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<h1 id="firstHeading" class="firstHeading"><span style="font-size:0.7em; line-height:130%">std::ranges::</span>is_permutation</h1>
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<div id="contentSub"><span class="subpages">&lt; <a href="cpp.html">cpp</a>&lrm; | <a href="cpp-algorithm.html">algorithm</a>&lrm; | <a href="cpp-algorithm-ranges.html">ranges</a></span></div>
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<div>&#23450;&#20041;&#20110;&#22836;&#25991;&#20214; <code><a href="cpp-header-algorithm.html">&lt;algorithm&gt;</a></code></div>
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<div>&#35843;&#29992;&#31614;&#21517;</div>
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<div><span class="mw-geshi cpp source-cpp"><span class="kw1">template</span><span class="sy1">&lt;</span>std<span class="sy4">::</span><span class="me2">forward_iterator</span> I1, std<span class="sy4">::</span><span class="me2">sentinel_for</span><span class="sy1">&lt;</span>I1<span class="sy1">&gt;</span> S1,<br /></span>
<p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;std<span class="sy4">::</span><span class="me2">forward_iterator</span> I2, std<span class="sy4">::</span><span class="me2">sentinel_for</span><span class="sy1">&lt;</span>I2<span class="sy1">&gt;</span> S2,<br />
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<span class="kw1">class</span> Proj1 <span class="sy1">=</span> std<span class="sy4">::</span><span class="me2">identity</span>, <span class="kw1">class</span> Proj2 <span class="sy1">=</span> std<span class="sy4">::</span><span class="me2">identity</span>,<br />
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;std<span class="sy4">::</span><span class="me2">indirect_equivalence_relation</span><span class="sy1">&lt;</span>std<span class="sy4">::</span><span class="me2">projected</span><span class="sy1">&lt;</span>I1, Proj1<span class="sy1">&gt;</span>,<br />
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; std<span class="sy4">::</span><span class="me2">projected</span><span class="sy1">&lt;</span>I2, Proj2<span class="sy1">&gt;&gt;</span><br />
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Pred <span class="sy1">=</span> ranges<span class="sy4">::</span><span class="me2">equal_to</span><span class="sy1">&gt;</span><br />
<span class="kw4">constexpr</span> <span class="kw4">bool</span> is_permutation<span class="br0">(</span>I1 first1, S1 last1, I2 first2, S2 last2,<br /></p>
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Pred pred <span class="sy1">=</span> <span class="br0">{</span><span class="br0">}</span>, Proj1 proj1 <span class="sy1">=</span> <span class="br0">{</span><span class="br0">}</span>, Proj2 proj2 <span class="sy1">=</span> <span class="br0">{</span><span class="br0">}</span><span class="br0">)</span><span class="sy4">;</span></div>
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<td>(1)</td>
<td><span class="t-mark-rev t-since-cxx20">(C++20 &#36215;)</span></td>
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<div><span class="mw-geshi cpp source-cpp"><span class="kw1">template</span><span class="sy1">&lt;</span>ranges<span class="sy4">::</span><span class="me2">forward_range</span> R1, ranges<span class="sy4">::</span><span class="me2">forward_range</span> R2,<br /></span>
<p>&nbsp; &nbsp; &nbsp;<span class="kw1">class</span> Proj1 <span class="sy1">=</span> std<span class="sy4">::</span><span class="me2">identity</span>, <span class="kw1">class</span> Proj2 <span class="sy1">=</span> std<span class="sy4">::</span><span class="me2">identity</span>,<br />
&nbsp; &nbsp; &nbsp;std<span class="sy4">::</span><span class="me2">indirect_equivalence_relation</span><span class="sy1">&lt;</span>std<span class="sy4">::</span><span class="me2">projected</span><span class="sy1">&lt;</span>ranges<span class="sy4">::</span><span class="me2">iterator_t</span><span class="sy1">&lt;</span>R1<span class="sy1">&gt;</span>, Proj1<span class="sy1">&gt;</span>,<br />
