/// Count up to `(2^32)-1` occurrences of a byte in a slice
/// of bytes, simple
/// Count occurrences of a byte in a slice of bytes, simple
/// Count the number of UTF-8 encoded Unicode codepoints in a slice of bytes, simple
///
/// This function is safe to use on any byte array, valid UTF-8 or not,
/// but the output is only meaningful for well-formed UTF-8.