Erroneous code example:
```compile_fail,E0580
-fn main() -> i32 { // error: main function has wrong type
- 0
+fn main(x: i32) { // error: main function has wrong type
+ println!("{}", x);
}
```
-The `main` function prototype should never take arguments or return type.
+The `main` function prototype should never take arguments.
Example:
```