diff --git a/sprout/algorithm/fixed/clamp_range_copy.hpp b/sprout/algorithm/fixed/clamp_range_copy.hpp
index afe8d93c..3c49c71b 100644
--- a/sprout/algorithm/fixed/clamp_range_copy.hpp
+++ b/sprout/algorithm/fixed/clamp_range_copy.hpp
@@ -4,7 +4,7 @@
 #include <iterator>
 #include <type_traits>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/container/traits.hpp>
 #include <sprout/container/functions.hpp>
 #include <sprout/container/indexes.hpp>
diff --git a/sprout/algorithm/fixed/copy.hpp b/sprout/algorithm/fixed/copy.hpp
index d5492058..8acbe50e 100644
--- a/sprout/algorithm/fixed/copy.hpp
+++ b/sprout/algorithm/fixed/copy.hpp
@@ -4,7 +4,7 @@
 #include <iterator>
 #include <type_traits>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/container/traits.hpp>
 #include <sprout/container/functions.hpp>
 #include <sprout/container/indexes.hpp>
diff --git a/sprout/algorithm/fixed/copy_backward.hpp b/sprout/algorithm/fixed/copy_backward.hpp
index 48c0b4c7..cffb2694 100644
--- a/sprout/algorithm/fixed/copy_backward.hpp
+++ b/sprout/algorithm/fixed/copy_backward.hpp
@@ -4,7 +4,7 @@
 #include <iterator>
 #include <type_traits>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/container/traits.hpp>
 #include <sprout/container/functions.hpp>
 #include <sprout/container/indexes.hpp>
diff --git a/sprout/algorithm/fixed/fill.hpp b/sprout/algorithm/fixed/fill.hpp
index d3d8b55e..f6667434 100644
--- a/sprout/algorithm/fixed/fill.hpp
+++ b/sprout/algorithm/fixed/fill.hpp
@@ -2,7 +2,7 @@
 #define SPROUT_ALGORITHM_FIXED_FILL_HPP
 
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/container/traits.hpp>
 #include <sprout/container/functions.hpp>
 #include <sprout/iterator/operation.hpp>
diff --git a/sprout/algorithm/fixed/fill_n.hpp b/sprout/algorithm/fixed/fill_n.hpp
index 8b9ae33b..1f32abe3 100644
--- a/sprout/algorithm/fixed/fill_n.hpp
+++ b/sprout/algorithm/fixed/fill_n.hpp
@@ -2,7 +2,7 @@
 #define SPROUT_ALGORITHM_FIXED_FILL_N_HPP
 
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/container/traits.hpp>
 #include <sprout/container/functions.hpp>
 #include <sprout/container/indexes.hpp>
diff --git a/sprout/algorithm/fixed/replace_copy.hpp b/sprout/algorithm/fixed/replace_copy.hpp
index 86611c49..7924b724 100644
--- a/sprout/algorithm/fixed/replace_copy.hpp
+++ b/sprout/algorithm/fixed/replace_copy.hpp
@@ -4,7 +4,7 @@
 #include <iterator>
 #include <type_traits>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/container/traits.hpp>
 #include <sprout/container/functions.hpp>
 #include <sprout/container/indexes.hpp>
diff --git a/sprout/algorithm/fixed/replace_copy_if.hpp b/sprout/algorithm/fixed/replace_copy_if.hpp
index 41c24b01..9c8f0cb3 100644
--- a/sprout/algorithm/fixed/replace_copy_if.hpp
+++ b/sprout/algorithm/fixed/replace_copy_if.hpp
@@ -4,7 +4,7 @@
 #include <iterator>
 #include <type_traits>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/container/traits.hpp>
 #include <sprout/container/functions.hpp>
 #include <sprout/container/indexes.hpp>
diff --git a/sprout/algorithm/fixed/reverse_copy.hpp b/sprout/algorithm/fixed/reverse_copy.hpp
index 2a877383..338d3211 100644
--- a/sprout/algorithm/fixed/reverse_copy.hpp
+++ b/sprout/algorithm/fixed/reverse_copy.hpp
@@ -4,7 +4,7 @@
 #include <iterator>
 #include <type_traits>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/container/traits.hpp>
 #include <sprout/container/functions.hpp>
 #include <sprout/container/indexes.hpp>
diff --git a/sprout/algorithm/fixed/rotate_copy.hpp b/sprout/algorithm/fixed/rotate_copy.hpp
index 4ca6257f..fcb71b11 100644
--- a/sprout/algorithm/fixed/rotate_copy.hpp
+++ b/sprout/algorithm/fixed/rotate_copy.hpp
@@ -4,7 +4,7 @@
 #include <iterator>
 #include <type_traits>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/container/traits.hpp>
 #include <sprout/container/functions.hpp>
 #include <sprout/container/indexes.hpp>
diff --git a/sprout/algorithm/fixed/shuffle.hpp b/sprout/algorithm/fixed/shuffle.hpp
index 8a923abe..421643ae 100644
--- a/sprout/algorithm/fixed/shuffle.hpp
+++ b/sprout/algorithm/fixed/shuffle.hpp
@@ -3,7 +3,7 @@
 
