How to access protected members in a derived class?

Question

From http://www.parashift.com/c++-faq-lite/basics-of-inheritance.html#faq-19.5

A member (either data member or member function) declared in a protecte

Answer 1

See this example:

#include 
using namespace std;

class X {
  private:
    int var;
  protected:
    void fun () 
    {
      var = 10;
      cout << "\nFrom X" << var; 
    }
};

class Y : public X {
  private:
    int var;
  public:
    void fun () 
    {
      var = 20;
      cout << "\nFrom Y" << var;
    }

    void call ()
    {
      fun(); /* call to Y::fun() */
      X::fun (); /* call to X::fun() */

      X objX;
      /* this will not compile, because fun is protected in X        
      objX.fun (); */

    }
};

int main(int argc, char ** argv)  {
  Y y;
  y.call();
  return 0;  
}

This yields

From Y20
From X10

Because you have overloaded the fun()-method in Y, you have to give the compiler a hint which one you mean if you want to call the fun-method in X by calling X::fun().