Rollup merge of rust-lang#129401 - workingjubilee:partial-initialization-of-stabilization, r=dtolnay,joboet

Partially stabilize `feature(new_uninit)`

Finished comment period: rust-lang#63291 (comment)

The following API has been stabilized from rust-lang#63291

```rust
impl<T> Box<T> { pub fn new_uninit() -> Box<MaybeUninit<T>> {…} }
impl<T> Rc<T> { pub fn new_uninit() -> Rc<MaybeUninit<T>> {…} }
impl<T> Arc<T> { pub fn new_uninit() -> Arc<MaybeUninit<T>> {…} }

impl<T> Box<[T]> { pub fn new_uninit_slice(len: usize) -> Box<[MaybeUninit<T>]> {…} }
impl<T> Rc<[T]> { pub fn new_uninit_slice(len: usize) -> Rc<[MaybeUninit<T>]> {…} }
impl<T> Arc<[T]> { pub fn new_uninit_slice(len: usize) -> Arc<[MaybeUninit<T>]> {…} }

impl<T> Box<MaybeUninit<T>> { pub unsafe fn assume_init(self) -> Box<T> {…} }
impl<T> Box<[MaybeUninit<T>]> { pub unsafe fn assume_init(self) -> Box<[T]> {…} }
impl<T> Rc<MaybeUninit<T>> { pub unsafe fn assume_init(self) -> Rc<T> {…} }
impl<T> Rc<[MaybeUninit<T>]> { pub unsafe fn assume_init(self) -> Rc<[T]> {…} }
impl<T> Arc<MaybeUninit<T>> { pub unsafe fn assume_init(self) -> Arc<T> {…} }
impl<T> Arc<[MaybeUninit<T>]> { pub unsafe fn assume_init(self) -> Arc<[T]> {…} }
```

The remaining API is split between new issues
- `new_zeroed_alloc`: rust-lang#129396
- `box_uninit_write`: rust-lang#129397

All relevant code is thus either stabilized or split out of that issue, so this closes rust-lang#63291 as, with the FCP concluded, that issue has served its purpose.

