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Rollup merge of #151365 - RalfJung:unsafe-unpin-opsem, r=BoxyUwU

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UnsafePinned: implement opsem effects of UnsafeUnpin

This implements the next step for https://github.com/rust-lang/rust/issues/125735: actually making `UnsafePinned` have special opsem effects by suppressing the `noalias` *even if* the type is wrapped in an `Unpin` wrapper.

For backwards compatibility we also still keep the `Unpin` hack, i.e. a type must be both `Unpin` and `UnsafeUnpin` to get `noalias`.
This commit is contained in:
Jonathan Brouwer 2026-02-14 22:11:53 +01:00 • committed by GitHub
commit 33c2a6eba9
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16 changed files with 123 additions and 36 deletions
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19
library/core/src/marker.rs
View file

@ -927,14 +927,20 @@ marker_impls! {
/// This is part of [RFC 3467](https://rust-lang.github.io/rfcs/3467-unsafe-pinned.html), and is
/// tracked by [#125735](https://github.com/rust-lang/rust/issues/125735).
#[lang = "unsafe_unpin"]
pub(crate) unsafe auto trait UnsafeUnpin {}
#[unstable(feature = "unsafe_unpin", issue = "125735")]
pub unsafe auto trait UnsafeUnpin {}
#[unstable(feature = "unsafe_unpin", issue = "125735")]
impl<T: ?Sized> !UnsafeUnpin for UnsafePinned<T> {}
unsafe impl<T: ?Sized> UnsafeUnpin for PhantomData<T> {}
unsafe impl<T: ?Sized> UnsafeUnpin for *const T {}
unsafe impl<T: ?Sized> UnsafeUnpin for *mut T {}
unsafe impl<T: ?Sized> UnsafeUnpin for &T {}
unsafe impl<T: ?Sized> UnsafeUnpin for &mut T {}
marker_impls! {
#[unstable(feature = "unsafe_unpin", issue = "125735")]
unsafe UnsafeUnpin for
{T: ?Sized} PhantomData<T>,
{T: ?Sized} *const T,
{T: ?Sized} *mut T,
{T: ?Sized} &T,
{T: ?Sized} &mut T,
}
/// Types that do not require any pinning guarantees.
///
@ -1027,6 +1033,7 @@ impl !Unpin for PhantomPinned {}
// continue working. Ideally PhantomPinned could just wrap an `UnsafePinned<()>` to get the same
// effect, but we can't add a new field to an already stable unit struct -- that would be a breaking
// change.
#[unstable(feature = "unsafe_unpin", issue = "125735")]
impl !UnsafeUnpin for PhantomPinned {}
marker_impls! {

2
library/core/src/num/nonzero.rs
View file

@ -31,7 +31,7 @@ use crate::{fmt, intrinsics, ptr, ub_checks};
issue = "none"
)]
pub unsafe trait ZeroablePrimitive: Sized + Copy + private::Sealed {
#[doc(hidden)]
/// A type like `Self` but with a niche that includes zero.
type NonZeroInner: Sized + Copy;
}