Make some methods of Pin<&mut T> unstable const

Make the following methods unstable const under the `const_pin` feature: - `into_ref` - `get_mut` - `get_unchecked_mut`
rust-lang · ecstatic-morse · Aug 4, 2020 · Sep 2, 2020 · Sep 11, 2020 · Sep 12, 2020
commit e3c6e46168758642f0bab64da374f93ed21b1cd0
diff --git a/library/core/src/pin.rs b/library/core/src/pin.rs
@@ -708,8  708,9 @@ impl<'a, T: ?Sized> Pin<&'a T> {
 impl<'a, T: ?Sized> Pin<&'a mut T> {
     /// Converts this `Pin<&mut T>` into a `Pin<&T>` with the same lifetime.
     #[inline(always)]
     #[rustc_const_unstable(feature = "const_pin", issue = "76654")]
     #[stable(feature = "pin", since = "1.33.0")]
-    pub fn into_ref(self) -> Pin<&'a T> {
     pub const fn into_ref(self) -> Pin<&'a T> {
         Pin { pointer: self.pointer }
     }
 
@@ -722,9  723,10 @@ impl<'a, T: ?Sized> Pin<&'a mut T> {
     /// that lives for as long as the borrow of the `Pin`, not the lifetime of
     /// the `Pin` itself. This method allows turning the `Pin` into a reference
     /// with the same lifetime as the original `Pin`.
-    #[stable(feature = "pin", since = "1.33.0")]
     #[inline(always)]
-    pub fn get_mut(self) -> &'a mut T
     #[stable(feature = "pin", since = "1.33.0")]
     #[rustc_const_unstable(feature = "const_pin", issue = "76654")]
     pub const fn get_mut(self) -> &'a mut T
     where
         T: Unpin,
     {
@@ -741,9  743,10 @@ impl<'a, T: ?Sized> Pin<&'a mut T> {
     ///
     /// If the underlying data is `Unpin`, `Pin::get_mut` should be used
     /// instead.
-    #[stable(feature = "pin", since = "1.33.0")]
     #[inline(always)]
-    pub unsafe fn get_unchecked_mut(self) -> &'a mut T {
     #[stable(feature = "pin", since = "1.33.0")]
     #[rustc_const_unstable(feature = "const_pin", issue = "76654")]
     pub const unsafe fn get_unchecked_mut(self) -> &'a mut T {
         self.pointer
     }
 

diff --git a/library/core/tests/lib.rs b/library/core/tests/lib.rs
@@ -39,6  39,7 @@
 #![feature(iter_order_by)]
 #![feature(cmp_min_max_by)]
 #![feature(iter_map_while)]
 #![feature(const_mut_refs)]
 #![feature(const_pin)]
 #![feature(const_slice_from_raw_parts)]
 #![feature(const_raw_ptr_deref)]

diff --git a/library/core/tests/pin.rs b/library/core/tests/pin.rs
@@ -17,5  17,15 @@ fn pin_const() {
     assert_eq!(INNER_UNCHECKED, POINTER);
 
     const REF: &'static usize = PINNED.get_ref();
-    assert_eq!(REF, POINTER)
     assert_eq!(REF, POINTER);
 
     // Note: `pin_mut_const` tests that the methods of `Pin<&mut T>` are usable in a const context.
     // A const fn is used because `&mut` is not (yet) usable in constants.
     const fn pin_mut_const() {
         let _ = Pin::new(&mut 2).into_ref();
         let _ = Pin::new(&mut 2).get_mut();
         let _ = unsafe { Pin::new(&mut 2).get_unchecked_mut() };
     }
 
     pin_mut_const();
 }