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<!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="Like `memchr`, but searches for either of two bytes instead of just one."><meta name="keywords" content="rust, rustlang, rust-lang, memchr2"><title>memchr2 in memchr - 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" type="text/css" href="../normalize.css"><link rel="stylesheet" type="text/css" href="../rustdoc.css" id="mainThemeStyle"><link rel="stylesheet" type="text/css" href="../ayu.css" disabled><link rel="stylesheet" type="text/css" href="../dark.css" disabled><link rel="stylesheet" type="text/css" 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 fn"><!--[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">&#9776;</button><a class="sidebar-logo" href="../memchr/index.html"><div class="logo-container"><img class="rust-logo" src="../rust-logo.svg" alt="logo"></div></a><h2 class="location"></h2></nav><nav class="sidebar"><a class="sidebar-logo" href="../memchr/index.html"><div class="logo-container"><img class="rust-logo" src="../rust-logo.svg" alt="logo"></div></a><div class="sidebar-elems"><h2 class="location"><a href="index.html">In memchr</a></h2></div></nav><main><div class="width-limiter"><div class="sub-container"><a class="sub-logo-container" href="../memchr/index.html"><img class="rust-logo" src="../rust-logo.svg" alt="logo"></a><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"><button type="button">?</button></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></div><section id="main-content" class="content"><div class="main-heading"><h1 class="fqn"><span class="in-band">Function <a href="index.html">memchr</a>::<wbr><a class="fn" href="#">memchr2</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></span></h1><span class="out-of-band"><a class="srclink" href="../src/memchr/memchr/mod.rs.html#151-178">source</a> · <a id="toggle-all-docs" href="javascript:void(0)" title="collapse all docs">[<span class="inner">&#x2212;</span>]</a></span></div><div class="docblock item-decl"><pre class="rust fn"><code>pub fn memchr2(needle1: <a class="primitive" href="https://doc.rust-lang.org/1.64.0/std/primitive.u8.html">u8</a>, needle2: <a class="primitive" href="https://doc.rust-lang.org/1.64.0/std/primitive.u8.html">u8</a>, haystack: &amp;[<a class="primitive" href="https://doc.rust-lang.org/1.64.0/std/primitive.u8.html">u8</a>]) -&gt; <a class="enum" href="https://doc.rust-lang.org/1.64.0/core/option/enum.Option.html" title="enum core::option::Option">Option</a>&lt;<a class="primitive" href="https://doc.rust-lang.org/1.64.0/std/primitive.usize.html">usize</a>&gt;</code></pre></div><details class="rustdoc-toggle top-doc" open><summary class="hideme"><span>Expand description</span></summary><div class="docblock"><p>Like <code>memchr</code>, but searches for either of two bytes instead of just one.</p>
<p>This returns the index corresponding to the first occurrence of <code>needle1</code>
or the first occurrence of <code>needle2</code> in <code>haystack</code> (whichever occurs
earlier), or <code>None</code> if neither one is found. If an index is returned, it is
guaranteed to be less than <code>usize::MAX</code>.</p>
<p>While this is operationally the same as something like
<code>haystack.iter().position(|&amp;b| b == needle1 || b == needle2)</code>, <code>memchr2</code>
will use a highly optimized routine that can be up to an order of magnitude
faster in some cases.</p>
<h2 id="example"><a href="#example">Example</a></h2>
<p>This shows how to find the first position of either of two bytes in a byte
string.</p>
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use</span> <span class="ident">memchr::memchr2</span>;
<span class="kw">let</span> <span class="ident">haystack</span> <span class="op">=</span> <span class="string">b&quot;the quick brown fox&quot;</span>;
<span class="macro">assert_eq!</span>(<span class="ident">memchr2</span>(<span class="string">b&#39;k&#39;</span>, <span class="string">b&#39;q&#39;</span>, <span class="ident">haystack</span>), <span class="prelude-val">Some</span>(<span class="number">4</span>));</code></pre></div>
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