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<title>std::multimap&lt;Key,T,Compare,Allocator&gt;::begin, std::multimap&lt;Key,T,Compare,Allocator&gt;::cbegin</title>
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<h1 id="firstHeading" class="firstHeading"><span style="font-size:0.7em; line-height:130%">std::multimap&lt;Key,T,Compare,Allocator&gt;::</span>begin, <span style="font-size:0.7em; line-height:130%">std::multimap&lt;Key,T,Compare,Allocator&gt;::</span>cbegin</h1>
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<div id="contentSub"><span class="subpages">&lt; <a href="cpp.html">cpp</a>&lrm; | <a href="cpp-container.html">container</a>&lrm; | <a href="cpp-container-multimap.html">multimap</a></span></div>
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<div><span class="mw-geshi cpp source-cpp">iterator begin<span class="br0">(</span><span class="br0">)</span><span class="sy4">;</span></span></div>
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<td><span class="t-mark-rev t-until-cxx11">(C++11 &#21069;)</span></td>
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<div><span class="mw-geshi cpp source-cpp">iterator begin<span class="br0">(</span><span class="br0">)</span> <span class="kw1">noexcept</span><span class="sy4">;</span></span></div>
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<td><span class="t-mark-rev t-since-cxx11">(C++11 &#36215;)</span></td>
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<div><span class="mw-geshi cpp source-cpp">const_iterator begin<span class="br0">(</span><span class="br0">)</span> <span class="kw4">const</span><span class="sy4">;</span></span></div>
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<td><span class="t-mark-rev t-until-cxx11">(C++11 &#21069;)</span></td>
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<div><span class="mw-geshi cpp source-cpp">const_iterator begin<span class="br0">(</span><span class="br0">)</span> <span class="kw4">const</span> <span class="kw1">noexcept</span><span class="sy4">;</span></span></div>
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<td><span class="t-mark-rev t-since-cxx11">(C++11 &#36215;)</span></td>
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<div><span class="mw-geshi cpp source-cpp">const_iterator cbegin<span class="br0">(</span><span class="br0">)</span> <span class="kw4">const</span> <span class="kw1">noexcept</span><span class="sy4">;</span></span></div>
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<p>&#36820;&#22238;&#25351;&#21521; <code>multimap</code> &#39318;&#20803;&#32032;&#30340;&#36845;&#20195;&#22120;&#12290;</p>
<p>&#33509; <code>multimap</code> &#20026;&#31354;&#65292;&#21017;&#36820;&#22238;&#30340;&#36845;&#20195;&#22120;&#23558;&#31561;&#20110; <span class="t-lc"><a href="cpp-container-multimap-end.html">end()</a></span> &#12290;</p>
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<p><img alt="range-begin-end.svg" src="range-begin-end.svg" width="546" height="157" /></p>
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<h3><span class="mw-headline" id=".E5.8F.82.E6.95.B0">&#21442;&#25968;</span></h3>
<p>&#65288;&#26080;&#65289;</p>
<h3><span class="mw-headline" id=".E8.BF.94.E5.9B.9E.E5.80.BC">&#36820;&#22238;&#20540;</span></h3>
<p>&#25351;&#21521;&#39318;&#20803;&#32032;&#30340;&#36845;&#20195;&#22120;&#12290;</p>
<h3><span class="mw-headline" id=".E5.A4.8D.E6.9D.82.E5.BA.A6">&#22797;&#26434;&#24230;</span></h3>
<p>&#24120;&#25968;&#12290;</p>
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<h3><span class="mw-headline" id=".E7.A4.BA.E4.BE.8B">&#31034;&#20363;</span></h3>
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<pre class="de1"><span class="co2">#include &lt;algorithm&gt;</span>
<span class="co2">#include &lt;cassert&gt;</span>
<span class="co2">#include &lt;iostream&gt;</span>
<span class="co2">#include &lt;map&gt;</span>
