From 81c00dde2b15120fd1e492909957feb720e33d0a Mon Sep 17 00:00:00 2001
From: Trevor Gross <tmgross@umich.edu>
Date: Wed, 21 Aug 2024 17:22:08 -0500
Subject: [PATCH] Add `const_cell_into_inner` to `OnceCell`
`Cell` and `RefCell` have their `into_inner` methods const unstable.
`OnceCell` has the same logic, so add it under the same gate.
Tracking issue: https://github.com/rust-lang/rust/issues/78729
---
library/core/src/cell/once.rs | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/library/core/src/cell/once.rs b/library/core/src/cell/once.rs
index 097fa86c93814..87df8a4e272e8 100644
--- a/library/core/src/cell/once.rs
+++ b/library/core/src/cell/once.rs
@@ -309,7 +309,8 @@ impl<T> OnceCell<T> {
/// ```
#[inline]
#[stable(feature = "once_cell", since = "1.70.0")]
- pub fn into_inner(self) -> Option<T> {
+ #[rustc_const_unstable(feature = "const_cell_into_inner", issue = "78729")]
+ pub const fn into_inner(self) -> Option<T> {
// Because `into_inner` takes `self` by value, the compiler statically verifies
// that it is not currently borrowed. So it is safe to move out `Option<T>`.
self.inner.into_inner()