Tracking Issue for const `ptr::drop_in_place`

[fee1-dead]

Feature gate: #![feature(const_drop_in_place)]

This is a tracking issue for using drop_in_place in const contexts

Public API

// core::ptr

pub const unsafe fn drop_in_place<T: ?Sized + ~const Destruct>(to_drop: *mut T);

Steps / History

• Implementation: Constified array::from_fn and ptr::drop_in_place #109122
• Final comment period (FCP)¹
• Stabilization PR

Unresolved Questions

• Confirm that things such as dyn Trait works with this as well

Footnotes

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

[juntyr]

@fee1-dead The summary seems to link a different implementation PR Upon rereading the PR, I saw you also constified drop_in_place there - perhaps the PR title could reflect this?

[clarfonthey]

With #146187 merged, the description should be updated to include the following functions added to this list:

• core::ptr::drop_in_place
• core::mem::ManuallyDrop::drop
• core::mem::MaybeUninit::assume_init_drop
• <[core::mem::MaybeUninit<_>]>::assume_init_drop
• <*mut _>::drop_in_place
• core::ptr::NonNull::drop_in_place

All of them are effectively wrappers over drop_in_place, so, they made sense to include in this feature flag. They also all depend on const_destruct (#133214) so that should be marked as a blocker for this as well.

[theemathas]

Currently, drop_in_place can be called on statics in consteval, which feels a bit odd to me. See #146187 (comment)

[clarfonthey]

It probably makes more sense to file a separate issue for that now that this feature has been implemented again. Generally, tracking issues are just for listing blockers to stabilisation, not for elaborating on specific ones, which should each have dedicated issues.