| <!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="Source of the Rust file `/root/.cargo/registry/src/github.com-1ecc6299db9ec823/memchr-2.5.0/src/memchr/fallback.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>fallback.rs - source</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="../../../source-script.js"></script><script defer src="../../../source-files.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 source"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><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></nav><main><div class="width-limiter"><nav class="sub"><a class="sub-logo-container" href="../../../memchr/index.html"><img class="rust-logo" src="../../../rust-logo.svg" alt="logo"></a><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="example-wrap"><pre class="src-line-numbers"><span id="1">1</span> |
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| </pre><pre class="rust"><code><span class="comment">// This module defines pure Rust platform independent implementations of all |
| // the memchr routines. We do our best to make them fast. Some of them may even |
| // get auto-vectorized. |
| |
| </span><span class="kw">use </span>core::{cmp, usize}; |
| |
| <span class="attribute">#[cfg(target_pointer_width = <span class="string">"16"</span>)] |
| </span><span class="kw">const </span>USIZE_BYTES: usize = <span class="number">2</span>; |
| |
| <span class="attribute">#[cfg(target_pointer_width = <span class="string">"32"</span>)] |
| </span><span class="kw">const </span>USIZE_BYTES: usize = <span class="number">4</span>; |
| |
| <span class="attribute">#[cfg(target_pointer_width = <span class="string">"64"</span>)] |
| </span><span class="kw">const </span>USIZE_BYTES: usize = <span class="number">8</span>; |
| |
| <span class="comment">// The number of bytes to loop at in one iteration of memchr/memrchr. |
| </span><span class="kw">const </span>LOOP_SIZE: usize = <span class="number">2 </span>* USIZE_BYTES; |
| |
| <span class="doccomment">/// Return `true` if `x` contains any zero byte. |
| /// |
| /// From *Matters Computational*, J. Arndt |
| /// |
| /// "The idea is to subtract one from each of the bytes and then look for |
| /// bytes where the borrow propagated all the way to the most significant |
| /// bit." |
| </span><span class="attribute">#[inline(always)] |
| </span><span class="kw">fn </span>contains_zero_byte(x: usize) -> bool { |
| <span class="kw">const </span>LO_U64: u64 = <span class="number">0x0101010101010101</span>; |
| <span class="kw">const </span>HI_U64: u64 = <span class="number">0x8080808080808080</span>; |
| |
| <span class="kw">const </span>LO_USIZE: usize = LO_U64 <span class="kw">as </span>usize; |
| <span class="kw">const </span>HI_USIZE: usize = HI_U64 <span class="kw">as </span>usize; |
| |
| x.wrapping_sub(LO_USIZE) & !x & HI_USIZE != <span class="number">0 |
| </span>} |
| |
| <span class="doccomment">/// Repeat the given byte into a word size number. That is, every 8 bits |
| /// is equivalent to the given byte. For example, if `b` is `\x4E` or |
| /// `01001110` in binary, then the returned value on a 32-bit system would be: |
| /// `01001110_01001110_01001110_01001110`. |
| </span><span class="attribute">#[inline(always)] |
