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<h1 id="firstHeading" class="firstHeading"><span style="font-size:0.7em; line-height:130%">std::reference_wrapper&lt;T&gt;::</span>operator()</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-functional.html">functional</a>&lrm; | <a href="cpp-utility-functional-reference_wrapper.html">reference wrapper</a></span></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>... <span class="me1">ArgTypes</span> <span class="sy1">&gt;</span><br /></span>
<p><span class="kw1">typename</span> <a href="cpp-types-result_of.html"><span class="kw639">std::<span class="me2">result_of</span></span></a><span class="sy1">&lt;</span>T<span class="sy3">&amp;</span><span class="br0">(</span>ArgTypes<span class="sy3">&amp;&amp;</span>...<span class="br0">)</span><span class="sy1">&gt;</span><span class="sy4">::</span><span class="me2">type</span><br /></p>
&nbsp; &nbsp; operator<span class="br0">(</span><span class="br0">)</span> <span class="br0">(</span> ArgTypes<span class="sy3">&amp;&amp;</span>... <span class="me1">args</span> <span class="br0">)</span> <span class="kw4">const</span><span class="sy4">;</span></div>
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<td><span class="t-mark-rev t-since-cxx11">(C++11 &#36215;)</span><br />
<span class="t-mark-rev t-until-cxx17">(C++17 &#21069;)</span></td>
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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>... <span class="me1">ArgTypes</span> <span class="sy1">&gt;</span><br /></span>
<p>std<span class="sy4">::</span><span class="me2">invoke_result_t</span><span class="sy1">&lt;</span>T<span class="sy3">&amp;</span>, ArgTypes...<span class="sy1">&gt;</span><br /></p>
&nbsp; &nbsp; operator<span class="br0">(</span><span class="br0">)</span> <span class="br0">(</span> ArgTypes<span class="sy3">&amp;&amp;</span>... <span class="me1">args</span> <span class="br0">)</span> <span class="kw4">const</span><span class="sy4">;</span></div>
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<td><span class="t-mark-rev t-since-cxx17">(C++17 &#36215;)</span><br />
<span class="t-mark-rev t-until-cxx20">(C++20 &#21069;)</span></td>
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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>... <span class="me1">ArgTypes</span> <span class="sy1">&gt;</span><br /></span>
<p><span class="kw4">constexpr</span> std<span class="sy4">::</span><span class="me2">invoke_result_t</span><span class="sy1">&lt;</span>T<span class="sy3">&amp;</span>, ArgTypes...<span class="sy1">&gt;</span><br /></p>
&nbsp; &nbsp; operator<span class="br0">(</span><span class="br0">)</span> <span class="br0">(</span> ArgTypes<span class="sy3">&amp;&amp;</span>... <span class="me1">args</span> <span class="br0">)</span> <span class="kw4">const</span><span class="sy4">;</span></div>
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<td><span class="t-mark-rev t-since-cxx20">(C++20 &#36215;)</span></td>
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<p>&#35843;&#29992;&#23384;&#20648;&#20854;&#24341;&#29992;&#30340;<a href="cpp-named_req-Callable.html"><span style="font-style:italic">&#21487;&#35843;&#29992;</span> <span style="font-family: Georgia, &#39;DejaVu Serif&#39;, serif; font-style:italic">(Callable)</span></a> &#23545;&#35937;&#12290;&#20165;&#33509;&#23384;&#20648;&#30340;&#24341;&#29992;&#25351;&#21521;<a href="cpp-named_req-Callable.html"><span style="font-style:italic">&#21487;&#35843;&#29992;</span> <span style="font-family: Georgia, &#39;DejaVu Serif&#39;, serif; font-style:italic">(Callable)</span></a> &#23545;&#35937;&#65292;&#27492;&#20989;&#25968;&#25165;&#21487;&#29992;&#12290;</p>
<p><code>T</code> &#24517;&#39035;&#26159;&#23436;&#25972;&#31867;&#22411;&#12290;</p>
<h3><span class="mw-headline" id=".E5.8F.82.E6.95.B0">&#21442;&#25968;</span></h3>
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<td>args</td>
<td>-</td>
<td>&#20256;&#36882;&#32473;&#34987;&#35843;&#29992;&#20989;&#25968;&#30340;&#21442;&#25968;</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>&#34987;&#35843;&#29992;&#20989;&#25968;&#30340;&#36820;&#22238;&#20540;&#12290;</p>
<h3><span class="mw-headline" id=".E5.BC.82.E5.B8.B8">&#24322;&#24120;</span></h3>
<p>&#21487;&#33021;&#25243;&#20986;&#23454;&#29616;&#23450;&#20041;&#30340;&#24322;&#24120;&#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;functional&gt;</span>
<span class="kw4">void</span> f1<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;reference to function called<span class="es1">\n</span>&quot;</span><span class="sy4">;</span>
<span class="br0">}</span>
<span class="kw4">void</span> f2<span class="br0">(</span><span class="kw4">int</span> n<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;bind expression called with &quot;</span> <span class="sy1">&lt;&lt;</span> n <span class="sy1">&lt;&lt;</span> <span class="st0">&quot; as the argument<span class="es1">\n</span>&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>
<a href="cpp-utility-functional-reference_wrapper.html"><span class="kw1068">std::<span class="me2">reference_wrapper</span></span></a><span class="sy1">&lt;</span><span class="kw4">void</span><span class="br0">(</span><span class="br0">)</span><span class="sy1">&gt;</span> ref1 <span class="sy1">=</span> <a href="cpp-utility-functional-ref.html"><span class="kw1069">std::<span class="me2">ref</span></span></a><span class="br0">(</span>f1<span class="br0">)</span><span class="sy4">;</span>
ref1<span class="br0">(</span><span class="br0">)</span><span class="sy4">;</span>
<span class="kw4">auto</span> b <span class="sy1">=</span> <a href="cpp-utility-functional-bind.html"><span class="kw1052">std::<span class="me2">bind</span></span></a><span class="br0">(</span>f2, std<span class="sy4">::</span><span class="me2">placeholders</span><span class="sy4">::</span>_1<span class="br0">)</span><span class="sy4">;</span>
<span class="kw4">auto</span> ref2 <span class="sy1">=</span> <a href="cpp-utility-functional-ref.html"><span class="kw1069">std::<span class="me2">ref</span></span></a><span class="br0">(</span>b<span class="br0">)</span><span class="sy4">;</span>
ref2<span class="br0">(</span><span class="nu0">7</span><span class="br0">)</span><span class="sy4">;</span>
<span class="kw4">auto</span> c <span class="sy1">=</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;lambda function called<span class="es1">\n</span>&quot;</span><span class="sy4">;</span> <span class="br0">}</span><span class="sy4">;</span>
<span class="kw4">auto</span> ref3 <span class="sy1">=</span> <a href="cpp-utility-functional-ref.html"><span class="kw1069">std::<span class="me2">ref</span></span></a><span class="br0">(</span>c<span class="br0">)</span><span class="sy4">;</span>
ref3<span class="br0">(</span><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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<pre class="de1">reference to function called
bind expression called with 7 as the argument
lambda function called</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-functional-reference_wrapper-get.html"><span class="t-lines"><span>get</span><span>operator T&amp;</span></span></a></div>
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<td>&#35775;&#38382;&#23384;&#20648;&#30340;&#24341;&#29992;<br />
<span class="t-mark">(&#20844;&#24320;&#25104;&#21592;&#20989;&#25968;)</span></td>
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