New lint suggestion: detect `HashMap/Set::iter()` followed by `take_while()/skip_while()/map_while()`.

What it does

Detects usage of HashMap/Set::iter() (or other iterator) followed by take_while()/skip_while()/map_while().

Categories (optional)

• Kind: suspicious, maybe correctness?

What is the advantage of the recommended code over the original code

iter() in HashMap/Set iterates in arbitrary order, and _while() methods usually make sense where is there some kind of order in the iterator. This would catch using a e.g. HashMap where a sorted structure would be required.

Drawbacks

False positives, but it seems unlikely.

Example

Note sure if anything useful can be suggested other than detecting the issue.

Start by reviewing how rust-clippy implements existing iterator-related lints and their tests, then compare the proposed HashMap/Set::iter() patterns with take_while(), skip_while(), and map_while(). Resolve the lint category and false-positive boundaries; done means the intended patterns are detected consistently with appropriate coverage.