Stabilize const_maybe_uninit_assume_init_read

[DaniPopes]

AFAICT the only reason this was not included in the maybe_uninit_extra stabilization was because ptr::read was unstable (#92768 (comment)), which has since been stabilized in 1.71.

Needs a separate FCP from the original maybe_uninit_extra one.

Tracking issue: #63567

[rustbot]

r? @thomcc

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[DaniPopes]

@rustbot label +T-libs-api -T-libs

[dtolnay]

@rust-lang/libs-api:
@rfcbot fcp merge

const for the following function, which has been stable since Rust 1.60.

impl<T> MaybeUninit<T> {
    pub const unsafe fn assume_init_read(&self) -> T;
}

[rfcbot]

Team member @dtolnay has proposed to merge this. The next step is review by the rest of the tagged team members:

• @Amanieu
• @BurntSushi
• @dtolnay
• @joshtriplett
• @m-ou-se

No concerns currently listed.

Once a majority of reviewers approve (and at most 2 approvals are outstanding), this will enter its final comment period. If you spot a major issue that hasn't been raised at any point in this process, please speak up!

See this document for info about what commands tagged team members can give me.

[rfcbot]

🔔 This is now entering its final comment period, as per the review above. 🔔

[rfcbot]

The final comment period, with a disposition to merge, as per the review above, is now complete.

As the automated representative of the governance process, I would like to thank the author for their work and everyone else who contributed.

This will be merged soon.

[dtolnay]

Thanks!

[dtolnay]

@bors r+

[bors]

📌 Commit 58ed8ad has been approved by dtolnay

It is now in the queue for this repository.

[bors]

⌛ Testing commit 58ed8ad with merge 57ef889...

[bors]

☀️ Test successful - checks-actions
Approved by: dtolnay
Pushing 57ef889 to master...

[rust-timer]

Finished benchmarking commit (57ef889): comparison URL.

Overall result: no relevant changes - no action needed

@rustbot label: -perf-regression

Instruction count

This benchmark run did not return any relevant results for this metric.

Max RSS (memory usage)

Results

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	3.5%	[3.5%, 3.5%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-2.6%	[-3.4%, -2.1%]	3
All ❌✅ (primary)	-	-	0

Cycles

This benchmark run did not return any relevant results for this metric.

Binary size

This benchmark run did not return any relevant results for this metric.

Bootstrap: 628.012s -> 628.692s (0.11%)
Artifact size: 271.32 MiB -> 271.29 MiB (-0.01%)