// LateBinding - in late binding the decision as to
//               which of two overloaded functions
//               to call is made at run time
#include <stdio.h>
#include <iostream.h>

class Student
{
  public:
    virtual double calcTuition()
    {
        return 0;
    }
};
class GraduateStudent : public Student
{
  public:
    virtual double calcTuition()
    {
        return 1;
    }
};

double fn(Student& fs)
{
    // since calcTuition() is declared virtual this
    // call uses the run time type of fs to resolve
    // the call
    return fs.calcTuition();
}


int main(int nArgc, char* pszArgs[])
{
    // the following expression calls
    // fn() with a Student object
    Student s;
    cout << "The value of s.calcTuition when\n"
         << "called virtually through fn() is "
         << fn(s)
         << "\n\n";

    // the following expression calls
    // fn() with a GraduateStudent object
    GraduateStudent gs;
    cout << "The value of gs.calcTuition when\n"
         << "called virtually through fn() is "
         << fn(gs)
         << "\n\n";
    return 0;
}