klarkxy/hustoj
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity
Files
c33c28794d7656d0e1daa2bf81e55af2cfd532f9
hustoj/web/cppreference-zh/chmhelp/cpp-chrono-duration-abs.html
klarkxy 196e706fe4 上传cppreference
2025-08-01 12:57:54 +08:00

122 lines
9.2 KiB
HTML
Raw Blame History

<!DOCTYPE html>
<html lang="zh" dir="ltr" class="client-nojs" xmlns="http://www.w3.org/1999/xhtml" xml:lang="zh">
<head><meta http-equiv="x-ua-compatible" content="ie=edge">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>std::chrono::abs(std::chrono::duration)</title>
<link rel="stylesheet" href="ext.css" />
<link rel="stylesheet" href="site_modules.css" />
</head>
<body class="mediawiki ltr sitedir-ltr ns-0 ns-subject page-cpp_chrono_duration_abs skin-cppreference2 action-view cpp-navbar">
<div id="cpp-content-base">
<div id="content"><a id="top"></a>
<h1 id="firstHeading" class="firstHeading"><span style="font-size:0.7em; line-height:130%">std::chrono::</span>abs<small>(std::chrono::duration)</small></h1>
<div id="bodyContent">
<div id="contentSub"><span class="subpages">&lt; <a href="cpp.html">cpp</a>&lrm; | <a href="cpp-chrono.html">chrono</a>&lrm; | <a href="cpp-chrono-duration.html">duration</a></span></div>
<div id="mw-content-text" lang="zh" dir="ltr" class="mw-content-ltr" xml:lang="zh">
<table class="t-dcl-begin">
<tbody>
<tr class="t-dsc-header">
<td>
<div>&#23450;&#20041;&#20110;&#22836;&#25991;&#20214; <code><a href="cpp-header-chrono.html">&lt;chrono&gt;</a></code></div>
</td>
<td></td>
<td></td>
</tr>
<tr class="t-dcl t-since-cxx17">
<td>
<div><span class="mw-geshi cpp source-cpp"><span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> Rep, <span class="kw1">class</span> Period<span class="sy1">&gt;</span><br />
<span class="kw4">constexpr</span> <a href="cpp-chrono-duration.html"><span class="kw993">std::<span class="me2">chrono</span><span class="sy4">::</span><span class="me2">duration</span></span></a><span class="sy1">&lt;</span>Rep, Period<span class="sy1">&gt;</span> abs<span class="br0">(</span> <a href="cpp-chrono-duration.html"><span class="kw993">std::<span class="me2">chrono</span><span class="sy4">::</span><span class="me2">duration</span></span></a><span class="sy1">&lt;</span>Rep, Period<span class="sy1">&gt;</span> d <span class="br0">)</span><span class="sy4">;</span></span></div>
</td>
<td class="t-dcl-nopad"></td>
<td><span class="t-mark-rev t-since-cxx17">(C++17 &#36215;)</span></td>
</tr>
<tr class="t-dcl-sep">
<td></td>
<td></td>
<td></td>
</tr>
</tbody>
</table>
<p>&#36820;&#22238;&#26102;&#26399; <code>d</code> &#30340;&#32477;&#23545;&#20540;&#12290;&#20855;&#20307;&#32780;&#35328;&#65292;&#33509; <span class="t-c"><span class="mw-geshi cpp source-cpp">d <span class="sy1">&gt;=</span> d.<span class="me1">zero</span><span class="br0">(</span><span class="br0">)</span></span></span> &#65292;&#21017;&#36820;&#22238; <span class="t-c"><span class="mw-geshi cpp source-cpp">d</span></span> &#65292;&#21542;&#21017;&#36820;&#22238; <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="sy2">-</span>d</span></span> &#12290;</p>
<p>&#35813;&#20989;&#25968;&#19981;&#21442;&#19982;&#37325;&#36733;&#20915;&#35758;&#65292;&#38500;&#38750; <span class="t-c"><span class="mw-geshi cpp source-cpp"><a href="cpp-types-numeric_limits.html"><span class="kw344">std::<span class="me2">numeric_limits</span></span></a><span class="sy1">&lt;</span>Rep<span class="sy1">&gt;</span><span class="sy4">::</span><span class="me2">is_signed</span></span></span> &#20026; <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="kw2">true</span></span></span> &#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>d</td>
<td>-</td>
<td>&#26102;&#26399;</td>
</tr>
</table>
<h3><span class="mw-headline" id=".E8.BF.94.E5.9B.9E.E5.80.BC">&#36820;&#22238;&#20540;</span></h3>
<p><code>d</code> &#30340;&#32477;&#23545;&#20540;</p>
<h3><span class="mw-headline" id=".E5.8F.AF.E8.83.BD.E7.9A.84.E5.AE.9E.E7.8E.B0">&#21487;&#33021;&#30340;&#23454;&#29616;</span></h3>
<table class="eq-fun-cpp-table">
<tr>
<td>
<div dir="ltr" class="mw-geshi" style="text-align: left;">
<div class="cpp source-cpp">
<pre class="de1"><span class="kw1">template</span> <span class="sy1">&lt;</span><span class="kw1">class</span> Rep, <span class="kw1">class</span> Period, <span class="kw1">class</span> <span class="sy1">=</span> <a href="cpp-types-enable_if.html"><span class="kw631">std::<span class="me2">enable_if_t</span></span></a><span class="sy1">&lt;</span>
