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<h1 id="firstHeading" class="firstHeading"><span style="font-size:0.7em; line-height:130%">std::</span>mbrtowc</h1>
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<div id="contentSub"><span class="subpages">&lt; <a href="cpp.html">cpp</a>&lrm; | <a href="cpp-string.html">string</a>&lrm; | <a href="cpp-string-multibyte.html">multibyte</a></span></div>
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<div>&#23450;&#20041;&#20110;&#22836;&#25991;&#20214; <code><a href="cpp-header-cwchar.html">&lt;cwchar&gt;</a></code></div>
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<div><span class="mw-geshi cpp source-cpp"><a href="cpp-types-size_t.html"><span class="kw100">std::<span class="me2">size_t</span></span></a> mbrtowc<span class="br0">(</span> <span class="kw4">wchar_t</span><span class="sy2">*</span> pwc,<br /></span>
<p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<span class="kw4">const</span> <span class="kw4">char</span><span class="sy2">*</span> s,<br />
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<a href="cpp-types-size_t.html"><span class="kw100">std::<span class="me2">size_t</span></span></a> n,<br /></p>
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<a href="cpp-string-multibyte-mbstate_t.html"><span class="kw1178">std::<span class="me2">mbstate_t</span></span></a><span class="sy2">*</span> ps <span class="br0">)</span><span class="sy4">;</span></div>
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<p>&#36716;&#25442;&#31364;&#22810;&#23383;&#33410;&#23383;&#31526;&#20026;&#23485;&#23383;&#31526;&#12290;</p>
<p>&#33509; <code>s</code> &#19981;&#26159;&#31354;&#25351;&#38024;&#65292;&#21017;&#20174; <code>s</code> &#25152;&#25351;&#21521;&#30340;&#23383;&#33410;&#36215;&#65292;&#23457;&#26597;&#22810;&#23383;&#33410;&#23383;&#31526;&#20018;&#30340;&#33267;&#22810; <code>n</code> &#20010;&#23383;&#33410;&#65292;&#20197;&#30830;&#23450;&#23436;&#25104;&#19979;&#20010;&#22810;&#23383;&#33410;&#23383;&#31526;&#65288;&#21253;&#21547;&#20219;&#20309;&#36801;&#31227;&#24207;&#21015;&#65289;&#30340;&#23383;&#33410;&#25968;&#12290;&#33509;&#35813;&#20989;&#25968;&#30830;&#23450; <code>s</code> &#30340;&#19979;&#20010;&#22810;&#23383;&#33410;&#23383;&#31526;&#23436;&#25972;&#19988;&#21512;&#27861;&#65292;&#21017;&#23558;&#23427;&#36716;&#25442;&#20026;&#23545;&#24212;&#30340;&#23485;&#23383;&#31526;&#65292;&#24182;&#23384;&#20648;&#20043;&#20110; <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="sy2">*</span>pwc</span></span> &#65288;&#33509; <code>pwc</code> &#38750;&#31354;&#65289;&#12290;</p>
<p>&#33509; <code>s</code> &#26159;&#31354;&#25351;&#38024;&#65292;&#21017;&#24573;&#30053; <code>n</code> &#21644; <code>pwc</code> &#30340;&#20540;&#65292;&#32780;&#35843;&#29992;&#31561;&#20215;&#20110; <span class="t-c"><span class="mw-geshi cpp source-cpp">std<span class="sy4">::</span><span class="me2">mbrtowc</span><span class="br0">(</span><a href="cpp-types-NULL.html"><span class="kw103">NULL</span></a>, <span class="st0">&quot;&quot;</span>, <span class="nu0">1</span>, ps<span class="br0">)</span></span></span> &#12290;</p>
<p>&#33509;&#20135;&#29983;&#30340;&#23485;&#23383;&#31526;&#26159;&#31354;&#23383;&#31526;&#65292;&#21017;&#23384;&#20648;&#20110; <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="sy2">*</span>ps</span></span> &#30340;&#36716;&#25442;&#29366;&#24577;&#20026;&#21021;&#22987;&#36801;&#31227;&#29366;&#24577;&#12290;</p>
<h3><span class="mw-headline" id=".E5.8F.82.E6.95.B0">&#21442;&#25968;</span></h3>
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<td>pwc</td>
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<td>&#25351;&#21521;&#35201;&#20889;&#20837;&#32467;&#26524;&#23485;&#23383;&#31526;&#20301;&#32622;&#30340;&#25351;&#38024;</td>
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<td>s</td>
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<td>&#25351;&#21521;&#29992;&#20316;&#36755;&#20837;&#30340;&#22810;&#23383;&#33410;&#23383;&#31526;&#20018;&#30340;&#25351;&#38024;</td>
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<td>n</td>
<td>-</td>
<td><code>s</code> &#20013;&#33021;&#34987;&#26816;&#39564;&#30340;&#23383;&#33410;&#25968;&#38480;&#21046;</td>
