rm const traits in libcore

library/alloc/src/boxed.rs

@@ -1234,8 +1234,7 @@ impl<T: Default> Default for Box<T> {
 
 #[cfg(not(no_global_oom_handling))]
 #[stable(feature = "rust1", since = "1.0.0")]
-#[rustc_const_unstable(feature = "const_default_impls", issue = "87864")]
-impl<T> const Default for Box<[T]> {
+impl<T> Default for Box<[T]> {
     #[inline]
     fn default() -> Self {
         let ptr: Unique<[T]> = Unique::<[T; 0]>::dangling();
@@ -1245,8 +1244,7 @@ impl<T> const Default for Box<[T]> {
 
 #[cfg(not(no_global_oom_handling))]
 #[stable(feature = "default_box_extra", since = "1.17.0")]
-#[rustc_const_unstable(feature = "const_default_impls", issue = "87864")]
-impl const Default for Box<str> {
+impl Default for Box<str> {
     #[inline]
     fn default() -> Self {
         // SAFETY: This is the same as `Unique::cast<U>` but with an unsized `U = str`.
@@ -1443,8 +1441,7 @@ impl<T> From<T> for Box<T> {
 }
 
 #[stable(feature = "pin", since = "1.33.0")]
-#[rustc_const_unstable(feature = "const_box", issue = "92521")]
-impl<T: ?Sized, A: Allocator> const From<Box<T, A>> for Pin<Box<T, A>>
+impl<T: ?Sized, A: Allocator> From<Box<T, A>> for Pin<Box<T, A>>
 where
     A: 'static,
 {
@@ -1880,8 +1877,7 @@ impl<T: ?Sized, A: Allocator> fmt::Pointer for Box<T, A> {
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
-#[rustc_const_unstable(feature = "const_box", issue = "92521")]
-impl<T: ?Sized, A: Allocator> const Deref for Box<T, A> {
+impl<T: ?Sized, A: Allocator> Deref for Box<T, A> {
     type Target = T;
 
     fn deref(&self) -> &T {
@@ -1890,8 +1886,7 @@ impl<T: ?Sized, A: Allocator> const Deref for Box<T, A> {
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
-#[rustc_const_unstable(feature = "const_box", issue = "92521")]
-impl<T: ?Sized, A: Allocator> const DerefMut for Box<T, A> {
+impl<T: ?Sized, A: Allocator> DerefMut for Box<T, A> {
     fn deref_mut(&mut self) -> &mut T {
         &mut **self
     }

library/alloc/src/string.rs

@@ -2247,8 +2247,7 @@ impl_eq! { Cow<'a, str>, &'b str }
 impl_eq! { Cow<'a, str>, String }
 
 #[stable(feature = "rust1", since = "1.0.0")]
-#[rustc_const_unstable(feature = "const_default_impls", issue = "87864")]
-impl const Default for String {
+impl Default for String {
     /// Creates an empty `String`.
     #[inline]
     fn default() -> String {

library/alloc/src/vec/mod.rs

@@ -3022,8 +3022,7 @@ unsafe impl<#[may_dangle] T, A: Allocator> Drop for Vec<T, A> {
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
-#[rustc_const_unstable(feature = "const_default_impls", issue = "87864")]
-impl<T> const Default for Vec<T> {
+impl<T> Default for Vec<T> {
     /// Creates an empty `Vec<T>`.
     ///
     /// The vector will not allocate until elements are pushed onto it.

library/alloc/tests/boxed.rs

@@ -61,7 +61,7 @@ fn box_deref_lval() {
 
 pub struct ConstAllocator;
 
