stabilize const_swap

Author: RalfJung

library/core/src/intrinsics/mod.rs

@@ -3954,7 +3954,8 @@ pub const fn is_val_statically_known<T: Copy>(_arg: T) -> bool {
 #[inline]
 #[rustc_intrinsic]
 // Const-unstable because `swap_nonoverlapping` is const-unstable.
-#[rustc_const_unstable(feature = "const_typed_swap", issue = "none")]
+#[rustc_intrinsic_const_stable_indirect]
+#[rustc_allow_const_fn_unstable(const_swap_nonoverlapping)] // this is anyway not called since CTFE implements the intrinsic
 pub const unsafe fn typed_swap<T>(x: *mut T, y: *mut T) {
     // SAFETY: The caller provided single non-overlapping items behind
     // pointers, so swapping them with `count: 1` is fine.

library/core/src/lib.rs

@@ -111,7 +111,6 @@
 #![feature(array_ptr_get)]
 #![feature(asm_experimental_arch)]
 #![feature(const_eval_select)]
-#![feature(const_typed_swap)]
 #![feature(core_intrinsics)]
 #![feature(coverage_attribute)]
 #![feature(internal_impls_macro)]

library/core/src/mem/mod.rs

@@ -725,7 +725,7 @@ pub unsafe fn uninitialized<T>() -> T {
 /// ```
 #[inline]
 #[stable(feature = "rust1", since = "1.0.0")]
-#[rustc_const_unstable(feature = "const_swap", issue = "83163")]
+#[rustc_const_stable(feature = "const_swap", since = "CURRENT_RUSTC_VERSION")]
 #[rustc_diagnostic_item = "mem_swap"]
 pub const fn swap<T>(x: &mut T, y: &mut T) {
     // SAFETY: `&mut` guarantees these are typed readable and writable

library/core/src/ptr/mod.rs

@@ -1009,9 +1009,8 @@ pub const fn slice_from_raw_parts_mut<T>(data: *mut T, len: usize) -> *mut [T] {
 /// ```
 #[inline]
 #[stable(feature = "rust1", since = "1.0.0")]
-#[rustc_const_unstable(feature = "const_swap", issue = "83163")]
+#[rustc_const_stable(feature = "const_swap", since = "CURRENT_RUSTC_VERSION")]
 #[rustc_diagnostic_item = "ptr_swap"]
-#[rustc_const_stable_indirect]
 pub const unsafe fn swap<T>(x: *mut T, y: *mut T) {
     // Give ourselves some scratch space to work with.
     // We do not have to worry about drops: `MaybeUninit` does nothing when dropped.

library/core/src/ptr/mut_ptr.rs

@@ -1594,7 +1594,7 @@ impl<T: ?Sized> *mut T {
     ///
     /// [`ptr::swap`]: crate::ptr::swap()
     #[stable(feature = "pointer_methods", since = "1.26.0")]
-    #[rustc_const_unstable(feature = "const_swap", issue = "83163")]
+    #[rustc_const_stable(feature = "const_swap", since = "CURRENT_RUSTC_VERSION")]
     #[inline(always)]
     pub const unsafe fn swap(self, with: *mut T)
     where

library/core/src/ptr/non_null.rs

@@ -1146,7 +1146,7 @@ impl<T: ?Sized> NonNull<T> {
     /// [`ptr::swap`]: crate::ptr::swap()
     #[inline(always)]
     #[stable(feature = "non_null_convenience", since = "1.80.0")]
-    #[rustc_const_unstable(feature = "const_swap", issue = "83163")]
+    #[rustc_const_stable(feature = "const_swap", since = "CURRENT_RUSTC_VERSION")]
     pub const unsafe fn swap(self, with: NonNull<T>)
     where
         T: Sized,

library/core/src/slice/mod.rs

@@ -913,7 +913,7 @@ impl<T> [T] {
     /// assert!(v == ["a", "b", "e", "d", "c"]);
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
-    #[rustc_const_unstable(feature = "const_swap", issue = "83163")]
+    #[rustc_const_stable(feature = "const_swap", since = "CURRENT_RUSTC_VERSION")]
     #[inline]
     #[track_caller]
     pub const fn swap(&mut self, a: usize, b: usize) {

library/core/tests/lib.rs

@@ -15,7 +15,6 @@
 #![feature(clone_to_uninit)]
 #![feature(const_black_box)]
 #![feature(const_eval_select)]
-#![feature(const_swap)]
 #![feature(const_swap_nonoverlapping)]
 #![feature(const_trait_impl)]
 #![feature(core_intrinsics)]

tests/ui/consts/issue-94371.rs

@@ -1,7 +1,5 @@
 //@ check-pass
 
-#![feature(const_swap)]
-
 #[repr(C)]
 struct Demo(u64, bool, u64, u32, u64, u64, u64);
 

tests/ui/consts/qualif-indirect-mutation-fail.rs

@@ -1,6 +1,5 @@
 //@ compile-flags: --crate-type=lib
 #![feature(const_precise_live_drops)]
-#![feature(const_swap)]
 
