#include <iostream>

#include "person.h"
#include "student.h"
#include <vector>

using namespace std;


ostream & operator<< (ostream & out, const Person & p) {
	p.print(out);
	return out;
}

void printVirtual() {
	Student s(222, "Sally Jones", 4.0 );
	s.print();
	cout << endl << endl;

	// What is printed?
	cout << "Experiment 1: Create Person reference pointing to Student object" << endl;;
	Person & person_ref = s;
	person_ref.print();
	cout << endl << endl;

	// What is printed?
	cout << "Experiment 2: Pass a Student to function expecting Person" << endl;;
	operator<<(cout, s);
	cout << endl << endl;

	// cout << s << endl;
}


// Use call-by-value
void slicing(Person p) {
  p.print();
  cout << endl;
}


void downcasting() {

	Person* personPtr = new Person(888, "Anne");

	// Downcast person to a student
	Student* studentPtr = (Student*)personPtr;

	// What is the gpa?
	cout << "Gpa: " << studentPtr->getGpa() << endl;

	// A safer way of downcasting
	//studentPtr = dynamic_cast<Student*>(personPtr);
	if(studentPtr == NULL)
		cout << "studentPtr is NULL!" << endl;
}


void simple() {

  // When using objects (i.e. not pointers or references) there is no real
  // way to exploit inheritance

  Person p(999, "Jane Smith");
  p.print();
  cout << endl;
  
  Student s(000, "Joey Smith", 3.9);
  s.print();
  cout << endl;  
}


int main() {
  // simple();
  // printVirtual();

  // Student s(999, "Billy Robot", 1.3);
  // slicing(s);
  
  // downcasting();
}