Function iter_set::cmp

pub fn cmp<T, L, R>(a: L, b: R) -> Option<Ordering> where
    T: Ord,
    L: IntoIterator<Item = T>,
    R: IntoIterator<Item = T>, 

Compare two sets represented by sorted, deduplicated iterators.

If the iterators are equal, then Some(Equal) is returned. If a is a subset of b then Some(Less) is returned. If a is a superset of b then Some(Greater) is returned. Otherwise, None is returned. If a and b are not sorted or contain duplicate values, the return value is unspecified.

Time complexity: O(a.len() + b.len()).