284 lines
28 KiB
HTML
284 lines
28 KiB
HTML
<!DOCTYPE html>
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<html lang="zh" dir="ltr" class="client-nojs" xmlns="http://www.w3.org/1999/xhtml" xml:lang="zh">
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<title>std::pow, std::powf, std::powl</title>
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<body class="mediawiki ltr sitedir-ltr ns-0 ns-subject page-cpp_numeric_math_pow skin-cppreference2 action-view cpp-navbar">
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<h1 id="firstHeading" class="firstHeading"><span style="font-size:0.7em; line-height:130%">std::</span>pow, <span style="font-size:0.7em; line-height:130%">std::</span>powf, <span style="font-size:0.7em; line-height:130%">std::</span>powl</h1>
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<div id="contentSub"><span class="subpages">< <a href="cpp.html">cpp</a>‎ | <a href="cpp-numeric.html">numeric</a>‎ | <a href="cpp-numeric-math.html">math</a></span></div>
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<div id="mw-content-text" lang="zh" dir="ltr" class="mw-content-ltr" xml:lang="zh">
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<table class="t-dcl-begin">
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<div>定义于头文件 <code><a href="cpp-header-cmath.html"><cmath></a></code></div>
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</td>
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<td></td>
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<td></td>
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<td rowspan="142">(1)</td>
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<td></td>
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<div><span class="mw-geshi cpp source-cpp"><span class="kw4">float</span> pow <span class="br0">(</span> <span class="kw4">float</span> base, <span class="kw4">float</span> exp <span class="br0">)</span><span class="sy4">;</span></span></div>
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<td class="t-dcl-nopad"></td>
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<div><span class="mw-geshi cpp source-cpp"><span class="kw4">float</span> powf<span class="br0">(</span> <span class="kw4">float</span> base, <span class="kw4">float</span> exp <span class="br0">)</span><span class="sy4">;</span></span></div>
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</td>
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<td class="t-dcl-nopad"></td>
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<td><span class="t-mark-rev t-since-cxx11">(C++11 起)</span></td>
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<div><span class="mw-geshi cpp source-cpp"><span class="kw4">double</span> pow <span class="br0">(</span> <span class="kw4">double</span> base, <span class="kw4">double</span> exp <span class="br0">)</span><span class="sy4">;</span></span></div>
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<td>(2)</td>
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<td class="t-dcl-nopad"></td>
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<td></td>
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<td rowspan="142">(3)</td>
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<div><span class="mw-geshi cpp source-cpp"><span class="kw4">long</span> <span class="kw4">double</span> pow <span class="br0">(</span> <span class="kw4">long</span> <span class="kw4">double</span> base, <span class="kw4">long</span> <span class="kw4">double</span> exp <span class="br0">)</span><span class="sy4">;</span></span></div>
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<td class="t-dcl-nopad"></td>
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<div><span class="mw-geshi cpp source-cpp"><span class="kw4">long</span> <span class="kw4">double</span> powl<span class="br0">(</span> <span class="kw4">long</span> <span class="kw4">double</span> base, <span class="kw4">long</span> <span class="kw4">double</span> exp <span class="br0">)</span><span class="sy4">;</span></span></div>
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<td><span class="t-mark-rev t-since-cxx11">(C++11 起)</span></td>
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<div><span class="mw-geshi cpp source-cpp"><span class="kw4">float</span> pow <span class="br0">(</span> <span class="kw4">float</span> base, <span class="kw4">int</span> iexp <span class="br0">)</span><span class="sy4">;</span></span></div>
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</td>
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<td>(4)</td>
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<td><span class="t-mark-rev t-until-cxx11">(C++11 前)</span></td>
