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<h1 id="firstHeading" class="firstHeading"><span style="font-size:0.7em; line-height:130%">std::</span>async</h1>
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<div id="contentSub"><span class="subpages">&lt; <a href="cpp.html">cpp</a>&lrm; | <a href="cpp-thread.html">thread</a></span></div>
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<div>&#23450;&#20041;&#20110;&#22836;&#25991;&#20214; <code><a href="cpp-header-future.html">&lt;future&gt;</a></code></div>
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<td rowspan="142">(1)</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> Function, <span class="kw1">class</span>... <span class="me1">Args</span><span class="sy1">&gt;</span><br /></span>
<p><a href="cpp-thread-future.html"><span class="kw2180">std::<span class="me2">future</span></span></a><span class="sy1">&lt;</span><a href="cpp-types-result_of.html"><span class="kw640">std::<span class="me2">result_of_t</span></span></a><span class="sy1">&lt;</span><a href="cpp-types-decay.html"><span class="kw629">std::<span class="me2">decay_t</span></span></a><span class="sy1">&lt;</span>Function<span class="sy1">&gt;</span><span class="br0">(</span><a href="cpp-types-decay.html"><span class="kw629">std::<span class="me2">decay_t</span></span></a><span class="sy1">&lt;</span>Args<span class="sy1">&gt;</span>...<span class="br0">)</span><span class="sy1">&gt;&gt;</span><br /></p>
&nbsp; &nbsp; async<span class="br0">(</span> Function<span class="sy3">&amp;&amp;</span> f, Args<span class="sy3">&amp;&amp;</span>... <span class="me1">args</span> <span class="br0">)</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> Function, <span class="kw1">class</span>... <span class="me1">Args</span><span class="sy1">&gt;</span><br /></span>
<p><a href="cpp-thread-future.html"><span class="kw2180">std::<span class="me2">future</span></span></a><span class="sy1">&lt;</span>std<span class="sy4">::</span><span class="me2">invoke_result_t</span><span class="sy1">&lt;</span><a href="cpp-types-decay.html"><span class="kw629">std::<span class="me2">decay_t</span></span></a><span class="sy1">&lt;</span>Function<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; &nbsp; <a href="cpp-types-decay.html"><span class="kw629">std::<span class="me2">decay_t</span></span></a><span class="sy1">&lt;</span>Args<span class="sy1">&gt;</span>...<span class="sy1">&gt;&gt;</span><br /></p>
&nbsp; &nbsp; async<span class="br0">(</span> Function<span class="sy3">&amp;&amp;</span> f, Args<span class="sy3">&amp;&amp;</span>... <span class="me1">args</span> <span class="br0">)</span><span class="sy4">;</span></div>
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<td class="t-dcl-nopad"></td>
<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> Function, <span class="kw1">class</span>... <span class="me1">Args</span><span class="sy1">&gt;</span><br /></span>
<p><span class="br0">[</span><span class="br0">[</span>nodiscard<span class="br0">]</span><span class="br0">]</span><br />
<a href="cpp-thread-future.html"><span class="kw2180">std::<span class="me2">future</span></span></a><span class="sy1">&lt;</span>std<span class="sy4">::</span><span class="me2">invoke_result_t</span><span class="sy1">&lt;</span><a href="cpp-types-decay.html"><span class="kw629">std::<span class="me2">decay_t</span></span></a><span class="sy1">&lt;</span>Function<span class="sy1">&gt;</span>,<br />
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<a href="cpp-types-decay.html"><span class="kw629">std::<span class="me2">decay_t</span></span></a><span class="sy1">&lt;</span>Args<span class="sy1">&gt;</span>...<span class="sy1">&gt;&gt;</span><br /></p>
&nbsp; &nbsp; async<span class="br0">(</span> Function<span class="sy3">&amp;&amp;</span> f, Args<span class="sy3">&amp;&amp;</span>... <span class="me1">args</span> <span class="br0">)</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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<td rowspan="142">(2)</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> Function, <span class="kw1">class</span>... <span class="me1">Args</span> <span class="sy1">&gt;</span><br /></span>
