How to forward declare nested managed class in C++/clr

OK, for the life of me, I can't find this answer. How can I forward declare a nested managed class? Here is an example of what I'm trying to accomplish:

Code:

---

namespace Geometry
{
  ref class Vectors;
  ref class Points;
  // ref class Points::Point2;  <-- won't compile but this is the idea...

  public ref class Vectors
  {
  public:
      ref class Vector2
      {
      };

      void SomeFunc( Points::Point2 ^ );  //  <===== C2027
  };

  public ref class Points
  {
  public:
      ref class Point2
      {
      };

      void SomeFunc( Vectors::Vector2 ^ );
  };
}

---

This is common C++ restriction, not only C++/CLI: You can only give a forward declaration of a nested class within the outer class declaration.