Nick

#include <iostream>

struct Test
{
    Test(int &i) : ref(i){}
    int& ref;
};

int main()
{
    std::cout << "Size of class: " << sizeof(Test) << std::endl;
    int x = 1;
    int y = 2;
    Test t(x); // t.ref refers to x

    std::cout << "Value of ref before hack: " << t.ref << std::endl;
    /* Assuming the reference is actually a pointer on the stack at address &t,
     * write &y to this loication */
    *(int**)(&t) = &y; // t.ref now refers to y
    std::cout << "Value of ref after hack: " << t.ref << std::endl;
    y = 3;
    std::cout << "Value of ref after hack, with y changed: " << t.ref << std::endl;
}