<span class="co2">#include &lt;string&gt;</span>
<span class="co2">#include &lt;cstddef&gt;</span>
<span class="kw4">int</span> main<span class="br0">(</span><span class="br0">)</span>
<span class="br0">{</span>
<span class="kw4">auto</span> show_node <span class="sy1">=</span> <span class="br0">[</span><span class="br0">]</span><span class="br0">(</span><span class="kw4">const</span> <span class="kw4">auto</span><span class="sy3">&amp;</span> node, <span class="kw4">char</span> ending <span class="sy1">=</span> <span class="st0">&#39;<span class="es1">\n</span>&#39;</span><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> <span class="st0">&quot;{ &quot;</span> <span class="sy1">&lt;&lt;</span> node.<span class="me1">first</span> <span class="sy1">&lt;&lt;</span> <span class="st0">&quot;, &quot;</span> <span class="sy1">&lt;&lt;</span> node.<span class="me1">second</span> <span class="sy1">&lt;&lt;</span> <span class="st0">&quot; }&quot;</span> <span class="sy1">&lt;&lt;</span> ending<span class="sy4">;</span>
<span class="br0">}</span><span class="sy4">;</span>
<a href="cpp-container-multimap.html"><span class="kw1285">std::<span class="me2">multimap</span></span></a><span class="sy1">&lt;</span><a href="cpp-types-size_t.html"><span class="kw100">std::<span class="me2">size_t</span></span></a>, <a href="cpp-string-basic_string.html"><span class="kw1230">std::<span class="me2">string</span></span></a><span class="sy1">&gt;</span> mmap<span class="sy4">;</span>
<a href="cpp-error-assert.html"><span class="kw774">assert</span></a><span class="br0">(</span>mmap.<span class="me1">begin</span><span class="br0">(</span><span class="br0">)</span> <span class="sy1">==</span> mmap.<span class="me1">end</span><span class="br0">(</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span> <span class="co1">// OK</span>
<a href="cpp-error-assert.html"><span class="kw774">assert</span></a><span class="br0">(</span>mmap.<span class="me1">cbegin</span><span class="br0">(</span><span class="br0">)</span> <span class="sy1">==</span> mmap.<span class="me1">cend</span><span class="br0">(</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span> <span class="co1">// OK</span>
mmap.<span class="me1">insert</span><span class="br0">(</span><span class="br0">{</span> sizeof<span class="br0">(</span><span class="kw4">long</span><span class="br0">)</span>, <span class="st0">&quot;LONG&quot;</span> <span class="br0">}</span><span class="br0">)</span><span class="sy4">;</span>
show_node<span class="br0">(</span><span class="sy2">*</span><span class="br0">(</span>mmap.<span class="me1">cbegin</span><span class="br0">(</span><span class="br0">)</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
<a href="cpp-error-assert.html"><span class="kw774">assert</span></a><span class="br0">(</span>mmap.<span class="me1">begin</span><span class="br0">(</span><span class="br0">)</span> <span class="sy3">!</span><span class="sy1">=</span> mmap.<span class="me1">end</span><span class="br0">(</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span> <span class="co1">// OK</span>
<a href="cpp-error-assert.html"><span class="kw774">assert</span></a><span class="br0">(</span>mmap.<span class="me1">cbegin</span><span class="br0">(</span><span class="br0">)</span> <span class="sy3">!</span><span class="sy1">=</span> mmap.<span class="me1">cend</span><span class="br0">(</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span> <span class="co1">// OK</span>
mmap.<span class="me1">begin</span><span class="br0">(</span><span class="br0">)</span><span class="sy2">-</span><span class="sy1">&gt;</span>second <span class="sy1">=</span> <span class="st0">&quot;long&quot;</span><span class="sy4">;</span>
show_node<span class="br0">(</span><span class="sy2">*</span><span class="br0">(</span>mmap.<span class="me1">cbegin</span><span class="br0">(</span><span class="br0">)</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
