pub fn memrchr(needle: u8, haystack: &[u8]) -> Option<usize>Expand description
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. If an index is returned, it is
guaranteed to be less than haystack.len().
While this is semantically the same as something like
haystack.iter().rposition(|&b| b == needle), this routine will attempt to
use highly optimized vector operations that can be an order of magnitude
faster (or more).
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));