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<div><span class="mw-geshi cpp source-cpp"><span class="kw4">double</span> pow <span class="br0">(</span> <span class="kw4">double</span> base, <span class="kw4">int</span> iexp <span class="br0">)</span><span class="sy4">;</span></span></div>
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</td>
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<td>(5)</td>
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<td><span class="t-mark-rev t-until-cxx11">(C++11 前)</span></td>
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</tr>
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<tr class="t-dcl t-until-cxx11">
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<div><span class="mw-geshi cpp source-cpp"><span class="kw4">long</span> <span class="kw4">double</span> pow <span class="br0">(</span> <span class="kw4">long</span> <span class="kw4">double</span> base, <span class="kw4">int</span> iexp <span class="br0">)</span><span class="sy4">;</span></span></div>
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</td>
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<td>(6)</td>
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<td><span class="t-mark-rev t-until-cxx11">(C++11 前)</span></td>
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<tr class="t-dcl t-since-cxx11">
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<div><span class="mw-geshi cpp source-cpp">Promoted pow <span class="br0">(</span> Arithmetic1 base, Arithmetic2 exp <span class="br0">)</span><span class="sy4">;</span></span></div>
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</td>
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<td>(7)</td>
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<td><span class="t-mark-rev t-since-cxx11">(C++11 起)</span></td>
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</tr>
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<div class="t-li1"><span class="t-li">1-6)</span> 计算 <code>base</code> 的 <code>exp</code> 或 <code>iexp</code> 次幂。</div>
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<div class="t-li1"><span class="t-li">7)</span> 1-3) 所不覆盖的所有算术类型组合的重载集或函数模板。若任何参数拥有<a href="cpp-types-is_integral.html">整数类型</a>，则将它转型为 <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="kw4">double</span></span></span> 。若任何参数为 <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="kw4">long</span> <span class="kw4">double</span></span></span> ，则返回类型 <code>Promoted</code> 亦为 <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="kw4">long</span> <span class="kw4">double</span></span></span> ，否则返回类型始终为 <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="kw4">double</span></span></span> 。</div>
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<h3><span class="mw-headline" id=".E5.8F.82.E6.95.B0">参数</span></h3>
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<table class="t-par-begin">
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<tr class="t-par">
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<td>base</td>
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<td>-</td>
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<td>作为底数的浮点或<a href="cpp-types-is_integral.html">整数类型</a>值</td>
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</tr>
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<tr class="t-par">
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<td>exp</td>
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<td>-</td>
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<td>作为指数的浮点或<a href="cpp-types-is_integral.html">整数类型</a>值</td>
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</tr>
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<tr class="t-par">
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<td>iexp</td>
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<td>-</td>
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<td>整数值指数</td>
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</tr>
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</table>
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<h3><span class="mw-headline" id=".E8.BF.94.E5.9B.9E.E5.80.BC">返回值</span></h3>
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<p>若不出现错误，则返回 <code>base</code> 的 <code>exp</code> 次幂（ <span class="texhtml" style="white-space: nowrap;">base<span class="t-su">exp<br /></span></span> ）。</p>
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<p>若出现定义域错误，则返回实现定义值（支持的平台上为 NaN ）。</p>
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<p>若出现极点错误或上溢所致的值域错误，则返回 <code>±HUGE_VAL</code> 、 <code>±HUGE_VALF</code> 或 <code>±HUGE_VALL</code> 。</p>
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<p>若出现下溢所致的值域错误，则返回（舍入后的）正确结果。</p>
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<h3><span class="mw-headline" id=".E9.94.99.E8.AF.AF.E5.A4.84.E7.90.86">错误处理</span></h3>