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; std<span class="sy4">::</span><span class="me2">projected</span><span class="sy1">&lt;</span>ranges<span class="sy4">::</span><span class="me2">iterator_t</span><span class="sy1">&lt;</span>R2<span class="sy1">&gt;</span>, Proj2<span class="sy1">&gt;&gt;</span><br />
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Pred <span class="sy1">=</span> ranges<span class="sy4">::</span><span class="me2">equal_to</span><span class="sy1">&gt;</span><br />
<span class="kw4">constexpr</span> <span class="kw4">bool</span> is_permutation<span class="br0">(</span>R1<span class="sy3">&amp;&amp;</span> r1, R2<span class="sy3">&amp;&amp;</span> r2, Pred pred <span class="sy1">=</span> <span class="br0">{</span><span class="br0">}</span>,<br /></p>
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Proj1 proj1 <span class="sy1">=</span> <span class="br0">{</span><span class="br0">}</span>, Proj2 proj2 <span class="sy1">=</span> <span class="br0">{</span><span class="br0">}</span><span class="br0">)</span><span class="sy4">;</span></div>
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<td>(2)</td>
<td><span class="t-mark-rev t-since-cxx20">(C++20 &#36215;)</span></td>
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<div class="t-li1"><span class="t-li">1)</span> &#33509;&#23384;&#22312;&#33539;&#22260; <code>[first1, last1)</code> &#20013;&#30340;&#20803;&#32032;&#30340;&#25490;&#21015;&#20351;&#24471;&#35813;&#33539;&#22260;<i>&#31561;&#20110;</i> <code>[first2, last2)</code> &#65288;&#22312;&#24212;&#29992;&#23545;&#24212;&#30340;&#25237;&#24433; <code>Proj1</code> &#21644; <code>Proj2</code> &#21518;&#65292;&#24182;&#20197; <code>Pred</code> &#20026;&#27604;&#36739;&#22120;&#65289;&#21017;&#36820;&#22238; <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="kw2">true</span></span></span> &#12290;&#21542;&#21017;&#36820;&#22238; <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="kw2">false</span></span></span> &#12290;</div>
<div class="t-li1"><span class="t-li">2)</span> &#21516; <span class="t-v">(1)</span> &#65292;&#20294;&#20197; <code>r1</code> &#20026;&#31532;&#19968;&#28304;&#33539;&#22260;&#24182;&#20197; <code>r2</code> &#20026;&#31532;&#20108;&#28304;&#33539;&#22260;&#65292;&#22914;&#21516;&#20197; <span class="t-c"><span class="mw-geshi cpp source-cpp">ranges<span class="sy4">::</span><span class="me2">begin</span><span class="br0">(</span>r1<span class="br0">)</span></span></span> &#20026; <code>first1</code> &#65292;&#20197; <span class="t-c"><span class="mw-geshi cpp source-cpp">ranges<span class="sy4">::</span><span class="me2">end</span><span class="br0">(</span>r1<span class="br0">)</span></span></span> &#20026; <code>last1</code> &#65292;&#20197; <span class="t-c"><span class="mw-geshi cpp source-cpp">ranges<span class="sy4">::</span><span class="me2">begin</span><span class="br0">(</span>r2<span class="br0">)</span></span></span> &#20026; <code>first2</code> &#65292;&#24182;&#20197; <span class="t-c"><span class="mw-geshi cpp source-cpp">ranges<span class="sy4">::</span><span class="me2">end</span><span class="br0">(</span>r2<span class="br0">)</span></span></span> &#20026; <code>last2</code> &#12290;</div>
<p>&#27492;&#39029;&#38754;&#19978;&#25551;&#36848;&#30340;&#20223;&#20989;&#25968;&#23454;&#20307;&#26159; <i>niebloid</i> &#65292;&#21363;&#65306;</p>
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<li>&#35843;&#29992;&#23427;&#20204;&#20013;&#30340;&#20219;&#20309;&#19968;&#32773;&#26102;&#19981;&#21487;&#25351;&#23450;&#26174;&#24335;&#27169;&#26495;&#23454;&#21442;&#12290;</li>
<li>&#23427;&#20204;&#26080;&#19968;&#23545;<a href="cpp-language-adl.html">&#23454;&#21442;&#20381;&#36182;&#26597;&#25214;</a>&#21487;&#35265;&#12290;</li>
<li>&#22312;<a href="cpp-language-unqualified_lookup.html">&#36890;&#24120;&#26080;&#38480;&#23450;&#26597;&#25214;</a>&#23547;&#25214;&#20989;&#25968;&#35843;&#29992;&#36816;&#31639;&#31526;&#24038;&#20391;&#30340;&#21517;&#31216;&#25214;&#21040;&#23427;&#20204;&#20043;&#19968;&#26102;&#65292;&#23427;&#31105;&#27490;<a href="cpp-language-adl.html">&#23454;&#21442;&#20381;&#36182;&#26597;&#25214;</a>&#12290;</li>
