It would be helpful to know how much typechecking is done by ZZ. I was under the impression it did full typechecking, so I was surprised to find that the following program transpiled to C without error:

using <stdio.h>::{printf};

fn output(int *x) {
    printf("%d\n", *x);
}

fn function() {}

export fn main() -> int {
    output(function);
}

Of course, clang halted compilation with an error. Either way, it would help to clarify in the documentation about typechecking.