semi_join

In std/collections.

fn semi_join<T, U, K>(self: Seq<T>, other: Seq<U>, *, left: T -> K, right: U -> K, on: (T, U) -> Bool) : Seq<T>
fn semi_join<T, U, K>(self: Seq<T>, other: Seq<U>, *, left: T -> K, right: U -> K) : Seq<T>
fn semi_join<T, U>(self: Seq<T>, other: Seq<U>, *, on: (T, U) -> Bool) : Seq<T>

The elements of the input that match some element of other, by keys, a predicate on, or both; each is kept at most once, in its position.