First of all I would like to thank u on the wonderful tutorials ..It really helped me… Just a small Doubt in this part

Base::PrintValue;

Here in above you have tried to change the access specifier to public by defining it into the public section of the derived class. However I tried the same and its giving me error .

class Base
{
public:
int m_a;
Base(int a=0): m_a(a)
{
cout<<"\n I am in base constructor \t"<<m_a<<endl;
}
protected:
void identify()
{
cout<<"\n I am in base class \t"<<m_a<<endl;
}
};

class Derived :public Base
{
public:
int m_b;
Derived(int a=0,int b=0):Base(a),m_b(b)
{
cout<<"\n I am in Derived constructor \t"<<m_b<<endl;
}
Base::identify;
};
int main()
{
Derived d_obj(7,9);
d_obj.identify();
return 0;
}

Below are the errors ::

Error 433: "inheritance.cpp", line 26 # The class name in an access declaration must be a base class.
Derived::identify;
^^^^^^^^^^^^^^^^^^
Error 182: "inheritance.cpp", line 36 # "int main()" cannot access protected member "void Base::identify()".
d_obj.identify();
^^^^^^^^^^^^^^^^

Please suggest on the same.

Inside the child class’s overloaded << operator, I created a reference variable NPC equal to the child class, then just simply outputted it.

NPC operator<<

ostream& operator<< (ostream &out, const NPC &cNPCTemp)
{
	out << ... << ... << ... << ...
		// code that outputs stuff
	return out;
}

Drone operator<<

ostream& operator<< (ostream& out, Drone &cDrone)
{
	NPC &rNPC = cDrone;	//cuz of Hungarian I didn't have to think about the names
	out << rNPC;

	out << ... << ... << ... << ...
		// code that outputs the Drone specific stuff
	return out;
}

I am, however, running into an issue where if I try this with multiple inheritance, it calls the base (NPC) overloaded function more than once; I do have the classes in between virtual (chain is actually — NPC ->(Drone, Special) -> Enemy)
Problem occurs when I call (cout << cEnemy) overloaded function.

Is it possible, or is this one of the problems Multiple inheritance has?

I have an inheritance chain
NPC -> Drone
I have overloaded the << operator, as a friend function, to output its info in the NPC (parent) class, then I created the Drone (child) class. When I make something like this

Drone cDr01; cout << cDr01;

Of course, it outputs all of the info kept in NPC as previously created, and nothing from Drone.
If I re-overload the << operator in Drone, it overrides the NPC version. I also don't want to have to duplicate code, as in copy all of the previous code to the new one with the extra functionality, especially if I possibly wouldn't have access to it. I tried doing what was instructed above, to add the function call to the base in the derived version, but since it's an I/O operator, I can't seem to make it work.

Basically, How do you add functionality to an overloaded << operator declared as a friend function.

-Tyler

It’s also common [b]to[/b] for developers to release header files containing class definitions

Thanks again for this absolutely wonderful tutorials!

 When a member function is called with a derived class object, the the compiler...

     int Identify() { cout << "I am a Derived" << endl; return 0;}

and it compiles ok.

Another thing, after cDerived.Identify() you forgot a “;” in this code part

int main()
{
    Base cBase(5);
    cBase.Identify();

    Derived cDerived(7);
    cDerived.Identify()

    return 0;
}