error[E0061]: this function takes 1 argument but 0 arguments were supplied
  --> $DIR/arg-count-mismatch.rs:5:28
   |
LL | fn main() { let i: (); i = f(); }
   |                            ^-- supplied 0 arguments
   |                            |
   |                            expected 1 argument
   |
note: function defined here
  --> $DIR/arg-count-mismatch.rs:3:4
   |
LL | fn f(x: isize) { }
   |    ^ --------

error: aborting due to previous error

For more information about this error, try `rustc --explain E0061`.