 #include <cstddef>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/array/array.hpp>
 #include <sprout/pit/pit.hpp>
 #include <sprout/container/traits.hpp>
diff --git a/sprout/algorithm/fixed/shuffle_result.hpp b/sprout/algorithm/fixed/shuffle_result.hpp
index 0fa334b8..d79ce00e 100644
--- a/sprout/algorithm/fixed/shuffle_result.hpp
+++ b/sprout/algorithm/fixed/shuffle_result.hpp
@@ -4,7 +4,7 @@
 #include <cstddef>
 #include <type_traits>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/array/array.hpp>
 #include <sprout/pit/pit.hpp>
 #include <sprout/container/traits.hpp>
diff --git a/sprout/algorithm/fixed/swap_element_copy.hpp b/sprout/algorithm/fixed/swap_element_copy.hpp
index 606fec5c..e1ed53ed 100644
--- a/sprout/algorithm/fixed/swap_element_copy.hpp
+++ b/sprout/algorithm/fixed/swap_element_copy.hpp
@@ -4,7 +4,7 @@
 #include <iterator>
 #include <type_traits>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/container/traits.hpp>
 #include <sprout/container/functions.hpp>
 #include <sprout/container/indexes.hpp>
diff --git a/sprout/algorithm/fixed/transform.hpp b/sprout/algorithm/fixed/transform.hpp
index caaabb45..1b04598c 100644
--- a/sprout/algorithm/fixed/transform.hpp
+++ b/sprout/algorithm/fixed/transform.hpp
@@ -4,7 +4,7 @@
 #include <iterator>
 #include <type_traits>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/container/traits.hpp>
 #include <sprout/container/functions.hpp>
 #include <sprout/container/indexes.hpp>
diff --git a/sprout/algorithm/string/join.hpp b/sprout/algorithm/string/join.hpp
index b0350cf1..8ad1e491 100644
--- a/sprout/algorithm/string/join.hpp
+++ b/sprout/algorithm/string/join.hpp
@@ -6,7 +6,7 @@
 #include <sprout/container/traits.hpp>
 #include <sprout/container/functions.hpp>
 #include <sprout/container/indexes.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/pit/pit.hpp>
 #include <sprout/iterator/type_traits/category.hpp>
 #include <sprout/range/adaptor/size_enumed.hpp>
diff --git a/sprout/array/array.hpp b/sprout/array/array.hpp
index 96ba8a79..232ddf48 100644
--- a/sprout/array/array.hpp
+++ b/sprout/array/array.hpp
@@ -6,7 +6,7 @@
 #include <utility>
 #include <stdexcept>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/container/traits.hpp>
 #include <sprout/container/functions.hpp>
 #include <sprout/iterator/operation.hpp>
diff --git a/sprout/array/make_array.hpp b/sprout/array/make_array.hpp
index d5208ecd..4a10636f 100644
--- a/sprout/array/make_array.hpp
+++ b/sprout/array/make_array.hpp
@@ -4,7 +4,7 @@
 #include <cstddef>
 #include <type_traits>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/array/array.hpp>
 #include <sprout/utility/forward.hpp>
 #include <sprout/type_traits/common_decay.hpp>
diff --git a/sprout/breed/detail/deduce_domain.hpp b/sprout/breed/detail/deduce_domain.hpp
index e80afc4c..f10b9a38 100644
--- a/sprout/breed/detail/deduce_domain.hpp
+++ b/sprout/breed/detail/deduce_domain.hpp
@@ -3,7 +3,7 @@
 
