386 lines
26 KiB
HTML
386 lines
26 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>rint, rintf, rintl, lrint, lrintf, lrintl, llrint, llrintf, llrintl</title>
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<body class="mediawiki ltr sitedir-ltr ns-0 ns-subject page-c_numeric_math_rint skin-cppreference2 action-view cpp-navbar">
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<div id="cpp-content-base">
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<div id="content"><a id="top"></a>
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<h1 id="firstHeading" class="firstHeading">rint, rintf, rintl, lrint, lrintf, lrintl, llrint, llrintf, llrintl</h1>
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<div id="bodyContent">
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<div id="contentSub"><span class="subpages">< <a href="c.html">c</a>‎ | <a href="c-numeric.html">numeric</a>‎ | <a href="c-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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<tbody>
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<td>
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<div>定义于头文件 <code><math.h></code></div>
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</td>
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<td></td>
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<td></td>
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<div><span class="mw-geshi c source-c"><span class="kw4">float</span> rintf<span class="br0">(</span> <span class="kw4">float</span> arg <span class="br0">)</span><span class="sy4">;</span></span></div>
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</td>
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<td>(1)</td>
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<td><span class="t-mark-rev t-since-c99">(C99 起)</span></td>
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</tr>
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<tr class="t-dcl t-since-c99">
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<div><span class="mw-geshi c source-c"><span class="kw4">double</span> rint<span class="br0">(</span> <span class="kw4">double</span> arg <span class="br0">)</span><span class="sy4">;</span></span></div>
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</td>
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<td>(2)</td>
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<td><span class="t-mark-rev t-since-c99">(C99 起)</span></td>
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</tr>
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<tr class="t-dcl t-since-c99">
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<div><span class="mw-geshi c source-c"><span class="kw4">long</span> <span class="kw4">double</span> rintl<span class="br0">(</span> <span class="kw4">long</span> <span class="kw4">double</span> arg <span class="br0">)</span><span class="sy4">;</span></span></div>
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</td>
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<td>(3)</td>
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<td><span class="t-mark-rev t-since-c99">(C99 起)</span></td>
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</tr>
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<tr class="t-dsc-header">
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<td>
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<div>定义于头文件 <code><tgmath.h></code></div>
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</td>
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<td></td>
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<td></td>
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<div><span class="mw-geshi c source-c"><span class="co2">#define rint( arg )</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-since-c99">(C99 起)</span></td>
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</tr>
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<tr class="t-dsc-header">
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<td>
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<div>定义于头文件 <code><math.h></code></div>
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</td>
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<td></td>
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<td></td>
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<tr class="t-dcl t-since-c99">
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<div><span class="mw-geshi c source-c"><span class="kw4">long</span> lrintf<span class="br0">(</span> <span class="kw4">float</span> arg <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-since-c99">(C99 起)</span></td>
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</tr>
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<tr class="t-dcl t-since-c99">
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<div><span class="mw-geshi c source-c"><span class="kw4">long</span> lrint<span class="br0">(</span> <span class="kw4">double</span> arg <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-since-c99">(C99 起)</span></td>
