Function hamming_distance 

pub fn hamming_distance(a: &[u8], b: &[u8]) -> u32

Count the number of differing bits between two equal-length packed-bit slices, dispatching to the best available SIMD kernel at runtime.

In debug builds, panics if a.len() != b.len(). In release builds, the shorter length is used and the tail of the longer slice is ignored.