 #include <type_traits>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/utility/pack.hpp>
 #include <sprout/breed/breed_fwd.hpp>
 
diff --git a/sprout/breed/generate.hpp b/sprout/breed/generate.hpp
index c8237cfd..48b246c3 100644
--- a/sprout/breed/generate.hpp
+++ b/sprout/breed/generate.hpp
@@ -3,7 +3,7 @@
 
 #include <type_traits>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/breed/breed_fwd.hpp>
 #include <sprout/breed/args.hpp>
 #include <sprout/breed/detail/std_result_of.hpp>
diff --git a/sprout/breed/transform/pass_through.hpp b/sprout/breed/transform/pass_through.hpp
index ce6ad919..7e8ee58a 100644
--- a/sprout/breed/transform/pass_through.hpp
+++ b/sprout/breed/transform/pass_through.hpp
@@ -3,7 +3,7 @@
 
 #include <type_traits>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/breed/breed_fwd.hpp>
 #include <sprout/breed/args.hpp>
 #include <sprout/breed/transform/impl.hpp>
diff --git a/sprout/container/indexes.hpp b/sprout/container/indexes.hpp
index 93c181d6..313a5863 100644
--- a/sprout/container/indexes.hpp
+++ b/sprout/container/indexes.hpp
@@ -2,8 +2,8 @@
 #define SPROUT_CONTAINER_INDEXES_HPP
 
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
-#include <sprout/index_tuple/detail/make_indexes_helper.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
+#include <sprout/index_tuple/enable_make_indexes.hpp>
 #include <sprout/container/container_traits.hpp>
 
 namespace sprout {
@@ -13,7 +13,7 @@ namespace sprout {
 		//
 		template<typename Container>
 		struct container_indexes
-			: public sprout::detail::make_indexes_helper<
+			: public sprout::enable_make_indexes<
 				sprout::make_index_tuple<sprout::container_traits<Container>::static_size>
 			>
 		{};
diff --git a/sprout/darkroom/lights/light_list.hpp b/sprout/darkroom/lights/light_list.hpp
index 2bfc9fe1..56650be1 100644
--- a/sprout/darkroom/lights/light_list.hpp
+++ b/sprout/darkroom/lights/light_list.hpp
@@ -3,7 +3,7 @@
 
 #include <limits>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/tuple/tuple.hpp>
 #include <sprout/darkroom/access/access.hpp>
 #include <sprout/darkroom/colors/rgb.hpp>
diff --git a/sprout/darkroom/pixels/generate.hpp b/sprout/darkroom/pixels/generate.hpp
index 973409bd..41cf6dd0 100644
--- a/sprout/darkroom/pixels/generate.hpp
+++ b/sprout/darkroom/pixels/generate.hpp
@@ -3,7 +3,7 @@
 
 #include <cstddef>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/array/array.hpp>
 #include <sprout/container/traits.hpp>
 #include <sprout/container/functions.hpp>
diff --git a/sprout/functional/bind/bind.hpp b/sprout/functional/bind/bind.hpp
index 069c8416..038c1f4f 100644
--- a/sprout/functional/bind/bind.hpp
+++ b/sprout/functional/bind/bind.hpp
@@ -6,7 +6,7 @@
 #include <tuple>
 #include <type_traits>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/utility/forward.hpp>
 #include <sprout/utility/lvalue_forward.hpp>
 #include <sprout/tuple/tuple/tuple.hpp>
diff --git a/sprout/index_tuple.hpp b/sprout/index_tuple.hpp
index f62b3236..34329b66 100644
--- a/sprout/index_tuple.hpp
+++ b/sprout/index_tuple.hpp
@@ -2,15 +2,9 @@
 #define SPROUT_INDEX_TUPLE_HPP
 
 #include <sprout/config.hpp>
-#include <sprout/index_tuple/integer_seq.hpp>
-#include <sprout/index_tuple/index_tuple.hpp>
+#include <sprout/index_tuple/class.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
+#include <sprout/index_tuple/utility.hpp>
 #include <sprout/index_tuple/tuple.hpp>
-#include <sprout/index_tuple/make_integer_seq.hpp>
-#include <sprout/index_tuple/make_index_tuple.hpp>
-#include <sprout/index_tuple/integer_range.hpp>
-#include <sprout/index_tuple/index_range.hpp>
-#include <sprout/index_tuple/integer_n.hpp>
-#include <sprout/index_tuple/index_n.hpp>
-#include <sprout/index_tuple/make_indexes.hpp>
 