| </span><span class="kw">fn </span>repeat_byte(b: u8) -> usize { |
| (b <span class="kw">as </span>usize) * (usize::MAX / <span class="number">255</span>) |
| } |
| |
| <span class="kw">pub fn </span>memchr(n1: u8, haystack: <span class="kw-2">&</span>[u8]) -> <span class="prelude-ty">Option</span><usize> { |
| <span class="kw">let </span>vn1 = repeat_byte(n1); |
| <span class="kw">let </span>confirm = |byte| byte == n1; |
| <span class="kw">let </span>loop_size = cmp::min(LOOP_SIZE, haystack.len()); |
| <span class="kw">let </span>align = USIZE_BYTES - <span class="number">1</span>; |
| <span class="kw">let </span>start_ptr = haystack.as_ptr(); |
| <span class="kw">let </span><span class="kw-2">mut </span>ptr = start_ptr; |
| |
| <span class="kw">unsafe </span>{ |
| <span class="kw">let </span>end_ptr = start_ptr.add(haystack.len()); |
| <span class="kw">if </span>haystack.len() < USIZE_BYTES { |
| <span class="kw">return </span>forward_search(start_ptr, end_ptr, ptr, confirm); |
| } |
| |
| <span class="kw">let </span>chunk = (ptr <span class="kw">as </span><span class="kw-2">*const </span>usize).read_unaligned(); |
| <span class="kw">if </span>contains_zero_byte(chunk ^ vn1) { |
| <span class="kw">return </span>forward_search(start_ptr, end_ptr, ptr, confirm); |
| } |
| |
| ptr = ptr.add(USIZE_BYTES - (start_ptr <span class="kw">as </span>usize & align)); |
| <span class="macro">debug_assert!</span>(ptr > start_ptr); |
| <span class="macro">debug_assert!</span>(end_ptr.sub(USIZE_BYTES) >= start_ptr); |
| <span class="kw">while </span>loop_size == LOOP_SIZE && ptr <= end_ptr.sub(loop_size) { |
| <span class="macro">debug_assert_eq!</span>(<span class="number">0</span>, (ptr <span class="kw">as </span>usize) % USIZE_BYTES); |
| |
| <span class="kw">let </span>a = <span class="kw-2">*</span>(ptr <span class="kw">as </span><span class="kw-2">*const </span>usize); |
| <span class="kw">let </span>b = <span class="kw-2">*</span>(ptr.add(USIZE_BYTES) <span class="kw">as </span><span class="kw-2">*const </span>usize); |
| <span class="kw">let </span>eqa = contains_zero_byte(a ^ vn1); |
| <span class="kw">let </span>eqb = contains_zero_byte(b ^ vn1); |
| <span class="kw">if </span>eqa || eqb { |
| <span class="kw">break</span>; |
| } |
| ptr = ptr.add(LOOP_SIZE); |
| } |
| forward_search(start_ptr, end_ptr, ptr, confirm) |
| } |
| } |
| |
| <span class="doccomment">/// Like `memchr`, but searches for two bytes instead of one. |
| </span><span class="kw">pub fn </span>memchr2(n1: u8, n2: u8, haystack: <span class="kw-2">&</span>[u8]) -> <span class="prelude-ty">Option</span><usize> { |
| <span class="kw">let </span>vn1 = repeat_byte(n1); |
| <span class="kw">let </span>vn2 = repeat_byte(n2); |
| <span class="kw">let </span>confirm = |byte| byte == n1 || byte == n2; |
| <span class="kw">let </span>align = USIZE_BYTES - <span class="number">1</span>; |
| <span class="kw">let </span>start_ptr = haystack.as_ptr(); |
| <span class="kw">let </span><span class="kw-2">mut </span>ptr = start_ptr; |
| |
| <span class="kw">unsafe </span>{ |
| <span class="kw">let </span>end_ptr = start_ptr.add(haystack.len()); |
| <span class="kw">if </span>haystack.len() < USIZE_BYTES { |
| <span class="kw">return </span>forward_search(start_ptr, end_ptr, ptr, confirm); |
| } |
| |