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<td>ps</td>
<td>-</td>
<td>&#25351;&#21521;&#36716;&#35793;&#22810;&#23383;&#33410;&#23383;&#31526;&#20018;&#26102;&#30340;&#36716;&#25442;&#29366;&#24577;&#30340;&#25351;&#38024;</td>
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<h3><span class="mw-headline" id=".E8.BF.94.E5.9B.9E.E5.80.BC">&#36820;&#22238;&#20540;</span></h3>
<p>&#19979;&#21015;&#39318;&#20010;&#21487;&#24212;&#29992;&#32773;&#65306;</p>
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<li>&#33509;&#36716;&#25442;&#33258; <code>s</code> &#30340;&#23383;&#31526;&#20026;&#31354;&#23383;&#31526;&#65292;&#21017;&#20026; <span class="t-c"><span class="mw-geshi cpp source-cpp">&#8203;<span class="nu0">0</span>&#8203;</span></span> &#65288;&#33509; <span class="t-c"><span class="mw-geshi cpp source-cpp">pwc</span></span> &#38750;&#31354;&#21017;&#23384;&#20648;&#20110; <code>*pwc</code> &#65289;</li>
<li>&#25104;&#21151;&#22320; <code>s</code> &#20174;&#36716;&#25442;&#30340;&#22810;&#23383;&#33410;&#23383;&#31526; <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="br0">[</span><span class="nu0">1</span>...<span class="me1">n</span><span class="br0">]</span></span></span> &#30340;&#23383;&#33410;&#25968;</li>
<li>&#33509;&#25509;&#19979;&#26469;&#30340; <code>n</code> &#23383;&#33410;&#32452;&#25104;&#19981;&#23436;&#25972;&#65292;&#20294;&#35813;&#37096;&#20998;&#21512;&#27861;&#30340;&#23485;&#23383;&#31526;&#65292;&#21017;&#20026; <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="kw1">static_cast</span><span class="sy1">&lt;</span><a href="cpp-types-size_t.html"><span class="kw100">std::<span class="me2">size_t</span></span></a><span class="sy1">&gt;</span><span class="br0">(</span><span class="sy2">-</span><span class="nu0">2</span><span class="br0">)</span></span></span> &#12290;&#19981;&#20889;&#20837; <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="sy2">*</span>pwc</span></span> &#12290;</li>
<li>&#33509;&#20986;&#29616;&#32534;&#30721;&#38169;&#35823;&#21017;&#20026; <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="kw1">static_cast</span><span class="sy1">&lt;</span><a href="cpp-types-size_t.html"><span class="kw100">std::<span class="me2">size_t</span></span></a><span class="sy1">&gt;</span><span class="br0">(</span><span class="sy2">-</span><span class="nu0">1</span><span class="br0">)</span></span></span> &#12290;&#19981;&#20889;&#20837; <code>*pwc</code> &#65292;&#23384;&#20648;&#20540; <span class="t-lc"><a href="cpp-error-errno_macros.html">EILSEQ</a></span> &#20110; <span class="t-lc"><a href="cpp-error-errno.html">errno</a></span> &#65292;&#24182;&#19988;&#32622; <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="sy2">*</span>ps</span></span> &#30340;&#20540;&#20026;&#26410;&#25351;&#23450;&#12290;</li>
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<h3><span class="mw-headline" id=".E7.A4.BA.E4.BE.8B">&#31034;&#20363;</span></h3>
<div class="t-example">
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<div class="cpp source-cpp">
<pre class="de1"><span class="co2">#include &lt;iostream&gt;</span>
<span class="co2">#include &lt;clocale&gt;</span>
<span class="co2">#include &lt;cstring&gt;</span>
<span class="co2">#include &lt;cwchar&gt;</span>
<span class="kw4">void</span> print_mb<span class="br0">(</span><span class="kw4">const</span> <span class="kw4">char</span><span class="sy2">*</span> ptr<span class="br0">)</span>
<span class="br0">{</span>
<a href="cpp-string-multibyte-mbstate_t.html"><span class="kw1178">std::<span class="me2">mbstate_t</span></span></a> state <span class="sy1">=</span> <a href="cpp-string-multibyte-mbstate_t.html"><span class="kw1178">std::<span class="me2">mbstate_t</span></span></a><span class="br0">(</span><span class="br0">)</span><span class="sy4">;</span> <span class="co1">// &#21021;&#22987;&#29366;&#24577;</span>
<span class="kw4">const</span> <span class="kw4">char</span><span class="sy2">*</span> end <span class="sy1">=</span> ptr <span class="sy2">+</span> <a href="cpp-string-byte-strlen.html"><span class="kw1145">std::<span class="me2">strlen</span></span></a><span class="br0">(</span>ptr<span class="br0">)</span><span class="sy4">;</span>
<span class="kw4">int</span> len<span class="sy4">;</span>