 #endif	// #ifndef SPROUT_INDEX_TUPLE_HPP
diff --git a/sprout/index_tuple/class.hpp b/sprout/index_tuple/class.hpp
new file mode 100644
index 00000000..b846f6a2
--- /dev/null
+++ b/sprout/index_tuple/class.hpp
@@ -0,0 +1,8 @@
+#ifndef SPROUT_INDEX_TUPLE_CLASS_HPP
+#define SPROUT_INDEX_TUPLE_CLASS_HPP
+
+#include <sprout/config.hpp>
+#include <sprout/index_tuple/integer_seq.hpp>
+#include <sprout/index_tuple/index_tuple.hpp>
+
+#endif	// #ifndef SPROUT_INDEX_TUPLE_CLASS_HPP
diff --git a/sprout/index_tuple/detail/make_indexes_helper.hpp b/sprout/index_tuple/detail/make_indexes_helper.hpp
deleted file mode 100644
index 37c48f9d..00000000
--- a/sprout/index_tuple/detail/make_indexes_helper.hpp
+++ /dev/null
@@ -1,22 +0,0 @@
-#ifndef SPROUT_INDEX_TUPLE_DETAIL_MAKE_INDEXES_HELPER_HPP
-#define SPROUT_INDEX_TUPLE_DETAIL_MAKE_INDEXES_HELPER_HPP
-
-#include <sprout/config.hpp>
-
-namespace sprout {
-	namespace detail {
-		template<typename IndexTupleType>
-		struct make_indexes_helper
-			: public IndexTupleType::type
-		{
-		public:
-			typedef typename IndexTupleType::type type;
-		public:
-			static SPROUT_CONSTEXPR type make() {
-				return type();
-			}
-		};
-	}	// namespace detail
-}	// namespace sprout
-
-#endif	// #ifndef SPROUT_INDEX_TUPLE_DETAIL_MAKE_INDEXES_HELPER_HPP
diff --git a/sprout/index_tuple/enable_make_indexes.hpp b/sprout/index_tuple/enable_make_indexes.hpp
new file mode 100644
index 00000000..d5ce36b1
--- /dev/null
+++ b/sprout/index_tuple/enable_make_indexes.hpp
@@ -0,0 +1,23 @@
+#ifndef SPROUT_INDEX_TUPLE_ENABLE_MAKE_INDEXES_HPP
+#define SPROUT_INDEX_TUPLE_ENABLE_MAKE_INDEXES_HPP
+
+#include <sprout/config.hpp>
+
+namespace sprout {
+	//
+	// enable_make_indexes
+	//
+	template<typename IndexTupleType>
+	struct enable_make_indexes
+		: public IndexTupleType::type
+	{
+	public:
+		typedef typename IndexTupleType::type type;
+	public:
+		static SPROUT_CONSTEXPR type make() {
+			return type();
+		}
+	};
+}	// namespace sprout
+
+#endif	// #ifndef SPROUT_INDEX_TUPLE_ENABLE_MAKE_INDEXES_HPP
diff --git a/sprout/index_tuple/index_n.hpp b/sprout/index_tuple/index_n.hpp
index 19eea94d..ea8fc2fa 100644
--- a/sprout/index_tuple/index_n.hpp
+++ b/sprout/index_tuple/index_n.hpp
@@ -4,7 +4,7 @@
 #include <cstddef>
 #include <sprout/config.hpp>
 #include <sprout/index_tuple/integer_n.hpp>
-#include <sprout/index_tuple/detail/make_indexes_helper.hpp>
+#include <sprout/index_tuple/enable_make_indexes.hpp>
 
