#include <iostream>

class Wilma {
  protected:
   void fredCallsWilma()
     {
       std::cout << "Wilma::fredCallsWilma()\n";
       wilmaCallsFred();
     }
   virtual void wilmaCallsFred() = 0;   // A pure virtual function

public:

  void WilmaShops() {
    std::cout << "Wilma:ChargeIt!" << std::endl;
  }
};
 
class Fred : protected Wilma {
public:
  void barney()
  {
    std::cout << "Fred::barney()\n";
    Wilma::fredCallsWilma();
    WilmaShops();
  }
protected:
  virtual void wilmaCallsFred()
  {
    std::cout << "Fred::wilmaCallsFred()\n";
  }
};

int main() {
  Fred frd;

  frd.barney();

  // frd.WilmaShops();  //this is illegal

  ((Wilma&)frd).WilmaShops();

  // this works but will not work in private inheritance
  Wilma &wm = frd;
  wm.WilmaShops();

  return 0;
}