pub fn join<A: Future, B: Future>(a: A, b: B) -> Join<A, B> ⓘExpand description
Drive two futures concurrently, returning both outputs once both complete.
Both futures are polled on each wake; neither starves the other. This is a minimal,
runtime-agnostic equivalent of futures::join! for the two-future case. The futures are boxed so
the combinator needs no unsafe pin projection.