Function memchr::memrchr3

pub fn memrchr3(
    needle1: u8, 
    needle2: u8, 
    needle3: u8, 
    haystack: &[u8]
) -> Option<usize>

Like memrchr, but searches for any of three bytes instead of just one.

This returns the index corresponding to the last occurrence of needle1, the last occurrence of needle2, or the last occurrence of needle3 in haystack (whichever occurs later), or None if none are found. If an index is returned, it is guaranteed to be less than usize::MAX.

While this is operationally the same as something like haystack.iter().rposition(|&b| b == needle1 || b == needle2 || b == needle3), memrchr3 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 any of three bytes in a byte string.

use memchr::memrchr3;

let haystack = b"the quick brown fox";
assert_eq!(memrchr3(b'k', b'q', b'e', haystack), Some(8));