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std::experi...::make_array(3) C++ Standard Libarystd::experi...::make_array(3)

NAME
       std::experimental::make_array - std::experimental::make_array

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

	  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::com-
       mon_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.

Notes
	  make_array is	removed	in Library Fundamentals	TS v3 because the  de-
       duction guide for
	  std::array and std::to_array have been already in C++20.

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::negation<is_ref_wrapper<std::de-
       cay_t<T>>>;

	  template <class D, class...> struct return_type_helper { using  type
       = D; };
	  template <class... Types>
	  struct     return_type_helper<void,	  Types...>	:    std::com-
       mon_type<Types...> {
	      static_assert(std::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)... };
	}

Example
       // Run this code

	#include <experimental/array>
	#include <iostream>
	#include <type_traits>

	int main()
	{
	    auto arr = std::experimental::make_array(1,	2, 3, 4, 5);
	    bool  is_array_of_5_ints  =	 std::is_same<decltype(arr),  std::ar-
       ray<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

See also
	  to_array Creates a std::array	object from a built-in array
		   (function template)

http://cppreference.com		  2022.07.31	 std::experi...::make_array(3)

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