macro_rules! ready {
($e:expr) => { ... };
}Extracts the successful type of a Poll<T>.
This macro bakes in propagation of Pending signals by returning early.
#![feature(future_readiness_fns)]
#![feature(ready_macro)]
use core::task::{ready, Context, Poll};
use core::future::{self, Future};
use core::pin::Pin;
pub fn do_poll(cx: &mut Context<'_>) -> Poll<()> {
let mut fut = future::ready(42);
let fut = Pin::new(&mut fut);
let num = ready!(fut.poll(cx));
// ... use num
Poll::Ready(())
}The ready! call expands to:
let num = match fut.poll(cx) {
Poll::Ready(t) => t,
Poll::Pending => return Poll::Pending,
};
© 2010 The Rust Project Developers
Licensed under the Apache License, Version 2.0 or the MIT license, at your option.
https://doc.rust-lang.org/std/task/macro.ready.html