Function intersection_sorted 

pub fn intersection_sorted<Item, Iter, Iters>(
    input: Iters,
) -> impl Iterator<Item = Item> + Send
where
    Iters: Iterator<Item = Iter> + Clone + Send,
    Iter: Iterator<Item = Item> + Send,
    Item: Eq + Ord,

Intersection of sets

Outputs the set of elements common to all input sets. Inputs must be sorted.