</ul>
<p>&#23454;&#38469;&#19978;&#65292;&#23427;&#20204;&#33021;&#20197;&#20989;&#25968;&#23545;&#35937;&#65292;&#25110;&#20197;&#26576;&#20123;&#29305;&#27530;&#32534;&#35793;&#22120;&#25193;&#23637;&#23454;&#29616;&#12290;</p>
<h3><span class="mw-headline" id=".E5.8F.82.E6.95.B0">&#21442;&#25968;</span></h3>
<table class="t-par-begin">
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<td>first1, last1</td>
<td>-</td>
<td>&#31532;&#19968;&#20803;&#32032;&#33539;&#22260;</td>
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<tr class="t-par">
<td>first2, last2</td>
<td>-</td>
<td>&#31532;&#20108;&#20803;&#32032;&#33539;&#22260;</td>
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<tr class="t-par">
<td>r1</td>
<td>-</td>
<td>&#31532;&#19968;&#20803;&#32032;&#33539;&#22260;</td>
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<tr class="t-par">
<td>r2</td>
<td>-</td>
<td>&#31532;&#20108;&#20803;&#32032;&#33539;&#22260;</td>
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<tr class="t-par">
<td>pred</td>
<td>-</td>
<td>&#24212;&#29992;&#21040;&#25237;&#24433;&#21518;&#20803;&#32032;&#30340;&#35859;&#35789;</td>
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<tr class="t-par">
<td>proj1</td>
<td>-</td>
<td>&#24212;&#29992;&#21040;&#31532;&#19968;&#33539;&#22260;&#20013;&#20803;&#32032;&#30340;&#25237;&#24433;</td>
</tr>
<tr class="t-par">
<td>proj2</td>
<td>-</td>
<td>&#24212;&#29992;&#21040;&#31532;&#19968;&#33539;&#22260;&#20013;&#20803;&#32032;&#30340;&#25237;&#24433;</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;&#33539;&#22260; <code>[first1, last1)</code> &#20026; <code>[first2, last2)</code> &#30340;&#37325;&#25490;&#21015;&#21017;&#20026; <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="kw2">true</span></span></span> &#12290;</p>
<h3><span class="mw-headline" id=".E5.A4.8D.E6.9D.82.E5.BA.A6">&#22797;&#26434;&#24230;</span></h3>
<p>&#33267;&#22810;&#24212;&#29992; <span class="mjax" style="display:none">\(\scriptsize \mathcal{O}(N^2)\)</span><span class="mjax-fallback texhtml" style="white-space: nowrap;">O(N<sup>2</sup>)</span> &#27425;&#35859;&#35789;&#21644;&#27599;&#20010;&#25237;&#24433;&#65292;&#25110;&#33509;&#24207;&#21015;&#24050;&#32463;&#30456;&#31561;&#21017;&#20934;&#30830;&#24212;&#29992; <span class="mjax" style="display:none">\(\scriptsize N\)</span><span class="mjax-fallback texhtml" style="white-space: nowrap;">N</span> &#27425;&#65292;&#20854;&#20013; <span class="mjax" style="display:none">\(\scriptsize N\)</span><span class="mjax-fallback texhtml" style="white-space: nowrap;">N</span> &#20026; <span class="t-c"><span class="mw-geshi cpp source-cpp">ranges<span class="sy4">::</span><span class="me2">distance</span><span class="br0">(</span>first1, last1<span class="br0">)</span></span></span> &#12290; &#28982;&#32780;&#33509; <span class="t-c"><span class="mw-geshi cpp source-cpp">ranges<span class="sy4">::</span><span class="me2">distance</span><span class="br0">(</span>first1, last1<span class="br0">)</span> <span class="sy3">!</span><span class="sy1">=</span> ranges<span class="sy4">::</span><span class="me2">distance</span><span class="br0">(</span>first2, last2<span class="br0">)</span></span></span> &#65292;&#21017;&#19981;&#24212;&#29992;&#35859;&#35789;&#21644;&#25237;&#24433;&#12290;</p>
<h3><span class="mw-headline" id=".E6.B3.A8.E8.A7.A3">&#27880;&#35299;</span></h3>
<p><i>&#25490;&#21015;</i>&#20851;&#31995;&#26159;<a href="https://en.wikipedia.org/wiki/equivalence_relation" class="extiw" title="enwiki:equivalence relation">&#31561;&#20215;&#20851;&#31995;</a>&#12290;</p>
