// 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 OpaqueTrait for T { } type OpaqueType = impl OpaqueTrait; fn mk_opaque() -> OpaqueType { () } #[derive(Debug)] struct D(T); trait AnotherTrait { } impl 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 { //~^ ERROR conflicting implementations of trait `AnotherTrait` for type `D` } fn main() {}