feat: add manual_is_variant_and lint

[yuxqiu]

changelog: add a new lint [manual_is_variant_and].

• Replace option.map(f).unwrap_or_default() and result.map(f).unwrap_or_default() with option.is_some_and(f) and result.is_ok_and(f) where f is a function or closure that returns bool.
• MSRV is set to 1.70.0 for this lint; when is_some_and and is_ok_and was stabilised

---

For example, for the following code:

let opt = Some(0);
opt.map(|x| x > 1).unwrap_or_default();

It suggests to instead write:

let opt = Some(0);
opt.is_some_and(|x| x > 1)

[rustbot]

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[bors]

☔ The latest upstream changes (presumably #11866) made this pull request unmergeable. Please resolve the merge conflicts.

[bors]

☔ The latest upstream changes (presumably #11977) made this pull request unmergeable. Please resolve the merge conflicts.

[Jarcho]

Sorry for the long delay. The implementation is fine, just have some small nits about it.

Can you change the name to something like manual_is_variant_and. Otherwise we'll end up with a pile of lints that do basically the same thing.

[yuxqiu]

Sorry for the long delay. The implementation is fine, just have some small nits about it.

Can you change the name to something like manual_is_variant_and. Otherwise we'll end up with a pile of lints that do basically the same thing.

No worries! Thank you for your review Jarcho! I have tried to resolved the problems you raised. Can you please see if the new code looks good?

[Jarcho]

Things look good. Just need to squash down the commits and then it's good.

[yuxqiu]

Things look good. Just need to squash down the commits and then it's good.

All done! Have a good holiday!

[bors]

☔ The latest upstream changes (presumably #12004) made this pull request unmergeable. Please resolve the merge conflicts.

[Jarcho]

Thank you. @bors r+

[bors]

📌 Commit c4a80f2 has been approved by Jarcho

It is now in the queue for this repository.

[bors]

⌛ Testing commit c4a80f2 with merge c6aeb28...

[bors]

☀️ Test successful - checks-action_dev_test, checks-action_remark_test, checks-action_test
Approved by: Jarcho
Pushing c6aeb28 to master...