<p><strong class="selflink"><tt>ranges::is_permutation</tt></strong> &#33021;&#29992;&#20110;&#25353;&#29031;&#20854;&#21517;&#31216;&#22320;<i>&#27979;&#35797;</i>&#37325;&#25490;&#31639;&#27861;&#65288;&#20363;&#22914;&#25490;&#24207;&#12289;&#25171;&#20081;&#12289;&#21010;&#20998;&#65289;&#30340;&#27491;&#30830;&#24615;&#12290;&#33509; <code>x</code> &#20026;&#21407;&#33539;&#22260;&#32780; <code>y</code> &#26159;<i>&#37325;&#25490;&#21518;</i>&#33539;&#22260;&#21017; <span class="t-c"><span class="mw-geshi cpp source-cpp"><a href="cpp-algorithm-is_permutation.html"><span class="kw1648">std::<span class="me2">is_permutation</span></span></a><span class="br0">(</span>x, y<span class="br0">)</span> <span class="sy1">==</span> <span class="kw2">true</span></span></span> &#34920;&#31034; <code>y</code> &#30001;&#21487;&#33021;&#20301;&#20110;&#20854;&#20182;&#20301;&#32622;&#30340;<i>&ldquo;&#30456;&#21516;&rdquo;</i>&#20803;&#32032;&#32452;&#25104;&#12290;</p>
<h3><span class="mw-headline" id=".E5.8F.AF.E8.83.BD.E7.9A.84.E5.AE.9E.E7.8E.B0">&#21487;&#33021;&#30340;&#23454;&#29616;</span></h3>
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<pre class="de1"><span class="kw1">struct</span> is_permutation_fn
<span class="br0">{</span>
<span class="kw1">template</span><span class="sy1">&lt;</span>std<span class="sy4">::</span><span class="me2">forward_iterator</span> I1, std<span class="sy4">::</span><span class="me2">sentinel_for</span><span class="sy1">&lt;</span>I1<span class="sy1">&gt;</span> S1,
std<span class="sy4">::</span><span class="me2">forward_iterator</span> I2, std<span class="sy4">::</span><span class="me2">sentinel_for</span><span class="sy1">&lt;</span>I2<span class="sy1">&gt;</span> S2,
<span class="kw1">class</span> Proj1 <span class="sy1">=</span> std<span class="sy4">::</span><span class="me2">identity</span>, <span class="kw1">class</span> Proj2 <span class="sy1">=</span> std<span class="sy4">::</span><span class="me2">identity</span>,
std<span class="sy4">::</span><span class="me2">indirect_equivalence_relation</span><span class="sy1">&lt;</span>std<span class="sy4">::</span><span class="me2">projected</span><span class="sy1">&lt;</span>I1, Proj1<span class="sy1">&gt;</span>,
std<span class="sy4">::</span><span class="me2">projected</span><span class="sy1">&lt;</span>I2, Proj2<span class="sy1">&gt;&gt;</span>
Pred <span class="sy1">=</span> ranges<span class="sy4">::</span><span class="me2">equal_to</span><span class="sy1">&gt;</span>
<span class="kw4">constexpr</span> <span class="kw4">bool</span> operator<span class="br0">(</span><span class="br0">)</span><span class="br0">(</span>I1 first1, S1 last1, I2 first2, S2 last2,
Pred pred <span class="sy1">=</span> <span class="br0">{</span><span class="br0">}</span>, Proj1 proj1 <span class="sy1">=</span> <span class="br0">{</span><span class="br0">}</span>, Proj2 proj2 <span class="sy1">=</span> <span class="br0">{</span><span class="br0">}</span><span class="br0">)</span> <span class="kw4">const</span> <span class="br0">{</span>
<span class="co1">// &#36339;&#36807;&#20844;&#20849;&#21069;&#32512;</span>
<span class="kw4">auto</span> ret <span class="sy1">=</span> std<span class="sy4">::</span><span class="me2">ranges</span><span class="sy4">::</span><span class="me2">mismatch</span><span class="br0">(</span>first1, last1, first2, last2,
<a href="cpp-utility-functional-ref.html"><span class="kw1069">std::<span class="me2">ref</span></span></a><span class="br0">(</span>pred<span class="br0">)</span>, <a href="cpp-utility-functional-ref.html"><span class="kw1069">std::<span class="me2">ref</span></span></a><span class="br0">(</span>proj1<span class="br0">)</span>, <a href="cpp-utility-functional-ref.html"><span class="kw1069">std::<span class="me2">ref</span></span></a><span class="br0">(</span>proj2<span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
first1 <span class="sy1">=</span> ret.<span class="me1">in1</span>, first2 <span class="sy1">=</span> ret.<span class="me1">in2</span><span class="sy4">;</span>
<span class="co1">// &#22312;&#21097;&#20313;&#37096;&#20998;&#36845;&#20195;&#65292;&#32479;&#35745;&#27599;&#20010;&#26469;&#33258; [first1, last1) &#20013;&#30340;&#20803;&#32032;&#22312; [first2, last2) &#20013;&#20986;&#29616;&#22810;&#23569;&#27425;</span>
