29992;&#25143;&#23450;&#20041;&#31867;&#22411;&#25152;&#36873;&#30340;&#37325;&#36733;&#21644;&#20986;&#29616;&#20110;&#21516;&#19968;&#37325;&#36733;&#38598;&#30340;&#26631;&#20934;&#24211;&#20989;&#25968;&#27169;&#26495;&#12290;</p>
<div dir="ltr" class="mw-geshi" style="text-align: left;">
<div class="cpp source-cpp">
<pre class="de1"><span class="kw1">template</span><span class="sy1">&lt;</span><span class="kw1">typename</span> Container, <span class="kw1">typename</span> Function<span class="sy1">&gt;</span>
<span class="kw4">void</span> for_each<span class="br0">(</span>Container<span class="sy3">&amp;&amp;</span> cont, Function f<span class="br0">)</span> <span class="br0">{</span>
<span class="kw1">using</span> std<span class="sy4">::</span><span class="me2">begin</span><span class="sy4">;</span>
<span class="kw4">auto</span> it <span class="sy1">=</span> begin<span class="br0">(</span>cont<span class="br0">)</span><span class="sy4">;</span>
<span class="kw1">using</span> <a href="cpp-iterator-end.html"><span class="kw678">std::<span class="me2">end</span></span></a><span class="sy4">;</span>
<span class="kw4">auto</span> end_it <span class="sy1">=</span> end<span class="br0">(</span>cont<span class="br0">)</span><span class="sy4">;</span>
<span class="kw1">while</span> <span class="br0">(</span>it <span class="sy3">!</span><span class="sy1">=</span> end_it<span class="br0">)</span> <span class="br0">{</span>
f<span class="br0">(</span><span class="sy2">*</span>it<span class="br0">)</span><span class="sy4">;</span>
<span class="sy2">++</span>it<span class="sy4">;</span>
<span class="br0">}</span>
<span class="br0">}</span></pre></div>
</div>
<table class="t-rev-begin">
<tr class="t-rev t-since-cxx20">
<td>
<p><a href="cpp-language-adl.html">&#23454;&#21442;&#20381;&#36182;&#26597;&#25214;</a>&#25152;&#25214;&#21040;&#30340; <code>begin</code> &#37325;&#36733;&#33021;&#29992;&#20110;&#23450;&#21046; <span class="t-c"><span class="mw-geshi cpp source-cpp">std<span class="sy4">::</span><span class="me2">ranges</span><span class="sy4">::</span><span class="me2">begin</span></span></span>&#12289; <span class="t-c"><span class="mw-geshi cpp source-cpp">std<span class="sy4">::</span><span class="me2">ranges</span><span class="sy4">::</span><span class="me2">cbegin</span></span></span> &#21450;&#20854;&#20182;&#20381;&#36182;&#20110; <span class="t-c"><span class="mw-geshi cpp source-cpp">std<span class="sy4">::</span><span class="me2">ranges</span><span class="sy4">::</span><span class="me2">begin</span></span></span> &#30340;&#23450;&#21046;&#28857;&#23545;&#35937;&#30340;&#34892;&#20026;&#12290;</p>
</td>
<td><span class="t-mark-rev t-since-cxx20">(C++20 &#36215;)</span></td>
</tr>
</table>
<h3><span class="mw-headline" id=".E6.B3.A8.E8.A7.A3">&#27880;&#35299;</span></h3>
<p><span class="t-v">(1,3)</span> &#20934;&#30830;&#22320;&#21453;&#26144; <span class="t-c"><span class="mw-geshi cpp source-cpp">C<span class="sy4">::</span><span class="me2">begin</span><span class="br0">(</span><span class="br0">)</span></span></span> &#30340;&#34892;&#20026;&#12290;&#33509;&#35813;&#25104;&#21592;&#20989;&#25968;&#26080;&#21512;&#29702;&#30340;&#23454;&#29616;&#65292;&#21017;&#23427;&#20204;&#30340;&#25928;&#26524;&#21487;&#33021;&#20196;&#20154;&#24778;&#24322;&#12290;</p>
<p><code>std::cbegin</code> &#26159;&#20026;&#32479;&#19968;&#25104;&#21592;&#19982;&#38750;&#25104;&#21592;&#33539;&#22260;&#35775;&#38382;&#24341;&#20837;&#30340;&#12290;&#21442;&#38405; <a rel="nofollow" class="external text" href="https://cplusplus.github.io/LWG/issue2128">LWG &#38382;&#39064; 2128</a> &#12290;</p>
