pub fn bisect_right<Collxn, Elm, Cmp>(
    collxn: &Collxn,
    idx_lo_incl: usize,
    idx_hi_excl: usize,
    cmp: Cmp
) -> usize
where Collxn: Index<usize, Output = Elm>, Cmp: Fn(&Elm) -> Ordering,