| <span class="kw">let </span>chunk = (ptr <span class="kw">as </span><span class="kw-2">*const </span>usize).read_unaligned(); |
| <span class="kw">let </span>eq1 = contains_zero_byte(chunk ^ vn1); |
| <span class="kw">let </span>eq2 = contains_zero_byte(chunk ^ vn2); |
| <span class="kw">if </span>eq1 || eq2 { |
| <span class="kw">return </span>forward_search(start_ptr, end_ptr, ptr, confirm); |
| } |
| |
| ptr = ptr.add(USIZE_BYTES - (start_ptr <span class="kw">as </span>usize & align)); |
| <span class="macro">debug_assert!</span>(ptr > start_ptr); |
| <span class="macro">debug_assert!</span>(end_ptr.sub(USIZE_BYTES) >= start_ptr); |
| <span class="kw">while </span>ptr <= end_ptr.sub(USIZE_BYTES) { |
| <span class="macro">debug_assert_eq!</span>(<span class="number">0</span>, (ptr <span class="kw">as </span>usize) % USIZE_BYTES); |
| |
| <span class="kw">let </span>chunk = <span class="kw-2">*</span>(ptr <span class="kw">as </span><span class="kw-2">*const </span>usize); |
| <span class="kw">let </span>eq1 = contains_zero_byte(chunk ^ vn1); |
| <span class="kw">let </span>eq2 = contains_zero_byte(chunk ^ vn2); |
| <span class="kw">if </span>eq1 || eq2 { |
| <span class="kw">break</span>; |
| } |
| ptr = ptr.add(USIZE_BYTES); |
| } |
| forward_search(start_ptr, end_ptr, ptr, confirm) |
| } |
| } |
| |
| <span class="doccomment">/// Like `memchr`, but searches for three bytes instead of one. |
| </span><span class="kw">pub fn </span>memchr3(n1: u8, n2: u8, n3: u8, haystack: <span class="kw-2">&</span>[u8]) -> <span class="prelude-ty">Option</span><usize> { |
| <span class="kw">let </span>vn1 = repeat_byte(n1); |
| <span class="kw">let </span>vn2 = repeat_byte(n2); |
| <span class="kw">let </span>vn3 = repeat_byte(n3); |
| <span class="kw">let </span>confirm = |byte| byte == n1 || byte == n2 || byte == n3; |
| <span class="kw">let </span>align = USIZE_BYTES - <span class="number">1</span>; |
| <span class="kw">let </span>start_ptr = haystack.as_ptr(); |
| <span class="kw">let </span><span class="kw-2">mut </span>ptr = start_ptr; |
| |
| <span class="kw">unsafe </span>{ |
| <span class="kw">let </span>end_ptr = start_ptr.add(haystack.len()); |
| <span class="kw">if </span>haystack.len() < USIZE_BYTES { |
| <span class="kw">return </span>forward_search(start_ptr, end_ptr, ptr, confirm); |
| } |
| |
| <span class="kw">let </span>chunk = (ptr <span class="kw">as </span><span class="kw-2">*const </span>usize).read_unaligned(); |
| <span class="kw">let </span>eq1 = contains_zero_byte(chunk ^ vn1); |
| <span class="kw">let </span>eq2 = contains_zero_byte(chunk ^ vn2); |
| <span class="kw">let </span>eq3 = contains_zero_byte(chunk ^ vn3); |
| <span class="kw">if </span>eq1 || eq2 || eq3 { |
| <span class="kw">return </span>forward_search(start_ptr, end_ptr, ptr, confirm); |
| } |
| |
| ptr = ptr.add(USIZE_BYTES - (start_ptr <span class="kw">as </span>usize & align)); |
| <span class="macro">debug_assert!</span>(ptr > start_ptr); |
| <span class="macro">debug_assert!</span>(end_ptr.sub(USIZE_BYTES) >= start_ptr); |
| <span class="kw">while </span>ptr <= end_ptr.sub(USIZE_BYTES) { |
| <span class="macro">debug_assert_eq!</span>(<span class="number">0</span>, (ptr <span class="kw">as </span>usize) % USIZE_BYTES); |
| |
