| <!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Extension trait for subsecond rounding or truncation to a maximum number of digits. Rounding can be used to decrease the error variance when serializing/persisting to lower precision. Truncation is the default behavior in Chrono display formatting. Either can be used to guarantee equality (e.g. for testing) when round-tripping through a lower precision format."><meta name="keywords" content="rust, rustlang, rust-lang, SubsecRound"><title>SubsecRound in chrono - Rust</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../SourceSerif4-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../FiraSans-Regular.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../FiraSans-Medium.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../SourceCodePro-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../SourceSerif4-Bold.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../SourceCodePro-Semibold.ttf.woff2"><link rel="stylesheet" href="../normalize.css"><link rel="stylesheet" href="../rustdoc.css" id="mainThemeStyle"><link rel="stylesheet" href="../ayu.css" disabled><link rel="stylesheet" href="../dark.css" disabled><link rel="stylesheet" href="../light.css" id="themeStyle"><script id="default-settings" ></script><script src="../storage.js"></script><script defer src="sidebar-items.js"></script><script defer src="../main.js"></script><noscript><link rel="stylesheet" href="../noscript.css"></noscript><link rel="alternate icon" type="image/png" href="../favicon-16x16.png"><link rel="alternate icon" type="image/png" href="../favicon-32x32.png"><link rel="icon" type="image/svg+xml" href="../favicon.svg"></head><body class="rustdoc trait"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="mobile-topbar"><button class="sidebar-menu-toggle">☰</button><a class="sidebar-logo" href="../chrono/index.html"><div class="logo-container"><img class="rust-logo" src="../rust-logo.svg" alt="logo"></div></a><h2></h2></nav><nav class="sidebar"><a class="sidebar-logo" href="../chrono/index.html"><div class="logo-container"><img class="rust-logo" src="../rust-logo.svg" alt="logo"></div></a><h2 class="location"><a href="#">SubsecRound</a></h2><div class="sidebar-elems"><section><h3><a href="#required-methods">Required Methods</a></h3><ul class="block"><li><a href="#tymethod.round_subsecs">round_subsecs</a></li><li><a href="#tymethod.trunc_subsecs">trunc_subsecs</a></li></ul><h3><a href="#implementors">Implementors</a></h3></section><h2><a href="index.html">In chrono</a></h2></div></nav><main><div class="width-limiter"><nav class="sub"><form class="search-form"><div class="search-container"><span></span><input class="search-input" name="search" autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"><div id="help-button" title="help" tabindex="-1"><a href="../help.html">?</a></div><div id="settings-menu" tabindex="-1"><a href="../settings.html" title="settings"><img width="22" height="22" alt="Change settings" src="../wheel.svg"></a></div></div></form></nav><section id="main-content" class="content"><div class="main-heading"><h1 class="fqn">Trait <a href="index.html">chrono</a>::<wbr><a class="trait" href="#">SubsecRound</a><button id="copy-path" onclick="copy_path(this)" title="Copy item path to clipboard"><img src="../clipboard.svg" width="19" height="18" alt="Copy item path"></button></h1><span class="out-of-band"><a class="srclink" href="../src/chrono/round.rs.html#20-45">source</a> · <a id="toggle-all-docs" href="javascript:void(0)" title="collapse all docs">[<span class="inner">−</span>]</a></span></div><div class="item-decl"><pre class="rust trait"><code>pub trait SubsecRound { |
| fn <a href="#tymethod.round_subsecs" class="fnname">round_subsecs</a>(self, digits: <a class="primitive" href="https://doc.rust-lang.org/nightly/core/primitive.u16.html">u16</a>) -> Self; |
| <span class="item-spacer"></span> fn <a href="#tymethod.trunc_subsecs" class="fnname">trunc_subsecs</a>(self, digits: <a class="primitive" href="https://doc.rust-lang.org/nightly/core/primitive.u16.html">u16</a>) -> Self; |
| }</code></pre></div><details class="rustdoc-toggle top-doc" open><summary class="hideme"><span>Expand description</span></summary><div class="docblock"><p>Extension trait for subsecond rounding or truncation to a maximum number |
| of digits. Rounding can be used to decrease the error variance when |
| serializing/persisting to lower precision. Truncation is the default |