<p><a href="cpp-thread-future.html"><span class="kw2180">std::<span class="me2">future</span></span></a><span class="sy1">&lt;</span><a href="cpp-types-result_of.html"><span class="kw640">std::<span class="me2">result_of_t</span></span></a><span class="sy1">&lt;</span><a href="cpp-types-decay.html"><span class="kw629">std::<span class="me2">decay_t</span></span></a><span class="sy1">&lt;</span>Function<span class="sy1">&gt;</span><span class="br0">(</span><a href="cpp-types-decay.html"><span class="kw629">std::<span class="me2">decay_t</span></span></a><span class="sy1">&lt;</span>Args<span class="sy1">&gt;</span>...<span class="br0">)</span><span class="sy1">&gt;&gt;</span><br /></p>
&nbsp; &nbsp; async<span class="br0">(</span> <a href="cpp-thread-launch.html"><span class="kw2184">std::<span class="me2">launch</span></span></a> policy, Function<span class="sy3">&amp;&amp;</span> f, Args<span class="sy3">&amp;&amp;</span>... <span class="me1">args</span> <span class="br0">)</span><span class="sy4">;</span></div>
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<td class="t-dcl-nopad"></td>
<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> Function, <span class="kw1">class</span>... <span class="me1">Args</span> <span class="sy1">&gt;</span><br /></span>
<p><a href="cpp-thread-future.html"><span class="kw2180">std::<span class="me2">future</span></span></a><span class="sy1">&lt;</span>std<span class="sy4">::</span><span class="me2">invoke_result_t</span><span class="sy1">&lt;</span><a href="cpp-types-decay.html"><span class="kw629">std::<span class="me2">decay_t</span></span></a><span class="sy1">&lt;</span>Function<span class="sy1">&gt;</span>,<br />
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<a href="cpp-types-decay.html"><span class="kw629">std::<span class="me2">decay_t</span></span></a><span class="sy1">&lt;</span>Args<span class="sy1">&gt;</span>...<span class="sy1">&gt;&gt;</span><br /></p>
&nbsp; &nbsp; async<span class="br0">(</span> <a href="cpp-thread-launch.html"><span class="kw2184">std::<span class="me2">launch</span></span></a> policy, Function<span class="sy3">&amp;&amp;</span> f, Args<span class="sy3">&amp;&amp;</span>... <span class="me1">args</span> <span class="br0">)</span><span class="sy4">;</span></div>
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<td class="t-dcl-nopad"></td>
<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> Function, <span class="kw1">class</span>... <span class="me1">Args</span> <span class="sy1">&gt;</span><br /></span>
<p><span class="br0">[</span><span class="br0">[</span>nodiscard<span class="br0">]</span><span class="br0">]</span><br />
<a href="cpp-thread-future.html"><span class="kw2180">std::<span class="me2">future</span></span></a><span class="sy1">&lt;</span>std<span class="sy4">::</span><span class="me2">invoke_result_t</span><span class="sy1">&lt;</span><a href="cpp-types-decay.html"><span class="kw629">std::<span class="me2">decay_t</span></span></a><span class="sy1">&lt;</span>Function<span class="sy1">&gt;</span>,<br />
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<a href="cpp-types-decay.html"><span class="kw629">std::<span class="me2">decay_t</span></span></a><span class="sy1">&lt;</span>Args<span class="sy1">&gt;</span>...<span class="sy1">&gt;&gt;</span><br /></p>
&nbsp; &nbsp; async<span class="br0">(</span> <a href="cpp-thread-launch.html"><span class="kw2184">std::<span class="me2">launch</span></span></a> policy, Function<span class="sy3">&amp;&amp;</span> f, Args<span class="sy3">&amp;&amp;</span>... <span class="me1">args</span> <span class="br0">)</span><span class="sy4">;</span></div>
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<td class="t-dcl-nopad"></td>
<td><span class="t-mark-rev t-since-cxx20">(C++20 &#36215;)</span></td>
