| use crate::stream::TryStreamExt; |
| use core::pin::Pin; |
| use futures_core::future::{FusedFuture, Future}; |
| use futures_core::stream::{FusedStream, TryStream}; |
| use futures_core::task::{Context, Poll}; |
| |
| /// Future for the [`try_next`](super::TryStreamExt::try_next) method. |
| #[derive(Debug)] |
| #[must_use = "futures do nothing unless you `.await` or poll them"] |
| pub struct TryNext<'a, St: ?Sized> { |
| stream: &'a mut St, |
| } |
| |
| impl<St: ?Sized + Unpin> Unpin for TryNext<'_, St> {} |
| |
| impl<'a, St: ?Sized + TryStream + Unpin> TryNext<'a, St> { |
| pub(super) fn new(stream: &'a mut St) -> Self { |
| TryNext { stream } |
| } |
| } |
| |
| impl<St: ?Sized + TryStream + Unpin + FusedStream> FusedFuture for TryNext<'_, St> { |
| fn is_terminated(&self) -> bool { |
| self.stream.is_terminated() |
| } |
| } |
| |
| impl<St: ?Sized + TryStream + Unpin> Future for TryNext<'_, St> { |
| type Output = Result<Option<St::Ok>, St::Error>; |
| |
| fn poll( |
| mut self: Pin<&mut Self>, |
| cx: &mut Context<'_>, |
| ) -> Poll<Self::Output> { |
| self.stream.try_poll_next_unpin(cx)?.map(Ok) |
| } |
| } |