error[E0593]: function is expected to take 1 argument, but it takes 2 arguments
  --> $DIR/issue-47706.rs:21:18
   |
LL |     pub fn new(foo: Option<i32>, _: ()) -> Foo {
   |     ------------------------------------------ takes 2 arguments
...
LL |         self.foo.map(Foo::new)
   |                  ^^^ expected function that takes 1 argument

error[E0593]: function is expected to take 0 arguments, but it takes 1 argument
  --> $DIR/issue-47706.rs:37:5
   |
LL |     Bar(i32),
   |     -------- takes 1 argument
...
LL |     foo(Qux::Bar);
   |     ^^^ expected function that takes 0 arguments
   |
note: required by `foo`
  --> $DIR/issue-47706.rs:30:1
   |
LL | / fn foo<F>(f: F)
LL | | where
LL | |     F: Fn(),
LL | | {
LL | | }
   | |_^

error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0593`.