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<p>&#20989;&#25968;&#27169;&#26495; <code>async</code> &#24322;&#27493;&#22320;&#36816;&#34892;&#20989;&#25968; <code>f</code> &#65288;&#28508;&#22312;&#22320;&#22312;&#21487;&#33021;&#26159;&#32447;&#31243;&#27744;&#19968;&#37096;&#20998;&#30340;&#20998;&#31163;&#32447;&#31243;&#20013;&#65289;&#65292;&#24182;&#36820;&#22238;&#26368;&#32456;&#23558;&#20445;&#26377;&#35813;&#20989;&#25968;&#35843;&#29992;&#32467;&#26524;&#30340; <span class="t-lc"><a href="cpp-thread-future.html">std::future</a></span> &#12290;</p>
<div class="t-li1"><span class="t-li">1)</span> &#34920;&#29616;&#22914;&#21516;&#20197; <span class="t-c"><span class="mw-geshi cpp source-cpp">policy</span></span> &#20026; <span class="t-c"><span class="mw-geshi cpp source-cpp"><a href="cpp-thread-launch.html"><span class="kw2185">std::<span class="me2">launch</span><span class="sy4">::</span><span class="me2">async</span></span></a> <span class="sy3">|</span> <a href="cpp-thread-launch.html"><span class="kw2186">std::<span class="me2">launch</span><span class="sy4">::</span><span class="me2">deferred</span></span></a></span></span> &#35843;&#29992; <span class="t-v">(2)</span> &#12290;&#25442;&#35328;&#20043;&#65292; <code>f</code> &#21487;&#33021;&#25191;&#34892;&#20110;&#21478;&#19968;&#32447;&#31243;&#65292;&#25110;&#32773;&#23427;&#21487;&#33021;&#22312;&#26597;&#35810;&#20135;&#29983;&#30340; <span class="t-lc"><a href="cpp-thread-future.html">std::future</a></span> &#30340;&#20540;&#26102;&#21516;&#27493;&#36816;&#34892;&#12290;</div>
<div class="t-li1"><span class="t-li">2)</span> &#25353;&#29031;&#29305;&#23450;&#30340;&#25191;&#34892;&#31574;&#30053; <code>policy</code> &#65292;&#20197;&#21442;&#25968; <code>args</code> &#35843;&#29992;&#20989;&#25968; <code>f</code> &#65306;
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<ul>
<li>&#33509;&#35774;&#32622; <i>async</i> &#26631;&#24535;&#65288;&#21363; <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="br0">(</span>policy <span class="sy3">&amp;</span> <a href="cpp-thread-launch.html"><span class="kw2185">std::<span class="me2">launch</span><span class="sy4">::</span><span class="me2">async</span></span></a><span class="br0">)</span> <span class="sy3">!</span><span class="sy1">=</span> <span class="nu0">0</span></span></span> &#65289;&#65292;&#21017; <code>async</code> &#22312;&#26032;&#30340;&#25191;&#34892;&#32447;&#31243;&#65288;&#21021;&#22987;&#21270;&#25152;&#26377;&#32447;&#31243;&#23616;&#22495;&#23545;&#35937;&#21518;&#65289;&#25191;&#34892;&#21487;&#35843;&#29992;&#23545;&#35937; <code>f</code> &#65292;&#22914;&#21516;&#20135;&#20986; <span class="t-c"><span class="mw-geshi cpp source-cpp"><a href="cpp-thread-thread.html"><span class="kw2146">std::<span class="me2">thread</span></span></a><span class="br0">(</span><a href="cpp-utility-forward.html"><span class="kw1117">std::<span class="me2">forward</span></span></a><span class="sy1">&lt;</span>F<span class="sy1">&gt;</span><span class="br0">(</span>f<span class="br0">)</span>, <a href="cpp-utility-forward.html"><span class="kw1117">std::<span class="me2">forward</span></span></a><span class="sy1">&lt;</span>Args<span class="sy1">&gt;</span><span class="br0">(</span>args<span class="br0">)</span>...<span class="br0">)</span></span></span> &#65292;&#38500;&#20102;&#33509; <code>f</code> &#36820;&#22238;&#20540;&#25110;&#25243;&#20986;&#24322;&#24120;&#65292;&#21017;&#20110;&#21487;&#36890;&#36807; <code>async</code> &#36820;&#22238;&#32473;&#35843;&#29992;&#26041;&#30340; <span class="t-lc"><a href="cpp-thread-future.html">std::future</a></span> &#35775;&#38382;&#30340;&#20849;&#20139;&#29366;&#24577;&#23384;&#20648;&#32467;&#26524;&#12290;</li>
