Alias for nested variadic templated struct in VC++2013 - c++

Question

For a templated nested struct I can define aliases like the following:
template<typename T>struct Struct
{
Struct(T value){}
template<typename T1> struct Nested
{
Nested(T1 value){}
};
};
template<typename T, typename T1>using NameT = struct Struct<T>::Nested<T1>;
using Name = NameT<int, double>; // Alias for a certain instance
Can someone please give me a hint how to declare an alias for the variadic one?
template<typename... T>struct Struct
{
Struct(T... value){}
template<typename T1> struct Nested
{
Nested(T1 value){}
};
};
template<typename... T, typename T1>using NameT = struct Struct<T...>::Nested<T1>; // This seems ok
using Name = NameT<int, double>; // error C976: 'Name': too few template arguments

Answer 1

This will work:
template<typename T1, typename... T>using NameT =
typename Struct<T...>::template Nested<T1>; // This seems ok
^^^^^^^^ ^^^^^^^^
using Name = NameT<int, double>;
Mind though that parameter pack must be at the end so the definition is slightly changed.
LIVE DEMO

Answer 2

Change your code to :
template<typename... T>
struct Struct
{
Struct(T... value){}
template<typename T1>
struct Nested
{
Nested(T1 value){}
};
};
template<typename T1, typename... T>
using NameT = typename Struct<T...>::template Nested<T1>;
using Name = NameT<int, double>;
int main()
{
Name f(1);
}
The variadic template has to be at the end of the template argument list.

Answer 3

#include <type_traits>
#include <tuple>
#include <utility>
template <typename... T>
struct Struct
{
Struct(T... value) {}
template <typename T1>
struct Nested
{
Nested(T1 value) {}
};
};
template <typename, typename>
struct split;
template <typename T, std::size_t... Is>
struct split<T, std::index_sequence<Is...>>
{
using type = typename Struct<typename std::tuple_element<Is, T>::type...>::template Nested<typename std::tuple_element<sizeof...(Is), T>::type>;
};
template <typename... T>
using NameT = typename split<std::tuple<T...>, std::make_index_sequence<sizeof...(T)-1>>::type;
int main()
{
static_assert(std::is_same<NameT<int, double, char>
, Struct<int, double>::Nested<char>>{}, "!");
}
DEMO