#![feature(auto_traits)] #![feature(negative_impls)] // Test for issue #56934 - that it is impossible to redundantly // implement an auto-trait for a trait object type that contains it. // Positive impl variant. auto trait Marker1 {} auto trait Marker2 {} trait Object: Marker1 {} // A supertrait marker is illegal... impl Marker1 for dyn Object + Marker2 { } //~ ERROR E0371 // ...and also a direct component. impl Marker2 for dyn Object + Marker2 { } //~ ERROR E0371 // But implementing a marker if it is not present is OK. impl Marker2 for dyn Object {} // OK // A non-principal trait-object type is orphan even in its crate. unsafe impl Send for dyn Marker2 {} //~ ERROR E0117 // And impl'ing a remote marker for a local trait object is forbidden // by one of these special orphan-like rules. unsafe impl Send for dyn Object {} //~ ERROR E0321 unsafe impl Send for dyn Object + Marker2 {} //~ ERROR E0321 fn main() { }