How to create a tuple of fix types whose size is a known at compile time in C++17?

Question

I would like to create a tuple type of common element type whose length is known at compile time. For example if I have

static constexpr const std::size_t compiletime_size = 2;

using tuple_int_size_2 = magic (int, compiletime_size);

tuple_int_size_2 should be the same type as std::tuple<int, int>

Answer 1

This can be done with recursion:

#include <tuple>

template <size_t N, typename Head, typename... T>
struct magic {
    using tuple_type = typename magic<N - 1, Head, Head, T...>::tuple_type;
};

template <typename... T>
struct magic<1, T...> {
    using tuple_type = std::tuple<T...>;
};

int main()
{
    auto t = typename magic<3, int>::tuple_type{};
    return 0;
}

I wonder, though, if std::array would be a much simpler and straight-forward solution to whatever task it is you're trying to solve.