In c++, how can I implement a function with an int template argument indicating the tuple length and produce a std::tuple with that length?
E.g.
func<2>() returns std::tuple<int, int>();
func<5>() returns std::tuple<int, int, int, int, int>().
Here is a recursive solution with alias template and it's implementable in C++11:
template <size_t I,typename T>
struct tuple_n{
template< typename...Args> using type = typename tuple_n<I-1, T>::template type<T, Args...>;
};
template <typename T>
struct tuple_n<0, T> {
template<typename...Args> using type = std::tuple<Args...>;
};
template <size_t I,typename T> using tuple_of = typename tuple_n<I,T>::template type<>;
For example if we want "tuple of 3 doubles"
we can write:
tuple_of<3, double> t;