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<h1 id="firstHeading" class="firstHeading"><span style="font-size:0.7em; line-height:130%">std::valarray&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-numeric.html">numeric</a>&lrm; | <a href="cpp-numeric-valarray.html">valarray</a></span></div>
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<div><span class="mw-geshi cpp source-cpp">valarray<span class="sy1">&lt;</span>T<span class="sy1">&gt;</span><span class="sy3">&amp;</span> operator<span class="sy1">=</span><span class="br0">(</span> <span class="kw4">const</span> valarray<span class="sy1">&lt;</span>T<span class="sy1">&gt;</span><span class="sy3">&amp;</span> other <span class="br0">)</span><span class="sy4">;</span></span></div>
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<div><span class="mw-geshi cpp source-cpp">valarray<span class="sy1">&lt;</span>T<span class="sy1">&gt;</span><span class="sy3">&amp;</span> operator<span class="sy1">=</span><span class="br0">(</span> valarray<span class="sy1">&lt;</span>T<span class="sy1">&gt;</span><span class="sy3">&amp;&amp;</span> other <span class="br0">)</span> <span class="kw1">noexcept</span><span class="sy4">;</span></span></div>
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<td><span class="t-mark-rev t-since-cxx11">(C++11 &#36215;)</span></td>
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<div><span class="mw-geshi cpp source-cpp">valarray<span class="sy1">&lt;</span>T<span class="sy1">&gt;</span><span class="sy3">&amp;</span> operator<span class="sy1">=</span><span class="br0">(</span> <span class="kw4">const</span> T<span class="sy3">&amp;</span> val <span class="br0">)</span><span class="sy4">;</span></span></div>
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<div><span class="mw-geshi cpp source-cpp">valarray<span class="sy1">&lt;</span>T<span class="sy1">&gt;</span><span class="sy3">&amp;</span> operator<span class="sy1">=</span><span class="br0">(</span> <span class="kw4">const</span> <a href="cpp-numeric-valarray-slice_array.html"><span class="kw1476">std::<span class="me2">slice_array</span></span></a><span class="sy1">&lt;</span>T<span class="sy1">&gt;</span><span class="sy3">&amp;</span> other<span class="br0">)</span><span class="sy4">;</span></span></div>
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<div><span class="mw-geshi cpp source-cpp">valarray<span class="sy1">&lt;</span>T<span class="sy1">&gt;</span><span class="sy3">&amp;</span> operator<span class="sy1">=</span><span class="br0">(</span> <span class="kw4">const</span> <a href="cpp-numeric-valarray-gslice_array.html"><span class="kw1477">std::<span class="me2">gslice_array</span></span></a><span class="sy1">&lt;</span>T<span class="sy1">&gt;</span><span class="sy3">&amp;</span> other<span class="br0">)</span><span class="sy4">;</span></span></div>
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<div><span class="mw-geshi cpp source-cpp">valarray<span class="sy1">&lt;</span>T<span class="sy1">&gt;</span><span class="sy3">&amp;</span> operator<span class="sy1">=</span><span class="br0">(</span> <span class="kw4">const</span> <a href="cpp-numeric-valarray-mask_array.html"><span class="kw1478">std::<span class="me2">mask_array</span></span></a><span class="sy1">&lt;</span>T<span class="sy1">&gt;</span><span class="sy3">&amp;</span> other <span class="br0">)</span><span class="sy4">;</span></span></div>