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<p>报告 <span class="t-lc"><a href="cpp-numeric-math-math_errhandling.html">math_errhandling</a></span> 中指定的错误。</p>
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<p>若 <code>base</code> 有限且为负，且 <code>exp</code> 有限且为非整数，则出现定义域错误，并可能出现值域错误。</p>
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<p>若 <code>base</code> 为零且 <code>exp</code> 为零，则可能出现定义域错误。</p>
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<p>若 <code>base</code> 为零且 <code>exp</code> 为负，则可能出现定义域错误或极点错误。</p>
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<p>若实现支持 IEEE 浮点算术（ IEC 60559 ），则</p>
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<ul>
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<li><span class="t-c"><span class="mw-geshi cpp source-cpp">pow<span class="br0">(</span><span class="sy2">+</span><span class="nu0">0</span>, exp<span class="br0">)</span></span></span> ，其中 <code>exp</code> 为负奇数，返回 <code>+∞</code> 并引发 <span class="t-lc"><a href="cpp-numeric-fenv-FE_exceptions.html">FE_DIVBYZERO</a></span></li>
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<li><span class="t-c"><span class="mw-geshi cpp source-cpp">pow<span class="br0">(</span><span class="sy2">-</span><span class="nu0">0</span>, exp<span class="br0">)</span></span></span> ，其中 <code>exp</code> 为负奇数，返回 <code>-∞</code> 并引发 <span class="t-lc"><a href="cpp-numeric-fenv-FE_exceptions.html">FE_DIVBYZERO</a></span></li>
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<li><span class="t-c"><span class="mw-geshi cpp source-cpp">pow<span class="br0">(</span>±<span class="nu0">0</span>, exp<span class="br0">)</span></span></span> ，其中 <code>exp</code> 为有限负数，且为偶数或非整数，则返回 +∞ 并引发 <span class="t-lc"><a href="cpp-numeric-fenv-FE_exceptions.html">FE_DIVBYZERO</a></span></li>
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<li><span class="t-c"><span class="mw-geshi cpp source-cpp">pow<span class="br0">(</span>±<span class="nu0">0</span>, <span class="sy2">-</span>∞<span class="br0">)</span></span></span> 返回 +∞ 并可能引发 <span class="t-lc"><a href="cpp-numeric-fenv-FE_exceptions.html">FE_DIVBYZERO</a></span></li>
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<li><span class="t-c"><span class="mw-geshi cpp source-cpp">pow<span class="br0">(</span><span class="sy2">+</span><span class="nu0">0</span>, exp<span class="br0">)</span></span></span> ，其中 <code>exp</code> 为正奇数，返回 +0</li>
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<li><span class="t-c"><span class="mw-geshi cpp source-cpp">pow<span class="br0">(</span><span class="sy2">-</span><span class="nu0">0</span>, exp<span class="br0">)</span></span></span> ，其中 <code>exp</code> 为正奇数，返回 -0</li>
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<li><span class="t-c"><span class="mw-geshi cpp source-cpp">pow<span class="br0">(</span>±<span class="nu0">0</span>, exp<span class="br0">)</span></span></span> ，其中 <code>exp</code> 为正非整数或正偶数，返回 +0</li>
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<li><span class="t-c"><span class="mw-geshi cpp source-cpp">pow<span class="br0">(</span><span class="sy2">-</span><span class="nu0">1</span>, ±∞<span class="br0">)</span></span></span> 返回 <code>1</code></li>
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<li><span class="t-c"><span class="mw-geshi cpp source-cpp">pow<span class="br0">(</span><span class="sy2">+</span><span class="nu0">1</span>, exp<span class="br0">)</span></span></span> 对于任何 <code>exp</code> 返回 <code>1</code> ，即使 <code>exp</code> 为 <code>NaN</code></li>
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<li><span class="t-c"><span class="mw-geshi cpp source-cpp">pow<span class="br0">(</span>base, ±<span class="nu0">0</span><span class="br0">)</span></span></span> 对于任何 <code>base</code> 返回 <code>1</code> ，即使 <code>base</code> 为 <code>NaN</code></li>
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<li><span class="t-c"><span class="mw-geshi cpp source-cpp">pow<span class="br0">(</span>base, exp<span class="br0">)</span></span></span> 返回 <code>NaN</code> 并引发 <span class="t-lc"><a href="cpp-numeric-fenv-FE_exceptions.html">FE_INVALID</a></span> ，若 <code>base</code> 为有限负数且 <code>exp</code> 为有限非整数。</li>
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<li><span class="t-c"><span class="mw-geshi cpp source-cpp">pow<span class="br0">(</span>base, <span class="sy2">-</span>∞<span class="br0">)</span></span></span> 对任何 <code>|base|<1</code> 返回 +∞</li>
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<li><span class="t-c"><span class="mw-geshi cpp source-cpp">pow<span class="br0">(</span>base, <span class="sy2">-</span>∞<span class="br0">)</span></span></span> 对任何 <code>|base|>1</code> 返回 +0</li>
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<li><span class="t-c"><span class="mw-geshi cpp source-cpp">pow<span class="br0">(</span>base, <span class="sy2">+</span>∞<span class="br0">)</span></span></span> 对任何 <code>|base|<1</code> 返回 +0</li>
