struct A
    {
        constexpr A(int &x) : ref(x) {}
        int &ref;
    };

    int toptional()
    {
        int n1 = 0, n2 = 0;
        One<A> opt(new A(n1));
        A* a=new A(n2);
        opt=a;
        opt->ref = 1;
        Cout() << n1 << " " << n2 << EOL;
    }