| <span class="kw">let </span>chunk = <span class="kw-2">*</span>(ptr <span class="kw">as </span><span class="kw-2">*const </span>usize); |
| <span class="kw">let </span>eq1 = contains_zero_byte(chunk ^ vn1); |
| <span class="kw">let </span>eq2 = contains_zero_byte(chunk ^ vn2); |
| <span class="kw">let </span>eq3 = contains_zero_byte(chunk ^ vn3); |
| <span class="kw">if </span>eq1 || eq2 || eq3 { |
| <span class="kw">break</span>; |
| } |
| ptr = ptr.add(USIZE_BYTES); |
| } |
| forward_search(start_ptr, end_ptr, ptr, confirm) |
| } |
| } |
| |
| <span class="doccomment">/// Return the last index matching the byte `x` in `text`. |
| </span><span class="kw">pub fn </span>memrchr(n1: u8, haystack: <span class="kw-2">&</span>[u8]) -> <span class="prelude-ty">Option</span><usize> { |
| <span class="kw">let </span>vn1 = repeat_byte(n1); |
| <span class="kw">let </span>confirm = |byte| byte == n1; |
| <span class="kw">let </span>loop_size = cmp::min(LOOP_SIZE, haystack.len()); |
| <span class="kw">let </span>align = USIZE_BYTES - <span class="number">1</span>; |
| <span class="kw">let </span>start_ptr = haystack.as_ptr(); |
| |
| <span class="kw">unsafe </span>{ |
| <span class="kw">let </span>end_ptr = start_ptr.add(haystack.len()); |
| <span class="kw">let </span><span class="kw-2">mut </span>ptr = end_ptr; |
| <span class="kw">if </span>haystack.len() < USIZE_BYTES { |
| <span class="kw">return </span>reverse_search(start_ptr, end_ptr, ptr, confirm); |
| } |
| |
| <span class="kw">let </span>chunk = (ptr.sub(USIZE_BYTES) <span class="kw">as </span><span class="kw-2">*const </span>usize).read_unaligned(); |
| <span class="kw">if </span>contains_zero_byte(chunk ^ vn1) { |
| <span class="kw">return </span>reverse_search(start_ptr, end_ptr, ptr, confirm); |
| } |
| |
| ptr = (end_ptr <span class="kw">as </span>usize & !align) <span class="kw">as </span><span class="kw-2">*const </span>u8; |
| <span class="macro">debug_assert!</span>(start_ptr <= ptr && ptr <= end_ptr); |
| <span class="kw">while </span>loop_size == LOOP_SIZE && ptr >= start_ptr.add(loop_size) { |
| <span class="macro">debug_assert_eq!</span>(<span class="number">0</span>, (ptr <span class="kw">as </span>usize) % USIZE_BYTES); |
| |
| <span class="kw">let </span>a = <span class="kw-2">*</span>(ptr.sub(<span class="number">2 </span>* USIZE_BYTES) <span class="kw">as </span><span class="kw-2">*const </span>usize); |
| <span class="kw">let </span>b = <span class="kw-2">*</span>(ptr.sub(<span class="number">1 </span>* USIZE_BYTES) <span class="kw">as </span><span class="kw-2">*const </span>usize); |
| <span class="kw">let </span>eqa = contains_zero_byte(a ^ vn1); |
| <span class="kw">let </span>eqb = contains_zero_byte(b ^ vn1); |
| <span class="kw">if </span>eqa || eqb { |
| <span class="kw">break</span>; |
| } |
| ptr = ptr.sub(loop_size); |
| } |
| reverse_search(start_ptr, end_ptr, ptr, confirm) |
| } |
| } |
| |
| <span class="doccomment">/// Like `memrchr`, but searches for two bytes instead of one. |
| </span><span class="kw">pub fn </span>memrchr2(n1: u8, n2: u8, haystack: <span class="kw-2">&</span>[u8]) -> <span class="prelude-ty">Option</span><usize> { |
| <span class="kw">let </span>vn1 = repeat_byte(n1); |
| <span class="kw">let </span>vn2 = repeat_byte(n2); |
| <span class="kw">let </span>confirm = |byte| byte == n1 || byte == n2; |
