#include <iostream>

struct X {
    X(int) { }
};
auto operator<<(std::ostream& o, X const&) -> std::ostream& {
    o << "exxxx";
    return o;
}

f: (out x: _) = {
    x = 42;
}

main: ()->int = {
    a: int;
    f(out a);
    std::cout << a << "\n";

    b: X;
    f(out b);
    std::cout << b << "\n";
}