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</tr>
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<tr class="t-dcl t-since-c99">
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<div><span class="mw-geshi c source-c"><span class="kw4">long</span> lrintl<span class="br0">(</span> <span class="kw4">long</span> <span class="kw4">double</span> arg <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-c99">(C99 起)</span></td>
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</tr>
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<tr class="t-dsc-header">
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<td>
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<div>定义于头文件 <code><tgmath.h></code></div>
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</td>
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<td></td>
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<td></td>
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<tr class="t-dcl t-since-c99">
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<td>
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<div><span class="mw-geshi c source-c"><span class="co2">#define lrint( arg )</span></span></div>
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</td>
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<td>(8)</td>
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<td><span class="t-mark-rev t-since-c99">(C99 起)</span></td>
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</tr>
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<tr class="t-dsc-header">
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<td>
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<div>定义于头文件 <code><math.h></code></div>
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</td>
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<td></td>
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<td></td>
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</tr>
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<tr class="t-dcl t-since-c99">
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<td>
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<div><span class="mw-geshi c source-c"><span class="kw4">long</span> <span class="kw4">long</span> llrintf<span class="br0">(</span> <span class="kw4">float</span> arg <span class="br0">)</span><span class="sy4">;</span></span></div>
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</td>
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<td>(9)</td>
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<td><span class="t-mark-rev t-since-c99">(C99 起)</span></td>
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</tr>
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<tr class="t-dcl t-since-c99">
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<td>
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<div><span class="mw-geshi c source-c"><span class="kw4">long</span> <span class="kw4">long</span> llrint<span class="br0">(</span> <span class="kw4">double</span> arg <span class="br0">)</span><span class="sy4">;</span></span></div>
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</td>
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<td>(10)</td>
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<td><span class="t-mark-rev t-since-c99">(C99 起)</span></td>
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</tr>
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<tr class="t-dcl t-since-c99">
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<td>
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<div><span class="mw-geshi c source-c"><span class="kw4">long</span> <span class="kw4">long</span> llrintl<span class="br0">(</span> <span class="kw4">long</span> <span class="kw4">double</span> arg <span class="br0">)</span><span class="sy4">;</span></span></div>
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</td>
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<td>(11)</td>
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<td><span class="t-mark-rev t-since-c99">(C99 起)</span></td>
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</tr>
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<tr class="t-dsc-header">
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<td>
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<div>定义于头文件 <code><tgmath.h></code></div>
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</td>
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<td></td>
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<td></td>
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</tr>
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<tr class="t-dcl t-since-c99">
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<div><span class="mw-geshi c source-c"><span class="co2">#define llrint( arg )</span></span></div>
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</td>
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<td>(12)</td>
