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<h1 id="firstHeading" class="firstHeading"><span style="font-size:0.7em; line-height:130%">std::ranges::</span>unique_copy, <span style="font-size:0.7em; line-height:130%">std::ranges::</span>unique_copy_result</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">input_iterator</span> I, std<span class="sy4">::</span><span class="me2">sentinel_for</span><span class="sy1">&lt;</span>I<span class="sy1">&gt;</span> S, std<span class="sy4">::</span><span class="me2">weakly_incrementable</span> O,<br /></span>
<p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <span class="kw1">class</span> Proj <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>I, Proj<span class="sy1">&gt;&gt;</span> C <span class="sy1">=</span> ranges<span class="sy4">::</span><span class="me2">equal_to</span> <span class="sy1">&gt;</span><br />
requires &nbsp;std<span class="sy4">::</span><span class="me2">indirectly_copyable</span><span class="sy1">&lt;</span>I, O<span class="sy1">&gt;</span> <span class="sy3">&amp;&amp;</span> <span class="br0">(</span>std<span class="sy4">::</span><span class="me2">forward_iterator</span><span class="sy1">&lt;</span>I<span class="sy1">&gt;</span> <span class="sy3">||</span><br />
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<span class="br0">(</span>std<span class="sy4">::</span><span class="me2">input_iterator</span><span class="sy1">&lt;</span>O<span class="sy1">&gt;</span> <span class="sy3">&amp;&amp;</span> std<span class="sy4">::</span><span class="me2">same_as</span><span class="sy1">&lt;</span>std<span class="sy4">::</span><span class="me2">iter_value_t</span><span class="sy1">&lt;</span>I<span class="sy1">&gt;</span>,<br />
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; std<span class="sy4">::</span><span class="me2">iter_value_t</span><span class="sy1">&lt;</span>O<span class="sy1">&gt;&gt;</span><span class="br0">)</span> <span class="sy3">||</span> std<span class="sy4">::</span><span class="me2">indirectly_copyable_storable</span><span class="sy1">&lt;</span>I, O<span class="sy1">&gt;</span><span class="br0">)</span><br />
<span class="kw4">constexpr</span> unique_copy_result<span class="sy1">&lt;</span>I, O<span class="sy1">&gt;</span><br /></p>
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; unique_copy<span class="br0">(</span> I first, S last, O result, C comp <span class="sy1">=</span> <span class="br0">{</span><span class="br0">}</span>, Proj proj <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">input_range</span> R, std<span class="sy4">::</span><span class="me2">weakly_incrementable</span> O, <span class="kw1">class</span> Proj <span class="sy1">=</span> std<span class="sy4">::</span><span class="me2">identity</span>,<br /></span>
<p>&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>ranges<span class="sy4">::</span><span class="me2">iterator_t</span><span class="sy1">&lt;</span>R<span class="sy1">&gt;</span>,<br />
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Proj<span class="sy1">&gt;&gt;</span> C <span class="sy1">=</span> ranges<span class="sy4">::</span><span class="me2">equal_to</span> <span class="sy1">&gt;</span><br />
requires &nbsp;std<span class="sy4">::</span><span class="me2">indirectly_copyable</span><span class="sy1">&lt;</span>ranges<span class="sy4">::</span><span class="me2">iterator_t</span><span class="sy1">&lt;</span>R<span class="sy1">&gt;</span>, O<span class="sy1">&gt;</span> <span class="sy3">&amp;&amp;</span><br />
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <span class="br0">(</span>std<span class="sy4">::</span><span class="me2">forward_iterator</span><span class="sy1">&lt;</span>ranges<span class="sy4">::</span><span class="me2">iterator_t</span><span class="sy1">&lt;</span>R<span class="sy1">&gt;&gt;</span> <span class="sy3">||</span><br />
