blob: 9d950161a1c9fbdb2f00501a2b7d817544ba760a [file] [log] [blame]
use core::marker::Unpin;
use core::mem::PinMut;
use futures_core::future::Future;
use futures_core::task::{self, Poll};
/// A future that is immediately ready with a value
///
/// Created by the [`ready()`] function.
#[derive(Debug, Clone)]
#[must_use = "futures do nothing unless polled"]
pub struct Ready<T>(Option<T>);
impl<T> Unpin for Ready<T> {}
impl<T> Future for Ready<T> {
type Output = T;
#[inline]
fn poll(mut self: PinMut<Self>, _cx: &mut task::Context) -> Poll<T> {
Poll::Ready(self.0.take().unwrap())
}
}
/// Create a future that is immediately ready with a value.
///
/// # Examples
///
/// ```
/// #![feature(async_await, await_macro, futures_api)]
/// # futures::executor::block_on(async {
/// use futures::future;
///
/// let a = future::ready(1);
/// assert_eq!(await!(a), 1);
/// # });
/// ```
pub fn ready<T>(t: T) -> Ready<T> {
Ready(Some(t))
}