difference_by_key

iter_set

Function difference_by_key 

Source 
pub fn difference_by_key<T, L, R, K, F>(
    a: L,
    b: R,
    key: F,
) -> impl Iterator<Item = T>
where
    L: IntoIterator<Item = T>,
    R: IntoIterator<Item = T>,
    K: Ord,
    F: FnMut(&T) -> K,
Expand description

Take the difference of two sets represented by sorted, deduplicated iterators, using a key extraction function.

See difference().