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <span class="br0">(</span>std<span class="sy4">::</span><span class="me2">input_iterator</span><span class="sy1">&lt;</span>O<span class="sy1">&gt;</span> <span class="sy3">&amp;&amp;</span> std<span class="sy4">::</span><span class="me2">same_as</span><span class="sy1">&lt;</span>ranges<span class="sy4">::</span><span class="me2">range_value_t</span><span class="sy1">&lt;</span>R<span class="sy1">&gt;</span>,<br />
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; std<span class="sy4">::</span><span class="me2">iter_value_t</span><span class="sy1">&lt;</span>O<span class="sy1">&gt;&gt;</span><span class="br0">)</span> <span class="sy3">||</span><br />
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; std<span class="sy4">::</span><span class="me2">indirectly_copyable_storable</span><span class="sy1">&lt;</span>ranges<span class="sy4">::</span><span class="me2">iterator_t</span><span class="sy1">&lt;</span>R<span class="sy1">&gt;</span>, O<span class="sy1">&gt;</span><span class="br0">)</span><br />
<span class="kw4">constexpr</span> unique_copy_result<span class="sy1">&lt;</span>ranges<span class="sy4">::</span><span class="me2">borrowed_iterator_t</span><span class="sy1">&lt;</span>R<span class="sy1">&gt;</span>, O<span class="sy1">&gt;</span><br /></p>
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; unique_copy<span class="br0">(</span> R<span class="sy3">&amp;&amp;</span> r, O result, C comp <span class="sy1">=</span> <span class="br0">{</span><span class="br0">}</span>, Proj proj <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>&#36741;&#21161;&#31867;&#22411;</div>
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<div><span class="mw-geshi cpp source-cpp"><span class="kw1">template</span><span class="sy1">&lt;</span><span class="kw1">class</span> I, <span class="kw1">class</span> O<span class="sy1">&gt;</span><br />
&nbsp; <span class="kw1">using</span> unique_copy_result <span class="sy1">=</span> ranges<span class="sy4">::</span><span class="me2">in_out_result</span><span class="sy1">&lt;</span>I, O<span class="sy1">&gt;</span><span class="sy4">;</span></span></div>
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<td>(3)</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> &#20174;&#28304;&#33539;&#22260; <code>[first, last)</code> &#22797;&#21046;&#20803;&#32032;&#21040;&#22987;&#20110; <code>result</code> &#30340;&#30446;&#26631;&#33539;&#22260;&#65292;&#20351;&#24471;&#26080;&#36830;&#32493;&#30340;&#20803;&#32032;&#27604;&#36739;&#30456;&#31561;&#12290;&#21482;&#22797;&#21046;&#27599;&#32676;&#30456;&#31561;&#20803;&#32032;&#20013;&#30340;&#31532;&#19968;&#20010;&#12290;</div>
<div class="t-li1"><span class="t-li"></span> &#33539;&#22260; <code>[first, last)</code> &#19982; <code>[result, result + N)</code> &#24517;&#39035;&#19981;&#37325;&#21472;&#12290; <span class="t-c"><span class="mw-geshi cpp source-cpp">N <span class="sy1">=</span> ranges<span class="sy4">::</span><span class="me2">distance</span><span class="br0">(</span>first, last<span class="br0">)</span></span></span>.</div>