<span class="kw1">for</span> <span class="br0">(</span><span class="kw4">auto</span> i<span class="br0">{</span> first1 <span class="br0">}</span><span class="sy4">;</span> i <span class="sy3">!</span><span class="sy1">=</span> last1<span class="sy4">;</span> <span class="sy2">++</span>i<span class="br0">)</span> <span class="br0">{</span>
<span class="kw4">const</span> <span class="kw4">auto</span> i_proj<span class="br0">{</span> <a href="cpp-utility-functional-invoke.html"><span class="kw1058">std::<span class="me2">invoke</span></span></a><span class="br0">(</span>proj1, <span class="sy2">*</span>i<span class="br0">)</span> <span class="br0">}</span><span class="sy4">;</span>
<span class="kw4">auto</span> i_cmp <span class="sy1">=</span> <span class="br0">[</span><span class="sy3">&amp;</span><span class="br0">]</span><span class="sy1">&lt;</span><span class="kw1">typename</span> T<span class="sy1">&gt;</span><span class="br0">(</span>T<span class="sy3">&amp;&amp;</span> t<span class="br0">)</span> <span class="br0">{</span>
<span class="kw1">return</span> <a href="cpp-utility-functional-invoke.html"><span class="kw1058">std::<span class="me2">invoke</span></span></a><span class="br0">(</span>pred, i_proj, <a href="cpp-utility-forward.html"><span class="kw1117">std::<span class="me2">forward</span></span></a><span class="sy1">&lt;</span>T<span class="sy1">&gt;</span><span class="br0">(</span>t<span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
<span class="br0">}</span><span class="sy4">;</span>
<span class="kw1">if</span> <span class="br0">(</span>i <span class="sy3">!</span><span class="sy1">=</span> ranges<span class="sy4">::</span><span class="me2">find_if</span><span class="br0">(</span>first1, i, i_cmp, proj1<span class="br0">)</span><span class="br0">)</span>
<span class="kw1">continue</span><span class="sy4">;</span> <span class="co1">// &#24050;&#26816;&#26597;&#36807;&#27492; *i</span>
<span class="kw1">if</span> <span class="br0">(</span><span class="kw4">const</span> <span class="kw4">auto</span> m<span class="br0">{</span> ranges<span class="sy4">::</span><span class="me2">count_if</span><span class="br0">(</span>first2, last2, i_cmp, proj2<span class="br0">)</span> <span class="br0">}</span><span class="sy4">;</span>
m <span class="sy1">==</span> <span class="nu0">0</span> or m <span class="sy3">!</span><span class="sy1">=</span> ranges<span class="sy4">::</span><span class="me2">count_if</span><span class="br0">(</span>i, last1, i_cmp, proj1<span class="br0">)</span><span class="br0">)</span>
<span class="kw1">return</span> <span class="kw2">false</span><span class="sy4">;</span>
<span class="br0">}</span>
<span class="kw1">return</span> <span class="kw2">true</span><span class="sy4">;</span>
<span class="br0">}</span>
<span class="kw1">template</span><span class="sy1">&lt;</span>ranges<span class="sy4">::</span><span class="me2">forward_range</span> R1, ranges<span class="sy4">::</span><span class="me2">forward_range</span> R2,
<span class="kw1">class</span> Proj1 <span class="sy1">=</span> std<span class="sy4">::</span><span class="me2">identity</span>, <span class="kw1">class</span> Proj2 <span class="sy1">=</span> std<span class="sy4">::</span><span class="me2">identity</span>,
std<span class="sy4">::</span><span class="me2">indirect_equivalence_relation</span><span class="sy1">&lt;</span>std<span class="sy4">::</span><span class="me2">projected</span><span class="sy1">&lt;</span>ranges<span class="sy4">::</span><span class="me2">iterator_t</span><span class="sy1">&lt;</span>R1<span class="sy1">&gt;</span>, Proj1<span class="sy1">&gt;</span>,
std<span class="sy4">::</span><span class="me2">projected</span><span class="sy1">&lt;</span>ranges<span class="sy4">::</span><span class="me2">iterator_t</span><span class="sy1">&lt;</span>R2<span class="sy1">&gt;</span>, Proj2<span class="sy1">&gt;&gt;</span>
Pred <span class="sy1">=</span> ranges<span class="sy4">::</span><span class="me2">equal_to</span><span class="sy1">&gt;</span>
<span class="kw4">constexpr</span> <span class="kw4">bool</span> operator<span class="br0">(</span><span class="br0">)</span><span class="br0">(</span>R1<span class="sy3">&amp;&amp;</span> r1, R2<span class="sy3">&amp;&amp;</span> r2, Pred pred <span class="sy1">=</span> <span class="br0">{</span><span class="br0">}</span>,
