Base Class's function gets called

[Alterah]

Here are the classes:

BaseClass.h

class BaseClass
{
    public:
        BaseClass();
        virtual ~BaseClass();
        virtual void printStuff() const;
    protected:
    private:
};

BaseClass.cpp

BaseClass::BaseClass()
{
    //ctor
}

BaseClass::~BaseClass()
{
    //dtor
}

void BaseClass::printStuff() const
{
    std::cout << "BaseClass" << std::endl;
}

DerivedClass.h

class DerivedClass : public BaseClass
{
    public:
        DerivedClass();
        virtual ~DerivedClass();
        virtual void printStuff() const;
    protected:
    private:
};

DerivedClass.cpp

DerivedClass::DerivedClass()
{
    //ctor
}

DerivedClass::~DerivedClass()
{
    //dtor
}

void DerivedClass::printStuff() const
{
    std::cout << "DerivedClass" << std::endl;
}

And here's main():

int main()
{
    DerivedClass* aDC = new DerivedClass();
    vector<BaseClass*> aVec;
    aVec.push_back( aDC );
    aVec[0]->printStuff();
    delete aDC;
    return 0;
}

When I call printStuff, the DerivedClass's function gets called. Now, if I remove the const part from the DerivedClass's printStuff function, we call the BaseClass's printStuff function. Can anyone explain why this happens? I tried a Google search, but not quite sure how to word this.

[laserlight]

If you do not declare the member function as const, then you are overloading, not overriding, the member function to have a non-const version. Thus, the polymorphism that comes with an override does not apply. I expect that the base class' version of the member function becomes hidden in the derived class (i.e., you would get an error if you tried calling it with a const DerivedClass object).

[ninja9578]

Was the code edited since laserlight's post? Because it looks like it's declared const to me.

[Alterah]

No, it wasn't. I just said "...Now, if I remove the const part from the DerivedClass's printStuff function...". If I leave the code the way it the way is, things behave as I would expect them to. But, if I remove the const from the DerivedClass's function, then the BaseClass's printStuff function is called. I think laserlight's explanation makes sense.

[D_Drmmr]

Note that C++11 has introduced the override keyword to flag this as a compiler error.