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<li><span class="t-c"><span class="mw-geshi cpp source-cpp">pow<span class="br0">(</span>base, <span class="sy2">+</span>∞<span class="br0">)</span></span></span> 对任何 <code>|base|>1</code> 返回 +∞</li>
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<li><span class="t-c"><span class="mw-geshi cpp source-cpp">pow<span class="br0">(</span><span class="sy2">-</span>∞, exp<span class="br0">)</span></span></span> 返回 -0 ，若 <code>exp</code> 为负奇整数</li>
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<li><span class="t-c"><span class="mw-geshi cpp source-cpp">pow<span class="br0">(</span><span class="sy2">-</span>∞, exp<span class="br0">)</span></span></span> 返回 +0 ，若 <code>exp</code> 为负非整数或负偶数</li>
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<li><span class="t-c"><span class="mw-geshi cpp source-cpp">pow<span class="br0">(</span><span class="sy2">-</span>∞, exp<span class="br0">)</span></span></span> 返回 -∞ ，若 <code>exp</code> 为正奇整数</li>
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<li><span class="t-c"><span class="mw-geshi cpp source-cpp">pow<span class="br0">(</span><span class="sy2">-</span>∞, exp<span class="br0">)</span></span></span> 返回 +∞ ，若 <code>exp</code> 为正非整数或正偶数</li>
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<li><span class="t-c"><span class="mw-geshi cpp source-cpp">pow<span class="br0">(</span><span class="sy2">+</span>∞, exp<span class="br0">)</span></span></span> 对任何 <code>exp</code> 返回 +0</li>
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<li><span class="t-c"><span class="mw-geshi cpp source-cpp">pow<span class="br0">(</span><span class="sy2">+</span>∞, exp<span class="br0">)</span></span></span> 对任何 <code>exp</code> 返回 +∞</li>
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<li>除了指定于上处，若任何参数为 NaN ，则返回 NaN</li>
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</ul>
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<h3><span class="mw-headline" id=".E6.B3.A8.E6.84.8F">注意</span></h3>
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<p><code>pow(float, int)</code> 在 C++11 前返回 <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="kw4">float</span></span></span> （由重载 4 ）但从 C++11 起返回 <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="kw4">double</span></span></span> （由重载 7 ）。</p>
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<p>尽管 <code>std::pow</code> 不能获得负数的开方根， <code>exp</code> 为 1/3 的常用情况还提供了 <span class="t-lc"><a href="cpp-numeric-math-cbrt.html">std::cbrt</a></span> 。</p>
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<h3><span class="mw-headline" id=".E7.A4.BA.E4.BE.8B">示例</span></h3>
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<div class="t-example">
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<div class="t-example-live-link"></div>
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<div dir="ltr" class="mw-geshi" style="text-align: left;">
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<div class="cpp source-cpp">
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<pre class="de1"><span class="co2">#include <iostream></span>
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<span class="co2">#include <cmath></span>
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<span class="co2">#include <cerrno></span>
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<span class="co2">#include <cfenv></span>
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<span class="co2">#include <cstring></span>
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<span class="co2">#pragma STDC FENV_ACCESS ON</span>
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<span class="kw4">int</span> main<span class="br0">(</span><span class="br0">)</span>
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<span class="br0">{</span>
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<span class="co1">// 通常用法</span>
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<a href="cpp-io-cout.html"><span class="kw1757">std::<span class="me2">cout</span></span></a> <span class="sy1"><<</span> <span class="st0">"pow(2, 10) = "</span> <span class="sy1"><<</span> std<span class="sy4">::</span><span class="me2">pow</span><span class="br0">(</span><span class="nu0">2</span>,<span class="nu0">10</span><span class="br0">)</span> <span class="sy1"><<</span> <span class="st0">'<span class="es1">\n</span>'</span>
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<span class="sy1"><<</span> <span class="st0">"pow(2, 0.5) = "</span> <span class="sy1"><<</span> std<span class="sy4">::</span><span class="me2">pow</span><span class="br0">(</span><span class="nu0">2</span>,<span class="nu16">0.5</span><span class="br0">)</span> <span class="sy1"><<</span> <span class="st0">'<span class="es1">\n</span>'</span>