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<div><span class="mw-geshi cpp source-cpp">valarray<span class="sy1">&lt;</span>T<span class="sy1">&gt;</span><span class="sy3">&amp;</span> operator<span class="sy1">=</span><span class="br0">(</span> <span class="kw4">const</span> <a href="cpp-numeric-valarray-indirect_array.html"><span class="kw1479">std::<span class="me2">indirect_array</span></span></a><span class="sy1">&lt;</span>T<span class="sy1">&gt;</span><span class="sy3">&amp;</span> other <span class="br0">)</span><span class="sy4">;</span></span></div>
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<div><span class="mw-geshi cpp source-cpp">valarray<span class="sy1">&lt;</span>T<span class="sy1">&gt;</span><span class="sy3">&amp;</span> operator<span class="sy1">=</span><span class="br0">(</span> <a href="cpp-utility-initializer_list.html"><span class="kw960">std::<span class="me2">initializer_list</span></span></a><span class="sy1">&lt;</span>T<span class="sy1">&gt;</span> il <span class="br0">)</span><span class="sy4">;</span></span></div>
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<td>(8)</td>
<td><span class="t-mark-rev t-since-cxx11">(C++11 &#36215;)</span></td>
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<p>&#26367;&#25442;&#25968;&#20540;&#25968;&#32452;&#30340;&#20869;&#23481;&#12290;</p>
<div class="t-li1"><span class="t-li">1)</span> &#22797;&#21046;&#36171;&#20540;&#36816;&#31639;&#31526;&#12290; <code>*this</code> &#30340;&#27599;&#20010;&#20803;&#32032;&#34987;&#36171; <code>other</code> &#30340;&#20540;&#12290;&#33509; <code>other</code> &#30340;&#38271;&#24230;&#19981;&#31561;&#20110; <code>*this</code> &#30340;&#38271;&#24230;&#65292;&#21017;<span class="t-rev-inl t-until-cxx11"><span>&#34892;&#20026;&#26410;&#23450;&#20041;</span> <span><span class="t-mark-rev t-until-cxx11">(C++11 &#21069;)</span></span></span><span class="t-rev-inl t-since-cxx11"><span>&#39318;&#20808;&#22914;&#36890;&#36807; <span class="t-c"><span class="mw-geshi cpp source-cpp">resize<span class="br0">(</span>other.<span class="me1">size</span><span class="br0">(</span><span class="br0">)</span><span class="br0">)</span></span></span> &#37325;&#32622;&#22823;&#23567;</span> <span><span class="t-mark-rev t-since-cxx11">(C++11 &#36215;)</span></span></span>&#12290;</div>
<div class="t-li1"><span class="t-li">2)</span> &#31227;&#21160;&#36171;&#20540;&#36816;&#31639;&#31526;&#12290;&#20197; <code>other</code> &#30340;&#20869;&#23481;&#26367;&#25442; <code>*this</code> &#30340;&#20869;&#23481;&#12290;&#27492;&#25805;&#20316;&#21518; <code>other</code> &#30340;&#20869;&#23481;&#26410;&#25351;&#23450;&#12290;&#33509; T &#25317;&#26377;&#38750;&#24179;&#20961;&#26500;&#36896;&#20989;&#25968;&#21017;&#27492;&#25805;&#20316;&#30340;&#22797;&#26434;&#24230;&#21487;&#33021;&#20026;&#32447;&#24615;&#65292;&#20294;&#21542;&#21017;&#36890;&#24120;&#20026;&#24120;&#25968;&#12290;</div>
<div class="t-li1"><span class="t-li">3)</span> &#20197;f <code>val</code> &#30340;&#21103;&#26412;&#26367;&#25442; <code>*this</code> &#20013;&#30340;&#27599;&#20010;&#20540;&#12290;</div>
<div class="t-li1"><span class="t-li">4-7)</span> &#20197;&#27867;&#22411;&#21270;&#19979;&#26631;&#36816;&#31639;&#30340;&#32467;&#26524;&#26367;&#25442; <code>*this</code> &#30340;&#20869;&#23481;&#12290;&#33509;&#21442;&#25968;&#30340;&#38271;&#24230;&#19981;&#31561;&#20110; <code>*this</code> &#30340;&#38271;&#24230;&#65292;&#25110;&#33509;&#20219;&#20309;&#24038;&#20391;&#30340;&#20540;&#20381;&#36182;&#21491;&#20391;&#30340;&#20540;&#65288;&#20363;&#22914; <span class="t-c"><span class="mw-geshi cpp source-cpp">v<span class="sy1">=</span>v<span class="br0">[</span>v<span class="sy1">&gt;</span><span class="nu0">2</span><span class="br0">]</span></span></span> &#65289;&#65292;&#21017;&#34892;&#20026;&#26410;&#23450;&#20041;&#12290;</div>