<a href="cpp-chrono-duration.html"><span class="kw993">std::<span class="me2">chrono</span><span class="sy4">::</span><span class="me2">duration</span></span></a><span class="sy1">&lt;</span>Rep, Period<span class="sy1">&gt;</span><span class="sy4">::</span><span class="me2">min</span><span class="br0">(</span><span class="br0">)</span> <span class="sy1">&lt;</span> <a href="cpp-chrono-duration.html"><span class="kw993">std::<span class="me2">chrono</span><span class="sy4">::</span><span class="me2">duration</span></span></a><span class="sy1">&lt;</span>Rep, Period<span class="sy1">&gt;</span><span class="sy4">::</span><span class="me2">zero</span><span class="br0">(</span><span class="br0">)</span><span class="sy1">&gt;&gt;</span>
<span class="kw4">constexpr</span> <a href="cpp-chrono-duration.html"><span class="kw993">std::<span class="me2">chrono</span><span class="sy4">::</span><span class="me2">duration</span></span></a><span class="sy1">&lt;</span>Rep, Period<span class="sy1">&gt;</span> abs<span class="br0">(</span><a href="cpp-chrono-duration.html"><span class="kw993">std::<span class="me2">chrono</span><span class="sy4">::</span><span class="me2">duration</span></span></a><span class="sy1">&lt;</span>Rep, Period<span class="sy1">&gt;</span> d<span class="br0">)</span>
<span class="br0">{</span>
<span class="kw1">return</span> d <span class="sy1">&gt;=</span> d.<span class="me1">zero</span><span class="br0">(</span><span class="br0">)</span> <span class="sy4">?</span> d <span class="sy4">:</span> <span class="sy2">-</span>d<span class="sy4">;</span>
<span class="br0">}</span></pre></div>
</div>
</td>
</tr>
</table>
<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;chrono&gt;</span>
<span class="kw4">int</span> main<span class="br0">(</span><span class="br0">)</span>
<span class="br0">{</span>
<span class="kw1">using</span> <span class="kw1">namespace</span> std<span class="sy4">::</span><span class="me2">chrono</span><span class="sy4">;</span>
static_assert<span class="br0">(</span>abs<span class="br0">(</span><span class="sy2">-</span>42s<span class="br0">)</span> <span class="sy1">==</span> std<span class="sy4">::</span><span class="me2">chrono</span><span class="sy4">::</span><span class="me2">abs</span><span class="br0">(</span>42s<span class="br0">)</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;abs(+3min) = &quot;</span> <span class="sy1">&lt;&lt;</span> abs<span class="br0">(</span>3min<span class="br0">)</span>.<span class="me1">count</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="sy1">&lt;&lt;</span> <span class="st0">&quot;abs(-3min) = &quot;</span> <span class="sy1">&lt;&lt;</span> abs<span class="br0">(</span><span class="sy2">-</span>3min<span class="br0">)</span>.<span class="me1">count</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="br0">}</span></pre></div>
</div>
<p>&#36755;&#20986;&#65306;</p>
<div dir="ltr" class="mw-geshi" style="text-align: left;">
<div class="text source-text">
<pre class="de1">abs(+3min) = 3
abs(-3min) = 3</pre></div>
</div>
</div>
<h3><span class="mw-headline" id=".E5.8F.82.E9.98.85">&#21442;&#38405;</span></h3>
<table class="t-dsc-begin">
<tr class="t-dsc">
<td>
<div class="t-dsc-member-div">
<div><a href="cpp-chrono-duration-operator_arith.html"><span class="t-lines"><span>operator+</span><span>operator-</span></span></a></div>
</div>
</td>
<td>&#23454;&#29616;&#19968;&#20803; + &#21644;&#19968;&#20803; -<br />
<span class="t-mark">(&#20844;&#24320;&#25104;&#21592;&#20989;&#25968;)</span></td>
</tr>
<tr class="t-dsc">
<td>
<div class="t-dsc-member-div">
<div><a href="cpp-numeric-math-abs.html"><span class="t-lines"><span>abs<span class="t-dsc-small">(int)</span></span><span>labs</span><span>llabs</span></span></a></div>
<div><span class="t-lines"><span></span><span></span><span><span class="t-mark-rev t-since-cxx11">(C++11)</span></span></span></div>
</div>
</td>
<td>&#35745;&#31639;&#25972;&#25968;&#20540;&#30340;&#32477;&#23545;&#20540;&#65288; <span class="mjax" style="display:none">\(\small{|x|}\)</span><span class="mjax-fallback texhtml" style="white-space: nowrap;">|x|</span> &#65289;<br />
<span class="t-mark">(&#20989;&#25968;)</span></td>
</tr>
</table>
</div>
<div class="visualClear"></div>
</div>
</div>
</div>
</body>
</html>
Reference in New Issue View Git Blame Copy Permalink