#include <iostream>
#include <cassert>
#include <string>
using namespace std;

class Person
{
public:
	Person(string _name) { name = _name; }
	string name;
	virtual void Greet() {
		cout << "Hi! My name is " << name 
			<< "." << endl;  
	}
};

class Doctor : public Person
{
public:
	Doctor(string _name, int _rating) : Person(_name)
	{ 
		rating = _rating;
	}
	int rating;
	void Reassure() {
		cout << "You probably won't die today."
			<< endl;
	}
	virtual void Greet() {
		cout << "Hi! My name is " << name
			<< ", I'm a doctor, you can trust me."
			<< endl;
	}
};

int main()
{
	// a regular person
	Person * p1 = new Person("Stan");
	p1->Greet();

	// a doctor, who also is-a person
	Doctor * p2 = new Doctor("Abby", 5);
	p2->Greet();
	p2->Reassure();

	// a doctor, who also is-a person, referred to as a person
	Person * p3 = p2;
	p3->Greet();
	// THIS WOULD ERROR: p3 is a person pointer, and a person can't reassure
	// (we don't know that the person p3 is pointing at is actually a doctor)
	//p3->Reassure();

	// Polymorphism
	// Everone in the array is referred to as a person
	Person * a[10];
	a[0] = new Person("Chelsea");
	a[1] = new Doctor("Villian", 3);
	a[2] = new Person("Bowwow");

	// However, Greet is virtual, so it will call Person::Greet or Doctor::Greet as appropriate
	for (int i = 0; i < 3; i++) {
		a[i]->Greet();
	}

	return 0;
}