From b3ce7296daab031eeaba669cc2db4508b96deb0a Mon Sep 17 00:00:00 2001
From: bolero-MURAKAMI <bolero.murakami@gmail.com>
Date: Thu, 14 Apr 2016 22:05:00 +0900
Subject: [PATCH] change tuple access traits

---
 sprout/tuple/tuple/get.hpp                 | 57 +++-----------------
 sprout/tuple/tuple/tuple_access_traits.hpp | 62 +++++++++++++++++++---
 2 files changed, 61 insertions(+), 58 deletions(-)

diff --git a/sprout/tuple/tuple/get.hpp b/sprout/tuple/tuple/get.hpp
index e5067896..9825a2e7 100644
--- a/sprout/tuple/tuple/get.hpp
+++ b/sprout/tuple/tuple/get.hpp
@@ -13,7 +13,6 @@
 #include <sprout/config.hpp>
 #include <sprout/workaround/std/cstddef.hpp>
 #include <sprout/utility/forward.hpp>
-#include <sprout/utility/move.hpp>
 #include <sprout/tuple/tuple/tuple.hpp>
 #include <sprout/tuple/tuple/tuple_size.hpp>
 #include <sprout/tuple/tuple/tuple_element.hpp>
@@ -22,7 +21,6 @@
 #include <sprout/type/algorithm/find_index.hpp>
 #include <sprout/type/algorithm/count.hpp>
 #include <sprout/type_traits/remove_cvref.hpp>
-#include <sprout/adl/not_found.hpp>
 
 namespace sprout {
 	namespace tuples {
@@ -49,65 +47,24 @@ namespace sprout {
 	using sprout::tuples::tuple_get;
 }	// namespace sprout
 
-namespace sprout_adl {
-	template<std::size_t I>
-	sprout::not_found_via_adl tuple_get(...);
-}	// namespace sprout_adl
-
-namespace sprout_tuple_detail {
-	using sprout_adl::tuple_get;
-
-	template<std::size_t I, typename T>
-	inline SPROUT_CONSTEXPR typename sprout::tuples::tuple_traits<T>::template lvalue_reference<I>::type
-	tuple_get(T& t)
-	SPROUT_NOEXCEPT_IF_EXPR(sprout::tuples::tuple_access_traits<T>::template tuple_get<I>(std::declval<T&>()))
-	{
-		return sprout::tuples::tuple_access_traits<T>::template tuple_get<I>(t);
-	}
-	template<std::size_t I, typename T>
-	inline SPROUT_CONSTEXPR typename std::enable_if<
-		!std::is_const<T>::value && !std::is_volatile<T>::value && !std::is_reference<T>::value,
-		typename sprout::tuples::tuple_traits<typename std::remove_reference<T>::type>::template rvalue_reference<I>::type
-	>::type
-	tuple_get(T&& t)
-	SPROUT_NOEXCEPT_IF_EXPR(sprout::tuples::tuple_access_traits<typename std::remove_reference<T>::type>::template tuple_get<I>(std::declval<T&&>()))
-	{
-		return sprout::move(sprout::tuples::tuple_access_traits<T>::template tuple_get<I>(t));
-	}
-	template<std::size_t I, typename T>
-	inline SPROUT_CONSTEXPR typename sprout::tuples::tuple_traits<T const>::template lvalue_reference<I>::type
-	tuple_get(T const& t)
-	SPROUT_NOEXCEPT_IF_EXPR(sprout::tuples::tuple_access_traits<T const>::template tuple_get<I>(std::declval<T const&>()))
-	{
-		return sprout::tuples::tuple_access_traits<T const>::template tuple_get<I>(t);
-	}
-
-	template<std::size_t I, typename T>
-	inline SPROUT_CONSTEXPR decltype(tuple_get<I>(std::declval<T>()))
-	call_tuple_get(T&& t)
-	SPROUT_NOEXCEPT_IF_EXPR(tuple_get<I>(std::declval<T>()))
-	{
-		return tuple_get<I>(SPROUT_FORWARD(T, t));
-	}
-}	// namespace sprout_tuple_detail
-
 namespace sprout {
 	namespace tuples {
 		//
 		// get
 		//
 		//	effect:
-		//		ADL callable tuple_get<I>(t) -> tuple_get<I>(t)
-		//		otherwise -> sprout::tuples::tuple_access_traits<T>::tuple_get<I>(t)
+		//		sprout::tuples::tuple_access_traits<typename std::remove_reference<T>::type>::template tuple_get<I>(t)
 		//		[default]
-		//			std::get<I>(t)
+		//			ADL callable tuple_get<I>(t) -> tuple_get<I>(t)
+		//			[default]
+		//				std::get<I>(t)
 		//
 		template<std::size_t I, typename T>
-		inline SPROUT_CONSTEXPR decltype(sprout_tuple_detail::call_tuple_get<I>(std::declval<T>()))
+		inline SPROUT_CONSTEXPR decltype(sprout::tuples::tuple_access_traits<typename std::remove_reference<T>::type>::template tuple_get<I>(std::declval<T>()))
 		get(T&& t)
-		SPROUT_NOEXCEPT_IF_EXPR(sprout_tuple_detail::call_tuple_get<I>(std::declval<T>()))
+		SPROUT_NOEXCEPT_IF_EXPR(sprout::tuples::tuple_access_traits<typename std::remove_reference<T>::type>::template tuple_get<I>(std::declval<T>()))
 		{
-			return sprout_tuple_detail::call_tuple_get<I>(SPROUT_FORWARD(T, t));
+			return sprout::tuples::tuple_access_traits<typename std::remove_reference<T>::type>::template tuple_get<I>(SPROUT_FORWARD(T, t));
 		}
 