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<span class="sy1"><<</span> <span class="st0">"pow(-2, -3) = "</span> <span class="sy1"><<</span> std<span class="sy4">::</span><span class="me2">pow</span><span class="br0">(</span><span class="sy2">-</span><span class="nu0">2</span>,<span class="sy2">-</span><span class="nu0">3</span><span class="br0">)</span> <span class="sy1"><<</span> <span class="st0">'<span class="es1">\n</span>'</span><span class="sy4">;</span>
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<span class="co1">// 特殊值</span>
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<a href="cpp-io-cout.html"><span class="kw1757">std::<span class="me2">cout</span></span></a> <span class="sy1"><<</span> <span class="st0">"pow(-1, NAN) = "</span> <span class="sy1"><<</span> std<span class="sy4">::</span><span class="me2">pow</span><span class="br0">(</span><span class="sy2">-</span><span class="nu0">1</span>,<a href="cpp-numeric-math-NAN.html"><span class="kw1377">NAN</span></a><span class="br0">)</span> <span class="sy1"><<</span> <span class="st0">'<span class="es1">\n</span>'</span>
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<span class="sy1"><<</span> <span class="st0">"pow(+1, NAN) = "</span> <span class="sy1"><<</span> std<span class="sy4">::</span><span class="me2">pow</span><span class="br0">(</span><span class="sy2">+</span><span class="nu0">1</span>,<a href="cpp-numeric-math-NAN.html"><span class="kw1377">NAN</span></a><span class="br0">)</span> <span class="sy1"><<</span> <span class="st0">'<span class="es1">\n</span>'</span>
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<span class="sy1"><<</span> <span class="st0">"pow(INFINITY, 2) = "</span> <span class="sy1"><<</span> std<span class="sy4">::</span><span class="me2">pow</span><span class="br0">(</span><a href="cpp-numeric-math-INFINITY.html"><span class="kw1376">INFINITY</span></a>, <span class="nu0">2</span><span class="br0">)</span> <span class="sy1"><<</span> <span class="st0">'<span class="es1">\n</span>'</span>
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<span class="sy1"><<</span> <span class="st0">"pow(INFINITY, -1) = "</span> <span class="sy1"><<</span> std<span class="sy4">::</span><span class="me2">pow</span><span class="br0">(</span><a href="cpp-numeric-math-INFINITY.html"><span class="kw1376">INFINITY</span></a>, <span class="sy2">-</span><span class="nu0">1</span><span class="br0">)</span> <span class="sy1"><<</span> <span class="st0">'<span class="es1">\n</span>'</span><span class="sy4">;</span>
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<span class="co1">// 错误处理</span>
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<span class="kw2">errno</span> <span class="sy1">=</span> <span class="nu0">0</span><span class="sy4">;</span>
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<a href="cpp-numeric-fenv-feclearexcept.html"><span class="kw1449">std::<span class="me2">feclearexcept</span></span></a><span class="br0">(</span><a href="cpp-numeric-fenv-FE_exceptions.html"><span class="kw1460">FE_ALL_EXCEPT</span></a><span class="br0">)</span><span class="sy4">;</span>
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<a href="cpp-io-cout.html"><span class="kw1757">std::<span class="me2">cout</span></span></a> <span class="sy1"><<</span> <span class="st0">"pow(-1, 1/3) = "</span> <span class="sy1"><<</span> std<span class="sy4">::</span><span class="me2">pow</span><span class="br0">(</span><span class="sy2">-</span><span class="nu0">1</span>, <span class="nu16">1.0</span><span class="sy2">/</span><span class="nu0">3</span><span class="br0">)</span> <span class="sy1"><<</span> <span class="st0">'<span class="es1">\n</span>'</span><span class="sy4">;</span>
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<span class="kw1">if</span> <span class="br0">(</span><span class="kw2">errno</span> <span class="sy1">==</span> <a href="cpp-error-errno_macros.html"><span class="kw810">EDOM</span></a><span class="br0">)</span>
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<a href="cpp-io-cout.html"><span class="kw1757">std::<span class="me2">cout</span></span></a> <span class="sy1"><<</span> <span class="st0">" errno == EDOM "</span> <span class="sy1"><<</span> <a href="cpp-string-byte-strerror.html"><span class="kw1161">std::<span class="me2">strerror</span></span></a><span class="br0">(</span><span class="kw2">errno</span><span class="br0">)</span> <span class="sy1"><<</span> <span class="st0">'<span class="es1">\n</span>'</span><span class="sy4">;</span>