try-job: x86_64-rust-for-linux

Author: workingjubilee

alloc/src/boxed.rs

@@ -262,8 +262,6 @@ impl<T> Box<T> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(new_uninit)]
-    ///
     /// let mut five = Box::<u32>::new_uninit();
     ///
     /// let five = unsafe {
@@ -276,7 +274,7 @@ impl<T> Box<T> {
     /// assert_eq!(*five, 5)
     /// ```
     #[cfg(not(no_global_oom_handling))]
-    #[unstable(feature = "new_uninit", issue = "63291")]
+    #[stable(feature = "new_uninit", since = "CURRENT_RUSTC_VERSION")]
     #[must_use]
     #[inline]
     pub fn new_uninit() -> Box<mem::MaybeUninit<T>> {
@@ -292,7 +290,6 @@ impl<T> Box<T> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(new_uninit)]
     /// #![feature(new_zeroed_alloc)]
     ///
     /// let zero = Box::<u32>::new_zeroed();
@@ -350,7 +347,7 @@ impl<T> Box<T> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(allocator_api, new_uninit)]
+    /// #![feature(allocator_api)]
     ///
     /// let mut five = Box::<u32>::try_new_uninit()?;
     ///
@@ -380,7 +377,7 @@ impl<T> Box<T> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(allocator_api, new_uninit)]
+    /// #![feature(allocator_api)]
     ///
     /// let zero = Box::<u32>::try_new_zeroed()?;
     /// let zero = unsafe { zero.assume_init() };
@@ -460,7 +457,7 @@ impl<T, A: Allocator> Box<T, A> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(allocator_api, new_uninit)]
+    /// #![feature(allocator_api)]
     ///
     /// use std::alloc::System;
     ///
@@ -498,7 +495,7 @@ impl<T, A: Allocator> Box<T, A> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(allocator_api, new_uninit)]
+    /// #![feature(allocator_api)]
     ///
     /// use std::alloc::System;
     ///
@@ -538,7 +535,7 @@ impl<T, A: Allocator> Box<T, A> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(allocator_api, new_uninit)]
+    /// #![feature(allocator_api)]
     ///
     /// use std::alloc::System;
     ///
@@ -576,7 +573,7 @@ impl<T, A: Allocator> Box<T, A> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(allocator_api, new_uninit)]
+    /// #![feature(allocator_api)]
     ///
     /// use std::alloc::System;
     ///
@@ -654,8 +651,6 @@ impl<T> Box<[T]> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(new_uninit)]
-    ///
     /// let mut values = Box::<[u32]>::new_uninit_slice(3);
     ///
     /// let values = unsafe {
@@ -670,7 +665,7 @@ impl<T> Box<[T]> {
     /// assert_eq!(*values, [1, 2, 3])
     /// ```
     #[cfg(not(no_global_oom_handling))]
-    #[unstable(feature = "new_uninit", issue = "63291")]
+    #[stable(feature = "new_uninit", since = "CURRENT_RUSTC_VERSION")]
     #[must_use]
     pub fn new_uninit_slice(len: usize) -> Box<[mem::MaybeUninit<T>]> {
         unsafe { RawVec::with_capacity(len).into_box(len) }
@@ -686,7 +681,6 @@ impl<T> Box<[T]> {
     ///
     /// ```
     /// #![feature(new_zeroed_alloc)]
-    /// #![feature(new_uninit)]
     ///
     /// let values = Box::<[u32]>::new_zeroed_slice(3);
     /// let values = unsafe { values.assume_init() };
@@ -708,7 +702,7 @@ impl<T> Box<[T]> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(allocator_api, new_uninit)]
+    /// #![feature(allocator_api)]
     ///
     /// let mut values = Box::<[u32]>::try_new_uninit_slice(3)?;
     /// let values = unsafe {
@@ -746,7 +740,7 @@ impl<T> Box<[T]> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(allocator_api, new_uninit)]
+    /// #![feature(allocator_api)]
     ///
     /// let values = Box::<[u32]>::try_new_zeroed_slice(3)?;
     /// let values = unsafe { values.assume_init() };
@@ -778,7 +772,7 @@ impl<T, A: Allocator> Box<[T], A> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(allocator_api, new_uninit)]
+    /// #![feature(allocator_api)]
     ///
     /// use std::alloc::System;
     ///
@@ -812,7 +806,7 @@ impl<T, A: Allocator> Box<[T], A> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(allocator_api, new_uninit)]
+    /// #![feature(allocator_api)]
     ///
     /// use std::alloc::System;
     ///
@@ -837,7 +831,7 @@ impl<T, A: Allocator> Box<[T], A> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(allocator_api, new_uninit)]
+    /// #![feature(allocator_api)]
     ///
     /// use std::alloc::System;
     ///
@@ -880,7 +874,7 @@ impl<T, A: Allocator> Box<[T], A> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(allocator_api, new_uninit)]
+    /// #![feature(allocator_api)]
     ///
     /// use std::alloc::System;
     ///
@@ -927,8 +921,6 @@ impl<T, A: Allocator> Box<mem::MaybeUninit<T>, A> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(new_uninit)]
-    ///
     /// let mut five = Box::<u32>::new_uninit();
     ///
     /// let five: Box<u32> = unsafe {
@@ -940,7 +932,7 @@ impl<T, A: Allocator> Box<mem::MaybeUninit<T>, A> {
     ///
     /// assert_eq!(*five, 5)
     /// ```
-    #[unstable(feature = "new_uninit", issue = "63291")]
+    #[stable(feature = "new_uninit", since = "CURRENT_RUSTC_VERSION")]
     #[inline]
     pub unsafe fn assume_init(self) -> Box<T, A> {
         let (raw, alloc) = Box::into_raw_with_allocator(self);
@@ -958,7 +950,6 @@ impl<T, A: Allocator> Box<mem::MaybeUninit<T>, A> {
     ///
     /// ```
     /// #![feature(box_uninit_write)]
-    /// #![feature(new_uninit)]
     ///
     /// let big_box = Box::<[usize; 1024]>::new_uninit();
     ///
@@ -1001,8 +992,6 @@ impl<T, A: Allocator> Box<[mem::MaybeUninit<T>], A> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(new_uninit)]
-    ///
     /// let mut values = Box::<[u32]>::new_uninit_slice(3);
     ///
     /// let values = unsafe {
@@ -1016,7 +1005,7 @@ impl<T, A: Allocator> Box<[mem::MaybeUninit<T>], A> {
     ///
     /// assert_eq!(*values, [1, 2, 3])
     /// ```
-    #[unstable(feature = "new_uninit", issue = "63291")]
+    #[stable(feature = "new_uninit", since = "CURRENT_RUSTC_VERSION")]
     #[inline]
     pub unsafe fn assume_init(self) -> Box<[T], A> {
         let (raw, alloc) = Box::into_raw_with_allocator(self);

alloc/src/lib.rs

@@ -93,7 +93,6 @@
 // tidy-alphabetical-start
 #![cfg_attr(not(no_global_oom_handling), feature(const_alloc_error))]
 #![cfg_attr(not(no_global_oom_handling), feature(const_btree_len))]
-#![cfg_attr(test, feature(new_uninit))]
 #![feature(alloc_layout_extra)]
 #![feature(allocator_api)]
 #![feature(array_chunks)]