 namespace sprout {
 	//
@@ -12,9 +12,9 @@ namespace sprout {
 	//
 	template<sprout::index_t I, std::size_t N>
 	struct index_n
-		: public sprout::detail::make_indexes_helper<
+		: public sprout::enable_make_indexes<
 			typename sprout::integer_n<sprout::index_t, I, N>::type
-				::template transfer<sprout::index_tuple<> >::type
+				::template transfer<sprout::index_tuple<> >
 		>
 	{};
 	//
@@ -22,9 +22,9 @@ namespace sprout {
 	//
 	template<sprout::uindex_t I, std::size_t N>
 	struct uindex_n
-		: public sprout::detail::make_indexes_helper<
+		: public sprout::enable_make_indexes<
 			typename sprout::integer_n<sprout::uindex_t, I, N>::type
-				::template transfer<sprout::uindex_tuple<> >::type
+				::template transfer<sprout::uindex_tuple<> >
 		>
 	{};
 }	// namespace sprout
diff --git a/sprout/index_tuple/index_range.hpp b/sprout/index_tuple/index_range.hpp
index 21f11640..2e5650ff 100644
--- a/sprout/index_tuple/index_range.hpp
+++ b/sprout/index_tuple/index_range.hpp
@@ -4,7 +4,7 @@
 #include <sprout/config.hpp>
 #include <sprout/index_tuple/index_tuple.hpp>
 #include <sprout/index_tuple/integer_range.hpp>
-#include <sprout/index_tuple/detail/make_indexes_helper.hpp>
+#include <sprout/index_tuple/enable_make_indexes.hpp>
 
 namespace sprout {
 	//
@@ -15,9 +15,9 @@ namespace sprout {
 		typename std::make_signed<sprout::index_t>::type Step = sprout::detail::integer_range_default_step<sprout::index_t, First, Last>::value
 	>
 	struct index_range
-		: public sprout::detail::make_indexes_helper<
+		: public sprout::enable_make_indexes<
 			typename sprout::integer_range<sprout::index_t, First, Last, Step>::type
-				::template transfer<sprout::index_tuple<> >::type
+				::template transfer<sprout::index_tuple<> >
 		>
 	{};
 	//
@@ -28,9 +28,9 @@ namespace sprout {
 		typename std::make_signed<sprout::uindex_t>::type Step = sprout::detail::integer_range_default_step<sprout::uindex_t, First, Last>::value
 	>
 	struct uindex_range
-		: public sprout::detail::make_indexes_helper<
+		: public sprout::enable_make_indexes<
 			typename sprout::integer_range<sprout::uindex_t, First, Last, Step>::type
-				::template transfer<sprout::uindex_tuple<> >::type
+				::template transfer<sprout::uindex_tuple<> >
 		>
 	{};
 }	// namespace sprout
diff --git a/sprout/index_tuple/integer_n.hpp b/sprout/index_tuple/integer_n.hpp
index 43a5a91d..783af0ca 100644
--- a/sprout/index_tuple/integer_n.hpp
+++ b/sprout/index_tuple/integer_n.hpp
@@ -5,7 +5,7 @@
 #include <type_traits>
 #include <sprout/config.hpp>
 #include <sprout/index_tuple/integer_seq.hpp>
-#include <sprout/index_tuple/detail/make_indexes_helper.hpp>
+#include <sprout/index_tuple/enable_make_indexes.hpp>
 
 namespace sprout {
 	//
@@ -64,7 +64,7 @@ namespace sprout {
 	}	// namespace detail
 	template<typename T, T I, std::size_t N>
 	struct integer_n
-		: public sprout::detail::make_indexes_helper<
+		: public sprout::enable_make_indexes<
 			sprout::detail::integer_n_impl<T, I, N>
 		>
 	{};
diff --git a/sprout/index_tuple/integer_range.hpp b/sprout/index_tuple/integer_range.hpp
index 7e3238b5..3e6aaddc 100644
--- a/sprout/index_tuple/integer_range.hpp
+++ b/sprout/index_tuple/integer_range.hpp
@@ -4,7 +4,7 @@
 #include <type_traits>
 #include <sprout/config.hpp>
 #include <sprout/index_tuple/integer_seq.hpp>
-#include <sprout/index_tuple/detail/make_indexes_helper.hpp>
+#include <sprout/index_tuple/enable_make_indexes.hpp>
 
 namespace sprout {
 	namespace detail {
@@ -86,7 +86,7 @@ namespace sprout {
 		typename std::make_signed<T>::type Step = sprout::detail::integer_range_default_step<T, First, Last>::value
 	>
 	struct integer_range
-		: public sprout::detail::make_indexes_helper<
+		: public sprout::enable_make_indexes<
 			sprout::detail::integer_range<T, First, Last, Step>
 		>
 	{
diff --git a/sprout/index_tuple/make_index_tuple.hpp b/sprout/index_tuple/make_index_tuple.hpp
index 056af9c8..28e0d4a2 100644
--- a/sprout/index_tuple/make_index_tuple.hpp
+++ b/sprout/index_tuple/make_index_tuple.hpp
@@ -5,7 +5,7 @@
 #include <sprout/config.hpp>
 #include <sprout/index_tuple/index_tuple.hpp>
 #include <sprout/index_tuple/make_integer_seq.hpp>
-#include <sprout/index_tuple/detail/make_indexes_helper.hpp>
+#include <sprout/index_tuple/enable_make_indexes.hpp>
 
