Rollup of 5 pull requests by jhpratt · Pull Request #155583 · rust-lang/rust

jhpratt · 2026-04-21T06:20:29Z

Successful merges:

Fix redundant boolean comparison in Mutex::try_lock #155532 (Fix redundant boolean comparison in Mutex::try_lock)
Clarify that isqrt returns the principal (non-negative) square root #155558 (Clarify that isqrt returns the principal (non-negative) square root)
add safety doc (section header) to two unsafe methods in NonZero #155559 (add safety doc (section header) to two unsafe methods in NonZero)
Implement const Default for &CStr #155564 (Implement const Default for &CStr)
constify Vec comparisons #155565 (constify Vec comparisons)

Fix redundant boolean comparison in `Mutex::try_lock` Simplify boolean return in `Mutex::try_lock`. Replace `expr == false` with `!expr` for cleaner code.

…ratt Clarify that isqrt returns the principal (non-negative) square root Clarify which root is returned from `isqrt` and `checked_isqrt` Fixes: rust-lang#154000 Previous PRs: rust-lang#154462

add safety doc (section header) to two unsafe methods in `NonZero` This PR adds a Safety section to two unsafe methods in `NonZero`: - [unchecked_add](https://doc.rust-lang.org/nightly/core/num/struct.NonZero.html#method.unchecked_add) - [unchecked_mul](https://doc.rust-lang.org/nightly/core/num/struct.NonZero.html#method.unchecked_mul) The safety documentation is now consistent with that of [`u8::unchecked_add`](https://doc.rust-lang.org/nightly/core/primitive.u8.html#method.unchecked_add) and [`u8::unchecked_mul`](https://doc.rust-lang.org/nightly/core/primitive.u8.html#method.unchecked_mul).

…ult/cstr, r=jhpratt Implement const Default for &CStr Implements `const Default` for `&CStr`. Tracking issue: rust-lang#143894.

…ratt constify `Vec` comparisons Tracking Issue: rust-lang#143800 Due to `Cow` not implementing `const Deref` (rust-lang#147964), the comparisons including a `Cow` were not constified.

jhpratt · 2026-04-21T06:20:43Z

@bors r+ rollup=never p=5

rust-bors · 2026-04-21T06:20:46Z

📌 Commit b4bab32 has been approved by jhpratt

It is now in the queue for this repository.

rust-bors · 2026-04-21T12:15:55Z

☀️ Test successful - CI
Approved by: jhpratt
Duration: 3h 16m 34s
Pushing 93637f3 to main...

rust-timer · 2026-04-21T12:17:25Z

📌 Perf builds for each rolled up PR:

PR#	Message	Perf Build Sha
#155532	Fix redundant boolean comparison in `Mutex::try_lock`	`7c4eef9b2977ce2f7474490dde32518a9ca84027` (link)
#155558	Clarify that isqrt returns the principal (non-negative) squ…	`460cf0fe97c353ae0b752eafa0a9c5d97f1e9919` (link)
#155559	add safety doc (section header) to two unsafe methods in `N…	`f45597a2b79637bd4bd82d512a6f47eab071e937` (link)
#155564	Implement const Default for &CStr	`dad6c24bacb18c22444330a8ec861d2a5b94b561` (link)
#155565	constify `Vec` comparisons	`9262e020eaf2358cb4fbc55f409e5040928dd649` (link)

previous master: 9ab01ae53c

In the case of a perf regression, run the following command for each PR you suspect might be the cause: @rust-timer build $SHA

github-actions · 2026-04-21T12:19:27Z

What is this?

This is an experimental post-merge analysis report that shows differences in test outcomes between the merged PR and its parent PR.

Comparing 9ab01ae (parent) -> 93637f3 (this PR)

Test differences

Show 3069 test diffs

Stage 1

ffi::cstr::const_default: [missing] -> pass (J0)

Stage 2

ffi::cstr::const_default: [missing] -> pass (J1)

Additionally, 3067 doctest diffs were found. These are ignored, as they are noisy.

Job group index

Test dashboard

Run

cargo run --manifest-path src/ci/citool/Cargo.toml -- \
    test-dashboard 93637f398f4d0d40badc6bf1ed3f241499d06f88 --output-dir test-dashboard

And then open test-dashboard/index.html in your browser to see an overview of all executed tests.

