#include <iostream>

using namespace std;

class Friendly{
    public:
       friend class Buddy;
       friend void GainAccess(Friendly & myFriend);

       int publicInt = 0;
       void PublicFunction() {
           cout << "I am the public function" << endl;
           return;
       }

       void TellAll() {
          cout << "In Tell All Friendly" << endl;
          cout << "\tpublicInt = " << publicInt << endl; 
          cout << "\tprotectedInt = " << protectedInt << endl; 
          cout << "\tprivateInt = " << privateInt << endl; 
          cout << endl;
          return;
       }

    protected:
       int protectedInt = 0;
       void ProtectedFunction() {
           cout << "I am the protected function" << endl;
           return;
       }

    private:
       int privateInt = 0;
       void PrivateFunction() {
           cout << "I am the private function" << endl;
           return;
       }

};

class DerivedFriend : public Friendly {
    public:
       void TellAll() {
          cout << "In Tell All DerivedFriend " << endl;
          cout << "\tpublicInt = " << publicInt << endl; 
          cout << "\tprotectedInt = " << protectedInt << endl; 
          //cout << "\tprivateInt = " << privateInt << endl; 
          cout << endl;

          return;
       }
    private:
        int derivedInt = 7;
};


class Buddy {
    public:
        void MessWithFriend( Friendly & myFriend) {
             myFriend.publicInt = 9; 
             myFriend.protectedInt = 9; 
             myFriend.privateInt = 9; 
             myFriend.PublicFunction();
             myFriend.ProtectedFunction();
             myFriend.PrivateFunction();
             return;
        }
/*
        void MessWithDerived(DerivedFriend & d) {
             d.derivedInt = 9;
             return;
        }
*/
};

void GainAccess(Friendly & myFriend);

int main() {
    Friendly f;
    DerivedFriend d;
    Buddy b;

    cout << " The base class tries to mess with me " << endl;
    f.TellAll();
    cout << endl;

    cout << " The derived class tries to mess with me " << endl;
    d.TellAll();
    cout << endl;


    cout << "My buddy is messing with me " << endl;
    b.MessWithFriend(f);
    f.TellAll();
    cout << endl;

    cout << "GainAccess is messing with me " << endl;
    GainAccess(f);
    f.TellAll();
    cout << endl;

    cout << "Messing wtih the derived class " << endl;
    b.MessWithFriend(d);

    return 0;
}


void GainAccess(Friendly & myFriend){
         myFriend.publicInt = 99; 
         myFriend.protectedInt = 99; 
         myFriend.privateInt = 99; 
         myFriend.PublicFunction();
         myFriend.ProtectedFunction();
         myFriend.PrivateFunction();
}