Type Definition futures::Poll

type Poll<T, E> = Result<Async<T>, E>;

Return type of the Future::poll method, indicates whether a future’s value is ready or not.

• Ok(Async::Ready(t)) means that a future has successfully resolved
• Ok(Async::NotReady) means that a future is not ready to complete yet
• Err(e) means that a future has completed with the given failure