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<span class="kw1">if</span> <span class="br0">(</span><a href="cpp-numeric-fenv-fetestexcept.html"><span class="kw1450">std::<span class="me2">fetestexcept</span></span></a><span class="br0">(</span><a href="cpp-numeric-fenv-FE_exceptions.html"><span class="kw1463">FE_INVALID</span></a><span class="br0">)</span><span class="br0">)</span>
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<a href="cpp-io-cout.html"><span class="kw1757">std::<span class="me2">cout</span></span></a> <span class="sy1"><<</span> <span class="st0">" FE_INVALID raised<span class="es1">\n</span>"</span><span class="sy4">;</span>
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<a href="cpp-numeric-fenv-feclearexcept.html"><span class="kw1449">std::<span class="me2">feclearexcept</span></span></a><span class="br0">(</span><a href="cpp-numeric-fenv-FE_exceptions.html"><span class="kw1460">FE_ALL_EXCEPT</span></a><span class="br0">)</span><span class="sy4">;</span>
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<a href="cpp-io-cout.html"><span class="kw1757">std::<span class="me2">cout</span></span></a> <span class="sy1"><<</span> <span class="st0">"pow(-0, -3) = "</span> <span class="sy1"><<</span> std<span class="sy4">::</span><span class="me2">pow</span><span class="br0">(</span><span class="sy2">-</span><span class="nu16">0.0</span>, <span class="sy2">-</span><span class="nu0">3</span><span class="br0">)</span> <span class="sy1"><<</span> <span class="st0">'<span class="es1">\n</span>'</span><span class="sy4">;</span>
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<span class="kw1">if</span> <span class="br0">(</span><a href="cpp-numeric-fenv-fetestexcept.html"><span class="kw1450">std::<span class="me2">fetestexcept</span></span></a><span class="br0">(</span><a href="cpp-numeric-fenv-FE_exceptions.html"><span class="kw1461">FE_DIVBYZERO</span></a><span class="br0">)</span><span class="br0">)</span>
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<a href="cpp-io-cout.html"><span class="kw1757">std::<span class="me2">cout</span></span></a> <span class="sy1"><<</span> <span class="st0">" FE_DIVBYZERO raised<span class="es1">\n</span>"</span><span class="sy4">;</span>
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<span class="br0">}</span></pre></div>
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</div>
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<p>可能的输出：</p>
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<div dir="ltr" class="mw-geshi" style="text-align: left;">
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<div class="text source-text">
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<pre class="de1">pow(2, 10) = 1024
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pow(2, 0.5) = 1.41421
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pow(-2, -3) = -0.125
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pow(-1, NAN) = nan
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pow(+1, NAN) = 1
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pow(INFINITY, 2) = inf
|
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pow(INFINITY, -1) = 0
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pow(-1, 1/3) = -nan
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errno == EDOM Numerical argument out of domain
|
|
FE_INVALID raised
|
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pow(-0, -3) = -inf
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FE_DIVBYZERO raised</pre></div>
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</div>
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</div>
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<h3><span class="mw-headline" id=".E5.8F.82.E9.98.85">参阅</span></h3>
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<table class="t-dsc-begin">
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<tr class="t-dsc">
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<td>
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<div class="t-dsc-member-div">
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<div><a href="cpp-numeric-math-sqrt.html"><span class="t-lines"><span>sqrt</span><span>sqrtf</span><span>sqrtl</span></span></a></div>
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<div><span class="t-lines"><span></span><span><span class="t-mark-rev t-since-cxx11">(C++11)</span></span><span><span class="t-mark-rev t-since-cxx11">(C++11)</span></span></span></div>
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</div>
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</td>
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<td>计算平方根（ <span class="mjax" style="display:none">\(\small{\sqrt{x} }\)</span><span class="mjax-fallback texhtml" style="white-space: nowrap;"><span class="t-mrad"><span>√</span><span>x</span></span></span> ）<br />
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<span class="t-mark">(函数)</span></td>