<div class="t-li1"><span class="t-li"></span> &#35748;&#20026;&#20108;&#20010;&#36830;&#32493;&#20803;&#32032; <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="sy2">*</span><span class="br0">(</span>i <span class="sy2">-</span> <span class="nu0">1</span><span class="br0">)</span></span></span> &#19982; <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="sy2">*</span>i</span></span> &#27604;&#36739;&#30456;&#31561;&#65292;&#33509; <span class="t-c"><span class="mw-geshi cpp source-cpp"><a href="cpp-utility-functional-invoke.html"><span class="kw1058">std::<span class="me2">invoke</span></span></a><span class="br0">(</span>comp, <a href="cpp-utility-functional-invoke.html"><span class="kw1058">std::<span class="me2">invoke</span></span></a><span class="br0">(</span>proj, <span class="sy2">*</span><span class="br0">(</span>i <span class="sy2">-</span> <span class="nu0">1</span><span class="br0">)</span><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>proj, <span class="sy2">*</span>i<span class="br0">)</span><span class="br0">)</span> <span class="sy1">==</span> <span class="kw2">true</span></span></span> &#65292;&#20854;&#20013; <code>i</code> &#20026;&#33539;&#22260; <code>[first + 1, last)</code> &#20013;&#30340;&#36845;&#20195;&#22120;&#12290;</div>
<div class="t-li1"><span class="t-li">2)</span> &#21516; <span class="t-v">(1)</span> &#65292;&#20294;&#20197; <code>r</code> &#20026;&#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>r<span class="br0">)</span></span></span> &#20026; <code>first</code> &#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>r<span class="br0">)</span></span></span> &#20026; <code>last</code> &#12290;</div>
<p>&#27492;&#39029;&#38754;&#19978;&#25551;&#36848;&#30340;&#20223;&#20989;&#25968;&#23454;&#20307;&#26159; <i>niebloid</i> &#65292;&#21363;&#65306;</p>
<ul>
<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">
<tr class="t-par">
<td>first, last</td>
<td>-</td>
<td>&#28304;&#20803;&#32032;&#33539;&#22260;</td>
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<tr class="t-par">
<td>r</td>
<td>-</td>
<td>&#28304;&#20803;&#32032;&#33539;&#22260;</td>
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<tr class="t-par">
<td>result</td>
<td>-</td>
<td>&#30446;&#26631;&#20803;&#32032;&#33539;&#22260;</td>
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<tr class="t-par">
<td>comp</td>
<td>-</td>
<td>&#27604;&#36739;&#25237;&#24433;&#21518;&#20803;&#32032;&#30340;&#35859;&#35789;</td>
</tr>
<tr class="t-par">
<td>proj</td>
<td>-</td>
<td>&#24212;&#29992;&#21040;&#35859;&#35789;&#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><span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="br0">{</span>last, result <span class="sy2">+</span> N<span class="br0">}</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>&#20934;&#30830;&#24212;&#29992; <span class="t-c"><span class="mw-geshi cpp source-cpp">N <span class="sy2">-</span> <span class="nu0">1</span></span></span> &#27425;&#23545;&#24212;&#30340;&#35859;&#35789; <code>comp</code> &#24182;&#24212;&#29992;&#19981;&#22810;&#20110;&#20854;&#27425;&#25968;&#20108;&#20493;&#30340;&#25237;&#24433; <code>proj</code> &#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>
<p>&#21442;&#38405; <a rel="nofollow" class="external text" href="https://github.com/gcc-mirror/gcc/blob/master/libstdc%2B%2B-v3/include/bits/ranges_algo.h#L1198-L1276">libstdc++</a> &#19982; <a rel="nofollow" class="external text" href="https://github.com/microsoft/STL/blob/472161105d596192194d4715ccad307c6c163b4a/stl/inc/algorithm#L4022-L4113">MSVC STL</a> &#65288;&#21450;&#31532;&#19977;&#26041;&#24211;&#65306; <a rel="nofollow" class="external text" href="https://github.com/CaseyCarter/cmcstl2/blob/master/include/stl2/detail/algorithm/unique_copy.hpp">cmcstl2</a>&#12289; <a rel="nofollow" class="external text" href="https://github.com/tcbrindle/NanoRange/blob/master/include/nanorange/algorithm/unique_copy.hpp">NanoRange</a> &#21644; <a rel="nofollow" class="external text" href="https://github.com/ericniebler/range-v3/blob/master/include/range/v3/algorithm/unique_copy.hpp">range-v3</a> &#65289;&#20013;&#30340;&#23454;&#29616;&#12290;</p>
