pub fn select3<A, B, C>(a: A, b: B, c: C) -> Select3<A, B, C>Notable traits for Select3<A, B, C>impl<A, B, C> Future for Select3<A, B, C> where
    A: Future,
    B: Future,
    C: Future
type Output = Either3<A::Output, B::Output, C::Output>;
where
    A: Future,
    B: Future,
    C: Future
Expand description

Same as select, but with more futures.