| <span class="kw">let </span>align = USIZE_BYTES - <span class="number">1</span>; |
| <span class="kw">let </span>start_ptr = haystack.as_ptr(); |
| |
| <span class="kw">unsafe </span>{ |
| <span class="kw">let </span>end_ptr = start_ptr.add(haystack.len()); |
| <span class="kw">let </span><span class="kw-2">mut </span>ptr = end_ptr; |
| <span class="kw">if </span>haystack.len() < USIZE_BYTES { |
| <span class="kw">return </span>reverse_search(start_ptr, end_ptr, ptr, confirm); |
| } |
| |
| <span class="kw">let </span>chunk = (ptr.sub(USIZE_BYTES) <span class="kw">as </span><span class="kw-2">*const </span>usize).read_unaligned(); |
| <span class="kw">let </span>eq1 = contains_zero_byte(chunk ^ vn1); |
| <span class="kw">let </span>eq2 = contains_zero_byte(chunk ^ vn2); |
| <span class="kw">if </span>eq1 || eq2 { |
| <span class="kw">return </span>reverse_search(start_ptr, end_ptr, ptr, confirm); |
| } |
| |
| ptr = (end_ptr <span class="kw">as </span>usize & !align) <span class="kw">as </span><span class="kw-2">*const </span>u8; |
| <span class="macro">debug_assert!</span>(start_ptr <= ptr && ptr <= end_ptr); |
| <span class="kw">while </span>ptr >= start_ptr.add(USIZE_BYTES) { |
| <span class="macro">debug_assert_eq!</span>(<span class="number">0</span>, (ptr <span class="kw">as </span>usize) % USIZE_BYTES); |
| |
| <span class="kw">let </span>chunk = <span class="kw-2">*</span>(ptr.sub(USIZE_BYTES) <span class="kw">as </span><span class="kw-2">*const </span>usize); |
| <span class="kw">let </span>eq1 = contains_zero_byte(chunk ^ vn1); |
| <span class="kw">let </span>eq2 = contains_zero_byte(chunk ^ vn2); |
| <span class="kw">if </span>eq1 || eq2 { |
| <span class="kw">break</span>; |
| } |
| ptr = ptr.sub(USIZE_BYTES); |
| } |
| reverse_search(start_ptr, end_ptr, ptr, confirm) |
| } |
| } |
| |
| <span class="doccomment">/// Like `memrchr`, but searches for three bytes instead of one. |
| </span><span class="kw">pub fn </span>memrchr3(n1: u8, n2: u8, n3: u8, haystack: <span class="kw-2">&</span>[u8]) -> <span class="prelude-ty">Option</span><usize> { |
| <span class="kw">let </span>vn1 = repeat_byte(n1); |
| <span class="kw">let </span>vn2 = repeat_byte(n2); |
| <span class="kw">let </span>vn3 = repeat_byte(n3); |
| <span class="kw">let </span>confirm = |byte| byte == n1 || byte == n2 || byte == n3; |
| <span class="kw">let </span>align = USIZE_BYTES - <span class="number">1</span>; |
| <span class="kw">let </span>start_ptr = haystack.as_ptr(); |
| |
| <span class="kw">unsafe </span>{ |
| <span class="kw">let </span>end_ptr = start_ptr.add(haystack.len()); |
| <span class="kw">let </span><span class="kw-2">mut </span>ptr = end_ptr; |
| <span class="kw">if </span>haystack.len() < USIZE_BYTES { |
| <span class="kw">return </span>reverse_search(start_ptr, end_ptr, ptr, confirm); |
| } |
| |
| <span class="kw">let </span>chunk = (ptr.sub(USIZE_BYTES) <span class="kw">as </span><span class="kw-2">*const </span>usize).read_unaligned(); |
| <span class="kw">let </span>eq1 = contains_zero_byte(chunk ^ vn1); |
| <span class="kw">let </span>eq2 = contains_zero_byte(chunk ^ vn2); |
| <span class="kw">let </span>eq3 = contains_zero_byte(chunk ^ vn3); |
| <span class="kw">if </span>eq1 || eq2 || eq3 { |
| <span class="kw">return </span>reverse_search(start_ptr, end_ptr, ptr, confirm); |
