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<h1 id="firstHeading" class="firstHeading"><span style="font-size:0.7em; line-height:130%">std::bitset&lt;N&gt;::</span>test</h1>
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<div id="contentSub"><span class="subpages">&lt; <a href="cpp.html">cpp</a>&lrm; | <a href="cpp-utility.html">utility</a>&lrm; | <a href="cpp-utility-bitset.html">bitset</a></span></div>
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<div><span class="mw-geshi cpp source-cpp"><span class="kw4">bool</span> test<span class="br0">(</span> <a href="cpp-types-size_t.html"><span class="kw100">std::<span class="me2">size_t</span></span></a> pos <span class="br0">)</span> <span class="kw4">const</span><span class="sy4">;</span></span></div>
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<p>&#36820;&#22238;&#20301;&#20110;&#20301;&#32622; <code>pos</code> &#30340;&#20301;&#30340;&#20540;&#12290;</p>
<p>&#19981;&#21516;&#20110; <span class="t-lc"><a href="cpp-utility-bitset-operator_at.html">operator[]</a></span> &#65292;&#23427;&#36827;&#34892;&#36793;&#30028;&#26816;&#26597;&#65292;&#19988;&#33509; <code>pos</code> &#19981;&#23545;&#24212; bitset &#20013;&#30340;&#21512;&#27861;&#20301;&#32622;&#21017;&#25243;&#20986; <span class="t-lc"><a href="cpp-error-out_of_range.html">std::out_of_range</a></span> &#12290;</p>
<h3><span class="mw-headline" id=".E5.8F.82.E6.95.B0">&#21442;&#25968;</span></h3>
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<td>pos</td>
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<td>&#35201;&#36820;&#22238;&#30340;&#20301;&#30340;&#20301;&#32622;</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>&#33509;&#25152;&#27714;&#20301;&#34987;&#35774;&#32622;&#21017;&#20026; <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="kw2">true</span></span></span> &#65292;&#21542;&#21017;&#20026; <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="kw2">false</span></span></span> &#12290;</p>
<h3><span class="mw-headline" id=".E5.BC.82.E5.B8.B8">&#24322;&#24120;</span></h3>
<p>&#33509; <code>pos</code> &#19981;&#23545;&#24212; bitset &#20013;&#30340;&#21512;&#27861;&#20301;&#32622;&#21017;&#25243;&#20986; <span class="t-lc"><a href="cpp-error-out_of_range.html">std::out_of_range</a></span> &#12290;</p>
<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;iostream&gt;</span>
<span class="co2">#include &lt;bitset&gt;</span>
<span class="kw4">int</span> main<span class="br0">(</span><span class="br0">)</span>
<span class="br0">{</span>
<a href="cpp-utility-bitset.html"><span class="kw1027">std::<span class="me2">bitset</span></span></a><span class="sy1">&lt;</span><span class="nu0">10</span><span class="sy1">&gt;</span> b1<span class="br0">(</span><span class="st0">&quot;1111010000&quot;</span><span class="br0">)</span><span class="sy4">;</span>
<a href="cpp-types-size_t.html"><span class="kw100">std::<span class="me2">size_t</span></span></a> idx <span class="sy1">=</span> <span class="nu0">0</span><span class="sy4">;</span>
<span class="kw1">while</span> <span class="br0">(</span>idx <span class="sy1">&lt;</span> b1.<span class="me1">size</span><span class="br0">(</span><span class="br0">)</span> <span class="sy3">&amp;&amp;</span> <span class="sy3">!</span>b1.<span class="me1">test</span><span class="br0">(</span>idx<span class="br0">)</span><span class="br0">)</span> <span class="br0">{</span>
<span class="sy2">++</span>idx<span class="sy4">;</span>
<span class="br0">}</span>
<span class="kw1">if</span> <span class="br0">(</span>idx <span class="sy1">&lt;</span> b1.<span class="me1">size</span><span class="br0">(</span><span class="br0">)</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;first set bit at index &quot;</span> <span class="sy1">&lt;&lt;</span> idx <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> <span class="kw1">else</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;no set bits<span class="es1">\n</span>&quot;</span><span class="sy4">;</span>
<span class="br0">}</span>
<span class="br0">}</span></pre></div>
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<p>&#36755;&#20986;&#65306;</p>
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<pre class="de1">first set bit at index 4</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-utility-bitset-operator_at.html"><span class="t-lines"><span>operator[]</span></span></a></div>
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<td>&#35775;&#38382;&#25351;&#23450;&#30340;&#20301;<br />
<span class="t-mark">(&#20844;&#24320;&#25104;&#21592;&#20989;&#25968;)</span></td>
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<div><a href="cpp-numeric-popcount.html"><span class="t-lines"><span>popcount</span></span></a></div>
<div><span class="t-lines"><span><span class="t-mark-rev t-since-cxx20">(C++20)</span></span></span></div>
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<td>&#35745;&#37327;&#26080;&#31526;&#21495;&#25972;&#25968;&#20013;&#20026; 1 &#30340;&#20301;&#30340;&#25968;&#37327;<br />
<span class="t-mark">(&#20989;&#25968;&#27169;&#26495;)</span></td>
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<div><a href="cpp-numeric-has_single_bit.html"><span class="t-lines"><span>has_single_bit</span></span></a></div>
<div><span class="t-lines"><span><span class="t-mark-rev t-since-cxx20">(C++20)</span></span></span></div>
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<td>&#26816;&#26597;&#19968;&#20010;&#25968;&#26159;&#21542;&#20026;&#20108;&#30340;&#25972;&#25968;&#27425;&#24130;<br />
<span class="t-mark">(&#20989;&#25968;&#27169;&#26495;)</span></td>
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