 		//
diff --git a/sprout/tuple/tuple/tuple_access_traits.hpp b/sprout/tuple/tuple/tuple_access_traits.hpp
index c8d15432..44182778 100644
--- a/sprout/tuple/tuple/tuple_access_traits.hpp
+++ b/sprout/tuple/tuple/tuple_access_traits.hpp
@@ -8,11 +8,57 @@
 #ifndef SPROUT_TUPLE_TUPLE_TUPLE_ACCESS_TRAITS_HPP
 #define SPROUT_TUPLE_TUPLE_TUPLE_ACCESS_TRAITS_HPP
 
+#include <utility>
+#include <type_traits>
 #include <tuple>
 #include <sprout/config.hpp>
 #include <sprout/workaround/std/cstddef.hpp>
+#include <sprout/utility/forward.hpp>
 #include <sprout/utility/move.hpp>
-#include <sprout/tuple/tuple/tuple_element.hpp>
+#include <sprout/tuple/tuple/tuple_traits.hpp>
+#include <sprout/adl/not_found.hpp>
+
+namespace sprout_adl {
+	template<std::size_t I>
+	sprout::not_found_via_adl tuple_get(...);
+}	// namespace sprout_adl
+
+namespace sprout_tuple_detail {
+	using sprout_adl::tuple_get;
+
+	template<std::size_t I, typename T>
+	inline SPROUT_CONSTEXPR decltype(std::get<I>(std::declval<T&>()))
+	tuple_get(T& t)
+	SPROUT_NOEXCEPT_IF_EXPR(std::get<I>(std::declval<T&>()))
+	{
+		return std::get<I>(t);
+	}
+	template<std::size_t I, typename T>
+	inline SPROUT_CONSTEXPR typename std::enable_if<
+		!std::is_const<T>::value && !std::is_volatile<T>::value && !std::is_reference<T>::value,
+		decltype(sprout::move(std::get<I>(std::declval<T&&>())))
+	>::type
+	tuple_get(T&& t)
+	SPROUT_NOEXCEPT_IF_EXPR(sprout::move(std::get<I>(std::declval<T&&>())))
+	{
+		return sprout::move(std::get<I>(t));
+	}
+	template<std::size_t I, typename T>
+	inline SPROUT_CONSTEXPR decltype(std::get<I>(std::declval<T const&>()))
+	tuple_get(T const& t)
+	SPROUT_NOEXCEPT_IF_EXPR(std::get<I>(std::declval<T const&>()))
+	{
+		return std::get<I>(t);
+	}
+
+	template<std::size_t I, typename T>
+	inline SPROUT_CONSTEXPR decltype(tuple_get<I>(std::declval<T>()))
+	call_tuple_get(T&& t)
+	SPROUT_NOEXCEPT_IF_EXPR(tuple_get<I>(std::declval<T>()))
+	{
+		return tuple_get<I>(SPROUT_FORWARD(T, t));
+	}
+}	// namespace sprout_tuple_detail
 
 namespace sprout {
 	namespace tuples {
@@ -23,26 +69,26 @@ namespace sprout {
 		struct tuple_access_traits {
 		public:
 			template<std::size_t I>
-			static SPROUT_CONSTEXPR typename sprout::tuples::tuple_element<I, Tuple>::type&
+			static SPROUT_CONSTEXPR typename sprout::tuples::tuple_traits<Tuple>::template lvalue_reference<I>::type
 			tuple_get(Tuple& t) SPROUT_NOEXCEPT {
-				return std::get<I>(t);
+				return sprout_tuple_detail::call_tuple_get<I>(t);
 			}
 			template<std::size_t I>
-			static SPROUT_CONSTEXPR typename sprout::tuples::tuple_element<I, Tuple>::type&&
+			static SPROUT_CONSTEXPR typename sprout::tuples::tuple_traits<Tuple>::template rvalue_reference<I>::type
 			tuple_get(Tuple&& t) SPROUT_NOEXCEPT {
-				return sprout::move(std::get<I>(t));
+				return sprout_tuple_detail::call_tuple_get<I>(sprout::move(t));
 			}
 			template<std::size_t I>
-			static SPROUT_CONSTEXPR typename sprout::tuples::tuple_element<I, Tuple>::type const&
+			static SPROUT_CONSTEXPR typename sprout::tuples::tuple_traits<Tuple const>::template lvalue_reference<I>::type
 			tuple_get(Tuple const& t) SPROUT_NOEXCEPT {
-				return std::get<I>(t);
+				return sprout_tuple_detail::call_tuple_get<I>(t);
 			}
 		};
 		template<typename Tuple>
 		struct tuple_access_traits<Tuple const> {
 		public:
 			template<std::size_t I>
-			static SPROUT_CONSTEXPR typename sprout::tuples::tuple_element<I, Tuple>::type const&
+			static SPROUT_CONSTEXPR typename sprout::tuples::tuple_traits<Tuple const>::template lvalue_reference<I>::type
 			tuple_get(Tuple const& t) SPROUT_NOEXCEPT {
 				return sprout::tuples::tuple_access_traits<Tuple>::template tuple_get<I>(t);
 			}