From 2a5a6680fcff4a1d429ac3c67764dab813afef40 Mon Sep 17 00:00:00 2001
From: woppopo <woppopo@protonmail.com>
Date: Mon, 13 Dec 2021 14:17:35 +0900
Subject: [PATCH] Make `MaybeUninit::zeroed` `const`

---
 library/core/src/mem/maybe_uninit.rs | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/library/core/src/mem/maybe_uninit.rs b/library/core/src/mem/maybe_uninit.rs
index 9a29094b52c46..783a4b08ec19f 100644
--- a/library/core/src/mem/maybe_uninit.rs
+++ b/library/core/src/mem/maybe_uninit.rs
@@ -394,10 +394,11 @@ impl<T> MaybeUninit<T> {
     /// // This is undefined behavior. ⚠️
     /// ```
     #[stable(feature = "maybe_uninit", since = "1.36.0")]
+    #[rustc_const_unstable(feature = "const_maybe_uninit_zeroed", issue = "91850")]
     #[must_use]
     #[inline]
     #[rustc_diagnostic_item = "maybe_uninit_zeroed"]
-    pub fn zeroed() -> MaybeUninit<T> {
+    pub const fn zeroed() -> MaybeUninit<T> {
         let mut u = MaybeUninit::<T>::uninit();
         // SAFETY: `u.as_mut_ptr()` points to allocated memory.
         unsafe {