template< typename X, typename EmptyList >
struct Append { using T = TypeList< X >; };

template< typename _X, typename _T, typename... _Ts >
struct Append< _X, TypeList< _T, _Ts... > > {
    using T = TypeList< _X, _T, _Ts... >;
};

template< template< typename > class Cond, typename List >
struct Filter : public
    std::conditional< Cond< typename List::Head >::value,
        Filter< Cond, typename List::Tail >,
        Append< typename List::Head,
            typename Filter< Cond, typename List::Tail >::T >
    >::type { };

template< template< typename > class Cond >
struct Filter< Cond, TypeList<> > { using T = TypeList<>; };

template< typename List >
struct Last : public Last< typename List::Tail > { };

template< typename _T >
struct Last< TypeList< _T > > {
    using T = _T;
};