private virtual in c++

source from http://blog.csdn.net/steedhorse/article/details/333664

// Test.cpp
#include <iostream>
using namespace std;   

class Base {
public:
    void f() {
        g();
    }  

private:
    virtual void g() {
        cout << "Hi, MorningStar! I am g() of Base!." << endl;
    }
};  

class Derived : public Base {
private:
    virtual void g() {
        cout << "Hi, MorningStar! I am g() of Derived." << endl;
    }
};  

int main() {
    Base *pB = new Derived();
    pB->f();
    delete pB;
    return 0;
}