<p>&#33509; <code>C</code> &#26159;&#27973; const &#30340;&#35270;&#22270;&#65292;&#21017; <code>std::cbegin</code> &#21487;&#33021;&#36820;&#22238;&#21487;&#21464;&#30340;&#36845;&#20195;&#22120;&#12290;&#26576;&#20123;&#29992;&#25143;&#19981;&#26399;&#24453;&#36825;&#31181;&#34892;&#20026;&#12290;&#21442;&#38405; <a rel="nofollow" class="external text" href="https://wg21.link/P2276">P2276</a> &#19982; <a rel="nofollow" class="external text" href="https://wg21.link/P2278">P2278</a> &#12290;</p>
<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;vector&gt;</span>
<span class="co2">#include &lt;iterator&gt;</span>
<span class="kw4">int</span> main<span class="br0">(</span><span class="br0">)</span>
<span class="br0">{</span>
<a href="cpp-container-vector.html"><span class="kw1267">std::<span class="me2">vector</span></span></a><span class="sy1">&lt;</span><span class="kw4">int</span><span class="sy1">&gt;</span> v <span class="sy1">=</span> <span class="br0">{</span> <span class="nu0">3</span>, <span class="nu0">1</span>, <span class="nu0">4</span> <span class="br0">}</span><span class="sy4">;</span>
<span class="kw4">auto</span> vi <span class="sy1">=</span> std<span class="sy4">::</span><span class="me2">begin</span><span class="br0">(</span>v<span class="br0">)</span><span class="sy4">;</span>
<a href="cpp-io-cout.html"><span class="kw1756">std::<span class="me2">cout</span></span></a> <span class="sy1">&lt;&lt;</span> <span class="sy2">*</span>vi <span class="sy1">&lt;&lt;</span> <span class="st0">&#39;<span class="es1">\n</span>&#39;</span><span class="sy4">;</span>
<span class="kw4">int</span> a<span class="br0">[</span><span class="br0">]</span> <span class="sy1">=</span> <span class="br0">{</span> <span class="sy2">-</span><span class="nu0">5</span>, <span class="nu0">10</span>, <span class="nu0">15</span> <span class="br0">}</span><span class="sy4">;</span>
<span class="kw4">auto</span> ai <span class="sy1">=</span> std<span class="sy4">::</span><span class="me2">begin</span><span class="br0">(</span>a<span class="br0">)</span><span class="sy4">;</span>
<a href="cpp-io-cout.html"><span class="kw1756">std::<span class="me2">cout</span></span></a> <span class="sy1">&lt;&lt;</span> <span class="sy2">*</span>ai <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">3
-5</pre></div>
</div>
</div>
<h3><span class="mw-headline" id=".E5.8F.82.E9.98.85">&#21442;&#38405;</span></h3>
<table class="t-dsc-begin">
<tr class="t-dsc">
<td>
<div class="t-dsc-member-div">
<div><a href="cpp-iterator-end.html"><span class="t-lines"><span>end</span><span>cend</span></span></a></div>
<div><span class="t-lines"><span><span class="t-mark-rev t-since-cxx11">(C++11)</span></span><span><span class="t-mark-rev t-since-cxx14">(C++14)</span></span></span></div>
</div>
</td>
<td>&#36820;&#22238;&#25351;&#21521;&#23481;&#22120;&#25110;&#25968;&#32452;&#32467;&#23614;&#30340;&#36845;&#20195;&#22120;<br />
<span class="t-mark">(&#20989;&#25968;&#27169;&#26495;)</span></td>
</tr>
<tr class="t-dsc">
<td>
<div class="t-dsc-member-div">
<div><a href="cpp-ranges-begin.html"><span class="t-lines"><span>ranges::begin</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>&#36820;&#22238;&#25351;&#21521;&#33539;&#22260;&#36215;&#22987;&#30340;&#36845;&#20195;&#22120;<br />
<span class="t-mark">(&#23450;&#21046;&#28857;&#23545;&#35937;)</span></td>
</tr>
<tr class="t-dsc">
<td>
<div class="t-dsc-member-div">
<div><a href="cpp-ranges-cbegin.html"><span class="t-lines"><span>ranges::cbegin</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>&#36820;&#22238;&#25351;&#21521;&#21482;&#35835;&#33539;&#22260;&#36215;&#22987;&#30340;&#36845;&#20195;&#22120;<br />
<span class="t-mark">(&#23450;&#21046;&#28857;&#23545;&#35937;)</span></td>
</tr>
</table>
</div>
<div class="visualClear"></div>
</div>
</div>
</div>
</body>
</html>
Reference in New Issue View Git Blame Copy Permalink