 namespace sprout {
 	//
@@ -13,7 +13,7 @@ namespace sprout {
 	//
 	template<sprout::index_t N>
 	struct make_index_tuple
-		: public sprout::detail::make_indexes_helper<
+		: public sprout::enable_make_indexes<
 			typename sprout::make_integer_seq<sprout::index_t, N>::type
 				::template transfer<sprout::index_tuple<> >::type
 		>
@@ -23,7 +23,7 @@ namespace sprout {
 	//
 	template<sprout::uindex_t N>
 	struct make_uindex_tuple
-		: public sprout::detail::make_indexes_helper<
+		: public sprout::enable_make_indexes<
 			typename sprout::make_integer_seq<sprout::uindex_t, N>::type
 				::template transfer<sprout::uindex_tuple<> >::type
 		>
diff --git a/sprout/index_tuple/make_integer_seq.hpp b/sprout/index_tuple/make_integer_seq.hpp
index 2d3519eb..cb1cbd88 100644
--- a/sprout/index_tuple/make_integer_seq.hpp
+++ b/sprout/index_tuple/make_integer_seq.hpp
@@ -3,7 +3,7 @@
 
 #include <sprout/config.hpp>
 #include <sprout/index_tuple/integer_range.hpp>
-#include <sprout/index_tuple/detail/make_indexes_helper.hpp>
+#include <sprout/index_tuple/enable_make_indexes.hpp>
 
 namespace sprout {
 	//
@@ -11,7 +11,7 @@ namespace sprout {
 	//
 	template<typename T, T N>
 	struct make_integer_seq
-		: public sprout::detail::make_indexes_helper<
+		: public sprout::enable_make_indexes<
 			sprout::integer_range<T, 0, N>
 		>
 	{};
diff --git a/sprout/index_tuple/metafunction.hpp b/sprout/index_tuple/metafunction.hpp
new file mode 100644
index 00000000..02eaaea0
--- /dev/null
+++ b/sprout/index_tuple/metafunction.hpp
@@ -0,0 +1,12 @@
+#ifndef SPROUT_INDEX_TUPLE_METAFUNCTION_HPP
+#define SPROUT_INDEX_TUPLE_METAFUNCTION_HPP
+
+#include <sprout/config.hpp>
+#include <sprout/index_tuple/make_integer_seq.hpp>
+#include <sprout/index_tuple/make_index_tuple.hpp>
+#include <sprout/index_tuple/integer_range.hpp>
+#include <sprout/index_tuple/index_range.hpp>
+#include <sprout/index_tuple/integer_n.hpp>
+#include <sprout/index_tuple/index_n.hpp>
+
+#endif	// #ifndef SPROUT_INDEX_TUPLE_METAFUNCTION_HPP
diff --git a/sprout/index_tuple/tuple.hpp b/sprout/index_tuple/tuple.hpp
index ca6c2ae4..b3117956 100644
--- a/sprout/index_tuple/tuple.hpp
+++ b/sprout/index_tuple/tuple.hpp
@@ -7,6 +7,7 @@
 #include <sprout/config.hpp>
 #include <sprout/index_tuple/integer_seq.hpp>
 #include <sprout/index_tuple/index_tuple.hpp>
+#include <sprout/utility/pack.hpp>
 
 namespace std {
 #if defined(__clang__)
@@ -27,7 +28,7 @@ namespace std {
 	struct tuple_element<I, sprout::integer_seq<T, Is...> > {
 		static_assert(I < sizeof...(Is), "tuple_element<>: index out of range");
 	public:
-		typedef T type;
+		typedef typename sprout::tppack_c_at<I, T, Is...>::type type;
 	};
 
