class A;
class B
{
public:
    int x;
    A* y;
};

class A
{
public:
    int x;
    B* m;

};

int f(long int x) //this is in shared lib
{
    A* y = (A*) x;
    B* z = y->m;
    return 0;
}

int main()
{
    A a;
    a.m = new B();
    f((long int) &a);
    return 0;
}