Proj1 proj1 <span class="sy1">=</span> <span class="br0">{</span><span class="br0">}</span>, Proj2 proj2 <span class="sy1">=</span> <span class="br0">{</span><span class="br0">}</span><span class="br0">)</span> <span class="kw4">const</span> <span class="br0">{</span>
<span class="kw1">return</span> <span class="br0">(</span><span class="sy2">*</span>this<span class="br0">)</span><span class="br0">(</span>ranges<span class="sy4">::</span><span class="me2">begin</span><span class="br0">(</span>r1<span class="br0">)</span>, ranges<span class="sy4">::</span><span class="me2">end</span><span class="br0">(</span>r1<span class="br0">)</span>,
ranges<span class="sy4">::</span><span class="me2">begin</span><span class="br0">(</span>r2<span class="br0">)</span>, ranges<span class="sy4">::</span><span class="me2">end</span><span class="br0">(</span>r2<span class="br0">)</span>,
std<span class="sy4">::</span><span class="me2">move</span><span class="br0">(</span>pred<span class="br0">)</span>, std<span class="sy4">::</span><span class="me2">move</span><span class="br0">(</span>proj1<span class="br0">)</span>, std<span class="sy4">::</span><span class="me2">move</span><span class="br0">(</span>proj2<span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
<span class="br0">}</span>
<span class="br0">}</span><span class="sy4">;</span>
<span class="kw1">inline</span> <span class="kw4">constexpr</span> is_permutation_fn is_permutation<span class="br0">{</span><span class="br0">}</span><span class="sy4">;</span></pre></div>
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</td>
</tr>
</table>
<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;algorithm&gt;</span>
<span class="co2">#include &lt;array&gt;</span>
<span class="co2">#include &lt;cmath&gt;</span>
<span class="co2">#include &lt;iostream&gt;</span>
<span class="co2">#include &lt;ranges&gt;</span>
<span class="kw4">auto</span><span class="sy3">&amp;</span> operator<span class="sy1">&lt;&lt;</span> <span class="br0">(</span><span class="kw4">auto</span><span class="sy3">&amp;</span> os, std<span class="sy4">::</span><span class="me2">ranges</span><span class="sy4">::</span><span class="me2">forward_range</span> <span class="kw4">auto</span> <span class="kw4">const</span><span class="sy3">&amp;</span> v<span class="br0">)</span> <span class="br0">{</span>
os <span class="sy1">&lt;&lt;</span> <span class="st0">&quot;{ &quot;</span><span class="sy4">;</span>
<span class="kw1">for</span> <span class="br0">(</span><span class="kw4">auto</span> <span class="kw4">const</span><span class="sy3">&amp;</span> e <span class="sy4">:</span> v<span class="br0">)</span> os <span class="sy1">&lt;&lt;</span> e <span class="sy1">&lt;&lt;</span> <span class="st0">&#39; &#39;</span><span class="sy4">;</span>
<span class="kw1">return</span> os <span class="sy1">&lt;&lt;</span> <span class="st0">&quot;}&quot;</span><span class="sy4">;</span>
<span class="br0">}</span>
<span class="kw4">int</span> main<span class="br0">(</span><span class="br0">)</span>
<span class="br0">{</span>
<span class="kw4">static</span> <span class="kw4">constexpr</span> <span class="kw4">auto</span> r1 <span class="sy1">=</span> <span class="br0">{</span><span class="nu0">1</span>,<span class="nu0">2</span>,<span class="nu0">3</span>,<span class="nu0">4</span>,<span class="nu0">5</span><span class="br0">}</span><span class="sy4">;</span>
<span class="kw4">static</span> <span class="kw4">constexpr</span> <span class="kw4">auto</span> r2 <span class="sy1">=</span> <span class="br0">{</span><span class="nu0">3</span>,<span class="nu0">5</span>,<span class="nu0">4</span>,<span class="nu0">1</span>,<span class="nu0">2</span><span class="br0">}</span><span class="sy4">;</span>
<span class="kw4">static</span> <span class="kw4">constexpr</span> <span class="kw4">auto</span> r3 <span class="sy1">=</span> <span class="br0">{</span><span class="nu0">3</span>,<span class="nu0">5</span>,<span class="nu0">4</span>,<span class="nu0">1</span>,<span class="nu0">1</span><span class="br0">}</span><span class="sy4">;</span>