<li>&#33509;&#35774;&#32622; <i>deferred</i> &#26631;&#24535;&#65288;&#21363; <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="br0">(</span>policy <span class="sy3">&amp;</span> <a href="cpp-thread-launch.html"><span class="kw2186">std::<span class="me2">launch</span><span class="sy4">::</span><span class="me2">deferred</span></span></a><span class="br0">)</span> <span class="sy3">!</span><span class="sy1">=</span> <span class="nu0">0</span></span></span> &#65289;&#65292;&#21017; <code>async</code> &#20197;&#21516; <span class="t-lc"><a href="cpp-thread-thread.html">std::thread</a></span> &#26500;&#36896;&#20989;&#25968;&#30340;&#26041;&#24335;&#36716;&#25442; <code>f</code> &#19982; <code>args...</code> &#65292;&#20294;&#19981;&#20135;&#20986;&#26032;&#30340;&#25191;&#34892;&#32447;&#31243;&#12290;&#32780;&#26159;&#36827;&#34892;<i>&#24816;&#24615;&#27714;&#20540;</i>&#65306;&#22312; <code>async</code> &#25152;&#36820;&#22238;&#30340; <span class="t-lc"><a href="cpp-thread-future.html">std::future</a></span> &#19978;&#39318;&#27425;&#35843;&#29992;&#38750;&#23450;&#26102;&#31561;&#24453;&#20989;&#25968;&#65292;&#23558;&#23548;&#33268;&#22312;&#24403;&#21069;&#32447;&#31243;&#65288;&#19981;&#24517;&#26159;&#26368;&#21021;&#35843;&#29992; <code>std::async</code> &#30340;&#32447;&#31243;&#65289;&#20013;&#65292;&#20197; <code>args...</code> &#65288;&#20316;&#20026;&#21491;&#20540;&#20256;&#36882;&#65289;&#30340;&#21103;&#26412;&#35843;&#29992; <code>f</code> &#65288;&#20134;&#20316;&#20026;&#21491;&#20540;&#65289;&#30340;&#21103;&#26412;&#12290;&#23558;&#32467;&#26524;&#25110;&#24322;&#24120;&#32622;&#20110;&#20851;&#32852;&#21040;&#35813; future &#30340;&#20849;&#20139;&#29366;&#24577;&#65292;&#28982;&#21518;&#25165;&#20196;&#23427;&#23601;&#32490;&#12290;&#23545;&#21516;&#19968; <span class="t-lc"><a href="cpp-thread-future.html">std::future</a></span> &#30340;&#25152;&#26377;&#21518;&#32493;&#35775;&#38382;&#37117;&#20250;&#31435;&#21363;&#36820;&#22238;&#32467;&#26524;&#12290;</li>
<li>&#33509; <code>policy</code> &#20013;&#35774;&#32622;&#20102; <span class="t-lc"><a href="cpp-thread-launch.html">std::launch::async</a></span> &#21644; <span class="t-lc"><a href="cpp-thread-launch.html">std::launch::deferred</a></span> &#20004;&#20010;&#26631;&#24535;&#65292;&#21017;&#36827;&#34892;&#24322;&#27493;&#25191;&#34892;&#36824;&#26159;&#24816;&#24615;&#27714;&#20540;&#21462;&#20915;&#20110;&#23454;&#29616;&#12290;</li>
<li>&#33509; <code>policy</code> &#20013;&#26410;&#35774;&#32622; <span class="t-lc"><a href="cpp-thread-launch.html">std::launch::async</a></span> &#25110; <span class="t-lc"><a href="cpp-thread-launch.html">std::launch::deferred</a></span> &#25110;&#20219;&#20309;&#23454;&#29616;&#23450;&#20041;&#31574;&#30053;&#26631;&#24535;&#65292;&#21017;&#34892;&#20026;&#26410;&#23450;&#20041;&#12290;</li>
</ul>
</dd>
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<p>&#20219;&#20309;&#24773;&#20917;&#19979;&#65292;&#23545; <code>std::async</code> &#30340;&#35843;&#29992;<i>&#21516;&#27493;&#20110;</i>&#65288;&#23450;&#20041;&#20110; <span class="t-lc"><a href="cpp-atomic-memory_order.html">std::memory_order</a></span> &#65289;&#23545; <code>f</code> &#30340;&#35843;&#29992;&#65292;&#19988; <code>f</code> &#30340;&#23436;&#25104;<i>&#20808;&#24207;&#20110;</i>&#20196;&#20849;&#20139;&#29366;&#24577;&#23601;&#32490;&#12290;&#33509;&#36873;&#25321; <code>async</code> &#31574;&#30053;&#65292;&#21017;&#20851;&#32852;&#32447;&#31243;&#30340;&#23436;&#25104;<i>&#21516;&#27493;&#20110;</i>&#39318;&#20010;&#31561;&#24453;&#20110;&#20849;&#20139;&#29366;&#24577;&#19978;&#30340;&#20989;&#25968;&#30340;&#25104;&#21151;&#36820;&#22238;&#65292;&#25110;&#26368;&#21518;&#19968;&#20010;&#37322;&#25918;&#20849;&#20139;&#29366;&#24577;&#30340;&#20989;&#25968;&#30340;&#36820;&#22238;&#65292;&#20004;&#32773;&#30340;&#20808;&#21040;&#26469;&#32773;&#12290;&#33509; <span class="t-c"><span class="mw-geshi cpp source-cpp"><a href="cpp-types-decay.html"><span class="kw628">std::<span class="me2">decay</span></span></a><span class="sy1">&lt;</span>Function<span class="sy1">&gt;</span><span class="sy4">::</span><span class="me2">type</span></span></span> &#25110; <span class="t-c"><span class="mw-geshi cpp source-cpp"><a href="cpp-types-decay.html"><span class="kw628">std::<span class="me2">decay</span></span></a><span class="sy1">&lt;</span>Args<span class="sy1">&gt;</span><span class="sy4">::</span><span class="me2">type</span></span></span> &#20013;&#30340;&#27599;&#20010;&#31867;&#22411;&#19981;&#33021;&#20174;&#20854;&#23545;&#24212;&#30340;&#23454;&#21442;&#26500;&#36896;&#65292;&#21017;&#31243;&#24207;&#20026;&#35884;&#26500;&#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>f</td>
