Suggest type next to visibility for const items

[reddevilmidzy]

resolve: #157368

Adjusts the type const suggestion to preserve visibility ordering, so pub const is suggested as pub type const instead of type pub const.

[rustbot]

HIR ty lowering was modified

cc @fmease

[rustbot]

r? @petrochenkov

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[petrochenkov]

r? compiler

[Kivooeo]

Hey, thanks for a PR, I'm a bit busy this week. I will try to review within next 3 days

[Unique-Usman]

I went through the pr, looks good. There is already an alternative test if it is an external crate(non-local) at tests/ui/const-generics/mgca/non-local-const-without-type_const.rs, so, not needed for this pr since it exist.

[estebank]

There is some code duplication between the branches, but that's ok. One thing that'd be nice to have is a check for whether the feature is enabled in order to add a note explaining that this change only would work on nightly (like we do in the errors when using a feature that isn't enabled).

Other than that, r=me.

[Kivooeo]

I'd change this match to something like this

View changes since this review

[Kivooeo]

@rustbot author

[reddevilmidzy]

There is some code duplication between the branches, but that's ok. One thing that'd be nice to have is a check for whether the feature is enabled in order to add a note explaining that this change only would work on nightly (like we do in the errors when using a feature that isn't enabled).

Other than that, r=me.

Am I understanding correctly that you mean we should add this note only when min_generic_const_args is disabled?

If that's my understanding, then for this test case, when MGCA is not enabled, the code compiles successfully instead of emitting an error with a suggestion to use type const.

[reddevilmidzy]

thank you for the review :)
@rustbot ready

[Kivooeo]

Am I understanding correctly that you mean we should add this note only when min_generic_const_args is disabled?

yes

[reddevilmidzy]

When min_generic_const_args is not enabled, using plain const does not produce an error. Likewise, when type const is used without min_generic_const_args enabled, the compiler already emits a help message suggesting that the feature gate should be enabled.

Given that, is there anything else you had in mind that should be added to the diagnostic?

[Kivooeo]

given that i think it's good

@bors r+ rollup

[rust-bors]

📌 Commit 5ea3958 has been approved by Kivooeo

It is now in the queue for this repository.

[jhpratt]

@rust-timer build 279b548

[rust-timer]

Missing artifact for sha 279b54833e22d63eb3e4aa3e6b230e267e64844d (https://ci-artifacts.rust-lang.org/rustc-builds/279b54833e22d63eb3e4aa3e6b230e267e64844d/rustc-nightly-x86_64-unknown-linux-gnu.tar.xz); not built yet, try again later.

[jhpratt]

@rust-timer build 279b548

[rust-timer]

Finished benchmarking commit (279b548): comparison URL.

Overall result: no relevant changes - no action needed

Benchmarking means the PR may be perf-sensitive. Consider adding rollup=never if this change is not fit for rolling up.

@rustbot label: -S-waiting-on-perf -perf-regression

Instruction count

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

Max RSS (memory usage)

Results (primary -1.1%, secondary -3.2%)

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

	mean	range	count
Regressions ❌ (primary)	2.3%	[2.3%, 2.3%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-2.3%	[-2.5%, -2.0%]	3
Improvements ✅ (secondary)	-3.2%	[-4.3%, -2.2%]	5
All ❌✅ (primary)	-1.1%	[-2.5%, 2.3%]	4

Cycles

Results (secondary -3.9%)

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)	-3.9%	[-3.9%, -3.9%]	1
All ❌✅ (primary)	-	-	0

Binary size

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

Bootstrap: 489.308s -> 481.474s (-1.60%)
Artifact size: 390.69 MiB -> 390.69 MiB (0.00%)