Function elipdotter::set::union

pub fn union<T, L, R>(a: L, b: R) -> impl Iterator<Item = T>where
    T: Ord,
    L: IntoIterator<Item = T>,
    R: IntoIterator<Item = T>,

Returns an iterator of all the items that occur in either a or b.

Both iterators must be sorted. The returned iterator is also sorted.