mmap.<span class="me1">insert</span><span class="br0">(</span><span class="br0">{</span> sizeof<span class="br0">(</span><span class="kw4">int</span><span class="br0">)</span>, <span class="st0">&quot;int&quot;</span> <span class="br0">}</span><span class="br0">)</span><span class="sy4">;</span>
show_node<span class="br0">(</span><span class="sy2">*</span>mmap.<span class="me1">cbegin</span><span class="br0">(</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
mmap.<span class="me1">insert</span><span class="br0">(</span><span class="br0">{</span> sizeof<span class="br0">(</span><span class="kw4">short</span><span class="br0">)</span>, <span class="st0">&quot;short&quot;</span> <span class="br0">}</span><span class="br0">)</span><span class="sy4">;</span>
show_node<span class="br0">(</span><span class="sy2">*</span>mmap.<span class="me1">cbegin</span><span class="br0">(</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
mmap.<span class="me1">insert</span><span class="br0">(</span><span class="br0">{</span> sizeof<span class="br0">(</span><span class="kw4">char</span><span class="br0">)</span>, <span class="st0">&quot;char&quot;</span> <span class="br0">}</span><span class="br0">)</span><span class="sy4">;</span>
show_node<span class="br0">(</span><span class="sy2">*</span>mmap.<span class="me1">cbegin</span><span class="br0">(</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
mmap.<span class="me1">insert</span><span class="br0">(</span><span class="br0">{</span><span class="br0">{</span> sizeof<span class="br0">(</span><span class="kw4">float</span><span class="br0">)</span>, <span class="st0">&quot;float&quot;</span> <span class="br0">}</span>, <span class="br0">{</span> sizeof<span class="br0">(</span><span class="kw4">double</span><span class="br0">)</span>, <span class="st0">&quot;double&quot;</span> <span class="br0">}</span><span class="br0">}</span><span class="br0">)</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">&lt;&lt;</span> <span class="st0">&quot;mmap = { &quot;</span><span class="sy4">;</span>
<a href="cpp-algorithm-for_each.html"><span class="kw1568">std::<span class="me2">for_each</span></span></a><span class="br0">(</span>mmap.<span class="me1">cbegin</span><span class="br0">(</span><span class="br0">)</span>, mmap.<span class="me1">cend</span><span class="br0">(</span><span class="br0">)</span>, <span class="br0">[</span><span class="sy3">&amp;</span><span class="br0">]</span><span class="br0">(</span><span class="kw4">const</span> <span class="kw4">auto</span><span class="sy3">&amp;</span> n<span class="br0">)</span> <span class="br0">{</span> show_node<span class="br0">(</span>n, <span class="st0">&#39; &#39;</span><span class="br0">)</span><span class="sy4">;</span> <span class="br0">}</span><span class="br0">)</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">&lt;&lt;</span> <span class="st0">&quot;};<span class="es1">\n</span>&quot;</span><span class="sy4">;</span>
<span class="br0">}</span></pre></div>
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<p>&#21487;&#33021;&#30340;&#36755;&#20986;&#65306;</p>
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<pre class="de1">{ 8, LONG }
{ 8, long }
{ 4, int }
{ 2, short }
{ 1, char }
mmap = { { 1, char } { 2, short } { 4, int } { 4, float } { 8, long } { 8, double } };</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><a href="cpp-container-multimap-end.html"><span class="t-lines"><span>end</span> <span>cend</span></span></a></div>
<div><span class="t-lines"><span></span><span><span class="t-mark-rev t-since-cxx11">(C++11)</span></span></span></div>
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<td>&#36820;&#22238;&#25351;&#21521;&#26411;&#23614;&#30340;&#36845;&#20195;&#22120;<br />
<span class="t-mark">(&#20844;&#24320;&#25104;&#21592;&#20989;&#25968;)</span></td>
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