-unsafe impl const Allocator for ConstAllocator {
+unsafe impl Allocator for ConstAllocator {
     fn allocate(&self, layout: Layout) -> Result<NonNull<[u8]>, AllocError> {
         match layout.size() {
             0 => Ok(NonNull::slice_from_raw_parts(layout.dangling(), 0)),

library/core/src/alloc/mod.rs

@@ -105,7 +105,6 @@ impl fmt::Display for AllocError {
 ///
 /// [*currently allocated*]: #currently-allocated-memory
 #[unstable(feature = "allocator_api", issue = "32838")]
-#[const_trait]
 pub unsafe trait Allocator {
     /// Attempts to allocate a block of memory.
     ///

library/core/src/any.rs

@@ -662,8 +662,7 @@ impl dyn Any + Send + Sync {
 /// While `TypeId` implements `Hash`, `PartialOrd`, and `Ord`, it is worth
 /// noting that the hashes and ordering will vary between Rust releases. Beware
 /// of relying on them inside of your code!
-#[derive(Clone, Copy, Debug, Hash, Eq)]
-#[derive_const(PartialEq, PartialOrd, Ord)]
+#[derive(Clone, Copy, Debug, Hash, PartialEq, Eq, PartialOrd, Ord)]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct TypeId {
     t: u64,

library/core/src/array/mod.rs

@@ -148,8 +148,7 @@ impl Error for TryFromSliceError {
 }
 
 #[stable(feature = "try_from_slice_error", since = "1.36.0")]
-#[rustc_const_unstable(feature = "const_convert", issue = "88674")]
-impl const From<Infallible> for TryFromSliceError {
+impl From<Infallible> for TryFromSliceError {
     fn from(x: Infallible) -> TryFromSliceError {
         match x {}
     }
@@ -172,16 +171,14 @@ impl<T, const N: usize> AsMut<[T]> for [T; N] {
 }
 
 #[stable(feature = "array_borrow", since = "1.4.0")]
-#[rustc_const_unstable(feature = "const_borrow", issue = "91522")]
-impl<T, const N: usize> const Borrow<[T]> for [T; N] {
+impl<T, const N: usize> Borrow<[T]> for [T; N] {
     fn borrow(&self) -> &[T] {
         self
     }
 }
 
 #[stable(feature = "array_borrow", since = "1.4.0")]
-#[rustc_const_unstable(feature = "const_borrow", issue = "91522")]
-impl<T, const N: usize> const BorrowMut<[T]> for [T; N] {
+impl<T, const N: usize> BorrowMut<[T]> for [T; N] {
     fn borrow_mut(&mut self) -> &mut [T] {
         self
     }
@@ -336,10 +333,9 @@ impl<'a, T, const N: usize> IntoIterator for &'a mut [T; N] {
 }
 
 #[stable(feature = "index_trait_on_arrays", since = "1.50.0")]
-#[rustc_const_unstable(feature = "const_slice_index", issue = "none")]
-impl<T, I, const N: usize> const Index<I> for [T; N]
+impl<T, I, const N: usize> Index<I> for [T; N]
 where
-    [T]: ~const Index<I>,
+    [T]: Index<I>,
 {
     type Output = <[T] as Index<I>>::Output;
 
@@ -350,10 +346,9 @@ where
 }
 
 #[stable(feature = "index_trait_on_arrays", since = "1.50.0")]
-#[rustc_const_unstable(feature = "const_slice_index", issue = "none")]
-impl<T, I, const N: usize> const IndexMut<I> for [T; N]
+impl<T, I, const N: usize> IndexMut<I> for [T; N]
 where
-    [T]: ~const IndexMut<I>,
+    [T]: IndexMut<I>,
 {
     #[inline]
     fn index_mut(&mut self, index: I) -> &mut Self::Output {
@@ -435,8 +430,7 @@ impl<T: Copy> SpecArrayClone for T {
 macro_rules! array_impl_default {
     {$n:expr, $t:ident $($ts:ident)*} => {
         #[stable(since = "1.4.0", feature = "array_default")]
-        #[rustc_const_unstable(feature = "const_default_impls", issue = "87864")]
-        impl<T> const Default for [T; $n] where T: ~const Default {
+        impl<T> Default for [T; $n] where T: Default {
             fn default() -> [T; $n] {
                 [$t::default(), $($ts::default()),*]
             }
@@ -445,8 +439,7 @@ macro_rules! array_impl_default {
     };
     {$n:expr,} => {
         #[stable(since = "1.4.0", feature = "array_default")]
-        #[rustc_const_unstable(feature = "const_default_impls", issue = "87864")]
-        impl<T> const Default for [T; $n] {
+        impl<T> Default for [T; $n] {
             fn default() -> [T; $n] { [] }
         }
     };

