| use crate::Stream; |
| |
| use core::future::Future; |
| use core::marker::PhantomPinned; |
| use core::pin::Pin; |
| use core::task::{Context, Poll}; |
| use pin_project_lite::pin_project; |
| |
| pin_project! { |
| /// Future for the [`next`](super::StreamExt::next) method. |
| #[derive(Debug)] |
| #[must_use = "futures do nothing unless you `.await` or poll them"] |
| pub struct Next<'a, St: ?Sized> { |
| stream: &'a mut St, |
| // Make this future `!Unpin` for compatibility with async trait methods. |
| #[pin] |
| _pin: PhantomPinned, |
| } |
| } |
| |
| impl<'a, St: ?Sized> Next<'a, St> { |
| pub(super) fn new(stream: &'a mut St) -> Self { |
| Next { |
| stream, |
| _pin: PhantomPinned, |
| } |
| } |
| } |
| |
| impl<St: ?Sized + Stream + Unpin> Future for Next<'_, St> { |
| type Output = Option<St::Item>; |
| |
| fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> { |
| let me = self.project(); |
| Pin::new(me.stream).poll_next(cx) |
| } |
| } |