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<td><span class="t-mark-rev t-since-c99">(C99 起)</span></td>
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</tr>
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<tr class="t-dcl-sep">
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<td></td>
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<td></td>
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<div class="t-li1"><span class="t-li">1-3)</span> 用<a href="c-numeric-fenv-FE_round.html">当前舍入模式</a>，舍入浮点参数 <code>arg</code> 为整数值（以浮点格式）。</div>
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<div class="t-li1"><span class="t-li">5-7, 9-11)</span> 用<a href="c-numeric-fenv-FE_round.html">当前舍入模式</a>，舍入浮点参数 <code>arg</code> 为整数值。</div>
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<div class="t-li1"><span class="t-li">4,8,12)</span> 泛型宏：若 <code>arg</code> 拥有 <span class="t-c"><span class="mw-geshi c source-c"><span class="kw4">long</span> <span class="kw4">double</span></span></span> 类型，，则调用 <code>rintl</code> 、 <code>lrintl</code> 、 <code>llrintl</code> 。否则若 <code>arg</code> 拥有整数或 <span class="t-c"><span class="mw-geshi c source-c"><span class="kw4">double</span></span></span> 类型，则调用 <code>rint</code> 、 <code>lrint</code> 、 <code>llrint</code> 。否则分别调用 <code>rintf</code> 、 <code>lrintf</code> 、 <code>llrintf</code> 。</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>arg</td>
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<td>-</td>
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<td>浮点值</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，则按照<a href="c-numeric-fenv-FE_round.html">当前舍入模式</a>的最接近整数值。</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 <a href="c-numeric-math-math_errhandling.html">math_errhandling</a> 中指定的错误。</p>
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<p>若 <code>lrint</code> 或 <code>llrint</code> 的结果在返回类型的可表示范围外，则可能出现定义域错误或值域错误。</p>
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<p>若实现支持 IEEE 浮点算术（ IEC 60559 ），则</p>
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<dl>
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<dd>对于 <code>rint</code> 函数：</dd>
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</dl>
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<ul>
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<li>若 <code>arg</code> 为 ±∞ ，则返回不修改的参数</li>
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<li>若 <code>arg</code> 为 ±0 ，则返回不修改的参数</li>
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<li>若 <code>arg</code> 为 NaN ，则返回 NaN</li>
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</ul>
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<dl>
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<dd>对于 <code>lrint</code> 和 <code>llrint</code> 函数：</dd>
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</dl>
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<ul>
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<li>若 <code>arg</code> 为 ±∞ ，则引发 <span class="t-lc"><a href="c-numeric-fenv-FE_exceptions.html">FE_INVALID</a></span> 并返回实现定义值</li>
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<li>若舍入结果在返回类型范围外，则引发 <span class="t-lc"><a href="c-numeric-fenv-FE_exceptions.html">FE_INVALID</a></span> 并返回实现定义值</li>
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<li>若 <code>arg</code> 为 NaN ，则引发 <span class="t-lc"><a href="c-numeric-fenv-FE_exceptions.html">FE_INVALID</a></span> 并返回实现定义值</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><a rel="nofollow" class="external text" href="http://pubs.opengroup.org/onlinepubs/9699919799/functions/lrint.html">POSIX 指定</a> <code>lrint</code> 或 <code>llrint</code> 引发 <span class="t-lc"><a href="c-numeric-fenv-FE_exceptions.html">FE_INEXACT</a></span> 的所有情况都是定义域错误。</p>
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<p>如指定于 <a href="c-numeric-math-math_errhandling.html">math_errhandling</a> ， <code>rint</code> 在舍入非整数有限值时可以（但不在非 IEEE 浮点平台上要求）引发 <span class="t-lc"><a href="c-numeric-fenv-FE_exceptions.html">FE_INEXACT</a></span> 。</p>
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<p><code>rint</code> 和 <span class="t-lc"><a href="c-numeric-math-nearbyint.html">nearbyint</a></span> 间仅有的区别是 <span class="t-lc"><a href="c-numeric-math-nearbyint.html">nearbyint</a></span> 决不引发 <span class="t-lc"><a href="c-numeric-fenv-FE_exceptions.html">FE_INEXACT</a></span> 。</p>
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<p>所有标准浮点格式中，最大可表示浮点值都是准确的整数，故 <code>rint</code> 自身决不上溢；然而在存储结果于整数对象时，结果可能溢出任何整数类型（包含 <span class="t-lc"><a href="c-types-integer.html">intmax_t</a></span> ）。</p>
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<p>若当前舍入模式为……</p>
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<ul>
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<li><span class="t-lc"><a href="c-numeric-fenv-FE_round.html">FE_DOWNWARD</a></span> ，则 <code>rint</code> 等价于 <span class="t-lc"><a href="c-numeric-math-floor.html">floor</a></span> 。</li>
