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

error: aborting due to previous error

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