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 usize::MAX
.
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));