Require Debug for Pointee::Metadata

[stepancheg]

Useful for debugging.

[rustbot]

r? @joboet

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[joboet]

r? libs-api

[jhpratt]

Diff LGTM, but I'll leave the decision to the team, as that's not my purview.

[Amanieu]

r? @the8472

[the8472]

@Amanieu are you sure you got the right person or the right issue? I'm not -api

But since I'm looking at it I might as well comment. The feature is unstable and already requires Hash and Ord which may not be super-trivial so Debug doesn't seem too onerous on top. The only source of doubt I have is that I don't know which additional metadata types we might gain in the future (for custom DSTs? pointers wider than 2 usizes have been discussed somewhere...) and the fewer constraints we impose on those the better, maybe...

[Amanieu]

Sorry I should have clarified. I don't have any opinions on this, but I believe you did some work related to pointer metadata so you may have more context. If you're happy with this, you can just go ahead and merge it.

[the8472]

I'm working on niches for usize pointer metadata, which is only vaguely related since it doesn't affect the user-visible types. If you don't see any issues with API forward-compat then sure...

@bors r=the8472,Amanieu rollup

[bors]

📌 Commit b110cb3 has been approved by the8472,Amanieu

It is now in the queue for this repository.

[bors]

⌛ Testing commit b110cb3 with merge 1aedc96...

[bors]

☀️ Test successful - checks-actions
Approved by: the8472,Amanieu
Pushing 1aedc96 to master...

[rust-timer]

Finished benchmarking commit (1aedc96): 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)	5.1%	[5.1%, 5.1%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	5.1%	[5.1%, 5.1%]	1

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: 668.99s -> 667.618s (-0.21%)
Artifact size: 315.70 MiB -> 315.66 MiB (-0.01%)