Turing completeness of C++ templates

tturing.cpp

#include <cstdio>

template <int D, int A, typename B>
struct K
{
    static const int x = K<D + 1, 0, K<D, A, B>>::x
        + K<D + 1, 1, K<D, A, B>>::x
        + K<D + 1, 2, K<D, A, B>>::x
        + K<D + 1, 3, K<D, A, B>>::x
        + K<D + 1, 4, K<D, A, B>>::x;
};

template <int A, typename B>
struct K<16, A, B>
{
    static const int x = 1;
};

static const int y = K<0, 0, int>::x;

int main()
{
    printf("%i\n", y);
    
    return 0;
}