<td>-</td>
<td>&#35201;&#35843;&#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;</td>
</tr>
<tr class="t-par">
<td>args...</td>
<td>-</td>
<td>&#20256;&#36882;&#32473; <code>f</code> &#30340;&#21442;&#25968;</td>
</tr>
<tr class="t-par">
<td>policy</td>
<td>-</td>
<td>&#20301;&#25513;&#30721;&#20540;&#65292;&#27599;&#20010;&#21333;&#29420;&#20301;&#25511;&#21046;&#20801;&#35768;&#30340;&#25191;&#34892;&#26041;&#27861;
<table class="t-dsc-begin">
<tr class="t-dsc-hitem">
<td>&#20301;</td>
<td>&#35299;&#37322;</td>
</tr>
<tr class="t-dsc">
<td><span class="t-lc"><a href="cpp-thread-launch.html">std::launch::async</a></span></td>
<td>&#21551;&#29992;&#24322;&#27493;&#27714;&#20540;</td>
</tr>
<tr class="t-dsc">
<td><span class="t-lc"><a href="cpp-thread-launch.html">std::launch::deferred</a></span></td>
<td>&#21551;&#29992;&#24816;&#24615;&#27714;&#20540;</td>
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<p><br /></p>
</td>
</tr>
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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>&#25351;&#20195;&#27492;&#27425;&#35843;&#29992; <code>std::async</code> &#25152;&#21019;&#24314;&#30340;&#20849;&#20139;&#29366;&#24577;&#30340; <span class="t-lc"><a href="cpp-thread-future.html">std::future</a></span> &#12290;</p>
<h3><span class="mw-headline" id=".E5.BC.82.E5.B8.B8">&#24322;&#24120;</span></h3>
<p>&#33509;&#36816;&#34892;&#31574;&#30053;&#31561;&#20110; <span class="t-lc"><a href="cpp-thread-launch.html">std::launch::async</a></span> &#19988;&#23454;&#29616;&#26080;&#27861;&#24320;&#22987;&#26032;&#32447;&#31243;&#65288;&#35813;&#24773;&#20917;&#19979;&#65292;&#33509;&#36816;&#34892;&#31574;&#30053;&#20026; <code>async|deferred</code> &#25110;&#35774;&#32622;&#20102;&#39069;&#22806;&#20301;&#65292;&#21017;&#23427;&#23558;&#22238;&#36864;&#21040; deferred &#25110;&#23454;&#29616;&#23450;&#20041;&#30340;&#31574;&#30053;&#65289;&#65292;&#21017;&#25243;&#20986;&#20197; <span class="t-lc"><a href="cpp-error-errc.html">std::errc::resource_unavailable_try_again</a></span> &#20026;&#38169;&#35823;&#26465;&#20214;&#30340; <span class="t-lc"><a href="cpp-error-system_error.html">std::system_error</a></span> &#65292;&#25110;&#32773;&#33509;&#26080;&#27861;&#20998;&#37197;&#20869;&#37096;&#25968;&#25454;&#32467;&#26500;&#25152;&#29992;&#30340;&#20869;&#23384;&#65292;&#21017;&#20026; <span class="t-lc"><a href="cpp-memory-new-bad_alloc.html">std::bad_alloc</a></span> &#12290;</p>
<h3><span class="mw-headline" id=".E6.B3.A8.E8.A7.A3">&#27880;&#35299;</span></h3>
<p>&#23454;&#29616;&#21487;&#20197;&#36890;&#36807;&#22312;&#40664;&#35748;&#36816;&#34892;&#31574;&#30053;&#20013;&#21551;&#29992;&#39069;&#22806;&#65288;&#23454;&#29616;&#23450;&#20041;&#30340;&#65289;&#20301;&#65292;&#25193;&#23637; <span class="t-lc"><strong class="selflink">std::async</strong></span> &#31532;&#19968;&#37325;&#36733;&#30340;&#34892;&#20026;&#12290;</p>
<p>&#23454;&#29616;&#23450;&#20041;&#30340;&#36816;&#34892;&#31574;&#30053;&#30340;&#20363;&#23376;&#26159;&#21516;&#27493;&#31574;&#30053;&#65288;&#22312; async &#35843;&#29992;&#20869;&#31435;&#21363;&#25191;&#34892;&#65289;&#21644;&#20219;&#21153;&#31574;&#30053;&#65288;&#31867;&#20284; async &#65292;&#20294;&#19981;&#28165;&#29702;&#32447;&#31243;&#23616;&#22495;&#23545;&#35937;&#65289;&#12290;</p>
