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std::experimental::make_array

From cppreference.com
Defined in header <experimental/array>
template <class D = void, class... Types>
constexpr std::array<VT /* see below */, sizeof...(Types)> make_array(Types&&... t);
(library fundamentals TS v2)

Creates a std::array whose size is equal to the number of arguments and whose elements are initialized from the corresponding arguments. Returns std::array<VT, sizeof...(Types)>{std::forward<Types>(t)...}

If D is void, then the deduced type VT is std::common_type_t<Types...>. Otherwise, it is D.

If D is void and any of std::decay_t<Types>... is a specialization of std::reference_wrapper, the program is ill-formed.

[edit] Possible implementation

namespace details {
  template<class> struct is_ref_wrapper : std::false_type {};
  template<class T> struct is_ref_wrapper<std::reference_wrapper<T>> : std::true_type {};
 
  template<class T>
  using not_ref_wrapper = std::experimental::negation<is_ref_wrapper<std::decay_t<T>>>;
 
  template <class D, class...> struct return_type_helper { using type = D; };
  template <class... Types>
  struct return_type_helper<void, Types...> : std::common_type<Types...> {
      static_assert(std::experimental::conjunction_v<not_ref_wrapper<Types>...>,
                    "Types cannot contain reference_wrappers when D is void");
  };
 
  template <class D, class... Types>
  using return_type = std::array<typename return_type_helper<D, Types...>::type,
                                 sizeof...(Types)>;
}
 
template < class D = void, class... Types>
constexpr details::return_type<D, Types...> make_array(Types&&... t) {
  return {std::forward<Types>(t)... };
}

[edit] Example

#include <experimental/array>
#include <iostream>
#include <type_traits>
 
int main()
{
    decltype(auto) arr = std::experimental::make_array(1, 2, 3, 4, 5);
    bool is_array_of_5_ints = std::is_same<decltype(arr), std::array<int, 5>>::value;
    std::cout << "Returns an array of five ints? ";
    std::cout << std::boolalpha << is_array_of_5_ints << '\n';
}

Output:

Returns an array of five ints? true

[edit] See also

Creates a std::array object from a built-in array
(function template) [edit]