library/core/src/bool.rs

@@ -1,7 +1,5 @@
 //! impl bool {}
 
-use crate::marker::Destruct;
-
 impl bool {
     /// Returns `Some(t)` if the `bool` is [`true`](../std/keyword.true.html),
     /// or `None` otherwise.
@@ -31,11 +29,8 @@ impl bool {
     /// assert_eq!(a, 2);
     /// ```
     #[stable(feature = "bool_to_option", since = "1.62.0")]
-    #[rustc_const_unstable(feature = "const_bool_to_option", issue = "91917")]
     #[inline]
-    pub const fn then_some<T>(self, t: T) -> Option<T>
-    where
-        T: ~const Destruct,
+    pub fn then_some<T>(self, t: T) -> Option<T>
     {
         if self { Some(t) } else { None }
     }
@@ -61,12 +56,8 @@ impl bool {
     /// assert_eq!(a, 1);
     /// ```
     #[stable(feature = "lazy_bool_to_option", since = "1.50.0")]
-    #[rustc_const_unstable(feature = "const_bool_to_option", issue = "91917")]
     #[inline]
-    pub const fn then<T, F>(self, f: F) -> Option<T>
-    where
-        F: ~const FnOnce() -> T,
-        F: ~const Destruct,
+    pub fn then<T, F: FnOnce() -> T>(self, f: F) -> Option<T>
     {
         if self { Some(f()) } else { None }
     }

library/core/src/borrow.rs

@@ -154,7 +154,6 @@
 /// [`String`]: ../../std/string/struct.String.html
 #[stable(feature = "rust1", since = "1.0.0")]
 #[rustc_diagnostic_item = "Borrow"]
-#[const_trait]
 pub trait Borrow<Borrowed: ?Sized> {
     /// Immutably borrows from an owned value.
     ///
@@ -185,7 +184,6 @@ pub trait Borrow<Borrowed: ?Sized> {
 /// an underlying type by providing a mutable reference. See [`Borrow<T>`]
 /// for more information on borrowing as another type.
 #[stable(feature = "rust1", since = "1.0.0")]
-#[const_trait]
 pub trait BorrowMut<Borrowed: ?Sized>: Borrow<Borrowed> {
     /// Mutably borrows from an owned value.
     ///
@@ -207,41 +205,36 @@ pub trait BorrowMut<Borrowed: ?Sized>: Borrow<Borrowed> {
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
-#[rustc_const_unstable(feature = "const_borrow", issue = "91522")]
-impl<T: ?Sized> const Borrow<T> for T {
+impl<T: ?Sized> Borrow<T> for T {
     #[rustc_diagnostic_item = "noop_method_borrow"]
     fn borrow(&self) -> &T {
         self
     }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
-#[rustc_const_unstable(feature = "const_borrow", issue = "91522")]
-impl<T: ?Sized> const BorrowMut<T> for T {
+impl<T: ?Sized> BorrowMut<T> for T {
     fn borrow_mut(&mut self) -> &mut T {
         self
     }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
-#[rustc_const_unstable(feature = "const_borrow", issue = "91522")]
-impl<T: ?Sized> const Borrow<T> for &T {
+impl<T: ?Sized> Borrow<T> for &T {
     fn borrow(&self) -> &T {
         &**self
     }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
-#[rustc_const_unstable(feature = "const_borrow", issue = "91522")]
-impl<T: ?Sized> const Borrow<T> for &mut T {
+impl<T: ?Sized> Borrow<T> for &mut T {
     fn borrow(&self) -> &T {
         &**self
     }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
-#[rustc_const_unstable(feature = "const_borrow", issue = "91522")]
-impl<T: ?Sized> const BorrowMut<T> for &mut T {
+impl<T: ?Sized> BorrowMut<T> for &mut T {
     fn borrow_mut(&mut self) -> &mut T {
         &mut **self
     }

library/core/src/cell.rs

@@ -370,8 +370,7 @@ impl<T: Ord + Copy> Ord for Cell<T> {
 }
 
 #[stable(feature = "cell_from", since = "1.12.0")]
-#[rustc_const_unstable(feature = "const_convert", issue = "88674")]
-impl<T> const From<T> for Cell<T> {
+impl<T> From<T> for Cell<T> {
     /// Creates a new `Cell<T>` containing the given value.
     fn from(t: T) -> Cell<T> {
         Cell::new(t)
@@ -1318,8 +1317,7 @@ impl<T: ?Sized + Ord> Ord for RefCell<T> {
 }
 