 // Mutable borrow of a field with drop impl.
 pub const fn f() {

tests/ui/consts/qualif-indirect-mutation-fail.stderr

@@ -1,5 +1,5 @@
 error[E0493]: destructor of `Option<String>` cannot be evaluated at compile-time
-  --> $DIR/qualif-indirect-mutation-fail.rs:13:9
+  --> $DIR/qualif-indirect-mutation-fail.rs:12:9
    |
 LL |     let mut x = None;
    |         ^^^^^ the destructor for this type cannot be evaluated in constants
@@ -19,13 +19,13 @@ note: inside `std::ptr::drop_in_place::<String> - shim(Some(String))`
 note: inside `std::ptr::drop_in_place::<Option<String>> - shim(Some(Option<String>))`
   --> $SRC_DIR/core/src/ptr/mod.rs:LL:COL
 note: inside `A1`
-  --> $DIR/qualif-indirect-mutation-fail.rs:19:1
+  --> $DIR/qualif-indirect-mutation-fail.rs:18:1
    |
 LL | };
    | ^
 
 error[E0493]: destructor of `Option<String>` cannot be evaluated at compile-time
-  --> $DIR/qualif-indirect-mutation-fail.rs:29:9
+  --> $DIR/qualif-indirect-mutation-fail.rs:28:9
    |
 LL |     let _z = x;
    |         ^^ the destructor for this type cannot be evaluated in constants
@@ -44,13 +44,13 @@ note: inside `std::ptr::drop_in_place::<String> - shim(Some(String))`
 note: inside `std::ptr::drop_in_place::<Option<String>> - shim(Some(Option<String>))`
   --> $SRC_DIR/core/src/ptr/mod.rs:LL:COL
 note: inside `A2`
-  --> $DIR/qualif-indirect-mutation-fail.rs:30:1
+  --> $DIR/qualif-indirect-mutation-fail.rs:29:1
    |
 LL | };
    | ^
 
 error[E0493]: destructor of `(u32, Option<String>)` cannot be evaluated at compile-time
-  --> $DIR/qualif-indirect-mutation-fail.rs:7:9
+  --> $DIR/qualif-indirect-mutation-fail.rs:6:9
    |
 LL |     let mut a: (u32, Option<String>) = (0, None);
    |         ^^^^^ the destructor for this type cannot be evaluated in constant functions
@@ -59,7 +59,7 @@ LL | }
    | - value is dropped here
 
 error[E0493]: destructor of `Option<T>` cannot be evaluated at compile-time
-  --> $DIR/qualif-indirect-mutation-fail.rs:34:9
+  --> $DIR/qualif-indirect-mutation-fail.rs:33:9
    |
 LL |     let x: Option<T> = None;
    |         ^ the destructor for this type cannot be evaluated in constant functions
@@ -68,15 +68,15 @@ LL | }
    | - value is dropped here
 
 error[E0493]: destructor of `Option<T>` cannot be evaluated at compile-time
-  --> $DIR/qualif-indirect-mutation-fail.rs:42:9
+  --> $DIR/qualif-indirect-mutation-fail.rs:41:9
    |
 LL |     let _y = x;
    |         ^^ the destructor for this type cannot be evaluated in constant functions
 LL | }
    | - value is dropped here
 
 error[E0493]: destructor of `Option<String>` cannot be evaluated at compile-time
-  --> $DIR/qualif-indirect-mutation-fail.rs:50:9
+  --> $DIR/qualif-indirect-mutation-fail.rs:49:9
    |
 LL |     let mut y: Option<String> = None;
    |         ^^^^^ the destructor for this type cannot be evaluated in constant functions
@@ -85,7 +85,7 @@ LL | }
    | - value is dropped here
 
 error[E0493]: destructor of `Option<String>` cannot be evaluated at compile-time
-  --> $DIR/qualif-indirect-mutation-fail.rs:47:9
+  --> $DIR/qualif-indirect-mutation-fail.rs:46:9
    |
 LL |     let mut x: Option<String> = None;
    |         ^^^^^ the destructor for this type cannot be evaluated in constant functions
@@ -94,7 +94,7 @@ LL | }
    | - value is dropped here
 
 error[E0493]: destructor of `Option<String>` cannot be evaluated at compile-time
-  --> $DIR/qualif-indirect-mutation-fail.rs:60:9
+  --> $DIR/qualif-indirect-mutation-fail.rs:59:9
    |
 LL |     let y: Option<String> = None;
    |         ^ the destructor for this type cannot be evaluated in constant functions
@@ -103,7 +103,7 @@ LL | }
    | - value is dropped here
 
 error[E0493]: destructor of `Option<String>` cannot be evaluated at compile-time
-  --> $DIR/qualif-indirect-mutation-fail.rs:57:9
+  --> $DIR/qualif-indirect-mutation-fail.rs:56:9
    |
 LL |     let x: Option<String> = None;
    |         ^ the destructor for this type cannot be evaluated in constant functions

tests/ui/thread-local/thread-local-static.rs

@@ -1,7 +1,6 @@
 //@ edition:2018
 
 #![feature(thread_local)]
-#![feature(const_swap)]
 #![allow(static_mut_refs)]
 
 #[thread_local]

tests/ui/thread-local/thread-local-static.stderr

@@ -1,13 +1,13 @@
 error[E0133]: use of mutable static is unsafe and requires unsafe function or block
-  --> $DIR/thread-local-static.rs:10:28
+  --> $DIR/thread-local-static.rs:9:28
    |
 LL |     std::mem::swap(x, &mut STATIC_VAR_2)
    |                            ^^^^^^^^^^^^ use of mutable static
    |
    = note: mutable statics can be mutated by multiple threads: aliasing violations or data races will cause undefined behavior
 
 error[E0625]: thread-local statics cannot be accessed at compile-time
-  --> $DIR/thread-local-static.rs:10:28
+  --> $DIR/thread-local-static.rs:9:28
    |
 LL |     std::mem::swap(x, &mut STATIC_VAR_2)
    |                            ^^^^^^^^^^^^