Tracking Issue for RFC 3467: UnsafePinned

This is a tracking issue for RFC 3467: UnsafePinned.

• https://github.com/rust-lang/rfcs/pull/3467

The feature gate for the issue is #![feature(unsafe_pinned)].

About tracking issues

Tracking issues are used to record the overall progress of implementation. They are also used as hubs connecting to other relevant issues, e.g., bugs or open design questions. A tracking issue is however not meant for large scale discussion, questions, or bug reports about a feature. Instead, open a dedicated issue for the specific matter and add the relevant feature gate label.

Steps

• Accept an RFC.
  • https://github.com/rust-lang/rfcs/pull/3467
• Implement.
  • https://github.com/rust-lang/rust/pull/137043
  • https://github.com/rust-lang/rust/pull/140638
  • https://github.com/rust-lang/rust/pull/139896
  • https://github.com/rust-lang/rust/pull/142162
  • https://github.com/rust-lang/rust/pull/151365
• Add documentation to the dev guide.
  • See the instructions.
• Add documentation to the reference.
  • See the instructions.
• Stabilize.

Unresolved Questions

• Do we want to bikeshed the name further before stabilization?
• Should &UnsafePinned permit mutation or not? Also see https://github.com/rust-lang/rust/issues/137750
  • This was decided via champion decision and meeting consensus in a shorthanded meeting; this item will need to receive attention in the stabilization report.
• Which of Send, Sync, Copy, Clone should this type implement under which conditions? Also see this.
• Do we want to stabilize Freeze first? And what about the equivalent trait for &mut aliasing (UnpinUnsafe in the RFC)?
  • See: https://github.com/rust-lang/rust/pull/140638#discussion_r2072913070
• Do we need all these get methods?
• https://github.com/rust-lang/rust/issues/156163
• What about variance?

Related

• https://github.com/rust-lang/rfcs/pull/3467

Implementation history

TODO.

Start by reading RFC 3467 and the implementation PRs listed in this tracking issue, then review the unresolved questions and the stabilization guidance. Work is complete only when the implementation, dev-guide and Reference documentation tasks, design decisions, and eventual stabilization are addressed; this is a coordination issue rather than a self-contained change.