 #[stable(feature = "cell_from", since = "1.12.0")]
-#[rustc_const_unstable(feature = "const_convert", issue = "88674")]
-impl<T> const From<T> for RefCell<T> {
+impl<T> From<T> for RefCell<T> {
     /// Creates a new `RefCell<T>` containing the given value.
     fn from(t: T) -> RefCell<T> {
         RefCell::new(t)
@@ -2126,8 +2124,7 @@ impl<T: Default> Default for UnsafeCell<T> {
 }
 
 #[stable(feature = "cell_from", since = "1.12.0")]
-#[rustc_const_unstable(feature = "const_convert", issue = "88674")]
-impl<T> const From<T> for UnsafeCell<T> {
+impl<T> From<T> for UnsafeCell<T> {
     /// Creates a new `UnsafeCell<T>` containing the given value.
     fn from(t: T) -> UnsafeCell<T> {
         UnsafeCell::new(t)
@@ -2226,8 +2223,7 @@ impl<T: Default> Default for SyncUnsafeCell<T> {
 }
 
 #[unstable(feature = "sync_unsafe_cell", issue = "95439")]
-#[rustc_const_unstable(feature = "const_convert", issue = "88674")]
-impl<T> const From<T> for SyncUnsafeCell<T> {
+impl<T> From<T> for SyncUnsafeCell<T> {
     /// Creates a new `SyncUnsafeCell<T>` containing the given value.
     fn from(t: T) -> SyncUnsafeCell<T> {
         SyncUnsafeCell::new(t)

library/core/src/cell/once.rs

@@ -284,8 +284,7 @@ impl<T: PartialEq> PartialEq for OnceCell<T> {
 impl<T: Eq> Eq for OnceCell<T> {}
 
 #[stable(feature = "once_cell", since = "CURRENT_RUSTC_VERSION")]
-#[rustc_const_unstable(feature = "const_convert", issue = "88674")]
-impl<T> const From<T> for OnceCell<T> {
+impl<T> From<T> for OnceCell<T> {
     /// Creates a new `OnceCell<T>` which already contains the given `value`.
     #[inline]
     fn from(value: T) -> Self {

library/core/src/char/convert.rs

@@ -27,8 +27,7 @@ pub(super) const unsafe fn from_u32_unchecked(i: u32) -> char {
 }
 
 #[stable(feature = "char_convert", since = "1.13.0")]
-#[rustc_const_unstable(feature = "const_convert", issue = "88674")]
-impl const From<char> for u32 {
+impl From<char> for u32 {
     /// Converts a [`char`] into a [`u32`].
     ///
     /// # Examples
@@ -47,8 +46,7 @@ impl const From<char> for u32 {
 }
 
 #[stable(feature = "more_char_conversions", since = "1.51.0")]
-#[rustc_const_unstable(feature = "const_convert", issue = "88674")]
-impl const From<char> for u64 {
+impl From<char> for u64 {
     /// Converts a [`char`] into a [`u64`].
     ///
     /// # Examples
@@ -69,8 +67,7 @@ impl const From<char> for u64 {
 }
 
 #[stable(feature = "more_char_conversions", since = "1.51.0")]
-#[rustc_const_unstable(feature = "const_convert", issue = "88674")]
-impl const From<char> for u128 {
+impl From<char> for u128 {
     /// Converts a [`char`] into a [`u128`].
     ///
     /// # Examples
@@ -123,8 +120,7 @@ impl TryFrom<char> for u8 {
 /// for a superset of Windows-1252 that fills the remaining blanks with corresponding
 /// C0 and C1 control codes.
 #[stable(feature = "char_convert", since = "1.13.0")]
-#[rustc_const_unstable(feature = "const_convert", issue = "88674")]
-impl const From<u8> for char {
+impl From<u8> for char {
     /// Converts a [`u8`] into a [`char`].
     ///
     /// # Examples