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<pre class="de1"><span class="kw1">struct</span> unique_copy_fn <span class="br0">{</span>
<span class="kw1">template</span><span class="sy1">&lt;</span>std<span class="sy4">::</span><span class="me2">input_iterator</span> I, std<span class="sy4">::</span><span class="me2">sentinel_for</span><span class="sy1">&lt;</span>I<span class="sy1">&gt;</span> S, std<span class="sy4">::</span><span class="me2">weakly_incrementable</span> O,
<span class="kw1">class</span> Proj <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>I, Proj<span class="sy1">&gt;&gt;</span> C <span class="sy1">=</span> ranges<span class="sy4">::</span><span class="me2">equal_to</span><span class="sy1">&gt;</span>
requires std<span class="sy4">::</span><span class="me2">indirectly_copyable</span><span class="sy1">&lt;</span>I, O<span class="sy1">&gt;</span> <span class="sy3">&amp;&amp;</span> <span class="br0">(</span>std<span class="sy4">::</span><span class="me2">forward_iterator</span><span class="sy1">&lt;</span>I<span class="sy1">&gt;</span> or
<span class="br0">(</span>std<span class="sy4">::</span><span class="me2">input_iterator</span><span class="sy1">&lt;</span>O<span class="sy1">&gt;</span> <span class="sy3">&amp;&amp;</span> std<span class="sy4">::</span><span class="me2">same_as</span><span class="sy1">&lt;</span>std<span class="sy4">::</span><span class="me2">iter_value_t</span><span class="sy1">&lt;</span>I<span class="sy1">&gt;</span>,
std<span class="sy4">::</span><span class="me2">iter_value_t</span><span class="sy1">&lt;</span>O<span class="sy1">&gt;&gt;</span><span class="br0">)</span> or std<span class="sy4">::</span><span class="me2">indirectly_copyable_storable</span><span class="sy1">&lt;</span>I, O<span class="sy1">&gt;</span><span class="br0">)</span>
<span class="kw4">constexpr</span> ranges<span class="sy4">::</span><span class="me2">unique_copy_result</span><span class="sy1">&lt;</span>I, O<span class="sy1">&gt;</span>
operator<span class="br0">(</span><span class="br0">)</span> <span class="br0">(</span> I first, S last, O result, C comp <span class="sy1">=</span> <span class="br0">{</span><span class="br0">}</span>, Proj proj <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">if</span> <span class="br0">(</span><span class="sy3">!</span><span class="br0">(</span>first <span class="sy1">==</span> last<span class="br0">)</span><span class="br0">)</span> <span class="br0">{</span>
std<span class="sy4">::</span><span class="me2">iter_value_t</span><span class="sy1">&lt;</span>I<span class="sy1">&gt;</span> value <span class="sy1">=</span> <span class="sy2">*</span>first<span class="sy4">;</span>
<span class="sy2">*</span>result <span class="sy1">=</span> value<span class="sy4">;</span>
<span class="sy2">++</span>result<span class="sy4">;</span>
<span class="kw1">while</span> <span class="br0">(</span><span class="sy3">!</span><span class="br0">(</span><span class="sy2">++</span>first <span class="sy1">==</span> last<span class="br0">)</span><span class="br0">)</span> <span class="br0">{</span>
<span class="kw4">auto</span><span class="sy3">&amp;&amp;</span> value2 <span class="sy1">=</span> <span class="sy2">*</span>first<span class="sy4">;</span>
<span class="kw1">if</span> <span class="br0">(</span><span class="sy3">!</span><a href="cpp-utility-functional-invoke.html"><span class="kw1058">std::<span class="me2">invoke</span></span></a><span class="br0">(</span>comp, <a href="cpp-utility-functional-invoke.html"><span class="kw1058">std::<span class="me2">invoke</span></span></a><span class="br0">(</span>proj, value2<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>proj, value<span class="br0">)</span><span class="br0">)</span><span class="br0">)</span> <span class="br0">{</span>
