rust/tests/ui/coherence/coherence-impl-trait-for-trait.rs
2023-01-11 09:32:08 +00:00

21 lines
485 B
Rust

// Test that we give suitable error messages when the user attempts to
// impl a trait `Trait` for its own object type.
trait Foo { fn dummy(&self) { } }
trait Bar: Foo { }
trait Baz: Bar { }
// Supertraits of Baz are not legal:
impl Foo for dyn Baz { }
//~^ ERROR E0371
impl Bar for dyn Baz { }
//~^ ERROR E0371
impl Baz for dyn Baz { }
//~^ ERROR E0371
// But other random traits are:
trait Other { }
impl Other for dyn Baz { } // OK, Other not a supertrait of Baz
fn main() { }