Function uncased_eq

pub fn uncased_eq<S1, S2>(s1: S1, s2: S2) -> bool
where
    S1: AsRef<str>,
    S2: AsRef<str>,

Returns true if s1 and s2 are equal without considering case.

That is, for ASCII strings, this function returns s1.to_lower() == s2.to_lower(), but does it in a much faster way.