Extend UNCONDITIONAL_RECURSION to check for ToString implementations

[GuillaumeGomez]

Follow-up of #11938.

r? @llogiq

changelog: Extend UNCONDITIONAL_RECURSION to check for ToString implementations

[llogiq]

Perhaps add another test where self is put into a local before calling its to_string?

And another one calling (self as &Self).to_string() just for extra fun? 😋

[GuillaumeGomez]

Perhaps add another test where self is put into a local before calling its to_string?

For that one, we agree that it's just for cases like:

let x = self;
x.to_string()

and nothing else? Because otherwise it becomes quite tricky to check if self was mutated... However if you know of a way to check it, I'm very interested. :)

And another one calling (self as &Self).to_string() just for extra fun? 😋

Sure. ^^'

[llogiq]

However if you know of a way to check it, I'm very interested. :)

There's the clippy_utils::expr_or_init function, which should be helpful for that.

@rustbot author

[GuillaumeGomez]

Done!

[GuillaumeGomez]

Updated and added the suggested tests. :)

[llogiq]

Thank you!

@bors r+

[bors]

📌 Commit d161f3b has been approved by llogiq

It is now in the queue for this repository.

[bors]

⌛ Testing commit d161f3b with merge 44c99a8...

[bors]

☀️ Test successful - checks-action_dev_test, checks-action_remark_test, checks-action_test
Approved by: llogiq
Pushing 44c99a8 to master...