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<li><span class="t-lc"><a href="c-numeric-fenv-FE_round.html">FE_UPWARD</a></span> ，则 <code>rint</code> 等价于 <span class="t-lc"><a href="c-numeric-math-ceil.html">ceil</a></span> 。</li>
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<li><span class="t-lc"><a href="c-numeric-fenv-FE_round.html">FE_TOWARDZERO</a></span> ，则 <code>rint</code> 等价于 <span class="t-lc"><a href="c-numeric-math-trunc.html">trunc</a></span> 。</li>
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<li><span class="t-lc"><a href="c-numeric-fenv-FE_round.html">FE_TONEAREST</a></span> ，则 <code>rint</code> 在中点情况和 <span class="t-lc"><a href="c-numeric-math-round.html">round</a></span> 的区别是前者始终舍入到偶数，而非远离零。</li>
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</ul>
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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="c source-c">
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<pre class="de1"><span class="co2">#include <stdio.h></span>
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<span class="co2">#include <math.h></span>
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<span class="co2">#include <fenv.h></span>
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<span class="co2">#include <limits.h></span>
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<span class="kw4">int</span> main<span class="br0">(</span><span class="kw4">void</span><span class="br0">)</span>
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<span class="br0">{</span>
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<span class="co2">#pragma STDC FENV_ACCESS ON</span>
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<a href="c-numeric-fenv-feround.html"><span class="kw721">fesetround</span></a><span class="br0">(</span><a href="c-numeric-fenv-FE_round.html"><span class="kw733">FE_TONEAREST</span></a><span class="br0">)</span><span class="sy4">;</span>
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<a href="c-io-fprintf.html"><span class="kw848">printf</span></a><span class="br0">(</span><span class="st0">"rounding to nearest (halfway cases to even):<span class="es1">\n</span>"</span>
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<span class="st0">"rint(+2.3) = %+.1f "</span>, rint<span class="br0">(</span><span class="nu16">2.3</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
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<a href="c-io-fprintf.html"><span class="kw848">printf</span></a><span class="br0">(</span><span class="st0">"rint(+2.5) = %+.1f "</span>, rint<span class="br0">(</span><span class="nu16">2.5</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
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<a href="c-io-fprintf.html"><span class="kw848">printf</span></a><span class="br0">(</span><span class="st0">"rint(+3.5) = %+.1f<span class="es1">\n</span>"</span>, rint<span class="br0">(</span><span class="nu16">3.5</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
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<a href="c-io-fprintf.html"><span class="kw848">printf</span></a><span class="br0">(</span><span class="st0">"rint(-2.3) = %+.1f "</span>, rint<span class="br0">(</span><span class="sy2">-</span><span class="nu16">2.3</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
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<a href="c-io-fprintf.html"><span class="kw848">printf</span></a><span class="br0">(</span><span class="st0">"rint(-2.5) = %+.1f "</span>, rint<span class="br0">(</span><span class="sy2">-</span><span class="nu16">2.5</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
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<a href="c-io-fprintf.html"><span class="kw848">printf</span></a><span class="br0">(</span><span class="st0">"rint(-3.5) = %+.1f<span class="es1">\n</span>"</span>, rint<span class="br0">(</span><span class="sy2">-</span><span class="nu16">3.5</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
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<a href="c-numeric-fenv-feround.html"><span class="kw721">fesetround</span></a><span class="br0">(</span><a href="c-numeric-fenv-FE_round.html"><span class="kw732">FE_DOWNWARD</span></a><span class="br0">)</span><span class="sy4">;</span>
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<a href="c-io-fprintf.html"><span class="kw848">printf</span></a><span class="br0">(</span><span class="st0">"rounding down: <span class="es1">\n</span>rint(+2.3) = %+.1f "</span>, rint<span class="br0">(</span><span class="nu16">2.3</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
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<a href="c-io-fprintf.html"><span class="kw848">printf</span></a><span class="br0">(</span><span class="st0">"rint(+2.5) = %+.1f "</span>, rint<span class="br0">(</span><span class="nu16">2.5</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
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<a href="c-io-fprintf.html"><span class="kw848">printf</span></a><span class="br0">(</span><span class="st0">"rint(+3.5) = %+.1f<span class="es1">\n</span>"</span>, rint<span class="br0">(</span><span class="nu16">3.5</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
