| // Tests that type alias impls traits do not leak auto-traits for |
| // the purposes of coherence checking |
| #![feature(type_alias_impl_trait)] |
| |
| trait OpaqueTrait {} |
| impl<T> OpaqueTrait for T {} |
| type OpaqueType = impl OpaqueTrait; |
| #[define_opaque(OpaqueType)] |
| fn mk_opaque() -> OpaqueType { |
| () |
| } |
| |
| #[derive(Debug)] |
| struct D<T>(T); |
| |
| trait AnotherTrait {} |
| impl<T: Send> AnotherTrait for T {} |
| |
| // This is in error, because we cannot assume that `OpaqueType: !Send`. |
| // (We treat opaque types as "foreign types" that could grow more impls |
| // in the future.) |
| impl AnotherTrait for D<OpaqueType> { |
| //~^ ERROR conflicting implementations of trait `AnotherTrait` for type `D<_>` |
| } |
| |
| fn main() {} |