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</tr>
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<tr class="t-dsc">
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<td>
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<div class="t-dsc-member-div">
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<div><a href="cpp-numeric-math-cbrt.html"><span class="t-lines"><span>cbrt</span><span>cbrtf</span><span>cbrtl</span></span></a></div>
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<div><span class="t-lines"><span><span class="t-mark-rev t-since-cxx11">(C++11)</span></span><span><span class="t-mark-rev t-since-cxx11">(C++11)</span></span><span><span class="t-mark-rev t-since-cxx11">(C++11)</span></span></span></div>
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</div>
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</td>
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<td>计算立方根（ <span class="mjax" style="display:none">\(\small{\sqrt[3]{x} }\)</span><span class="mjax-fallback texhtml" style="white-space: nowrap;"><span class="t-mrad"><span>3</span><span>√</span><span>x</span></span></span> ）<br />
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<span class="t-mark">(函数)</span></td>
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</tr>
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<tr class="t-dsc">
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<td>
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<div class="t-dsc-member-div">
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<div><a href="cpp-numeric-math-hypot.html"><span class="t-lines"><span>hypot</span><span>hypotf</span><span>hypotl</span></span></a></div>
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<div><span class="t-lines"><span><span class="t-mark-rev t-since-cxx11">(C++11)</span></span><span><span class="t-mark-rev t-since-cxx11">(C++11)</span></span><span><span class="t-mark-rev t-since-cxx11">(C++11)</span></span></span></div>
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</div>
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</td>
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<td>计算两个给定数的平方和的平方根（ <span class="mjax" style="display:none">\(\scriptsize{\sqrt{x^2+y^2} }\)</span><span class="mjax-fallback texhtml" style="white-space: nowrap;"><span class="t-mrad"><span>√</span><span>x<span class="t-su">2<br /></span>+y<span class="t-su">2<br /></span></span></span></span> ）<br />
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<span class="t-mark">(函数)</span></td>
|
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</tr>
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<tr class="t-dsc">
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<td>
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<div class="t-dsc-member-div">
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<div><a href="cpp-numeric-complex-pow.html"><span class="t-lines"><span>pow<span class="t-dsc-small">(std::complex)</span></span></span></a></div>
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</div>
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</td>
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<td>复数幂，一或两个参数可为复数<br />
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<span class="t-mark">(函数模板)</span></td>
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</tr>
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<tr class="t-dsc">
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<td>
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<div class="t-dsc-member-div">
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<div><a href="cpp-numeric-valarray-pow.html"><span class="t-lines"><span>pow<span class="t-dsc-small">(std::valarray)</span></span></span></a></div>
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</div>
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</td>
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<td>应用函数 <span class="t-lc"><strong class="selflink">std::pow</strong></span> 到二个 valarray 或一个 valarray 与一个值<br />
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<span class="t-mark">(函数模板)</span></td>
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</tr>
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</table>
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</div>
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<div class="visualClear"></div>
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</div>
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</div>
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</div>
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</body>
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</html>
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