Stabilize non_null_convenience

[tgross35]

Fully stabilize the following API, including const where applicable:

impl <T> NonNull<T> {
    pub const unsafe fn offset(self, count: isize) -> Self;
    pub const unsafe fn add(self, count: usize) -> Self;
    pub const unsafe fn sub(self, count: usize) -> Self;
    pub const unsafe fn offset_from(self, origin: NonNull<T>) -> isize;
    pub const unsafe fn read(self) -> T;
    pub unsafe fn read_volatile(self) -> T;
    pub const unsafe fn read_unaligned(self) -> T;
    pub unsafe fn write_volatile(self, val: T);
    pub unsafe fn replace(self, src: T) -> T;
}

impl<T: ?Sized> NonNull<T> {
    pub const unsafe fn byte_offset(self, count: isize) -> Self;
    pub const unsafe fn byte_add(self, count: usize) -> Self;
    pub const unsafe fn byte_sub(self, count: usize) -> Self;
    pub const unsafe fn byte_offset_from<U: ?Sized>(self, origin: NonNull<U>) -> isize;
    pub unsafe fn drop_in_place(self);
}

Stabilize the following without const:

impl <T> NonNull<T> {
    // const under `const_intrinsic_copy`
    pub const unsafe fn copy_to(self, dest: NonNull<T>, count: usize);
    pub const unsafe fn copy_to_nonoverlapping(self, dest: NonNull<T>, count: usize);
    pub const unsafe fn copy_from(self, src: NonNull<T>, count: usize);
    pub const unsafe fn copy_from_nonoverlapping(self, src: NonNull<T>, count: usize);

    // const under `const_ptr_write`
    pub const unsafe fn write(self, val: T);
    pub const unsafe fn write_bytes(self, val: u8, count: usize);
    pub const unsafe fn write_unaligned(self, val: T);

    // const under `const_swap`
    pub const unsafe fn swap(self, with: NonNull<T>);

    // const under `const_align_offset`
    pub const fn align_offset(self, align: usize) -> usize;

    // const under `const_pointer_is_aligned`
    pub const fn is_aligned(self) -> bool;
}

Left the following unstable:

impl <T> NonNull<T> {
    // moved gate to `ptr_sub_ptr`
    pub const unsafe fn sub_ptr(self, subtracted: NonNull<T>) -> usize;
}

impl <T: ?Sized> NonNull<T> {
    // moved gate to `pointer_is_aligned_to`
    pub const fn is_aligned_to(self, align: usize) -> bool;
}

Fixes: #117691

[rustbot]

r? @Amanieu

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[tgross35]

FCP complete at #117691 (comment)

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

[jhpratt]

@rustbot claim

@bors r+

[bors]

📌 Commit e0f8202 has been approved by jhpratt

It is now in the queue for this repository.

[tgross35]

Thanks!

[jhpratt]

Library stabilizations are simple enough, so I figured why not review when I saw the email 😄

[saethlin]

Do we have a preferred attribute order? I'm never sure which order people prefer, if anyone even cares. If there is preference, I'd prefer to have a tool to make it happen.

[tgross35]

Whenever I touch functions I sort them from smallest to largest (exception being rustc_stable always before rustc_const_stable), which does seem a bit silly but looks nice IMO. Looking through libs, I think this is somewhat common?

Didn't actually mean to change these here since they're not related to the stabilization, but it doesn't hurt anything.

[bors]

⌛ Testing commit e0f8202 with merge c99bba3...

[rust-log-analyzer]

The job aarch64-gnu failed! Check out the build log: (web) (plain)

Click to see the possible cause of the failure (guessed by this bot)

[RUSTC-TIMING] rustc_ast_lowering test:false 68.517
   Compiling rustc_hir_analysis v0.0.0 (/checkout/compiler/rustc_hir_analysis)
[RUSTC-TIMING] rustc_metadata test:false 69.715
   Compiling rustc_ty_utils v0.0.0 (/checkout/compiler/rustc_ty_utils)
##[error]The runner has received a shutdown signal. This can happen when the runner service is stopped, or a manually started runner is canceled.

Session terminated, killing shell...::group::Clock drift check
  network time:  ...killed.
##[error]The operation was canceled.
Cleaning up orphan processes

[bors]

💔 Test failed - checks-actions

[jhpratt]

@bors retry

[bors]

⌛ Testing commit e0f8202 with merge 5fe8b69...

[bors]

☀️ Test successful - checks-actions
Approved by: jhpratt
Pushing 5fe8b69 to master...

[rust-timer]

Finished benchmarking commit (5fe8b69): 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)	1.7%	[1.7%, 1.7%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-0.1%	[-0.1%, -0.1%]	1
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.8%	[-0.1%, 1.7%]	2

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: 674.021s -> 674.79s (0.11%)
Artifact size: 316.00 MiB -> 315.95 MiB (-0.02%)