Calling a Base Class Function through Derived Class Object

Question

Why won't the compiler call the base class function (parameterized one) through the derived class object? The derived class inherits the function from the base class, right?

#include<iostream>
using namespace std;

class Base
{
public:
    int fun()  { cout << "Base::fun() called"; }
    int fun(int i)  { cout << "Base::fun(int i) called"; }
};

class Derived: public Base
{
public:
    int fun() {  cout << "Derived::fun() called"; }
};

int main()
{
    Derived d;
    d.fun(5);
    return 0;
}

However, when I used the scope resolution operator, I got the desired output. Can anyone provide me a logical explanation behind this? Can I still call the base class function (parameterized one) through derived class object? Thanks!

int main() 
{
    Derived d;
    d.Base::fun(5);
    return 0;
}

score 4 · Accepted Answer · answered Jun 04 '15 at 18:49

The derived function Derived::fun() hides all members with the same name from the base class. So you can only use the base class member via scope resolution. To avoid hiding, you can do:

class Derived: public Base
{
public:
    int fun() {  cout << "Derived::fun() called"; }
    using Base::fun;
};

Calling a Base Class Function through Derived Class Object

1 Answers1