/* I've witten the following code example while reading the great book
 * "C++ Templates - The Complete Guide"
 * by David Vandevoorde and Nicolai M. Josuttis, Addison-Wesley, 2002
 *
 * After reading about template recursion and template metaprogramming
 * I've written this code example for calculating the nth Fibonacci
 * number.
 *
 * (C) Copyright Andre Alexander Bell <andre.bell@gmx.de> 2003.
 * Permission to copy, use, modify, sell and distribute this software
 * is granted provided this copyright notice appears in all copies.
 * This software is provided "as is" without express or implied
 * warranty, and with no claim as to its suitability for any purpose.
 */
#include <iostream>

template<int N>
struct factorial
{
	enum { result = N*factorial<N-1>::result };
};

// Get the template recursion stop at these initial values
template<>
struct factorial<1>
{
	enum { result = 1 };
};

template<>
struct factorial<0>
{
	enum { result = 1 };
};

int main()
{
	// Factorials 0! to 4!
	// 1, 1, 2, 2*3=6, 4*6=24
	// Now print out the 5 factorials with this template:
	std::cout << "0! = " << factorial<0>::result << std::endl;
	std::cout << "1! = " << factorial<1>::result << std::endl;
	std::cout << "2! = " << factorial<2>::result << std::endl;
	std::cout << "3! = " << factorial<3>::result << std::endl;
	std::cout << "4! = " << factorial<4>::result << std::endl;

	return 0;
}