blob: 0d9537e8cf9beb8285c3f784733ac25f8fca8d5f [file] [log] [blame]
use core::marker::Unpin;
use core::pin::PinMut;
use futures_core::future::Future;
use futures_core::stream::Stream;
use futures_core::task::{self, Poll};
/// A future of the next element of a stream.
#[derive(Debug)]
#[must_use = "futures do nothing unless polled"]
pub struct Next<'a, St: 'a> {
stream: &'a mut St,
}
impl<St: Stream + Unpin> Unpin for Next<'_, St> {}
impl<'a, St: Stream + Unpin> Next<'a, St> {
pub(super) fn new(stream: &'a mut St) -> Self {
Next { stream }
}
}
impl<St: Stream + Unpin> Future for Next<'_, St> {
type Output = Option<St::Item>;
fn poll(
mut self: PinMut<Self>,
cx: &mut task::Context,
) -> Poll<Self::Output> {
PinMut::new(&mut *self.stream).poll_next(cx)
}
}