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-rw-r--r--library/core/src/future/mod.rs45
1 files changed, 0 insertions, 45 deletions
diff --git a/library/core/src/future/mod.rs b/library/core/src/future/mod.rs
index c4fb36209..46cbcd435 100644
--- a/library/core/src/future/mod.rs
+++ b/library/core/src/future/mod.rs
@@ -56,51 +56,6 @@ unsafe impl Send for ResumeTy {}
#[unstable(feature = "gen_future", issue = "50547")]
unsafe impl Sync for ResumeTy {}
-/// Wrap a generator in a future.
-///
-/// This function returns a `GenFuture` underneath, but hides it in `impl Trait` to give
-/// better error messages (`impl Future` rather than `GenFuture<[closure.....]>`).
-// This is `const` to avoid extra errors after we recover from `const async fn`
-#[doc(hidden)]
-#[unstable(feature = "gen_future", issue = "50547")]
-#[rustc_const_unstable(feature = "gen_future", issue = "50547")]
-#[inline]
-pub const fn from_generator<T>(gen: T) -> impl Future<Output = T::Return>
-where
- T: crate::ops::Generator<ResumeTy, Yield = ()>,
-{
- use crate::{
- ops::{Generator, GeneratorState},
- pin::Pin,
- task::Poll,
- };
-
- #[rustc_diagnostic_item = "gen_future"]
- struct GenFuture<T: Generator<ResumeTy, Yield = ()>>(T);
-
- // We rely on the fact that async/await futures are immovable in order to create
- // self-referential borrows in the underlying generator.
- impl<T: Generator<ResumeTy, Yield = ()>> !Unpin for GenFuture<T> {}
-
- impl<T: Generator<ResumeTy, Yield = ()>> Future for GenFuture<T> {
- type Output = T::Return;
- #[track_caller]
- fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
- // SAFETY: Safe because we're !Unpin + !Drop, and this is just a field projection.
- let gen = unsafe { Pin::map_unchecked_mut(self, |s| &mut s.0) };
-
- // Resume the generator, turning the `&mut Context` into a `NonNull` raw pointer. The
- // `.await` lowering will safely cast that back to a `&mut Context`.
- match gen.resume(ResumeTy(NonNull::from(cx).cast::<Context<'static>>())) {
- GeneratorState::Yielded(()) => Poll::Pending,
- GeneratorState::Complete(x) => Poll::Ready(x),
- }
- }
- }
-
- GenFuture(gen)
-}
-
#[lang = "get_context"]
#[doc(hidden)]
#[unstable(feature = "gen_future", issue = "50547")]