error[E0049]: method `bar` has 1 type parameter but its trait declaration has 0 type parameters --> $DIR/generics-mismatch.rs:8:12 | LL | fn bar(&self) -> impl Sized; | - expected 0 type parameters ... LL | fn bar(&self) {} | ^ found 1 type parameter error: aborting due to previous error For more information about this error, try `rustc --explain E0049`.