This crate provides a safe interface `libc`'s `memchr` and `memrchr`. This crate also provides fallback implementations when either function is unavailable. [![Build status](https://api.travis-ci.org/BurntSushi/rust-memchr.png)](https://travis-ci.org/BurntSushi/rust-memchr) [![Build status](https://ci.appveyor.com/api/projects/status/8i9484t8l4w7uql0/branch/master?svg=true)](https://ci.appveyor.com/project/BurntSushi/rust-memchr/branch/master) [![](http://meritbadge.herokuapp.com/memchr)](https://crates.io/crates/memchr) Dual-licensed under MIT or the [UNLICENSE](http://unlicense.org). ### Documentation [https://docs.rs/memchr](https://docs.rs/memchr) ### no_std memchr links to the standard library by default, but you can disable the `use_std` feature if you want to use it in a `#![no_std]` crate: ```toml [dependencies] memchr = { version = "1.0", default-features = false } ``` ### Performance On my system (Linux/amd64), `memchr` is about an order of magnitude faster than the more idiomatic `haystack.iter().position(|&b| b == needle)`: ``` test iterator ... bench: 5,280 ns/iter (+/- 13) = 1893 MB/s test iterator_reversed ... bench: 5,271 ns/iter (+/- 7) = 1897 MB/s test libc_memchr ... bench: 202 ns/iter (+/- 0) = 49504 MB/s test libc_memrchr ... bench: 197 ns/iter (+/- 1) = 50761 MB/s ```