116 lines
7.8 KiB
HTML
116 lines
7.8 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::codecvt<InternT,ExternT,State>::unshift, do_unshift</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_locale_codecvt_unshift 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::codecvt<InternT,ExternT,State>::</span>unshift, do_unshift</h1>
|
|
<div id="bodyContent">
|
|
<div id="contentSub"><span class="subpages">< <a href="cpp.html">cpp</a>‎ | <a href="cpp-locale.html">locale</a>‎ | <a href="cpp-locale-codecvt.html">codecvt</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-locale.html"><locale></a></code></div>
|
|
</td>
|
|
<td></td>
|
|
<td></td>
|
|
</tr>
|
|
<tr class="t-dcl">
|
|
<td>
|
|
<div><span class="mw-geshi cpp source-cpp"><span class="kw1">public</span><span class="sy4">:</span><br /></span>
|
|
<p>result unshift<span class="br0">(</span> StateT<span class="sy3">&</span> state,<br />
|
|
ExternT<span class="sy2">*</span> to,<br />
|
|
ExternT<span class="sy2">*</span> to_end,<br /></p>
|
|
ExternT<span class="sy2">*</span><span class="sy3">&</span> to_next<span class="br0">)</span> <span class="kw4">const</span><span class="sy4">;</span></div>
|
|
</td>
|
|
<td>(1)</td>
|
|
<td class="t-dcl-nopad"></td>
|
|
</tr>
|
|
<tr class="t-dcl">
|
|
<td>
|
|
<div><span class="mw-geshi cpp source-cpp"><span class="kw1">protected</span><span class="sy4">:</span><br /></span>
|
|
<p><span class="kw1">virtual</span> result do_unshift<span class="br0">(</span> StateT<span class="sy3">&</span> state,<br />
|
|
ExternT<span class="sy2">*</span> to,<br />
|
|
ExternT<span class="sy2">*</span> to_end,<br /></p>
|
|
ExternT<span class="sy2">*</span><span class="sy3">&</span> to_next<span class="br0">)</span> <span class="kw4">const</span><span class="sy4">;</span></div>
|
|
</td>
|
|
<td>(2)</td>
|
|
<td class="t-dcl-nopad"></td>
|
|
</tr>
|
|
<tr class="t-dcl-sep">
|
|
<td></td>
|
|
<td></td>
|
|
<td></td>
|
|
</tr>
|
|
</tbody>
|
|
</table>
|
|
<div class="t-li1"><span class="t-li">1)</span> 公开成员函数，调用最终导出类的成员函数 <code>do_unshift</code> 。</div>
|
|
<div class="t-li1"><span class="t-li">2)</span> 若此 <code>codecvt</code> 所表示的编码依赖状态，而 <code>state</code> 表示的转换状态不是初始迁移状态，则写入返回初始迁移状态所需的字符。字符被写入首元素为 <code>to</code> 所指向的字符数组。不写入多于 <code>to_end-to</code> 个字符。更新参数 <code>to_next</code> 以指向最后写入字符的后一位置。</div>
|
|
<h3><span class="mw-headline" id=".E8.BF.94.E5.9B.9E.E5.80.BC">返回值</span></h3>
|
|
<p><span class="t-lc"><a href="cpp-locale-codecvt_base.html">std::codecvt_base::result</a></span> 类型值，指示成功状况如下：</p>
|
|
<table class="t-dsc-begin">
|
|
<tr class="t-dsc">
|
|
<td><code>ok</code></td>
|
|
<td>已写入所有所需字符。 <code>state</code> 现在表示初始迁移状态</td>
|
|
</tr>
|
|
<tr class="t-dsc">
|
|
<td><code>partial</code></td>
|
|
<td>输出缓冲区中空间不足。 <span class="t-c"><span class="mw-geshi cpp source-cpp">to_next <span class="sy1">==</span> to_end</span></span></td>
|
|
</tr>
|
|
<tr class="t-dsc">
|
|
<td><code>error</code></td>
|
|
<td>出现未指明的错误</td>
|
|
</tr>
|
|
<tr class="t-dsc">
|
|
<td><code>noconv</code></td>
|
|
<td>编码不依赖状态，不需要终止序列</td>
|
|
</tr>
|
|
</table>
|
|
<p>非转换特化 <span class="t-c"><span class="mw-geshi cpp source-cpp"><a href="cpp-locale-codecvt.html"><span class="kw1939">std::<span class="me2">codecvt</span></span></a><span class="sy1"><</span><span class="kw4">char</span>, <span class="kw4">char</span>, <a href="cpp-string-multibyte-mbstate_t.html"><span class="kw1179">std::<span class="me2">mbstate_t</span></span></a><span class="sy1">></span></span></span> 始终返回 <span class="t-lc"><a href="cpp-locale-codecvt_base.html">std::codecvt_base::noconv</a></span> 。</p>
|
|
<h3><span class="mw-headline" id=".E6.B3.A8.E6.84.8F">注意</span></h3>
|
|
<p>此函数为 <span class="t-c"><span class="mw-geshi cpp source-cpp">std<span class="sy4">::</span><span class="me2">basic_filebuf</span><span class="sy4">::</span><span class="me2">close</span><span class="br0">(</span><span class="br0">)</span></span></span> 所调用，并在终止化依赖状态的多字节序列的情形中被调用。</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-string-multibyte-wcrtomb.html"><span class="t-lines"><span>wcrtomb</span></span></a></div>
|
|
</div>
|
|
</td>
|
|
<td>给定状态，转换宽字符到其多字节表示<br />
|
|
<span class="t-mark">(函数)</span></td>
|
|
</tr>
|
|
<tr class="t-dsc">
|
|
<td>
|
|
<div class="t-dsc-member-div">
|
|
<div><a href="cpp-locale-codecvt-out.html"><span class="t-lines"><span>do_out</span></span></a></div>
|
|
<div><span class="t-lines"><span><span class="t-cmark">[虚]</span></span></span></div>
|
|
</div>
|
|
</td>
|
|
<td>从 internT 转换字符串为 externT 转换字符串，如在写入文件时<br />
|
|
<span class="t-mark">(虚受保护成员函数)</span></td>
|
|
</tr>
|
|
</table>
|
|
</div>
|
|
<div class="visualClear"></div>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
</body>
|
|
</html>
|