| use core::mem; |
| use core::pin::Pin; |
| use futures_core::future::{FusedFuture, Future}; |
| use futures_core::stream::{FusedStream, TryStream}; |
| use futures_core::task::{Context, Poll}; |
| use pin_utils::{unsafe_pinned, unsafe_unpinned}; |
| |
| /// Future for the [`try_collect`](super::TryStreamExt::try_collect) method. |
| #[derive(Debug)] |
| #[must_use = "futures do nothing unless you `.await` or poll them"] |
| pub struct TryCollect<St, C> { |
| stream: St, |
| items: C, |
| } |
| |
| impl<St: TryStream, C: Default> TryCollect<St, C> { |
| unsafe_pinned!(stream: St); |
| unsafe_unpinned!(items: C); |
| |
| pub(super) fn new(s: St) -> TryCollect<St, C> { |
| TryCollect { |
| stream: s, |
| items: Default::default(), |
| } |
| } |
| |
| fn finish(self: Pin<&mut Self>) -> C { |
| mem::replace(self.items(), Default::default()) |
| } |
| } |
| |
| impl<St: Unpin + TryStream, C> Unpin for TryCollect<St, C> {} |
| |
| impl<St, C> FusedFuture for TryCollect<St, C> |
| where |
| St: TryStream + FusedStream, |
| C: Default + Extend<St::Ok>, |
| { |
| fn is_terminated(&self) -> bool { |
| self.stream.is_terminated() |
| } |
| } |
| |
| impl<St, C> Future for TryCollect<St, C> |
| where |
| St: TryStream, |
| C: Default + Extend<St::Ok>, |
| { |
| type Output = Result<C, St::Error>; |
| |
| fn poll( |
| mut self: Pin<&mut Self>, |
| cx: &mut Context<'_>, |
| ) -> Poll<Self::Output> { |
| loop { |
| match ready!(self.as_mut().stream().try_poll_next(cx)?) { |
| Some(x) => self.as_mut().items().extend(Some(x)), |
| None => return Poll::Ready(Ok(self.as_mut().finish())), |
| } |
| } |
| } |
| } |