2944454540
Slightly improve mismatched GAT where clause error This makes the error reporting a bit more standardized between `where` on GATs and functions. cc #99206 (`@BoxyUwU),` don't want to mark this as as "fixed" because they're still not perfect, but this is still an improvement IMO so I want to land it incrementally. regarding "consider adding where clause to trait definition", we don't actually do that for methods as far as i can tell? i could file an issue to look into that maybe.
For high-level intro to how type checking works in rustc, see the type checking chapter of the rustc dev guide.