JDI instantiation blindspot

template<typename x> class isint {
  typedef double t;
};
template<> class isint<int> {
  typedef int t;
};

template<typename x> class X {
  template<typename y> class Y {
    typedef x ff;
    typedef typename isint<y>::t fff;
  };
};

template<typename z> class Z {
  typedef typename X<z>::template Y<z>::ff  one;
  typedef typename X<z>::template Y<z>::fff two;
};

Z<int> d;