value <span class="sy1">=</span> <a href="cpp-utility-forward.html"><span class="kw1117">std::<span class="me2">forward</span></span></a><span class="sy1">&lt;</span>decltype<span class="br0">(</span>value2<span class="br0">)</span><span class="sy1">&gt;</span><span class="br0">(</span>value2<span class="br0">)</span><span class="sy4">;</span>
<span class="sy2">*</span>result <span class="sy1">=</span> value<span class="sy4">;</span>
<span class="sy2">++</span>result<span class="sy4">;</span>
<span class="br0">}</span>
<span class="br0">}</span>
<span class="br0">}</span>
<span class="kw1">return</span> <span class="br0">{</span>std<span class="sy4">::</span><span class="me2">move</span><span class="br0">(</span>first<span class="br0">)</span>, std<span class="sy4">::</span><span class="me2">move</span><span class="br0">(</span>result<span class="br0">)</span><span class="br0">}</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">input_range</span> R, std<span class="sy4">::</span><span class="me2">weakly_incrementable</span> O, <span class="kw1">class</span> Proj <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>R<span class="sy1">&gt;</span>,
Proj<span class="sy1">&gt;&gt;</span> C <span class="sy1">=</span> ranges<span class="sy4">::</span><span class="me2">equal_to</span><span class="sy1">&gt;</span>
requires std<span class="sy4">::</span><span class="me2">indirectly_copyable</span><span class="sy1">&lt;</span>ranges<span class="sy4">::</span><span class="me2">iterator_t</span><span class="sy1">&lt;</span>R<span class="sy1">&gt;</span>, O<span class="sy1">&gt;</span> <span class="sy3">&amp;&amp;</span>
<span class="br0">(</span>std<span class="sy4">::</span><span class="me2">forward_iterator</span><span class="sy1">&lt;</span>ranges<span class="sy4">::</span><span class="me2">iterator_t</span><span class="sy1">&lt;</span>R<span class="sy1">&gt;&gt;</span> or
<span class="br0">(</span>std<span class="sy4">::</span><span class="me2">input_iterator</span><span class="sy1">&lt;</span>O<span class="sy1">&gt;</span> <span class="sy3">&amp;&amp;</span> std<span class="sy4">::</span><span class="me2">same_as</span><span class="sy1">&lt;</span>ranges<span class="sy4">::</span><span class="me2">range_value_t</span><span class="sy1">&lt;</span>R<span class="sy1">&gt;</span>,
std<span class="sy4">::</span><span class="me2">iter_value_t</span><span class="sy1">&lt;</span>O<span class="sy1">&gt;&gt;</span><span class="br0">)</span> <span class="sy3">||</span>
std<span class="sy4">::</span><span class="me2">indirectly_copyable_storable</span><span class="sy1">&lt;</span>ranges<span class="sy4">::</span><span class="me2">iterator_t</span><span class="sy1">&lt;</span>R<span class="sy1">&gt;</span>, O<span class="sy1">&gt;</span><span class="br0">)</span>
<span class="kw4">constexpr</span> ranges<span class="sy4">::</span><span class="me2">unique_copy_result</span><span class="sy1">&lt;</span>ranges<span class="sy4">::</span><span class="me2">borrowed_iterator_t</span><span class="sy1">&lt;</span>R<span class="sy1">&gt;</span>, O<span class="sy1">&gt;</span>
operator<span class="br0">(</span><span class="br0">)</span> <span class="br0">(</span> R<span class="sy3">&amp;&amp;</span> r, O result, C comp <span class="sy1">=</span> <span class="br0">{</span><span class="br0">}</span>, Proj proj <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>r<span class="br0">)</span>, ranges<span class="sy4">::</span><span class="me2">end</span><span class="br0">(</span>r<span class="br0">)</span>, std<span class="sy4">::</span><span class="me2">move</span><span class="br0">(</span>result<span class="br0">)</span>,