static_assert<span class="br0">(</span>
std<span class="sy4">::</span><span class="me2">ranges</span><span class="sy4">::</span><span class="me2">is_permutation</span><span class="br0">(</span>r1, r1<span class="br0">)</span> <span class="sy3">&amp;&amp;</span>
std<span class="sy4">::</span><span class="me2">ranges</span><span class="sy4">::</span><span class="me2">is_permutation</span><span class="br0">(</span>r1, r2<span class="br0">)</span> <span class="sy3">&amp;&amp;</span>
std<span class="sy4">::</span><span class="me2">ranges</span><span class="sy4">::</span><span class="me2">is_permutation</span><span class="br0">(</span>r2, r1<span class="br0">)</span> <span class="sy3">&amp;&amp;</span>
std<span class="sy4">::</span><span class="me2">ranges</span><span class="sy4">::</span><span class="me2">is_permutation</span><span class="br0">(</span>r1.<span class="me1">begin</span><span class="br0">(</span><span class="br0">)</span>, r1.<span class="me1">end</span><span class="br0">(</span><span class="br0">)</span>, r2.<span class="me1">begin</span><span class="br0">(</span><span class="br0">)</span>, r2.<span class="me1">end</span><span class="br0">(</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> <a href="cpp-io-manip-boolalpha.html"><span class="kw1764">std::<span class="me2">boolalpha</span></span></a>
<span class="sy1">&lt;&lt;</span> <span class="st0">&quot;is_permutation( &quot;</span> <span class="sy1">&lt;&lt;</span> r1 <span class="sy1">&lt;&lt;</span> <span class="st0">&quot;, &quot;</span> <span class="sy1">&lt;&lt;</span> r2 <span class="sy1">&lt;&lt;</span> <span class="st0">&quot; ): &quot;</span>
<span class="sy1">&lt;&lt;</span> std<span class="sy4">::</span><span class="me2">ranges</span><span class="sy4">::</span><span class="me2">is_permutation</span><span class="br0">(</span>r1, r2<span class="br0">)</span> <span class="sy1">&lt;&lt;</span> <span class="st0">&#39;<span class="es1">\n</span>&#39;</span>
<span class="sy1">&lt;&lt;</span> <span class="st0">&quot;is_permutation( &quot;</span> <span class="sy1">&lt;&lt;</span> r1 <span class="sy1">&lt;&lt;</span> <span class="st0">&quot;, &quot;</span> <span class="sy1">&lt;&lt;</span> r3 <span class="sy1">&lt;&lt;</span> <span class="st0">&quot; ): &quot;</span>
<span class="sy1">&lt;&lt;</span> std<span class="sy4">::</span><span class="me2">ranges</span><span class="sy4">::</span><span class="me2">is_permutation</span><span class="br0">(</span>r1, r3<span class="br0">)</span> <span class="sy1">&lt;&lt;</span> <span class="st0">&#39;<span class="es1">\n</span>&#39;</span>
<span class="sy1">&lt;&lt;</span> <span class="st0">&quot;is_permutation with custom predicate and projections: &quot;</span>
<span class="sy1">&lt;&lt;</span> std<span class="sy4">::</span><span class="me2">ranges</span><span class="sy4">::</span><span class="me2">is_permutation</span><span class="br0">(</span>
<a href="cpp-container-array.html"><span class="kw1268">std::<span class="me2">array</span></span></a><span class="br0">{</span> <span class="sy2">-</span><span class="nu0">14</span>, <span class="sy2">-</span><span class="nu0">11</span>, <span class="sy2">-</span><span class="nu0">13</span>, <span class="sy2">-</span><span class="nu0">15</span>, <span class="sy2">-</span><span class="nu0">12</span> <span class="br0">}</span>, <span class="co1">// &#31532;&#19968;&#33539;&#22260;</span>
<a href="cpp-container-array.html"><span class="kw1268">std::<span class="me2">array</span></span></a><span class="br0">{</span> <span class="st0">&#39;F&#39;</span>, <span class="st0">&#39;E&#39;</span>, <span class="st0">&#39;C&#39;</span>, <span class="st0">&#39;B&#39;</span>, <span class="st0">&#39;D&#39;</span> <span class="br0">}</span>, <span class="co1">// &#31532;&#20108;&#33539;&#22260;</span>
