New upstream version 1.48.0~beta.8+dfsg1

[rustc.git] / library / core / src / pin.rs

diff --git a/library/core/src/pin.rs b/library/core/src/pin.rs
index 290aa797fd964971df6a2aebfbe3160b366a9978..9f0284d5d95425e0fd6a3d68ac1a23fd63dd47c5 100644 (file)
--- a/library/core/src/pin.rs
+++ b/library/core/src/pin.rs
@@ -471,10 +471,11 @@ impl<P: Deref<Target: Unpin>> Pin<P> {
     ///
     /// Unlike `Pin::new_unchecked`, this method is safe because the pointer
     /// `P` dereferences to an [`Unpin`] type, which cancels the pinning guarantees.
-    #[stable(feature = "pin", since = "1.33.0")]
     #[inline(always)]
-    pub fn new(pointer: P) -> Pin<P> {
-        // Safety: the value pointed to is `Unpin`, and so has no requirements
+    #[rustc_const_unstable(feature = "const_pin", issue = "76654")]
+    #[stable(feature = "pin", since = "1.33.0")]
+    pub const fn new(pointer: P) -> Pin<P> {
+        // SAFETY: the value pointed to is `Unpin`, and so has no requirements
         // around pinning.
         unsafe { Pin::new_unchecked(pointer) }
     }
@@ -483,9 +484,10 @@ impl<P: Deref<Target: Unpin>> Pin<P> {
     ///
     /// This requires that the data inside this `Pin` is [`Unpin`] so that we
     /// can ignore the pinning invariants when unwrapping it.
-    #[stable(feature = "pin_into_inner", since = "1.39.0")]
     #[inline(always)]
-    pub fn into_inner(pin: Pin<P>) -> P {
+    #[rustc_const_unstable(feature = "const_pin", issue = "76654")]
+    #[stable(feature = "pin_into_inner", since = "1.39.0")]
+    pub const fn into_inner(pin: Pin<P>) -> P {
         pin.pointer
     }
 }
@@ -541,7 +543,7 @@ impl<P: Deref> Pin<P> {
     /// use std::pin::Pin;
     ///
     /// fn move_pinned_rc<T>(mut x: Rc<T>) {
-    ///     let pinned = unsafe { Pin::new_unchecked(x.clone()) };
+    ///     let pinned = unsafe { Pin::new_unchecked(Rc::clone(&x)) };
     ///     {
     ///         let p: Pin<&T> = pinned.as_ref();
     ///         // This should mean the pointee can never move again.
@@ -555,10 +557,11 @@ impl<P: Deref> Pin<P> {
     ///  ```
     ///
     /// [`mem::swap`]: crate::mem::swap
-    #[cfg_attr(not(bootstrap), lang = "new_unchecked")]
-    #[stable(feature = "pin", since = "1.33.0")]
+    #[lang = "new_unchecked"]
     #[inline(always)]
-    pub unsafe fn new_unchecked(pointer: P) -> Pin<P> {
+    #[rustc_const_unstable(feature = "const_pin", issue = "76654")]
+    #[stable(feature = "pin", since = "1.33.0")]
+    pub const unsafe fn new_unchecked(pointer: P) -> Pin<P> {
         Pin { pointer }
     }
 
@@ -589,9 +592,10 @@ impl<P: Deref> Pin<P> {
     ///
     /// If the underlying data is [`Unpin`], [`Pin::into_inner`] should be used
     /// instead.
-    #[stable(feature = "pin_into_inner", since = "1.39.0")]
     #[inline(always)]
-    pub unsafe fn into_inner_unchecked(pin: Pin<P>) -> P {
+    #[rustc_const_unstable(feature = "const_pin", issue = "76654")]
+    #[stable(feature = "pin_into_inner", since = "1.39.0")]
+    pub const unsafe fn into_inner_unchecked(pin: Pin<P>) -> P {
         pin.pointer
     }
 }
@@ -661,7 +665,7 @@ impl<'a, T: ?Sized> Pin<&'a T> {
     /// because it is one of the fields of that value), and also that you do
     /// not move out of the argument you receive to the interior function.
     ///
-    /// [`pin` module]: ../../std/pin/index.html#projections-and-structural-pinning
+    /// [`pin` module]: self#projections-and-structural-pinning
     #[stable(feature = "pin", since = "1.33.0")]
     pub unsafe fn map_unchecked<U, F>(self, func: F) -> Pin<&'a U>
     where
@@ -692,19 +696,21 @@ impl<'a, T: ?Sized> Pin<&'a T> {
     /// the `Pin` itself. This method allows turning the `Pin` into a reference
     /// with the same lifetime as the original `Pin`.
     ///
-    /// ["pinning projections"]: ../../std/pin/index.html#projections-and-structural-pinning
-    #[stable(feature = "pin", since = "1.33.0")]
+    /// ["pinning projections"]: self#projections-and-structural-pinning
     #[inline(always)]
-    pub fn get_ref(self) -> &'a T {
+    #[rustc_const_unstable(feature = "const_pin", issue = "76654")]
+    #[stable(feature = "pin", since = "1.33.0")]
+    pub const fn get_ref(self) -> &'a T {
         self.pointer
     }
 }
 
 impl<'a, T: ?Sized> Pin<&'a mut T> {
     /// Converts this `Pin<&mut T>` into a `Pin<&T>` with the same lifetime.
-    #[stable(feature = "pin", since = "1.33.0")]
     #[inline(always)]
-    pub fn into_ref(self) -> Pin<&'a T> {
+    #[rustc_const_unstable(feature = "const_pin", issue = "76654")]
+    #[stable(feature = "pin", since = "1.33.0")]
+    pub const fn into_ref(self) -> Pin<&'a T> {
         Pin { pointer: self.pointer }
     }
 
@@ -717,9 +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,
     {
@@ -736,9 +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
     }
 
@@ -756,7 +764,7 @@ impl<'a, T: ?Sized> Pin<&'a mut T> {
     /// because it is one of the fields of that value), and also that you do
     /// not move out of the argument you receive to the interior function.
     ///
-    /// [`pin` module]: ../../std/pin/index.html#projections-and-structural-pinning
+    /// [`pin` module]: self#projections-and-structural-pinning
     #[stable(feature = "pin", since = "1.33.0")]
     pub unsafe fn map_unchecked_mut<U, F>(self, func: F) -> Pin<&'a mut U>
     where