Tracking Issue for `ManuallyDrop<T>::pinned_*`

[asder8215]

Feature gate: #![feature(manually_drop_pinned)]

This is a tracking issue for rust-langs/libs-team#580. It introduces a few methods to ManuallyDrop<T> for the purpose of constructing a new mutable/immutable Pin over T out of Pin<&mut ManuallyDrop<T>> and Pin<&ManuallyDrop<T>> as well as be able to drop pinned contained values.

Public API

// use core::mem::ManuallyDrop;

impl<T> ManuallyDrop<T> {
    fn pinned_deref_mut(pinned: Pin<&mut ManuallyDrop<T>>) -> Pin<&mut T> { ... }

    fn pinned_deref(pinned: Pin<&ManuallyDrop<T>>) -> Pin<&T> { ... }
}

impl<T: ?Sized> ManuallyDrop<T> {
    pub unsafe fn pinned_drop(pinned: Pin<&mut ManuallyDrop<T>>) { ... }
}

Steps / History

(Remember to update the S-tracking-* label when checking boxes.)

• ACP: ACP: ManuallyDrop<T>::pinned_* methods libs-team#580
• Implementation: Implement ManuallyDrop<T>::pinned_* methods #157269
• Final comment period (FCP)¹
• Stabilization PR

Unresolved Questions

• None yet.

Footnotes

1. https://std-dev-guide.rust-lang.org/feature-lifecycle/stabilization.html ↩

[theemathas]

This API is unfortunately unsound. See #157269 (comment)

[asder8215]

As theemathas pointed out, this API is unsound.