C++ Access private member of nested class

Question

The title might be a bit misleading. I have the following problem: I have a tree consisting of leaves and internal nodes. The user should be able to store any information in

Answer 1

You may do

class Outer {
   private: // maybe protected:
   class Inner {
      public:
      ....
   };
};

or

class Outer {
   public:
   class Inner {
      friend class Outer;
      private:
      ....
   };
};