Stabilize Iterator::intersperse

[jhpratt]

FCP completed in #79524

[rust-highfive]

r? @Mark-Simulacrum

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[rustbot]

Hey! It looks like you've submitted a new PR for the library teams!

If this PR contains changes to any rust-lang/rust public library APIs then please comment with @rustbot label +T-libs-api -T-libs to tag it appropriately. If this PR contains changes to any unstable APIs please edit the PR description to add a link to the relevant API Change Proposal or create one if you haven't already. If you're unsure where your change falls no worries, just leave it as is and the reviewer will take a look and make a decision to forward on if necessary.

Examples of T-libs-api changes:

• Stabilizing library features
• Introducing insta-stable changes such as new implementations of existing stable traits on existing stable types
• Introducing new or changing existing unstable library APIs (excluding permanently unstable features / features without a tracking issue)
• Changing public documentation in ways that create new stability guarantees
• Changing observable runtime behavior of library APIs

Some changes occurred in src/tools/clippy

cc @rust-lang/clippy

[jyn514]

@bors try

[bors]

⌛ Trying commit d031a44 with merge 5bc97a20e5cc382ae6d19f727a9e73eeb2734548...

[Mark-Simulacrum]

Has something happened to mitigate the problems that caused us to revert this the last time? (#88967)

[vacuus]

The linked FCP is the original, not a new one. There hasn't been recent discussion in that issue or the tracking issue, so if progress has been made, it should probably be referenced in one or both of the issues. It doesn't seem like anything has happened, though.

[ehuss]

I believe rfc#3240 was opened with intersperse being a prime example of needing some mitigating factor before it could be stabilized. I believe that's where the most recent discussion went.

[jhpratt]

For reference, the primary reason I created this was to have a crater run (the queue is empty, so why not). This would let us judge whether anything has happened on the ecosystem side of things, not just the compiler's. It's been ~10 months since the previous crater run, so I just wanted an update on that front.

[vacuus]

It would be helpful for the PR title to have something like [DONT MERGE] or [CRATER] and explain more (if you think it's necessary) in the PR description.

[jhpratt]

The reason I didn't do that is because it should be merged if crater comes back clean. Which, to be honest, is not expected — I presume there are still some root regressions.

[bors]

☀️ Try build successful - checks-actions
Build commit: 5bc97a20e5cc382ae6d19f727a9e73eeb2734548 (5bc97a20e5cc382ae6d19f727a9e73eeb2734548)

[jyn514]

@craterbot run mode=build-and-test crates=list:https://crater-reports.s3.amazonaws.com/beta-1.56-2/retry-regressed-list.txt

[craterbot]

🚨 Error: missing desired crates: {"https://crater-reports.s3.amazonaws.com/beta-1.56-2/retry-regressed-list.txt"}

🆘 If you have any trouble with Crater please ping @rust-lang/infra!
ℹ️ Crater is a tool to run experiments across parts of the Rust ecosystem. Learn more

[Mark-Simulacrum]

@craterbot run mode=build-and-test crates=https://crater-reports.s3.amazonaws.com/beta-1.56-2/retry-regressed-list.txt

[craterbot]

🚨 Error: missing desired crates: {"crw-types"}

🆘 If you have any trouble with Crater please ping @rust-lang/infra!
ℹ️ Crater is a tool to run experiments across parts of the Rust ecosystem. Learn more

[Mark-Simulacrum]

@craterbot run mode=build-and-test

[craterbot]

👌 Experiment pr-99093 created and queued.
🤖 Automatically detected try build 5bc97a20e5cc382ae6d19f727a9e73eeb2734548
🔍 You can check out the queue and this experiment's details.

ℹ️ Crater is a tool to run experiments across parts of the Rust ecosystem. Learn more

[craterbot]

🚧 Experiment pr-99093 is now running

ℹ️ Crater is a tool to run experiments across parts of the Rust ecosystem. Learn more

[craterbot]

🎉 Experiment pr-99093 is completed!
📊 460 regressed and 161 fixed (239215 total)
📰 Open the full report.

⚠️ If you notice any spurious failure please add them to the blacklist!
ℹ️ Crater is a tool to run experiments across parts of the Rust ecosystem. Learn more

[jhpratt]

I think it's safe to say that the situation has not improved since the last crater run. As such I am closing this. #88967 is probably the only way forward given the lack of "natural" progress towards disambiguation.