error[E0593]: function is expected to take 1 argument, but it takes 2 arguments
  --> $DIR/issue-47706.rs:11:22
   |
LL |     pub fn new(foo: Option<i32>, _: ()) -> Foo {
   |     ------------------------------------------ takes 2 arguments
...
LL |         self.foo.map(Foo::new)
   |                  --- ^^^^^^^^ expected function that takes 1 argument
   |                  |
   |                  required by a bound introduced by this call
   |
note: required by a bound in `Option::<T>::map`
  --> $SRC_DIR/core/src/option.rs:LL:COL

error[E0593]: function is expected to take 0 arguments, but it takes 1 argument
  --> $DIR/issue-47706.rs:27:9
   |
LL |     Bar(i32),
   |     --- takes 1 argument
...
LL |     foo(Qux::Bar);
   |     --- ^^^^^^^^ expected function that takes 0 arguments
   |     |
   |     required by a bound introduced by this call
   |
note: required by a bound in `foo`
  --> $DIR/issue-47706.rs:22:8
   |
LL | fn foo<F>(f: F)
   |    --- required by a bound in this
LL | where
LL |     F: Fn(),
   |        ^^^^ required by this bound in `foo`

error: aborting due to 2 previous errors

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