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Tracking Issue for const_ptr_as_ref #91822

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lilasta opened this issue Dec 12, 2021 · 2 comments
Open
1 of 3 tasks

Tracking Issue for const_ptr_as_ref #91822

lilasta opened this issue Dec 12, 2021 · 2 comments
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C-tracking-issue Category: A tracking issue for an RFC or an unstable feature. T-libs-api Relevant to the library API team, which will review and decide on the PR/issue.

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@lilasta
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lilasta commented Dec 12, 2021 •
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Feature gate: #![feature(const_ptr_as_ref)]

This is a tracking issue for implementing const PTR::[as_ref|as_mut|as_uninit_ref|as_uninit_slice].

Public API

// core::ptr
impl<T: ?Sized> *const T {
    pub const unsafe fn as_ref<'a>(self) -> Option<&'a T>;
    pub const unsafe fn as_ref_unchecked<'a>(self) -> &'a T;
    pub const unsafe fn as_uninit_ref<'a>(self) -> Option<&'a MaybeUninit<T>>
    where
        T: Sized;
    pub const unsafe fn as_uninit_slice<'a>(self) -> Option<&'a [MaybeUninit<T>]>;
}

impl<T: ?Sized> *mut T {
    pub const unsafe fn as_ref<'a>(self) -> Option<&'a T>;
    pub const unsafe fn as_ref_unchecked<'a>(self) -> &'a T;
    pub const unsafe fn as_uninit_ref<'a>(self) -> Option<&'a MaybeUninit<T>>
    where
        T: Sized;
    pub const unsafe fn as_mut<'a>(self) -> Option<&'a mut T>;
    pub const unsafe fn as_mut_unchecked<'a>(self) -> &'a mut T;
    pub const unsafe fn as_uninit_mut<'a>(self) -> Option<&'a mut MaybeUninit<T>>
    where
        T: Sized;
    pub const unsafe fn as_uninit_slice<'a>(self) -> Option<&'a [MaybeUninit<T>]>;
    pub const unsafe fn as_uninit_slice_mut<'a>(self) -> Option<&'a mut [MaybeUninit<T>]>;
}

impl<T: Sized> NonNull<T> {
    pub const unsafe fn as_uninit_ref<'a>(&self) -> &'a MaybeUninit<T>;
    pub const unsafe fn as_uninit_mut<'a>(&mut self) -> &'a mut MaybeUninit<T>;
}

impl<T: ?Sized> NonNull<T> {
    /*
    pub const unsafe fn as_ref<'a>(&self) -> &'a T;
    */
    pub const unsafe fn as_mut<'a>(&mut self) -> &'a mut T;
    pub const unsafe fn as_uninit_slice<'a>(&self) -> &'a [MaybeUninit<T>];
    pub const unsafe fn as_uninit_slice_mut<'a>(&self) -> &'a mut [MaybeUninit<T>];
}

Steps / History

Unresolved Questions

  • None yet.
@lilasta lilasta added C-tracking-issue Category: A tracking issue for an RFC or an unstable feature. T-libs-api Relevant to the library API team, which will review and decide on the PR/issue. labels Dec 12, 2021
@lilasta lilasta mentioned this issue Dec 12, 2021
Merged
matthiaskrgr added a commit to matthiaskrgr/rust that referenced this issue Dec 21, 2021
@matthiaskrgr
Rollup merge of rust-lang#91823 - woppopo:const_ptr_as_ref, r=lcnr
4d840a6 
Make `PTR::as_ref` and similar methods `const`.

Tracking issue: rust-lang#91822
Feature gate: `#![feature(const_ptr_as_ref)]`

```rust
// core::ptr
impl<T: ?Sized> *const T {
    pub const unsafe fn as_ref<'a>(self) -> Option<&'a T>;
    pub const unsafe fn as_uninit_ref<'a>(self) -> Option<&'a MaybeUninit<T>>
    where
        T: Sized;
    pub const unsafe fn as_uninit_slice<'a>(self) -> Option<&'a [MaybeUninit<T>]>;
}

impl<T: ?Sized> *mut T {
    pub const unsafe fn as_ref<'a>(self) -> Option<&'a T>;
    pub const unsafe fn as_uninit_ref<'a>(self) -> Option<&'a MaybeUninit<T>>
    where
        T: Sized;
    pub const unsafe fn as_mut<'a>(self) -> Option<&'a mut T>;
    pub const unsafe fn as_uninit_mut<'a>(self) -> Option<&'a mut MaybeUninit<T>>
    where
        T: Sized;
    pub const unsafe fn as_uninit_slice<'a>(self) -> Option<&'a [MaybeUninit<T>]>;
    pub const unsafe fn as_uninit_slice_mut<'a>(self) -> Option<&'a mut [MaybeUninit<T>]>;
}

impl<T: Sized> NonNull<T> {
    pub const unsafe fn as_uninit_ref<'a>(&self) -> &'a MaybeUninit<T>;
    pub const unsafe fn as_uninit_mut<'a>(&mut self) -> &'a mut MaybeUninit<T>;
}

impl<T: ?Sized> NonNull<T> {
    pub const unsafe fn as_ref<'a>(&self) -> &'a T;
    pub const unsafe fn as_mut<'a>(&mut self) -> &'a mut T;
    pub const unsafe fn as_uninit_slice<'a>(&self) -> &'a [MaybeUninit<T>];
    pub const unsafe fn as_uninit_slice_mut<'a>(&self) -> &'a mut [MaybeUninit<T>];
}
```
@lukas-code lukas-code mentioned this issue Sep 23, 2022
Merged
Dylan-DPC added a commit to Dylan-DPC/rust that referenced this issue Jul 30, 2023
@Dylan-DPC
Rollup merge of rust-lang#102198 - lukas-code:nonnull_as_ref, r=Amanieu
786011b 
`const`-stablilize `NonNull::as_ref`

