27 lines · cpp
1template <class T, T... I>2struct Seq {3 static constexpr T PackSize = sizeof...(I);4};5 6template <typename T, T N>7using MakeSeq = __make_integer_seq<Seq, T, N>;8 9 10using SizeT = decltype(sizeof(int));11 12template <SizeT i, typename ...T>13using TypePackElement = __type_pack_element<i, T...>;14 15template <int i>16struct X;17 18using X0 = X<0>;19template <int I>20using SameAsX = X<I>;21 22template <template <class...> class Templ, class...Types>23using TypePackDedup = Templ<__builtin_dedup_pack<Types...>...>;24 25template <class ...Ts>26struct TypeList {};27