#include <array>

template <std::size_t, typename T>
using alwaysT = T;

template <typename T, typename Seq> struct TestHelper;

template <typename T, std::size_t ... Is>
struct TestHelper<T, std::index_sequence<Is...>>
{
    TestHelper(alwaysT<Is, T>... arr) {}
};

template<std::size_t V>
class Test : TestHelper<const std::array<int, 3>&, std::make_index_sequence<V>>
{
public:
    using TestHelper<const std::array<int, 3>&, std::make_index_sequence<V>>::TestHelper;

    Test() = default;
};

int main()
{
    auto t = Test<1>({ 1, 2, 3 });
    auto t2 = Test<2>(
        { 1, 2, 3 },
        { 4, 5, 6 }
    );
    
    static_cast<void>(t); // Avoid warning for unused variable
    static_cast<void>(t2); // Avoid warning for unused variable
}