| #![feature(trait_alias)] |
| |
| // Ensure that relaxed bounds are not permitted in the `Self` bounds of trait aliases because trait |
| // aliases (like traits) aren't implicitly bounded by `Sized` so there's nothing to relax. |
| |
| trait Alias0 = ?Sized; //~ ERROR relaxed bounds are not permitted in trait alias bounds |
| trait Alias1 = where Self: ?Sized; //~ ERROR this relaxed bound is not permitted here |
| |
| trait Alias2<T: ?Sized> =; // OK |
| trait Alias3<T> = where T: ?Sized; // OK |
| |
| // Make sure that we don't permit "relaxing" trait aliases since we don't want to expand trait |
| // aliases during sized elaboration for simplicity as we'd need to handle relaxing arbitrary bounds |
| // (e.g., ones with modifiers, outlives-bounds, …) and where-clauses. |
| |
| trait SizedAlias = Sized; |
| fn take<T: ?SizedAlias>() {} //~ ERROR bound modifier `?` can only be applied to `Sized` |
| |
| fn main() {} |
