error[E0308]: mismatched types
  --> $DIR/issue-17033.rs:2:10
   |
LL |     (*p)(())
   |     ---- ^^ expected `&mut ()`, found `()`
   |     |
   |     arguments to this function are incorrect
   |
help: consider mutably borrowing here
   |
LL |     (*p)(&mut ())
   |          ++++

error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0308`.