std<span class="sy4">::</span><span class="me2">move</span><span class="br0">(</span>comp<span class="br0">)</span>, std<span class="sy4">::</span><span class="me2">move</span><span class="br0">(</span>proj<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> unique_copy_fn unique_copy<span class="br0">{</span><span class="br0">}</span><span class="sy4">;</span></pre></div>
</div>
</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;cmath&gt;</span>
<span class="co2">#include &lt;iostream&gt;</span>
<span class="co2">#include &lt;iterator&gt;</span>
<span class="co2">#include &lt;list&gt;</span>
<span class="co2">#include &lt;string&gt;</span>
<span class="co2">#include &lt;type_traits&gt;</span>
<span class="kw4">void</span> print<span class="br0">(</span><span class="kw4">const</span> <span class="kw4">auto</span><span class="sy3">&amp;</span> rem, <span class="kw4">const</span> <span class="kw4">auto</span><span class="sy3">&amp;</span> v<span class="br0">)</span> <span class="br0">{</span>
<span class="kw1">using</span> V <span class="sy1">=</span> std<span class="sy4">::</span><span class="me2">remove_cvref_t</span><span class="sy1">&lt;</span>decltype<span class="br0">(</span>v<span class="br0">)</span><span class="sy1">&gt;</span><span class="sy4">;</span>
<span class="kw4">constexpr</span> <span class="kw4">bool</span> sep <span class="br0">{</span><a href="cpp-types-is_same.html"><span class="kw589">std::<span class="me2">is_same_v</span></span></a><span class="sy1">&lt;</span><span class="kw1">typename</span> V<span class="sy4">::</span><span class="me2">value_type</span>, <span class="kw4">int</span><span class="sy1">&gt;</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> rem <span class="sy1">&lt;&lt;</span> <a href="cpp-io-manip-showpos.html"><span class="kw1770">std::<span class="me2">showpos</span></span></a><span class="sy4">;</span>
<span class="kw1">for</span> <span class="br0">(</span><span class="kw4">const</span> <span class="kw4">auto</span><span class="sy3">&amp;</span> e <span class="sy4">:</span> v<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> e <span class="sy1">&lt;&lt;</span> <span class="br0">(</span>sep <span class="sy4">?</span> <span class="st0">&quot; &quot;</span> <span class="sy4">:</span> <span class="st0">&quot;&quot;</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">&#39;<span class="es1">\n</span>&#39;</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>
<a href="cpp-string-basic_string.html"><span class="kw1230">std::<span class="me2">string</span></span></a> s1 <span class="br0">{</span><span class="st0">&quot;The string with many spaces!&quot;</span><span class="br0">}</span><span class="sy4">;</span>
print<span class="br0">(</span><span class="st0">&quot;s1: &quot;</span>, s1<span class="br0">)</span><span class="sy4">;</span>
<a href="cpp-string-basic_string.html"><span class="kw1230">std::<span class="me2">string</span></span></a> s2<span class="sy4">;</span>
std<span class="sy4">::</span><span class="me2">ranges</span><span class="sy4">::</span><span class="me2">unique_copy</span><span class="br0">(</span>
s1.<span class="me1">begin</span><span class="br0">(</span><span class="br0">)</span>, s1.<span class="me1">end</span><span class="br0">(</span><span class="br0">)</span>, <a href="cpp-iterator-back_inserter.html"><span class="kw665">std::<span class="me2">back_inserter</span></span></a><span class="br0">(</span>s2<span class="br0">)</span>,
<span class="br0">[</span><span class="br0">]</span><span class="br0">(</span><span class="kw4">char</span> c1, <span class="kw4">char</span> c2<span class="br0">)</span><span class="br0">{</span> <span class="kw1">return</span> c1 <span class="sy1">==</span> <span class="st0">&#39; &#39;</span> <span class="sy3">&amp;&amp;</span> c2 <span class="sy1">==</span> <span class="st0">&#39; &#39;</span><span class="sy4">;</span> <span class="br0">}</span>
