I am working on a project which is nested templates. How to refer to typename’s typename?
See examples below.

template<typename T>
class point1{
   public:
     T x, y;
     point1(T v1, T v2):x(v1), y(v2){}
}
template<typename T>
class point2{
   public:
     T a, b;
     point2(T v1, T v2):a(v1), b(v2){}
}
template<typename pointarray>
class coordinates{
   public:
     pointarray & _pp;
   void printsum(){
   using pointtype = typename pointarry::value_type;
   // pointarray could be like vector<point1<int>>, deque<point2<double>>
   // now pointtype could be point1 or point2
   // there will be compiling issues in below.
   auto intORdouble = pointtype::value_type;
   intORdouble ssumm = 0;
  }
}

The more I learned about template in C++, the more complicated it seemed to be.