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<a href="c-io-fprintf.html"><span class="kw848">printf</span></a><span class="br0">(</span><span class="st0">"rint(-2.3) = %+.1f "</span>, rint<span class="br0">(</span><span class="sy2">-</span><span class="nu16">2.3</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
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<a href="c-io-fprintf.html"><span class="kw848">printf</span></a><span class="br0">(</span><span class="st0">"rint(-2.5) = %+.1f "</span>, rint<span class="br0">(</span><span class="sy2">-</span><span class="nu16">2.5</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
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<a href="c-io-fprintf.html"><span class="kw848">printf</span></a><span class="br0">(</span><span class="st0">"rint(-3.5) = %+.1f<span class="es1">\n</span>"</span>, rint<span class="br0">(</span><span class="sy2">-</span><span class="nu16">3.5</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
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<a href="c-io-fprintf.html"><span class="kw848">printf</span></a><span class="br0">(</span><span class="st0">"rounding down with lrint: <span class="es1">\n</span>lrint(+2.3) = %ld "</span>, lrint<span class="br0">(</span><span class="nu16">2.3</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
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<a href="c-io-fprintf.html"><span class="kw848">printf</span></a><span class="br0">(</span><span class="st0">"lrint(+2.5) = %ld "</span>, lrint<span class="br0">(</span><span class="nu16">2.5</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
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<a href="c-io-fprintf.html"><span class="kw848">printf</span></a><span class="br0">(</span><span class="st0">"lrint(+3.5) = %ld<span class="es1">\n</span>"</span>, lrint<span class="br0">(</span><span class="nu16">3.5</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
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<a href="c-io-fprintf.html"><span class="kw848">printf</span></a><span class="br0">(</span><span class="st0">"lrint(-2.3) = %ld "</span>, lrint<span class="br0">(</span><span class="sy2">-</span><span class="nu16">2.3</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
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<a href="c-io-fprintf.html"><span class="kw848">printf</span></a><span class="br0">(</span><span class="st0">"lrint(-2.5) = %ld "</span>, lrint<span class="br0">(</span><span class="sy2">-</span><span class="nu16">2.5</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
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|
<a href="c-io-fprintf.html"><span class="kw848">printf</span></a><span class="br0">(</span><span class="st0">"lrint(-3.5) = %ld<span class="es1">\n</span>"</span>, lrint<span class="br0">(</span><span class="sy2">-</span><span class="nu16">3.5</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
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<a href="c-io-fprintf.html"><span class="kw848">printf</span></a><span class="br0">(</span><span class="st0">"lrint(-0.0) = %ld<span class="es1">\n</span>"</span>, lrint<span class="br0">(</span><span class="sy2">-</span><span class="nu16">0.0</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
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<a href="c-io-fprintf.html"><span class="kw848">printf</span></a><span class="br0">(</span><span class="st0">"lrint(-Inf) = %ld<span class="es1">\n</span>"</span>, lrint<span class="br0">(</span><span class="sy2">-</span>INFINITY<span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span> <span class="co1">// 引发 FE_INVALID</span>
|
|
|
|
<span class="co1">// 错误处理</span>
|
|
<a href="c-numeric-fenv-feclearexcept.html"><span class="kw715">feclearexcept</span></a><span class="br0">(</span><a href="c-numeric-fenv-FE_exceptions.html"><span class="kw726">FE_ALL_EXCEPT</span></a><span class="br0">)</span><span class="sy4">;</span>
|
|
<a href="c-io-fprintf.html"><span class="kw848">printf</span></a><span class="br0">(</span><span class="st0">"rint(1.1) = %.1f<span class="es1">\n</span>"</span>, rint<span class="br0">(</span><span class="nu16">1.1</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
|
|
<span class="kw1">if</span><span class="br0">(</span><a href="c-numeric-fenv-fetestexcept.html"><span class="kw716">fetestexcept</span></a><span class="br0">(</span><a href="c-numeric-fenv-FE_exceptions.html"><span class="kw728">FE_INEXACT</span></a><span class="br0">)</span><span class="br0">)</span> <a href="c-io-puts.html"><span class="kw833">puts</span></a><span class="br0">(</span><span class="st0">" FE_INEXACT was raised"</span><span class="br0">)</span><span class="sy4">;</span>
|
|
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|
