false positives on unit_cmp (needs macro check)

[llogiq]

If you auto-derive PartialEq or PartialOrd on a struct containing unit, this will trigger unit_cmp.

Example (from Rust, src/libcollections/string.rs:1035-1036:

#[derive(PartialEq)]
pub struct ParseError(());

[Manishearth]

We should macro check this one.

[llogiq]

Yes. I already wrote that in the title.

[Manishearth]

Oh, wow, I'm an idiot 😝