| } |
| |
| ptr = (end_ptr <span class="kw">as </span>usize & !align) <span class="kw">as </span><span class="kw-2">*const </span>u8; |
| <span class="macro">debug_assert!</span>(start_ptr <= ptr && ptr <= end_ptr); |
| <span class="kw">while </span>ptr >= start_ptr.add(USIZE_BYTES) { |
| <span class="macro">debug_assert_eq!</span>(<span class="number">0</span>, (ptr <span class="kw">as </span>usize) % USIZE_BYTES); |
| |
| <span class="kw">let </span>chunk = <span class="kw-2">*</span>(ptr.sub(USIZE_BYTES) <span class="kw">as </span><span class="kw-2">*const </span>usize); |
| <span class="kw">let </span>eq1 = contains_zero_byte(chunk ^ vn1); |
| <span class="kw">let </span>eq2 = contains_zero_byte(chunk ^ vn2); |
| <span class="kw">let </span>eq3 = contains_zero_byte(chunk ^ vn3); |
| <span class="kw">if </span>eq1 || eq2 || eq3 { |
| <span class="kw">break</span>; |
| } |
| ptr = ptr.sub(USIZE_BYTES); |
| } |
| reverse_search(start_ptr, end_ptr, ptr, confirm) |
| } |
| } |
| |
| <span class="attribute">#[inline(always)] |
| </span><span class="kw">unsafe fn </span>forward_search<F: Fn(u8) -> bool>( |
| start_ptr: <span class="kw-2">*const </span>u8, |
| end_ptr: <span class="kw-2">*const </span>u8, |
| <span class="kw-2">mut </span>ptr: <span class="kw-2">*const </span>u8, |
| confirm: F, |
| ) -> <span class="prelude-ty">Option</span><usize> { |
| <span class="macro">debug_assert!</span>(start_ptr <= ptr); |
| <span class="macro">debug_assert!</span>(ptr <= end_ptr); |
| |
| <span class="kw">while </span>ptr < end_ptr { |
| <span class="kw">if </span>confirm(<span class="kw-2">*</span>ptr) { |
| <span class="kw">return </span><span class="prelude-val">Some</span>(sub(ptr, start_ptr)); |
| } |
| ptr = ptr.offset(<span class="number">1</span>); |
| } |
| <span class="prelude-val">None |
| </span>} |
| |
| <span class="attribute">#[inline(always)] |
| </span><span class="kw">unsafe fn </span>reverse_search<F: Fn(u8) -> bool>( |
| start_ptr: <span class="kw-2">*const </span>u8, |
| end_ptr: <span class="kw-2">*const </span>u8, |
| <span class="kw-2">mut </span>ptr: <span class="kw-2">*const </span>u8, |
| confirm: F, |
| ) -> <span class="prelude-ty">Option</span><usize> { |
| <span class="macro">debug_assert!</span>(start_ptr <= ptr); |
| <span class="macro">debug_assert!</span>(ptr <= end_ptr); |
| |
| <span class="kw">while </span>ptr > start_ptr { |
| ptr = ptr.offset(-<span class="number">1</span>); |
| <span class="kw">if </span>confirm(<span class="kw-2">*</span>ptr) { |
| <span class="kw">return </span><span class="prelude-val">Some</span>(sub(ptr, start_ptr)); |
| } |
| } |
| <span class="prelude-val">None |
| </span>} |
| |
| <span class="doccomment">/// Subtract `b` from `a` and return the difference. `a` should be greater than |
| /// or equal to `b`. |
| </span><span class="kw">fn </span>sub(a: <span class="kw-2">*const </span>u8, b: <span class="kw-2">*const </span>u8) -> usize { |
| <span class="macro">debug_assert!</span>(a >= b); |
| (a <span class="kw">as </span>usize) - (b <span class="kw">as </span>usize) |
| } |
| </code></pre></div> |
| </section></div></main><div id="rustdoc-vars" data-root-path="../../../" data-current-crate="memchr" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html> |