Async

The Future Trait Has A Missing State

Yoshua Wuyts argues that Rust's Future trait lacks a way to report that a future has already completed: polling after Ready may panic or misbehave, forcing bookkeeping wrappers like MaybeDone and adding code size. He sketches fixing Poll and CoroutineState with a 'done' state, explores even more states, and urges not repeating the mistake in the Coroutine trait and gen keyword.

Blog post · Rust · Programming Languages · Async