2 files changed, 31 insertions, 4 deletions
diff --git a/library/core/src/future/poll_fn.rs b/library/core/src/future/poll_fn.rs
index db2a52332..90cb79739 100644
--- a/library/core/src/future/poll_fn.rs
+++ b/library/core/src/future/poll_fn.rs
@@ -5,7 +5,9 @@ use crate::task::{Context, Poll};
 
 /// Creates a future that wraps a function returning [`Poll`].
 ///
-/// Polling the future delegates to the wrapped function.
+/// Polling the future delegates to the wrapped function. If the returned future is pinned, then the
+/// captured environment of the wrapped function is also pinned in-place, so as long as the closure
+/// does not move out of its captures it can soundly create pinned references to them.
 ///
 /// # Examples
 ///
@@ -41,7 +43,7 @@ pub struct PollFn<F> {
 }
 
 #[stable(feature = "future_poll_fn", since = "1.64.0")]
-impl<F> Unpin for PollFn<F> {}
+impl<F: Unpin> Unpin for PollFn<F> {}
 
 #[stable(feature = "future_poll_fn", since = "1.64.0")]
 impl<F> fmt::Debug for PollFn<F> {
@@ -57,7 +59,8 @@ where
 {
     type Output = T;
 
-    fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<T> {
-        (&mut self.f)(cx)
+    fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<T> {
+        // SAFETY: We are not moving out of the pinned field.
+        (unsafe { &mut self.get_unchecked_mut().f })(cx)
     }
 }
diff --git a/library/core/src/future/ready.rs b/library/core/src/future/ready.rs
index 48f20f90a..a07b63fb6 100644
--- a/library/core/src/future/ready.rs
+++ b/library/core/src/future/ready.rs
@@ -24,6 +24,30 @@ impl<T> Future for Ready<T> {
     }
 }
 
+impl<T> Ready<T> {
+    /// Consumes the `Ready`, returning the wrapped value.
+    ///
+    /// # Panics
+    ///
+    /// Will panic if this [`Ready`] was already polled to completion.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(ready_into_inner)]
+    /// use std::future;
+    ///
+    /// let a = future::ready(1);
+    /// assert_eq!(a.into_inner(), 1);
+    /// ```
+    #[unstable(feature = "ready_into_inner", issue = "101196")]
+    #[must_use]
+    #[inline]
+    pub fn into_inner(self) -> T {
+        self.0.expect("Called `into_inner()` on `Ready` after completion")
+    }
+}
+
 /// Creates a future that is immediately ready with a value.
 ///
 /// Futures created through this function are functionally similar to those