1 error: type parameter `impl Deref<Target = Self>` is part of concrete type but not used in parameter list for the `impl Trait` type alias
2 --> $DIR/issue-57700.rs:15:58
4 LL | fn foo(self: impl Deref<Target = Self>) -> Self::Bar {
5 | __________________________________________________________^
11 error: aborting due to previous error