error[E0605]: non-primitive cast: `&dyn Foo` as `&dyn Bar<_>` --> $DIR/type-checking-test-1.rs:16:13 | LL | let _ = x as &dyn Bar<_>; // Ambiguous | ^^^^^^^^^^^^^^^^ invalid cast | help: consider borrowing the value | LL | let _ = &x as &dyn Bar<_>; // Ambiguous | + error[E0277]: the trait bound `&dyn Foo: Bar<_>` is not satisfied --> $DIR/type-checking-test-1.rs:16:13 | LL | let _ = x as &dyn Bar<_>; // Ambiguous | ^ the trait `Bar<_>` is not implemented for `&dyn Foo` | = note: required for the cast from `&dyn Foo` to the object type `dyn Bar<_>` error: aborting due to 2 previous errors Some errors have detailed explanations: E0277, E0605. For more information about an error, try `rustc --explain E0277`.