error[E0599]: no method named `foo` found for fn item `fn() -> Foo {Foo}` in the current scope
  --> $DIR/empty-tuple-method.rs:12:15
   |
LL |     thing.bar.foo();
   |               ^^^ method not found in `fn() -> Foo {Foo}`
   |
help: use parentheses to construct this tuple struct
   |
LL |     (thing.bar)().foo();
   |     +         +++

error: aborting due to previous error

For more information about this error, try `rustc --explain E0599`.