From 0d6c9152fa8cfaf4b430beef643565ede7de1067 Mon Sep 17 00:00:00 2001 From: Noa Date: Tue, 27 Aug 2024 15:56:05 -0500 Subject: [PATCH] Fix Pin::set bounds regression --- library/core/src/pin.rs | 21 ++++++++++++--------- 1 file changed, 12 insertions(+), 9 deletions(-) diff --git a/library/core/src/pin.rs b/library/core/src/pin.rs index 780e476f531f4..65f6bfb7ee176 100644 --- a/library/core/src/pin.rs +++ b/library/core/src/pin.rs @@ -1370,7 +1370,15 @@ impl Pin { // SAFETY: see documentation on this function unsafe { Pin::new_unchecked(&*self.__pointer) } } +} +// These methods being in a `Ptr: DerefMut` impl block concerns semver stability. +// Currently, calling e.g. `.set()` on a `Pin<&T>` sees that `Ptr: DerefMut` +// doesn't hold, and goes to check for a `.set()` method on `T`. But, if the +// `where Ptr: DerefMut` bound is moved to the method, rustc sees the impl block +// as a valid candidate, and doesn't go on to check other candidates when it +// sees that the bound on the method. +impl Pin { /// Gets a mutable reference to the pinned value this `Pin` points to. /// /// This is a generic method to go from `&mut Pin>` to `Pin<&mut T>`. @@ -1402,10 +1410,7 @@ impl Pin { /// ``` #[stable(feature = "pin", since = "1.33.0")] #[inline(always)] - pub fn as_mut(&mut self) -> Pin<&mut Ptr::Target> - where - Ptr: DerefMut, - { + pub fn as_mut(&mut self) -> Pin<&mut Ptr::Target> { // SAFETY: see documentation on this function unsafe { Pin::new_unchecked(&mut *self.__pointer) } } @@ -1420,10 +1425,7 @@ impl Pin { #[unstable(feature = "pin_deref_mut", issue = "86918")] #[must_use = "`self` will be dropped if the result is not used"] #[inline(always)] - pub fn as_deref_mut(self: Pin<&mut Pin>) -> Pin<&mut Ptr::Target> - where - Ptr: DerefMut, - { + pub fn as_deref_mut(self: Pin<&mut Pin>) -> Pin<&mut Ptr::Target> { // SAFETY: What we're asserting here is that going from // // Pin<&mut Pin> @@ -1475,12 +1477,13 @@ impl Pin { #[inline(always)] pub fn set(&mut self, value: Ptr::Target) where - Ptr: DerefMut, Ptr::Target: Sized, { *(self.__pointer) = value; } +} +impl Pin { /// Unwraps this `Pin`, returning the underlying `Ptr`. /// /// # Safety