#include #include using namespace std; // I know this code can be really hard to read, it is for me even though I made it ^^ // If you need explaination on some points, do not hesitate to ask ! // simple pack, used to store the result template struct Pack{}; // odd and even declarations template struct Odd; template struct Even; // odd definition // end point of the template recursion template struct Odd> { using type = Pack; }; // Odd, T, V...> becomes Even, V...> as odd is equal to even template struct Odd, T, V...> : Even, V...>{}; // odd starting point : we do not keep the first type and go to even starting point template struct Odd : Even{}; // even // second end point of the recursion template struct Even> { using type = Pack; }; //Even becomes odd while saving the first type after Pack in Pack because even = > template struct Even, T, V...> : Odd, V...>{}; // even starting point : we keep the first type template struct Even : Odd, U...>{}; // tuple maker template struct MakeTuple; template class C> struct MakeTuple >{ static const tuple value; }; template struct MakeTuple{ static const tuple value; }; // helpers template using odd = typename Odd::type; template using even = typename Even::type; // display class template struct Display{ void display() const{ cout << N << endl; } }; typedef Display<0> A; typedef Display<1> B; typedef Display<2> C; typedef Display<3> D; int main() { auto t1 = MakeTuple >::value; get<0>(t1).display(); // should be 1 get<1>(t1).display(); // should be 3 auto t2 = MakeTuple >::value; get<0>(t2).display(); // should be 0 get<1>(t2).display(); // should be 2 return 0; }

keep only odd/even placed templates