| behavior in Chrono display formatting. Either can be used to guarantee |
| equality (e.g. for testing) when round-tripping through a lower precision |
| format.</p> |
| </div></details><h2 id="required-methods" class="small-section-header">Required Methods<a href="#required-methods" class="anchor"></a></h2><div class="methods"><details class="rustdoc-toggle method-toggle" open><summary><section id="tymethod.round_subsecs" class="method has-srclink"><a class="srclink rightside" href="../src/chrono/round.rs.html#32">source</a><h4 class="code-header">fn <a href="#tymethod.round_subsecs" class="fnname">round_subsecs</a>(self, digits: <a class="primitive" href="https://doc.rust-lang.org/nightly/core/primitive.u16.html">u16</a>) -> Self</h4></section></summary><div class="docblock"><p>Return a copy rounded to the specified number of subsecond digits. With |
| 9 or more digits, self is returned unmodified. Halfway values are |
| rounded up (away from zero).</p> |
| <h5 id="example"><a href="#example">Example</a></h5> |
| <div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">let </span>dt = NaiveDate::from_ymd_opt(<span class="number">2018</span>, <span class="number">1</span>, <span class="number">11</span>).unwrap().and_hms_milli_opt(<span class="number">12</span>, <span class="number">0</span>, <span class="number">0</span>, <span class="number">154</span>).unwrap().and_local_timezone(Utc).unwrap(); |
| <span class="macro">assert_eq!</span>(dt.round_subsecs(<span class="number">2</span>).nanosecond(), <span class="number">150_000_000</span>); |
| <span class="macro">assert_eq!</span>(dt.round_subsecs(<span class="number">1</span>).nanosecond(), <span class="number">200_000_000</span>);</code></pre></div> |
| </div></details><details class="rustdoc-toggle method-toggle" open><summary><section id="tymethod.trunc_subsecs" class="method has-srclink"><a class="srclink rightside" href="../src/chrono/round.rs.html#44">source</a><h4 class="code-header">fn <a href="#tymethod.trunc_subsecs" class="fnname">trunc_subsecs</a>(self, digits: <a class="primitive" href="https://doc.rust-lang.org/nightly/core/primitive.u16.html">u16</a>) -> Self</h4></section></summary><div class="docblock"><p>Return a copy truncated to the specified number of subsecond |
| digits. With 9 or more digits, self is returned unmodified.</p> |
| <h5 id="example-1"><a href="#example-1">Example</a></h5> |
| <div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">let </span>dt = NaiveDate::from_ymd_opt(<span class="number">2018</span>, <span class="number">1</span>, <span class="number">11</span>).unwrap().and_hms_milli_opt(<span class="number">12</span>, <span class="number">0</span>, <span class="number">0</span>, <span class="number">154</span>).unwrap().and_local_timezone(Utc).unwrap(); |
| <span class="macro">assert_eq!</span>(dt.trunc_subsecs(<span class="number">2</span>).nanosecond(), <span class="number">150_000_000</span>); |
| <span class="macro">assert_eq!</span>(dt.trunc_subsecs(<span class="number">1</span>).nanosecond(), <span class="number">100_000_000</span>);</code></pre></div> |
| </div></details></div><h2 id="implementors" class="small-section-header">Implementors<a href="#implementors" class="anchor"></a></h2><div id="implementors-list"><section id="impl-SubsecRound-for-T" class="impl has-srclink"><a class="srclink rightside" href="../src/chrono/round.rs.html#47-75">source</a><a href="#impl-SubsecRound-for-T" class="anchor"></a><h3 class="code-header">impl<T> <a class="trait" href="trait.SubsecRound.html" title="trait chrono::SubsecRound">SubsecRound</a> for T<span class="where fmt-newline">where<br> T: <a class="trait" href="trait.Timelike.html" title="trait chrono::Timelike">Timelike</a> + <a class="trait" href="https://doc.rust-lang.org/nightly/core/ops/arith/trait.Add.html" title="trait core::ops::arith::Add">Add</a><<a class="struct" href="struct.Duration.html" title="struct chrono::Duration">Duration</a>, Output = T> + <a class="trait" href="https://doc.rust-lang.org/nightly/core/ops/arith/trait.Sub.html" title="trait core::ops::arith::Sub">Sub</a><<a class="struct" href="struct.Duration.html" title="struct chrono::Duration">Duration</a>, Output = T>,</span></h3></section></div><script src="../implementors/chrono/round/trait.SubsecRound.js" async></script></section></div></main><div id="rustdoc-vars" data-root-path="../" data-current-crate="chrono" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html> |