<span class="kw4">wchar_t</span> wc<span class="sy4">;</span>
<span class="kw1">while</span><span class="br0">(</span><span class="br0">(</span>len <span class="sy1">=</span> std<span class="sy4">::</span><span class="me2">mbrtowc</span><span class="br0">(</span><span class="sy3">&amp;</span>wc, ptr, end<span class="sy2">-</span>ptr, <span class="sy3">&amp;</span>state<span class="br0">)</span><span class="br0">)</span> <span class="sy1">&gt;</span> <span class="nu0">0</span><span class="br0">)</span> <span class="br0">{</span>
<a href="cpp-io-cout.html"><span class="kw1758">std::<span class="me2">wcout</span></span></a> <span class="sy1">&lt;&lt;</span> <span class="st0">&quot;Next &quot;</span> <span class="sy1">&lt;&lt;</span> len <span class="sy1">&lt;&lt;</span> <span class="st0">&quot; bytes are the character &quot;</span> <span class="sy1">&lt;&lt;</span> wc <span class="sy1">&lt;&lt;</span> <span class="st0">&#39;<span class="es1">\n</span>&#39;</span><span class="sy4">;</span>
ptr <span class="sy2">+</span><span class="sy1">=</span> len<span class="sy4">;</span>
<span class="br0">}</span>
<span class="br0">}</span>
<span class="kw4">int</span> main<span class="br0">(</span><span class="br0">)</span>
<span class="br0">{</span>
<a href="cpp-locale-setlocale.html"><span class="kw1989">std::<span class="me2">setlocale</span></span></a><span class="br0">(</span><a href="cpp-locale-LC_categories.html"><span class="kw1992">LC_ALL</span></a>, <span class="st0">&quot;en_US.utf8&quot;</span><span class="br0">)</span><span class="sy4">;</span>
<span class="co1">// UTF-8 &#31364;&#22810;&#23383;&#33410;&#32534;&#30721;</span>
<span class="kw4">const</span> <span class="kw4">char</span><span class="sy2">*</span> str <span class="sy1">=</span> u8<span class="st0">&quot;z<span class="es3">\u00df</span><span class="es3">\u6c34</span><span class="es4">\U0001d10b</span>&quot;</span><span class="sy4">;</span> <span class="co1">// &#25110; u8&quot;z&szlig;&#27700;&#119051;&quot;</span>
<span class="co1">// &#25110; &quot;\x7a\xc3\x9f\xe6\xb0\xb4\xf0\x9d\x84\x8b&quot;;</span>
print_mb<span class="br0">(</span>str<span class="br0">)</span><span class="sy4">;</span>
<span class="br0">}</span></pre></div>
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<p>&#36755;&#20986;&#65306;</p>
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<div class="text source-text">
<pre class="de1">Next 1 bytes are the character z
Next 2 bytes are the character &szlig;
Next 3 bytes are the character &#27700;
Next 4 bytes are the character &#119051;</pre></div>
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<h3><span class="mw-headline" id=".E5.8F.82.E9.98.85">&#21442;&#38405;</span></h3>
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<div class="t-dsc-member-div">
<div><a href="cpp-string-multibyte-mbtowc.html"><span class="t-lines"><span>mbtowc</span></span></a></div>
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<td>&#23558;&#19979;&#19968;&#20010;&#22810;&#23383;&#33410;&#23383;&#31526;&#36716;&#25442;&#25104;&#23485;&#23383;&#31526;<br />
<span class="t-mark">(&#20989;&#25968;)</span></td>
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<div class="t-dsc-member-div">
<div><a href="cpp-string-multibyte-wcrtomb.html"><span class="t-lines"><span>wcrtomb</span></span></a></div>
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<td>&#32473;&#23450;&#29366;&#24577;&#65292;&#36716;&#25442;&#23485;&#23383;&#31526;&#21040;&#20854;&#22810;&#23383;&#33410;&#34920;&#31034;<br />
<span class="t-mark">(&#20989;&#25968;)</span></td>
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<div class="t-dsc-member-div">
<div><a href="cpp-locale-codecvt-in.html"><span class="t-lines"><span>do_in</span></span></a></div>
<div><span class="t-lines"><span><span class="t-cmark">[&#34394;]</span></span></span></div>
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<td>&#20174; externT &#36716;&#25442;&#23383;&#31526;&#20018;&#20026; internT &#65292;&#22914;&#22312;&#20174;&#25991;&#20214;&#35835;&#21462;&#26102;<br />
<span class="t-mark">(<code>std::codecvt&lt;InternT,ExternT,State&gt;</code> &#30340;&#34394;&#21463;&#20445;&#25252;&#25104;&#21592;&#20989;&#25968;)</span></td>
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