Rollup merge of rust-lang#88722 - WaffleLapkin:unsafe_cell_const_get_mut, r=dtolnay

Manishearth · web-flow · commit 1a91d5754396 · 2021-09-12T10:50:42.000-07:00
Make `UnsafeCell::get_mut` const
diff --git a/library/core/src/cell.rs b/library/core/src/cell.rs
@@ -1916,7 +1916,8 @@ impl<T: ?Sized> UnsafeCell<T> {
     /// ```
     #[inline(always)]
     #[stable(feature = "unsafe_cell_get_mut", since = "1.50.0")]
-    pub fn get_mut(&mut self) -> &mut T {
+    #[rustc_const_unstable(feature = "const_unsafecell_get_mut", issue = "88836")]
+    pub const fn get_mut(&mut self) -> &mut T {
         &mut self.value
     }
 

Original file line number	Diff line number	Diff line change
`@@ -1916,7 +1916,8 @@ impl<T: ?Sized> UnsafeCell<T> {`
`1916`	`1916`	/// ```
`1917`	`1917`	`#[inline(always)]`
`1918`	`1918`	`#[stable(feature = "unsafe_cell_get_mut", since = "1.50.0")]`
`1919`		`- pub fn get_mut(&mut self) -> &mut T {`
	`1919`	`+ #[rustc_const_unstable(feature = "const_unsafecell_get_mut", issue = "88836")]`
	`1920`	`+ pub const fn get_mut(&mut self) -> &mut T {`
`1920`	`1921`	`&mut self.value`
`1921`	`1922`	`}`
`1922`	`1923`