idea: Combination of str_to_string and needless_closure

[llogiq]

Currently, the str_to_string lint and the needless_closure lint miss the following: x.map(|s| s.to_string()) (where x is an iterator of &str). This can be replaced with x.map(str::to_owned), to both remove the closure and change the function.

[llogiq]

It should be possible to special-case eta_reduction for this. Perhaps with a sort of whitelist of { input_ref: &[RefType], input_type: &[&'static str], method_name: &'static str, replacement: &'static str } or some such. Though I struggle to find more examples than the above and maybe x.map(|s| s.to_string())(where x is already a IntoIter<Item=&String>), which can be completely removed, or changed to clone.

[Manishearth]

This actually doesn't always work, since autoderef is usually acting when running s.to_owned() over an iterator (it's probably an &String or something since iterators often end up adding more &ptrs)

[samueltardieu]

Triaging.

Right now, clippy::redundant-closure-for-method-calls suggests the (ugly) std::string::ToString::to_string η-reduction. Is that sufficient to close this issue?