alloc/src/rc.rs

@@ -503,7 +503,6 @@ impl<T> Rc<T> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(new_uninit)]
     /// #![feature(get_mut_unchecked)]
     ///
     /// use std::rc::Rc;
@@ -518,7 +517,7 @@ impl<T> Rc<T> {
     /// assert_eq!(*five, 5)
     /// ```
     #[cfg(not(no_global_oom_handling))]
-    #[unstable(feature = "new_uninit", issue = "63291")]
+    #[stable(feature = "new_uninit", since = "CURRENT_RUSTC_VERSION")]
     #[must_use]
     pub fn new_uninit() -> Rc<mem::MaybeUninit<T>> {
         unsafe {
@@ -540,7 +539,6 @@ impl<T> Rc<T> {
     ///
     /// ```
     /// #![feature(new_zeroed_alloc)]
-    /// #![feature(new_uninit)]
     ///
     /// use std::rc::Rc;
     ///
@@ -594,7 +592,7 @@ impl<T> Rc<T> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(allocator_api, new_uninit)]
+    /// #![feature(allocator_api)]
     /// #![feature(get_mut_unchecked)]
     ///
     /// use std::rc::Rc;
@@ -630,7 +628,7 @@ impl<T> Rc<T> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(allocator_api, new_uninit)]
+    /// #![feature(allocator_api)]
     ///
     /// use std::rc::Rc;
     ///
@@ -692,7 +690,6 @@ impl<T, A: Allocator> Rc<T, A> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(new_uninit)]
     /// #![feature(get_mut_unchecked)]
     /// #![feature(allocator_api)]
     ///
@@ -736,7 +733,6 @@ impl<T, A: Allocator> Rc<T, A> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(new_uninit)]
     /// #![feature(allocator_api)]
     ///
     /// use std::rc::Rc;
@@ -799,7 +795,7 @@ impl<T, A: Allocator> Rc<T, A> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(allocator_api, new_uninit)]
+    /// #![feature(allocator_api)]
     /// #![feature(get_mut_unchecked)]
     ///
     /// use std::rc::Rc;
@@ -843,7 +839,7 @@ impl<T, A: Allocator> Rc<T, A> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(allocator_api, new_uninit)]
+    /// #![feature(allocator_api)]
     ///
     /// use std::rc::Rc;
     /// use std::alloc::System;
@@ -967,7 +963,6 @@ impl<T> Rc<[T]> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(new_uninit)]
     /// #![feature(get_mut_unchecked)]
     ///
     /// use std::rc::Rc;
@@ -985,7 +980,7 @@ impl<T> Rc<[T]> {
     /// assert_eq!(*values, [1, 2, 3])
     /// ```
     #[cfg(not(no_global_oom_handling))]
-    #[unstable(feature = "new_uninit", issue = "63291")]
+    #[stable(feature = "new_uninit", since = "CURRENT_RUSTC_VERSION")]
     #[must_use]
     pub fn new_uninit_slice(len: usize) -> Rc<[mem::MaybeUninit<T>]> {
         unsafe { Rc::from_ptr(Rc::allocate_for_slice(len)) }
@@ -1000,7 +995,6 @@ impl<T> Rc<[T]> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(new_uninit)]
     /// #![feature(new_zeroed_alloc)]
     ///
     /// use std::rc::Rc;
@@ -1035,7 +1029,6 @@ impl<T, A: Allocator> Rc<[T], A> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(new_uninit)]
     /// #![feature(get_mut_unchecked)]
     /// #![feature(allocator_api)]
     ///
@@ -1072,7 +1065,6 @@ impl<T, A: Allocator> Rc<[T], A> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(new_uninit)]
     /// #![feature(allocator_api)]
     ///
     /// use std::rc::Rc;
@@ -1122,7 +1114,6 @@ impl<T, A: Allocator> Rc<mem::MaybeUninit<T>, A> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(new_uninit)]
     /// #![feature(get_mut_unchecked)]
     ///
     /// use std::rc::Rc;
@@ -1136,7 +1127,7 @@ impl<T, A: Allocator> Rc<mem::MaybeUninit<T>, A> {
     ///
     /// assert_eq!(*five, 5)
     /// ```
-    #[unstable(feature = "new_uninit", issue = "63291")]
+    #[stable(feature = "new_uninit", since = "CURRENT_RUSTC_VERSION")]
     #[inline]
     pub unsafe fn assume_init(self) -> Rc<T, A> {
         let (ptr, alloc) = Rc::into_inner_with_allocator(self);
@@ -1160,7 +1151,6 @@ impl<T, A: Allocator> Rc<[mem::MaybeUninit<T>], A> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(new_uninit)]
     /// #![feature(get_mut_unchecked)]
     ///
     /// use std::rc::Rc;
@@ -1177,7 +1167,7 @@ impl<T, A: Allocator> Rc<[mem::MaybeUninit<T>], A> {
     ///
     /// assert_eq!(*values, [1, 2, 3])
     /// ```
-    #[unstable(feature = "new_uninit", issue = "63291")]
+    #[stable(feature = "new_uninit", since = "CURRENT_RUSTC_VERSION")]
     #[inline]
     pub unsafe fn assume_init(self) -> Rc<[T], A> {
         let (ptr, alloc) = Rc::into_inner_with_allocator(self);