A bunch of pointer to reference methods have been made unstably const some time ago in rust-lang#91823 under the feature gate `const_ptr_as_ref`.
Out of these, `NonNull::as_ref` can be implemented as a `const fn` in stable rust today, so i hereby propose to const stabilize this function only.

Tracking issue: rust-lang#91822

`@rustbot` label +T-libs-api -T-libs
matthiaskrgr added a commit to matthiaskrgr/rust that referenced this issue Jul 30, 2023
@matthiaskrgr
Rollup merge of rust-lang#102198 - lukas-code:nonnull_as_ref, r=Amanieu
e3ca397 
`const`-stablilize `NonNull::as_ref`

A bunch of pointer to reference methods have been made unstably const some time ago in rust-lang#91823 under the feature gate `const_ptr_as_ref`.
Out of these, `NonNull::as_ref` can be implemented as a `const fn` in stable rust today, so i hereby propose to const stabilize this function only.

Tracking issue: rust-lang#91822

``@rustbot`` label +T-libs-api -T-libs
@GrigorenkoPV GrigorenkoPV mentioned this issue Mar 14, 2024
Merged
workingjubilee added a commit to workingjubilee/rustc that referenced this issue May 3, 2024
@workingjubilee
Rollup merge of rust-lang#122492 - GrigorenkoPV:ptr_as_ref_unchecked,…
cce23b1 
… r=workingjubilee

Implement ptr_as_ref_unchecked

Implementation of rust-lang#122034.

Prefixed the feature name with `ptr_` for clarity.

Linked const-unstability to rust-lang#91822, so the post there should probably be updated to mentions the 3 new methods when/if this PR is merged.
matthiaskrgr added a commit to matthiaskrgr/rust that referenced this issue May 3, 2024
@matthiaskrgr
Rollup merge of rust-lang#122492 - GrigorenkoPV:ptr_as_ref_unchecked,…
96c3f44 
… r=workingjubilee

Implement ptr_as_ref_unchecked

Implementation of rust-lang#122034.

Prefixed the feature name with `ptr_` for clarity.

Linked const-unstability to rust-lang#91822, so the post there should probably be updated to mentions the 3 new methods when/if this PR is merged.
matthiaskrgr added a commit to matthiaskrgr/rust that referenced this issue May 3, 2024
@matthiaskrgr
Rollup merge of rust-lang#122492 - GrigorenkoPV:ptr_as_ref_unchecked,…
a296693 
… r=workingjubilee

Implement ptr_as_ref_unchecked

Implementation of rust-lang#122034.

Prefixed the feature name with `ptr_` for clarity.

Linked const-unstability to rust-lang#91822, so the post there should probably be updated to mentions the 3 new methods when/if this PR is merged.
rust-timer added a commit to rust-lang-ci/rust that referenced this issue May 3, 2024
@rust-timer
Unrolled build for rust-lang#122492
2e596f5 
Rollup merge of rust-lang#122492 - GrigorenkoPV:ptr_as_ref_unchecked, r=workingjubilee

Implement ptr_as_ref_unchecked

Implementation of rust-lang#122034.

Prefixed the feature name with `ptr_` for clarity.

Linked const-unstability to rust-lang#91822, so the post there should probably be updated to mentions the 3 new methods when/if this PR is merged.
@GrigorenkoPV
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Hello!

Now that #122492 has been merged, 3 new methods are also const-gated behind this flag

  • <*const T>::as_ref_unchecked
  • <*mut T>::as_ref_unchecked
  • <*mut T>::as_mut_unchecked

Should they be added to the OP?

@lilasta
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lilasta commented May 4, 2024

I have added them to the list.

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