Function memchr::memrchr

pub fn memrchr(needle: u8, haystack: &[u8]) -> Option<usize>

Search for the last occurrence of a byte in a slice.

This returns the index corresponding to the last occurrence of needle in haystack, or None if one is not found.

While this is operationally the same as something like haystack.iter().rposition(|&b| b == needle), memrchr will use a highly optimized routine that can be up to an order of magnitude faster in some cases.

Example

This shows how to find the last position of a byte in a byte string.

use memchr::memrchr;

let haystack = b"the quick brown fox";
assert_eq!(memrchr(b'o', haystack), Some(17));