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use crate::fmt;
use crate::future::Future;
use crate::pin::Pin;
use crate::task::{Context, Poll};
#[unstable(feature = "future_poll_fn", issue = "72302")]
pub fn poll_fn<T, F>(f: F) -> PollFn<F>
where
    F: FnMut(&mut Context<'_>) -> Poll<T>,
{
    PollFn { f }
}
#[must_use = "futures do nothing unless you `.await` or poll them"]
#[unstable(feature = "future_poll_fn", issue = "72302")]
pub struct PollFn<F> {
    f: F,
}
#[unstable(feature = "future_poll_fn", issue = "72302")]
impl<F> Unpin for PollFn<F> {}
#[unstable(feature = "future_poll_fn", issue = "72302")]
impl<F> fmt::Debug for PollFn<F> {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        f.debug_struct("PollFn").finish()
    }
}
#[unstable(feature = "future_poll_fn", issue = "72302")]
impl<T, F> Future for PollFn<F>
where
    F: FnMut(&mut Context<'_>) -> Poll<T>,
{
    type Output = T;
    fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<T> {
        (&mut self.f)(cx)
    }
}