| use core::pin::Pin; |
| use futures_core::future::{FusedFuture, Future, TryFuture}; |
| use futures_core::task::{Context, Poll}; |
| use pin_utils::{unsafe_pinned, unsafe_unpinned}; |
| |
| /// Future for the [`map_ok_or_else`](super::TryFutureExt::map_ok_or_else) method. |
| #[derive(Debug)] |
| #[must_use = "futures do nothing unless you `.await` or poll them"] |
| pub struct MapOkOrElse<Fut, F, E> { |
| future: Fut, |
| f: Option<F>, |
| e: Option<E>, |
| } |
| |
| impl<Fut, F, E> MapOkOrElse<Fut, F, E> { |
| unsafe_pinned!(future: Fut); |
| unsafe_unpinned!(f: Option<F>); |
| unsafe_unpinned!(e: Option<E>); |
| |
| /// Creates a new MapOkOrElse. |
| pub(super) fn new(future: Fut, e: E, f: F) -> Self { |
| Self { future, f: Some(f), e: Some(e) } |
| } |
| } |
| |
| impl<Fut: Unpin, F, E> Unpin for MapOkOrElse<Fut, F, E> {} |
| |
| impl<Fut, F, E, T> FusedFuture for MapOkOrElse<Fut, F, E> |
| where Fut: TryFuture, |
| F: FnOnce(Fut::Ok) -> T, |
| E: FnOnce(Fut::Error) -> T, |
| { |
| fn is_terminated(&self) -> bool { |
| self.f.is_none() || self.e.is_none() |
| } |
| } |
| |
| impl<Fut, F, E, T> Future for MapOkOrElse<Fut, F, E> |
| where Fut: TryFuture, |
| F: FnOnce(Fut::Ok) -> T, |
| E: FnOnce(Fut::Error) -> T, |
| { |
| type Output = T; |
| |
| fn poll( |
| mut self: Pin<&mut Self>, |
| cx: &mut Context<'_>, |
| ) -> Poll<Self::Output> { |
| self.as_mut() |
| .future() |
| .try_poll(cx) |
| .map(|result| { |
| match result { |
| Ok(i) => (self.as_mut().f().take().expect("MapOkOrElse must not be polled after it returned `Poll::Ready`"))(i), |
| Err(e) => (self.as_mut().e().take().expect("MapOkOrElse must not be polled after it returned `Poll::Ready`"))(e), |
| } |
| }) |
| } |
| } |