<div class="t-li1"><span class="t-li">8)</span> &#36171;&#20540; <code>il</code> &#30340;&#20869;&#23481;&#12290;&#31561;&#20215;&#20110; <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="sy2">*</span>this <span class="sy1">=</span> valarray<span class="br0">(</span>il<span class="br0">)</span></span></span> &#12290;</div>
<h3><span class="mw-headline" id=".E5.8F.82.E6.95.B0">&#21442;&#25968;</span></h3>
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<td>other</td>
<td>-</td>
<td>&#35201;&#36171;&#20540;&#30340;&#21478;&#19968;&#25968;&#20540;&#25968;&#32452;&#65288;&#25110;&#25513;&#30721;&#65289;</td>
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<td>val</td>
<td>-</td>
<td>&#29992;&#20197;&#21021;&#22987;&#21270;&#27599;&#20010;&#20803;&#32032;&#30340;&#20540;</td>
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<td>il</td>
<td>-</td>
<td>&#35201;&#36171;&#20540;&#30340; initializer_list</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="sy2">*</span>this</span></span></p>
<h3><span class="mw-headline" id=".E5.BC.82.E5.B8.B8">&#24322;&#24120;</span></h3>
<div class="t-li1"><span class="t-li">1, 3-8)</span> &#21487;&#33021;&#25243;&#20986;&#23454;&#29616;&#23450;&#20041;&#30340;&#24322;&#24120;&#12290;</div>
<h3><span class="mw-headline" id=".E7.A4.BA.E4.BE.8B">&#31034;&#20363;</span></h3>
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<div class="cpp source-cpp">
<pre class="de1"><span class="co2">#include &lt;iomanip&gt;</span>
<span class="co2">#include &lt;iostream&gt;</span>
<span class="co2">#include &lt;valarray&gt;</span>
<span class="kw4">void</span> print<span class="br0">(</span><span class="kw4">const</span> <span class="kw4">char</span><span class="sy2">*</span> rem, <span class="kw4">const</span> <a href="cpp-numeric-valarray.html"><span class="kw1473">std::<span class="me2">valarray</span></span></a><span class="sy1">&lt;</span><span class="kw4">int</span><span class="sy1">&gt;</span><span class="sy3">&amp;</span> v<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> <a href="cpp-io-manip-left.html"><span class="kw1779">std::<span class="me2">left</span></span></a> <span class="sy1">&lt;&lt;</span> <a href="cpp-io-manip-setw.html"><span class="kw1797">std::<span class="me2">setw</span></span></a><span class="br0">(</span><span class="nu0">36</span><span class="br0">)</span> <span class="sy1">&lt;&lt;</span> rem <span class="sy1">&lt;&lt;</span> <a href="cpp-io-manip-left.html"><span class="kw1780">std::<span class="me2">right</span></span></a><span class="sy4">;</span>
<span class="kw1">for</span> <span class="br0">(</span><span class="kw4">int</span> n<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> <a href="cpp-io-manip-setw.html"><span class="kw1797">std::<span class="me2">setw</span></span></a><span class="br0">(</span><span class="nu0">3</span><span class="br0">)</span> <span class="sy1">&lt;&lt;</span> n<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-numeric-valarray.html"><span class="kw1473">std::<span class="me2">valarray</span></span></a><span class="sy1">&lt;</span><span class="kw4">int</span><span class="sy1">&gt;</span> v1<span class="br0">(</span><span class="nu0">3</span><span class="br0">)</span><span class="sy4">;</span>
