How about a solution for primes below a number using Sieve of Eratosthenes: template<int H=-1, typename T=void> struct tl { enum {head=H}; type

How about a solution for primes below a number using Sieve of Eratosthenes: template<int H=-1, typename T=void> struct tl { enum {head=H}; typedef T tail; }; template<> struct tl<> { }; template<int N, typename Then, typename Else> struct if_c { typedef Then type; }; template<typename Then, typename Else> struct if_c<false, Then, Else> { typedef Else type; }; template<int N, typename SoFar> struct is_prime { enum {value = N%SoFar::head && is_prime<N, SoFar::tail>::value}; }; template<int N> struct is_prime<N, tl<>> { enum {value = 1}; }; template<int N, int C, typename SoFar=tl<>> struct prime { typedef typename prime<N+1, C-1, typename if_c<is_prime<N, SoFar>::value, tl<N, SoFar>, SoFar>::type>::type type; }; template<int N, typename SoFar> struct prime<N, 0, SoFar> { typedef SoFar type; }; template<int N> struct number : prime<2, N-2> { }; template<> struct number<0> { }; template<> struct number<1> { }; template<typename T> struct print { }; void main() { typedef print<number<300>::type>::type type; } Here is result from Visual Studio 2005: c:\console.cpp(113) : error C2039: 'type' : is not a member of 'print<T>' with [T=tl<293,tl<283,tl<281,tl<277,tl<271,tl<269,tl<263,tl<257,tl<251,tl<241,tl<239,tl<233,tl<229,tl<227,tl<223,tl<211,tl<199,tl<197,tl<193,tl<191,tl<181,tl<179,tl<173,tl<167,tl<163,tl<157,tl<151,tl<149,tl<139,tl<137,tl<131,tl<127,tl<113,tl<109,tl<107,tl<103,tl<101,tl<97,tl<89,tl<83,tl<79,tl<73,tl<71,tl<67,tl<61,tl<59,tl<53,tl<47,tl<43,tl<41,tl<37,tl<31,tl<29,tl<23,tl<19,tl<17,tl<13,tl<11,tl<7,tl<5,tl<3,tl<2,tl<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>]