<span class="br0">[</span><span class="br0">]</span><span class="br0">(</span><span class="kw4">int</span> x, <span class="kw4">int</span> y<span class="br0">)</span> <span class="br0">{</span> <span class="kw1">return</span> abs<span class="br0">(</span>x<span class="br0">)</span> <span class="sy1">==</span> abs<span class="br0">(</span>y<span class="br0">)</span><span class="sy4">;</span> <span class="br0">}</span>, <span class="co1">// &#35859;&#35789;</span>
<span class="br0">[</span><span class="br0">]</span><span class="br0">(</span><span class="kw4">int</span> x<span class="br0">)</span> <span class="br0">{</span> <span class="kw1">return</span> x <span class="sy2">+</span> <span class="nu0">10</span><span class="sy4">;</span> <span class="br0">}</span>, <span class="co1">// &#31532;&#19968;&#33539;&#22260;&#30340;&#25237;&#24433;</span>
<span class="br0">[</span><span class="br0">]</span><span class="br0">(</span><span class="kw4">char</span> y<span class="br0">)</span> <span class="br0">{</span> <span class="kw1">return</span> <span class="kw4">int</span><span class="br0">(</span>y <span class="sy2">-</span> <span class="st0">&#39;A&#39;</span><span class="br0">)</span><span class="sy4">;</span> <span class="br0">}</span><span class="br0">)</span> <span class="co1">// &#31532;&#20108;&#33539;&#22260;&#30340;&#25237;&#24433;</span>
<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">is_permutation( { 1 2 3 4 5 }, { 3 5 4 1 2 } ): true
is_permutation( { 1 2 3 4 5 }, { 3 5 4 1 1 } ): false
is_permutation with custom predicate and projections: true</pre></div>
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</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-algorithm-ranges-next_permutation.html"><span class="t-lines"><span>ranges::next_permutation</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>&#20135;&#29983;&#26576;&#20010;&#20803;&#32032;&#33539;&#22260;&#30340;&#25353;&#23383;&#20856;&#24207;&#19979;&#19968;&#20010;&#36739;&#22823;&#30340;&#25490;&#21015;<br />
<span class="t-mark">(niebloid)</span></td>
</tr>
<tr class="t-dsc">
<td>
<div class="t-dsc-member-div">
<div><a href="cpp-algorithm-ranges-prev_permutation.html"><span class="t-lines"><span>ranges::prev_permutation</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>&#20135;&#29983;&#26576;&#20010;&#20803;&#32032;&#33539;&#22260;&#30340;&#25353;&#23383;&#20856;&#24207;&#19979;&#19968;&#20010;&#36739;&#23567;&#30340;&#25490;&#21015;<br />
<span class="t-mark">(niebloid)</span></td>
</tr>
<tr class="t-dsc">
<td>
<div class="t-dsc-member-div">
<div><a href="cpp-algorithm-is_permutation.html"><span class="t-lines"><span>is_permutation</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>&#21028;&#26029;&#19968;&#20010;&#24207;&#21015;&#26159;&#21542;&#20026;&#21478;&#19968;&#20010;&#24207;&#21015;&#30340;&#25490;&#21015;<br />
<span class="t-mark">(&#20989;&#25968;&#27169;&#26495;)</span></td>
</tr>
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<td>
<div class="t-dsc-member-div">
<div><a href="cpp-algorithm-next_permutation.html"><span class="t-lines"><span>next_permutation</span></span></a></div>
</div>
</td>
<td>&#20135;&#29983;&#26576;&#20010;&#20803;&#32032;&#33539;&#22260;&#30340;&#25353;&#23383;&#20856;&#39034;&#24207;&#30340;&#19979;&#19968;&#20010;&#36739;&#22823;&#30340;&#25490;&#21015;<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-algorithm-prev_permutation.html"><span class="t-lines"><span>prev_permutation</span></span></a></div>
</div>
</td>
<td>&#20135;&#29983;&#26576;&#20010;&#20803;&#32032;&#33539;&#22260;&#30340;&#25353;&#23383;&#20856;&#39034;&#24207;&#30340;&#19979;&#19968;&#20010;&#36739;&#23567;&#30340;&#25490;&#21015;<br />
<span class="t-mark">(&#20989;&#25968;&#27169;&#26495;)</span></td>
</tr>
<tr class="t-dsc">
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<div class="t-dsc-member-div">
<div><a href="cpp-concepts-equivalence_relation.html"><span class="t-lines"><span>equivalence_relation</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>&#25351;&#23450; <a href="cpp-concepts-relation.html"><code>relation</code></a> &#26045;&#21152;&#31561;&#20215;&#20851;&#31995;<br />
<span class="t-mark">(&#27010;&#24565;)</span></td>
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