<a href="c-numeric-fenv-feclearexcept.html"><span class="kw715">feclearexcept</span></a><span class="br0">(</span><a href="c-numeric-fenv-FE_exceptions.html"><span class="kw726">FE_ALL_EXCEPT</span></a><span class="br0">)</span><span class="sy4">;</span>
|
|
<a href="c-io-fprintf.html"><span class="kw848">printf</span></a><span class="br0">(</span><span class="st0">"lrint(LONG_MIN-2048.0) = %ld<span class="es1">\n</span>"</span>, lrint<span class="br0">(</span>LONG_MIN<span class="sy2">-</span><span class="nu16">2048.0</span><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span>
|
|
<span class="kw1">if</span><span class="br0">(</span><a href="c-numeric-fenv-fetestexcept.html"><span class="kw716">fetestexcept</span></a><span class="br0">(</span><a href="c-numeric-fenv-FE_exceptions.html"><span class="kw729">FE_INVALID</span></a><span class="br0">)</span><span class="br0">)</span> <a href="c-io-puts.html"><span class="kw833">puts</span></a><span class="br0">(</span><span class="st0">" FE_INVALID was raised"</span><span class="br0">)</span><span class="sy4">;</span>
|
|
<span class="br0">}</span></pre></div>
|
|
</div>
|
|
<p>可能的输出：</p>
|
|
<div dir="ltr" class="mw-geshi" style="text-align: left;">
|
|
<div class="text source-text">
|
|
<pre class="de1">rounding to nearest (halfway cases to even):
|
|
rint(+2.3) = +2.0 rint(+2.5) = +2.0 rint(+3.5) = +4.0
|
|
rint(-2.3) = -2.0 rint(-2.5) = -2.0 rint(-3.5) = -4.0
|
|
rounding down:
|
|
rint(+2.3) = +2.0 rint(+2.5) = +2.0 rint(+3.5) = +3.0
|
|
rint(-2.3) = -3.0 rint(-2.5) = -3.0 rint(-3.5) = -4.0
|
|
rounding down with lrint:
|
|
lrint(+2.3) = 2 lrint(+2.5) = 2 lrint(+3.5) = 3
|
|
lrint(-2.3) = -3 lrint(-2.5) = -3 lrint(-3.5) = -4
|
|
lrint(-0.0) = 0
|
|
lrint(-Inf) = -9223372036854775808
|
|
rint(1.1) = 1.0
|
|
FE_INEXACT was raised
|
|
lrint(LONG_MIN-2048.0) = -9223372036854775808
|
|
FE_INVALID was raised</pre></div>
|
|
</div>
|
|
</div>
|
|
<h3><span class="mw-headline" id=".E5.BC.95.E7.94.A8">引用</span></h3>
|
|
<div class="t-ref-std-11">
|
|
<ul>
|
|
<li>C11 标准（ISO/IEC 9899:2011）：</li>
|
|
</ul>
|
|
<dl>
|
|
<dd>
|
|
<ul>
|
|
<li>7.12.9.4 The rint functions (p: 252)</li>
|
|
</ul>
|
|
</dd>
|
|
</dl>
|
|
<dl>
|
|
<dd>
|
|
<ul>
|
|
<li>7.12.9.5 The lrint and llrint functions (p: 252)</li>
|
|
</ul>
|
|
</dd>
|
|
</dl>
|
|
<dl>
|
|
<dd>
|
|
<ul>
|
|
<li>7.25 Type-generic math <tgmath.h> (p: 373-375)</li>
|
|
</ul>
|
|
</dd>
|
|
</dl>
|
|
<dl>
|
|
<dd>
|
|
<ul>
|
|
<li>F.10.6.4 The rint functions (p: 527)</li>
|
|
</ul>
|
|
</dd>
|
|
</dl>
|
|
<dl>
|
|
<dd>
|
|
<ul>
|
|
<li>F.10.6.5 The lrint and llrint functions (p: 527)</li>
|
|
</ul>
|
|
</dd>
|
|
</dl>
|
|
<div class="t-ref-std-c99">
|
|
<ul>
|
|
<li>C99 标准（ISO/IEC 9899:1999）：</li>
|
|
</ul>
|
|
<dl>
|
|
<dd>
|
|
<ul>
|
|
<li>7.12.9.4 The rint functions (p: 232-233)</li>
|
|
</ul>
|
|
</dd>
|
|
</dl>
|
|
<dl>
|
|
<dd>
|
|
<ul>
|
|
<li>7.12.9.5 The lrint and llrint functions (p: 233)</li>
|
|
</ul>
|
|
</dd>
|
|
</dl>
|
|
<dl>
|
|
<dd>
|
|
<ul>
|
|
<li>7.22 Type-generic math <tgmath.h> (p: 335-337)</li>
|
|
</ul>
|
|
</dd>
|
|
</dl>
|
|
<dl>
|
|
<dd>
|
|
<ul>
|
|
<li>F.9.6.4 The rint functions (p: 463)</li>
|
|
</ul>
|
|
</dd>
|
|
</dl>
|
|
<dl>
|
|
<dd>
|
|
<ul>
|
|
<li>F.9.6.5 The lrint and llrint functions (p: 463)</li>
|
|
</ul>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
<h3><span class="mw-headline" id=".E5.8F.82.E9.98.85">参阅</span></h3>
|
|
<table class="t-dsc-begin">
|
|
<tr class="t-dsc">
|
|
<td>
|
|
<div class="t-dsc-member-div">
|
|
<div><a href="c-numeric-math-trunc.html"><span class="t-lines"><span>trunc</span><span>truncf</span><span>truncl</span></span></a></div>
|
|
<div><span class="t-lines"><span><span class="t-mark-rev t-since-c99">(C99)</span></span><span><span class="t-mark-rev t-since-c99">(C99)</span></span><span><span class="t-mark-rev t-since-c99">(C99)</span></span></span></div>
|
|
</div>
|
|
</td>
|
|
<td>取整到绝对值不大于给定值的最接近整数<br />
|
|
<span class="t-mark">(函数)</span></td>
|
|
</tr>
|
|
<tr class="t-dsc">
|
|
<td>
|
|
<div class="t-dsc-member-div">
|
|
<div><a href="c-numeric-math-nearbyint.html"><span class="t-lines"><span>nearbyint</span><span>nearbyintf</span><span>nearbyintl</span></span></a></div>
|
|
<div><span class="t-lines"><span><span class="t-mark-rev t-since-c99">(C99)</span></span><span><span class="t-mark-rev t-since-c99">(C99)</span></span><span><span class="t-mark-rev t-since-c99">(C99)</span></span></span></div>
|
|
</div>
|
|
</td>
|
|
<td>用当前舍入模式取整到整数<br />
|
|
<span class="t-mark">(函数)</span></td>
|
|
</tr>
|
|
<tr class="t-dsc">
|
|
<td>
|
|
<div class="t-dsc-member-div">
|
|
<div><a href="c-numeric-fenv-feround.html"><span class="t-lines"><span>fegetround</span><span>fesetround</span></span></a></div>
|
|
<div><span class="t-lines"><span><span class="t-mark-rev t-since-c99">(C99)</span></span><span><span class="t-mark-rev t-since-c99">(C99)</span></span></span></div>
|
|
</div>
|
|
</td>
|
|
<td>获得或设置数字的舍入方向<br />
|
|
<span class="t-mark">(函数)</span></td>
|
|
</tr>
|
|
</table>
|
|
</div>
|
|
</div>
|
|
<div class="visualClear"></div>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
</body>
|
|
</html>
|