<p>&#33509;&#20174; <code>std::async</code> &#33719;&#24471;&#30340; <code>std::future</code> &#26410;&#34987;&#31227;&#21160;&#25110;&#32465;&#23450;&#21040;&#24341;&#29992;&#65292;&#21017;&#22312;&#23436;&#25972;&#34920;&#36798;&#24335;&#32467;&#23614;&#65292; <span class="t-lc"><a href="cpp-thread-future.html">std::future</a></span> &#30340;&#26512;&#26500;&#20989;&#25968;&#23558;&#38459;&#22622;&#30452;&#33267;&#24322;&#27493;&#35745;&#31639;&#23436;&#25104;&#65292;&#23454;&#36136;&#19978;&#20196;&#22914;&#19979;&#20195;&#30721;&#21516;&#27493;&#65306;</p>
<div dir="ltr" class="mw-geshi" style="text-align: left;">
<div class="cpp source-cpp">
<pre class="de1">std<span class="sy4">::</span><span class="me2">async</span><span class="br0">(</span><a href="cpp-thread-launch.html"><span class="kw2185">std::<span class="me2">launch</span><span class="sy4">::</span><span class="me2">async</span></span></a>, <span class="br0">[</span><span class="br0">]</span><span class="br0">{</span> f<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="co1">// &#20020;&#26102;&#37327;&#30340;&#26512;&#26500;&#20989;&#25968;&#31561;&#24453; f()</span>
std<span class="sy4">::</span><span class="me2">async</span><span class="br0">(</span><a href="cpp-thread-launch.html"><span class="kw2185">std::<span class="me2">launch</span><span class="sy4">::</span><span class="me2">async</span></span></a>, <span class="br0">[</span><span class="br0">]</span><span class="br0">{</span> g<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="co1">// f() &#23436;&#25104;&#21069;&#19981;&#24320;&#22987;</span></pre></div>
</div>
<p>&#65288;&#27880;&#24847;&#65292;&#20197;&#35843;&#29992; std::async &#20197;&#22806;&#30340;&#26041;&#24335;&#33719;&#24471;&#30340; std::future &#30340;&#26512;&#26500;&#20989;&#25968;&#20915;&#19981;&#38459;&#22622;&#65289;</p>
<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;iostream&gt;</span>
<span class="co2">#include &lt;vector&gt;</span>
<span class="co2">#include &lt;algorithm&gt;</span>
<span class="co2">#include &lt;numeric&gt;</span>
<span class="co2">#include &lt;future&gt;</span>
<span class="co2">#include &lt;string&gt;</span>
<span class="co2">#include &lt;mutex&gt;</span>
<a href="cpp-thread-mutex.html"><span class="kw2154">std::<span class="me2">mutex</span></span></a> m<span class="sy4">;</span>
<span class="kw1">struct</span> X <span class="br0">{</span>
<span class="kw4">void</span> foo<span class="br0">(</span><span class="kw4">int</span> i, <span class="kw4">const</span> <a href="cpp-string-basic_string.html"><span class="kw1230">std::<span class="me2">string</span></span></a><span class="sy3">&amp;</span> str<span class="br0">)</span> <span class="br0">{</span>
<a href="cpp-thread-lock_guard.html"><span class="kw2166">std::<span class="me2">lock_guard</span></span></a><span class="sy1">&lt;</span><a href="cpp-thread-mutex.html"><span class="kw2154">std::<span class="me2">mutex</span></span></a><span class="sy1">&gt;</span> lk<span class="br0">(</span>m<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> str <span class="sy1">&lt;&lt;</span> <span class="st0">&#39; &#39;</span> <span class="sy1">&lt;&lt;</span> i <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">void</span> bar<span class="br0">(</span><span class="kw4">const</span> <a href="cpp-string-basic_string.html"><span class="kw1230">std::<span class="me2">string</span></span></a><span class="sy3">&amp;</span> str<span class="br0">)</span> <span class="br0">{</span>
<a href="cpp-thread-lock_guard.html"><span class="kw2166">std::<span class="me2">lock_guard</span></span></a><span class="sy1">&lt;</span><a href="cpp-thread-mutex.html"><span class="kw2154">std::<span class="me2">mutex</span></span></a><span class="sy1">&gt;</span> lk<span class="br0">(</span>m<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> str <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> operator<span class="br0">(</span><span class="br0">)</span><span class="br0">(</span><span class="kw4">int</span> i<span class="br0">)</span> <span class="br0">{</span>