Job duration changes

dist-android: 23m 11s -> 29m 17s (+26.3%)
dist-sparcv9-solaris: 1h 32m -> 1h 12m (-21.9%)
dist-x86_64-apple: 2h 19m -> 2h 2m (-12.2%)
x86_64-mingw-1: 2h 45m -> 3h 3m (+10.8%)
x86_64-msvc-ext2: 1h 57m -> 1h 46m (-9.7%)
i686-msvc-1: 2h 48m -> 3h 3m (+9.5%)
x86_64-msvc-2: 2h 38m -> 2h 23m (-9.4%)
x86_64-gnu: 2h 22m -> 2h 9m (-9.1%)
dist-aarch64-llvm-mingw: 1h 45m -> 1h 54m (+9.1%)
x86_64-gnu-debug: 1h 59m -> 1h 50m (-8.1%)

How to interpret the job duration changes?

Job durations can vary a lot, based on the actual runner instance
that executed the job, system noise, invalidated caches, etc. The table above is provided
mostly for t-infra members, for simpler debugging of potential CI slow-downs.

rust-timer · 2026-04-21T12:56:33Z

Finished benchmarking commit (93637f3): comparison URL.

Overall result: no relevant changes - no action needed

@rustbot label: -perf-regression

Instruction count

This perf run didn't have relevant results for this metric.

Max RSS (memory usage)

Results (primary 2.4%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	2.4%	[2.4%, 2.4%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	2.4%	[2.4%, 2.4%]	1

Cycles

Results (secondary -3.1%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-3.1%	[-3.1%, -3.1%]	1
All ❌✅ (primary)	-	-	0

Binary size

Results (secondary 0.1%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	0.1%	[0.1%, 0.1%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Bootstrap: 490.352s -> 492.256s (0.39%)
Artifact size: 394.40 MiB -> 394.33 MiB (-0.02%)

StepfenShawn and others added 10 commits April 20, 2026 09:49

Fix redundant boolean comparison in Mutex::try_lock

e1059f6

update doc to be more clear

6b8cb42

add safety sections to two unsafe methods in NonZero

0bfdb18

Implement const Default for &CStr

339a2f0

constify vec comparisons

2ba7b3b

Rollup merge of rust-lang#155532 - StepfenShawn:patch-1, r=jhpratt

387df6e

Fix redundant boolean comparison in `Mutex::try_lock` Simplify boolean return in `Mutex::try_lock`. Replace `expr == false` with `!expr` for cleaner code.

Rollup merge of rust-lang#155558 - nivekithan:issue-154000-fix, r=jhp…

156cc9f

…ratt Clarify that isqrt returns the principal (non-negative) square root Clarify which root is returned from `isqrt` and `checked_isqrt` Fixes: rust-lang#154000 Previous PRs: rust-lang#154462

Rollup merge of rust-lang#155564 - tshakalekholoane:tshaka/const_defa…

53b9b9a

…ult/cstr, r=jhpratt Implement const Default for &CStr Implements `const Default` for `&CStr`. Tracking issue: rust-lang#143894.

Rollup merge of rust-lang#155565 - Lars-Schumann:const-vec-cmp, r=jhp…

b4bab32

…ratt constify `Vec` comparisons Tracking Issue: rust-lang#143800 Due to `Cow` not implementing `const Deref` (rust-lang#147964), the comparisons including a `Cow` were not constified.

rust-bors bot added the rollup A PR which is a rollup label Apr 21, 2026

rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. T-libs Relevant to the library team, which will review and decide on the PR/issue. labels Apr 21, 2026

rust-bors bot added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Apr 21, 2026

jhpratt mentioned this pull request Apr 21, 2026

Rollup of 3 pull requests #155581

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rust-bors bot added merged-by-bors This PR was explicitly merged by bors. and removed S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. labels Apr 21, 2026

rust-bors bot merged commit 93637f3 into rust-lang:main Apr 21, 2026
12 checks passed

rustbot added this to the 1.97.0 milestone Apr 21, 2026

rust-bors bot mentioned this pull request Apr 21, 2026

implement PartialEq<Vec<U>> for [T; N] and &[T; N] #149045

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Rollup of 5 pull requests#155583

Rollup of 5 pull requests#155583
rust-bors[bot] merged 10 commits intorust-lang:mainfrom
jhpratt:rollup-HPCle0C

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Overall result: no relevant changes - no action needed

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