# Function memchr::memchr [−] [src]

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

A safe interface to `memchr`.

Returns the index corresponding to the first occurrence of `needle` in `haystack`, or `None` if one is not found.

memchr reduces to super-optimized machine code at around an order of magnitude faster than `haystack.iter().position(|&b| b == needle)`. (See benchmarks.)

# Example

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

    use memchr::memchr;

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

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