error[E0277]: the trait bound `(): Foo` is not satisfied
  --> $DIR/wf-foreign-fn-decl-ret.rs:11:25
   |
LL | pub trait Foo {
   | ------------- required by this bound in `Foo`
...
LL |     pub fn lint_me() -> <() as Foo>::Assoc;
   |                         ^^^^^^^^^^^^^^^^^^ the trait `Foo` is not implemented for `()`

error[E0277]: the trait bound `u32: Unsatisfied` is not satisfied
  --> $DIR/wf-foreign-fn-decl-ret.rs:14:32
   |
LL | pub struct Bar<T: Unsatisfied>(T);
   |                   ----------- required by this bound in `Bar`
...
LL |     pub fn lint_me_aswell() -> Bar<u32>;
   |                                ^^^^^^^^ the trait `Unsatisfied` is not implemented for `u32`

error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0277`.