Split a C++ class declaration

Question

I want to know if I can split a C++ class declaration

Original class

    class P
    {
        private: 
           int id;
           //some really          


        

Answer 1

You can heritage the second part like this:

//Class P_Hetitage definition

class P_Heritage {
      protected:
                int id;
                //some really secret method
                int secretMethod();
}

//Class P definition

class P : private P_Heritage {
      protected:
                int x;
      public:
             P();
             int getX();
};

Below a straightforward explanation how inheritance works:

Inheritance the class P_Heritage as:

public

1. public elements are public to class P
2. protected elements are private to class P

private

1. public elements are private to class P
2. protected elements are private to class P

P_Heritage's private elements can not be seen by class P