module mylib::ifaces;
interface IOp
{
	fn void op();
}
module mylib <Type>;
import std::io;
import mylib::ifaces;
struct Op (IOp)
{
	Type data;
}
fn void Op.op(&self) @dynamic => io::printn("op");
module myapp;
import mylib;
fn void test(void* tptr)
{
	// this work
	IOp iop = (Op{int}*)tptr;
	iop.op();

	// this don't work
	iop = tptr; // #error: Casting a 'void*' to 'IOp' is not permitted
	iop.op();
}
fn void main(String[] args)
{
	Op{int}* t = mem::new(Op{int}, {.data = 1});
	test(&t);
}
