Rollup merge of rust-lang#148757 - nxsaken:const_mem_take, r=scottmcm

Zalathar · web-flow · commit 968cfd347b90 · 2025-11-17T16:04:23.000+11:00
Constify `mem::take` Feature: `const_default` (rust-lang#143894)
diff --git a/library/core/src/mem/mod.rs b/library/core/src/mem/mod.rs
@@ -808,7 +808,8 @@ pub const fn swap<T>(x: &mut T, y: &mut T) {
 /// ```
 #[inline]
 #[stable(feature = "mem_take", since = "1.40.0")]
-pub fn take<T: Default>(dest: &mut T) -> T {
+#[rustc_const_unstable(feature = "const_default", issue = "143894")]
+pub const fn take<T: [const] Default>(dest: &mut T) -> T {
     replace(dest, T::default())
 }
 

Original file line number	Diff line number	Diff line change
`@@ -808,7 +808,8 @@ pub const fn swap<T>(x: &mut T, y: &mut T) {`
`808`	`808`	/// ```
`809`	`809`	`#[inline]`
`810`	`810`	`#[stable(feature = "mem_take", since = "1.40.0")]`
`811`		`-pub fn take<T: Default>(dest: &mut T) -> T {`
	`811`	`+#[rustc_const_unstable(feature = "const_default", issue = "143894")]`
	`812`	`+pub const fn take<T: [const] Default>(dest: &mut T) -> T {`
`812`	`813`	`replace(dest, T::default())`
`813`	`814`	`}`
`814`	`815`