v1 <span class="sy1">=</span> <span class="sy2">-</span><span class="nu0">1</span><span class="sy4">;</span> <span class="co1">// (3) &#20174;&#26631;&#37327;</span>
print<span class="br0">(</span><span class="st0">&quot;assigned from scalar: &quot;</span>, v1<span class="br0">)</span><span class="sy4">;</span>
v1 <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="nu0">6</span><span class="br0">}</span><span class="sy4">;</span> <span class="co1">// (8) &#65306;&#20174;&#19981;&#21516;&#22823;&#23567;&#30340;&#21021;&#22987;&#21270;&#22120;&#21015;&#34920;</span>
print<span class="br0">(</span><span class="st0">&quot;assigned from initializer_list:&quot;</span>, v1<span class="br0">)</span><span class="sy4">;</span>
<a href="cpp-numeric-valarray.html"><span class="kw1473">std::<span class="me2">valarray</span></span></a><span class="sy1">&lt;</span><span class="kw4">int</span><span class="sy1">&gt;</span> v2<span class="br0">(</span><span class="nu0">3</span><span class="br0">)</span><span class="sy4">;</span>
v2 <span class="sy1">=</span> v1<span class="br0">[</span><a href="cpp-numeric-valarray-slice.html"><span class="kw1474">std::<span class="me2">slice</span></span></a><span class="br0">(</span><span class="nu0">0</span>,<span class="nu0">3</span>,<span class="nu0">2</span><span class="br0">)</span><span class="br0">]</span><span class="sy4">;</span> <span class="co1">// (4) &#65306;&#20174;&#20999;&#29255;&#25968;&#32452;</span>
print<span class="br0">(</span><span class="st0">&quot;every 2nd element starting at pos 0:&quot;</span>, v2<span class="br0">)</span><span class="sy4">;</span>
v2 <span class="sy1">=</span> v1<span class="br0">[</span>v1 <span class="sy2">%</span> <span class="nu0">2</span> <span class="sy1">==</span> <span class="nu0">0</span><span class="br0">]</span><span class="sy4">;</span> <span class="co1">// (6) &#65306;&#20174;&#25513;&#30721;&#25968;&#32452;</span>
print<span class="br0">(</span><span class="st0">&quot;values that are even:&quot;</span>, v2<span class="br0">)</span><span class="sy4">;</span>
<a href="cpp-numeric-valarray.html"><span class="kw1473">std::<span class="me2">valarray</span></span></a><span class="sy1">&lt;</span><a href="cpp-types-size_t.html"><span class="kw100">std::<span class="me2">size_t</span></span></a><span class="sy1">&gt;</span> idx <span class="sy1">=</span> <span class="br0">{</span><span class="nu0">0</span>,<span class="nu0">1</span>,<span class="nu0">2</span>,<span class="nu0">4</span><span class="br0">}</span><span class="sy4">;</span> <span class="co1">// &#19979;&#26631;&#25968;&#32452;</span>
v2.<span class="me1">resize</span><span class="br0">(</span><span class="nu0">4</span><span class="br0">)</span><span class="sy4">;</span> <span class="co1">// &#20174;&#29983;&#25104;&#19979;&#26631;&#36171;&#20540;&#26102;&#22823;&#23567;&#24517;&#39035;&#21305;&#37197;</span>
v2 <span class="sy1">=</span> v1<span class="br0">[</span>idx<span class="br0">]</span><span class="sy4">;</span> <span class="co1">// (7) &#65306;&#20174;&#38388;&#25509;&#25968;&#32452;</span>
print<span class="br0">(</span><span class="st0">&quot;values at positions 0, 1, 2, 4:&quot;</span>, v2<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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<div class="text source-text">
<pre class="de1">assigned from scalar: -1 -1 -1
assigned from initializer_list: 1 2 3 4 5 6
every 2nd element starting at pos 0: 1 3 5
values that are even: 2 4 6
values at positions 0, 1, 2, 4: 1 2 3 5</pre></div>
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