<a href="cpp-thread-lock_guard.html"><span class="kw2166">std::<span class="me2">lock_guard</span></span></a><span class="sy1">&lt;</span><a href="cpp-thread-mutex.html"><span class="kw2154">std::<span class="me2">mutex</span></span></a><span class="sy1">&gt;</span> lk<span class="br0">(</span>m<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> i <span class="sy1">&lt;&lt;</span> <span class="st0">&#39;<span class="es1">\n</span>&#39;</span><span class="sy4">;</span>
<span class="kw1">return</span> i <span class="sy2">+</span> <span class="nu0">10</span><span class="sy4">;</span>
<span class="br0">}</span>
<span class="br0">}</span><span class="sy4">;</span>
<span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">typename</span> RandomIt<span class="sy1">&gt;</span>
<span class="kw4">int</span> parallel_sum<span class="br0">(</span>RandomIt beg, RandomIt end<span class="br0">)</span>
<span class="br0">{</span>
<span class="kw4">auto</span> len <span class="sy1">=</span> end <span class="sy2">-</span> beg<span class="sy4">;</span>
<span class="kw1">if</span> <span class="br0">(</span>len <span class="sy1">&lt;</span> <span class="nu0">1000</span><span class="br0">)</span>
<span class="kw1">return</span> <a href="cpp-algorithm-accumulate.html"><span class="kw1651">std::<span class="me2">accumulate</span></span></a><span class="br0">(</span>beg, end, <span class="nu0">0</span><span class="br0">)</span><span class="sy4">;</span>
RandomIt mid <span class="sy1">=</span> beg <span class="sy2">+</span> len<span class="sy2">/</span><span class="nu0">2</span><span class="sy4">;</span>
<span class="kw4">auto</span> handle <span class="sy1">=</span> std<span class="sy4">::</span><span class="me2">async</span><span class="br0">(</span><a href="cpp-thread-launch.html"><span class="kw2185">std::<span class="me2">launch</span><span class="sy4">::</span><span class="me2">async</span></span></a>,
parallel_sum<span class="sy1">&lt;</span>RandomIt<span class="sy1">&gt;</span>, mid, end<span class="br0">)</span><span class="sy4">;</span>
<span class="kw4">int</span> sum <span class="sy1">=</span> parallel_sum<span class="br0">(</span>beg, mid<span class="br0">)</span><span class="sy4">;</span>
<span class="kw1">return</span> sum <span class="sy2">+</span> handle.<span class="me1">get</span><span class="br0">(</span><span class="br0">)</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-container-vector.html"><span class="kw1269">std::<span class="me2">vector</span></span></a><span class="sy1">&lt;</span><span class="kw4">int</span><span class="sy1">&gt;</span> v<span class="br0">(</span><span class="nu0">10000</span>, <span class="nu0">1</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;The sum is &quot;</span> <span class="sy1">&lt;&lt;</span> parallel_sum<span class="br0">(</span>v.<span class="me1">begin</span><span class="br0">(</span><span class="br0">)</span>, v.<span class="me1">end</span><span class="br0">(</span><span class="br0">)</span><span class="br0">)</span> <span class="sy1">&lt;&lt;</span> <span class="st0">&#39;<span class="es1">\n</span>&#39;</span><span class="sy4">;</span>
X x<span class="sy4">;</span>
<span class="co1">// &#20197;&#40664;&#35748;&#31574;&#30053;&#35843;&#29992; x.foo(42, &quot;Hello&quot;) &#65306;</span>
<span class="co1">// &#21487;&#33021;&#21516;&#26102;&#25171;&#21360; &quot;Hello 42&quot; &#25110;&#24310;&#36831;&#25191;&#34892;</span>
<span class="kw4">auto</span> a1 <span class="sy1">=</span> std<span class="sy4">::</span><span class="me2">async</span><span class="br0">(</span><span class="sy3">&amp;</span>X<span class="sy4">::</span><span class="me2">foo</span>, <span class="sy3">&amp;</span>x, <span class="nu0">42</span>, <span class="st0">&quot;Hello&quot;</span><span class="br0">)</span><span class="sy4">;</span>
<span class="co1">// &#20197; deferred &#31574;&#30053;&#35843;&#29992; x.bar(&quot;world!&quot;)</span>
<span class="co1">// &#35843;&#29992; a2.get() &#25110; a2.wait() &#26102;&#25171;&#21360; &quot;world!&quot;</span>