<span class="br0">)</span><span class="sy4">;</span>
print<span class="br0">(</span><span class="st0">&quot;s2: &quot;</span>, s2<span class="br0">)</span><span class="sy4">;</span>
<span class="kw4">const</span> <span class="kw4">auto</span> v1 <span class="sy1">=</span> <span class="br0">{</span> <span class="sy2">-</span><span class="nu0">1</span>, <span class="sy2">+</span><span class="nu0">1</span>, <span class="sy2">+</span><span class="nu0">2</span>, <span class="sy2">-</span><span class="nu0">2</span>, <span class="sy2">-</span><span class="nu0">3</span>, <span class="sy2">+</span><span class="nu0">3</span>, <span class="sy2">-</span><span class="nu0">3</span>, <span class="br0">}</span><span class="sy4">;</span>
print<span class="br0">(</span><span class="st0">&quot;v1: &quot;</span>, v1<span class="br0">)</span><span class="sy4">;</span>
<a href="cpp-container-list.html"><span class="kw1275">std::<span class="me2">list</span></span></a><span class="sy1">&lt;</span><span class="kw4">int</span><span class="sy1">&gt;</span> v2<span class="sy4">;</span>
std<span class="sy4">::</span><span class="me2">ranges</span><span class="sy4">::</span><span class="me2">unique_copy</span><span class="br0">(</span>
v1, <a href="cpp-iterator-back_inserter.html"><span class="kw665">std::<span class="me2">back_inserter</span></span></a><span class="br0">(</span>v2<span class="br0">)</span>,
<span class="br0">{</span><span class="br0">}</span>, <span class="co1">// &#40664;&#35748;&#27604;&#36739;&#22120; std::ranges::equal_to</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> std<span class="sy4">::</span><span class="me2">abs</span><span class="br0">(</span>x<span class="br0">)</span><span class="sy4">;</span> <span class="br0">}</span> <span class="co1">// &#25237;&#24433;</span>
<span class="br0">)</span><span class="sy4">;</span>
print<span class="br0">(</span><span class="st0">&quot;v2: &quot;</span>, v2<span class="br0">)</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">s1: The string with many spaces!
s2: The string with many spaces!
v1: -1 +1 +2 -2 -3 +3 -3
v2: -1 +2 -3</pre></div>
</div>
</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-unique.html"><span class="t-lines"><span>ranges::unique</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>&#31227;&#38500;&#33539;&#22260;&#20013;&#30340;&#36830;&#32493;&#37325;&#22797;&#20803;&#32032;<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-copy.html"><span class="t-lines"><span>ranges::copy</span><span>ranges::copy_if</span></span></a></div>
<div><span class="t-lines"><span><span class="t-mark-rev t-since-cxx20">(C++20)</span></span><span><span class="t-mark-rev t-since-cxx20">(C++20)</span></span></span></div>
</div>
</td>
<td>&#23558;&#26576;&#19968;&#33539;&#22260;&#30340;&#20803;&#32032;&#22797;&#21046;&#21040;&#19968;&#20010;&#26032;&#30340;&#20301;&#32622;<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-adjacent_find.html"><span class="t-lines"><span>ranges::adjacent_find</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>&#26597;&#25214;&#39318;&#23545;&#30456;&#37051;&#30340;&#30456;&#21516;&#65288;&#25110;&#28385;&#36275;&#32473;&#23450;&#35859;&#35789;&#30340;&#65289;&#20803;&#32032;<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-unique_copy.html"><span class="t-lines"><span>unique_copy</span></span></a></div>
</div>
</td>
<td>&#21019;&#24314;&#26576;&#33539;&#22260;&#30340;&#19981;&#21547;&#36830;&#32493;&#37325;&#22797;&#20803;&#32032;&#30340;&#21103;&#26412;<br />
<span class="t-mark">(&#20989;&#25968;&#27169;&#26495;)</span></td>
</tr>
</table>
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