Added implementation of std::experimental::make_array

CMakeLists.txt

@@ -358,6 +358,7 @@ target_link_libraries(rhubarb-time
 
 # ... rhubarb-tools
 add_library(rhubarb-tools
+	src/tools/array.h
 	src/tools/EnumConverter.h
 	src/tools/exceptions.cpp
 	src/tools/exceptions.h

src/tools/array.h

@@ -0,0 +1,41 @@
+#pragma once
+
+#include <array>
+
+// This file contains an implementation of std::experimental::make_array.
+
+namespace details {
+	template<class B>
+	struct negation : std::integral_constant<bool, !B::value> {};
+
+	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 = negation<is_ref_wrapper<std::decay_t<T>>>;
+
+	template<class...> struct conjunction : std::true_type { };
+	template<class B1> struct conjunction<B1> : B1 { };
+	template<class B1, class... Bn>
+	struct conjunction<B1, Bn...>
+		: std::conditional_t<bool(B1::value), conjunction<Bn...>, B1> {};
+
+	template<class... B>
+	constexpr bool conjunction_v = conjunction<B...>::value;
+
+	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(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)...};
+}