<span class="kw4">auto</span> a2 <span class="sy1">=</span> std<span class="sy4">::</span><span class="me2">async</span><span class="br0">(</span><a href="cpp-thread-launch.html"><span class="kw2186">std::<span class="me2">launch</span><span class="sy4">::</span><span class="me2">deferred</span></span></a>, <span class="sy3">&amp;</span>X<span class="sy4">::</span><span class="me2">bar</span>, x, <span class="st0">&quot;world!&quot;</span><span class="br0">)</span><span class="sy4">;</span>
<span class="co1">// &#20197; async &#31574;&#30053;&#35843;&#29992; X()(43) &#65306;</span>
<span class="co1">// &#21516;&#26102;&#25171;&#21360; &quot;43&quot;</span>
<span class="kw4">auto</span> a3 <span class="sy1">=</span> std<span class="sy4">::</span><span class="me2">async</span><span class="br0">(</span><a href="cpp-thread-launch.html"><span class="kw2185">std::<span class="me2">launch</span><span class="sy4">::</span><span class="me2">async</span></span></a>, X<span class="br0">(</span><span class="br0">)</span>, <span class="nu0">43</span><span class="br0">)</span><span class="sy4">;</span>
a2.<span class="me1">wait</span><span class="br0">(</span><span class="br0">)</span><span class="sy4">;</span> <span class="co1">// &#25171;&#21360; &quot;world!&quot;</span>
<a href="cpp-io-cout.html"><span class="kw1758">std::<span class="me2">cout</span></span></a> <span class="sy1">&lt;&lt;</span> a3.<span class="me1">get</span><span class="br0">(</span><span class="br0">)</span> <span class="sy1">&lt;&lt;</span> <span class="st0">&#39;<span class="es1">\n</span>&#39;</span><span class="sy4">;</span> <span class="co1">// &#25171;&#21360; &quot;53&quot;</span>
<span class="br0">}</span> <span class="co1">// &#33509; a1 &#22312;&#27492;&#28857;&#26410;&#23436;&#25104;&#65292;&#21017; a1 &#30340;&#26512;&#26500;&#20989;&#25968;&#22312;&#27492;&#25171;&#21360; &quot;Hello 42&quot;</span></pre></div>
</div>
<p>&#21487;&#33021;&#30340;&#36755;&#20986;&#65306;</p>
<div dir="ltr" class="mw-geshi" style="text-align: left;">
<div class="text source-text">
<pre class="de1">The sum is 10000
43
world!
53
Hello 42</pre></div>
</div>
</div>
<h3><span class="mw-headline" id=".E7.BC.BA.E9.99.B7.E6.8A.A5.E5.91.8A">&#32570;&#38519;&#25253;&#21578;</span></h3>
<p>&#19979;&#21015;&#26356;&#25913;&#34892;&#20026;&#30340;&#32570;&#38519;&#25253;&#21578;&#36861;&#28335;&#22320;&#24212;&#29992;&#20110;&#20197;&#21069;&#20986;&#29256;&#30340; C++ &#26631;&#20934;&#12290;</p>
<table class="dsctable" style="font-size:0.8em">
<tr>
<th>DR</th>
<th>&#24212;&#29992;&#20110;</th>
<th>&#20986;&#29256;&#26102;&#30340;&#34892;&#20026;</th>
<th>&#27491;&#30830;&#34892;&#20026;</th>
</tr>
<tr>
<td><a rel="nofollow" class="external text" href="https://cplusplus.github.io/LWG/issue2021">LWG 2021</a></td>
<td>C++11</td>
<td>&#36820;&#22238;&#31867;&#22411;&#19981;&#27491;&#30830;&#65292; deferred &#30340;&#24773;&#20917;&#19979;&#21442;&#25968;&#30340;&#20540;&#31867;&#21035;&#19981;&#26126;</td>
<td>&#26356;&#27491;&#36820;&#22238;&#31867;&#22411;&#65292;&#26126;&#30830;&#20351;&#29992;&#21491;&#20540;</td>
</tr>
<tr>
<td><a rel="nofollow" class="external text" href="https://cplusplus.github.io/LWG/issue2120">LWG 2120</a></td>
<td>C++11</td>
<td>&#26410;&#35774;&#32622;&#26631;&#20934;&#25110;&#23454;&#29616;&#23450;&#20041;&#30340;&#31574;&#30053;&#30340;&#24773;&#20917;&#19979;&#34892;&#20026;&#19981;&#26126;</td>
<td>&#34892;&#20026;&#26410;&#23450;&#20041;</td>
</tr>
<tr>
<td><a rel="nofollow" class="external text" href="https://cplusplus.github.io/LWG/issue3476">LWG 3476</a></td>
<td>C++11</td>
<td>&#35201;&#27714; <code>Function</code> &#19982; <code>Args...</code> &#20026;<a href="cpp-named_req-MoveConstructible.html"><span style="font-style:italic">&#21487;&#31227;&#21160;&#26500;&#36896;</span> <span style="font-family: Georgia, &#39;DejaVu Serif&#39;, serif; font-style:italic">(MoveConstructible)</span></a> &#32780;&#26080;&#25351;&#23450;&#30340;&#39069;&#22806;&#31227;&#21160;&#26500;&#36896;</td>
<td>&#31227;&#38500;&#35201;&#27714;</td>
</tr>
</table>
</div>
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