IDEA: Template meta-programming

[Sang-drax]

Template programming is quite a challenge.

Simple example: "Write a template struct that determines whether a number is even or odd"

template <int num, int mod2=-1>
struct Num
{
   static const bool isOdd = Num<num,num%2>::isOdd;
};
template <int num>
struct Num<num,0>
{
   static const bool isOdd = false;
};
template <int num>
struct Num<num,1>
{
   static const bool isOdd = true;
};

//in main
cout << "45 is odd: " << Num<45>::isOdd;

The contest should be harder than that though.