 	//
@@ -64,4 +65,39 @@ namespace std {
 #endif
 }	// namespace std
 
+namespace sprout {
+	//
+	// tuple_get
+	//
+	template<std::size_t I, typename T, T... Is>
+	inline SPROUT_CONSTEXPR typename std::tuple_element<I, sprout::integer_seq<T, Is...> >::type
+	tuple_get(sprout::integer_seq<T, Is...>) SPROUT_NOEXCEPT {
+		static_assert(I < sizeof...(Is), "tuple_get: index out of range");
+		typedef typename std::tuple_element<I, sprout::integer_seq<T, Is...> >::type type;
+		return type();
+	}
+
+	//
+	// tuple_get
+	//
+	template<std::size_t I, sprout::index_t... Indexes>
+	inline SPROUT_CONSTEXPR typename std::tuple_element<I, sprout::index_tuple<Indexes...> >::type
+	tuple_get(sprout::index_tuple<Indexes...>) SPROUT_NOEXCEPT {
+		static_assert(I < sizeof...(Indexes), "tuple_get: index out of range");
+		typedef typename std::tuple_element<I, sprout::index_tuple<Indexes...> >::type type;
+		return type();
+	}
+
+	//
+	// tuple_get
+	//
+	template<std::size_t I, sprout::uindex_t... Indexes>
+	inline SPROUT_CONSTEXPR typename std::tuple_element<I, sprout::uindex_tuple<Indexes...> >::type
+	tuple_get(sprout::uindex_tuple<Indexes...>) SPROUT_NOEXCEPT {
+		static_assert(I < sizeof...(Indexes), "tuple_get: index out of range");
+		typedef typename std::tuple_element<I, sprout::uindex_tuple<Indexes...> >::type type;
+		return type();
+	}
+}	// namespace sprout
+
 #endif	// #ifndef SPROUT_INDEX_TUPLE_TUPLE_HPP
diff --git a/sprout/index_tuple/utility.hpp b/sprout/index_tuple/utility.hpp
new file mode 100644
index 00000000..26165edd
--- /dev/null
+++ b/sprout/index_tuple/utility.hpp
@@ -0,0 +1,8 @@
+#ifndef SPROUT_INDEX_TUPLE_UTILITY_HPP
+#define SPROUT_INDEX_TUPLE_UTILITY_HPP
+
+#include <sprout/config.hpp>
+#include <sprout/index_tuple/make_indexes.hpp>
+#include <sprout/index_tuple/enable_make_indexes.hpp>
+
+#endif	// #ifndef SPROUT_INDEX_TUPLE_UTILITY_HPP
diff --git a/sprout/io.hpp b/sprout/io.hpp
index 1f2b6fd7..10362c24 100644
--- a/sprout/io.hpp
+++ b/sprout/io.hpp
@@ -6,7 +6,7 @@
 #include <utility>
 #include <type_traits>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/array/array.hpp>
 #include <sprout/string.hpp>
 #include <sprout/pit/pit.hpp>
diff --git a/sprout/numeric/dft/fixed/amplitude_spectrum.hpp b/sprout/numeric/dft/fixed/amplitude_spectrum.hpp
index 2cebc8bc..39201ce0 100644
--- a/sprout/numeric/dft/fixed/amplitude_spectrum.hpp
+++ b/sprout/numeric/dft/fixed/amplitude_spectrum.hpp
@@ -4,7 +4,7 @@
 #include <iterator>
 #include <type_traits>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/container/traits.hpp>
 #include <sprout/container/functions.hpp>
 #include <sprout/container/indexes.hpp>
diff --git a/sprout/numeric/dft/fixed/dft.hpp b/sprout/numeric/dft/fixed/dft.hpp
index 91cdeec0..935a5e8b 100644
--- a/sprout/numeric/dft/fixed/dft.hpp
+++ b/sprout/numeric/dft/fixed/dft.hpp
@@ -4,7 +4,7 @@
 #include <iterator>
 #include <type_traits>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/container/traits.hpp>
 #include <sprout/container/functions.hpp>
 #include <sprout/container/indexes.hpp>
diff --git a/sprout/numeric/dft/fixed/idft.hpp b/sprout/numeric/dft/fixed/idft.hpp
index c66555a3..b5d14c8d 100644
--- a/sprout/numeric/dft/fixed/idft.hpp
+++ b/sprout/numeric/dft/fixed/idft.hpp
@@ -4,7 +4,7 @@
 #include <iterator>
 #include <type_traits>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/container/traits.hpp>
 #include <sprout/container/functions.hpp>
 #include <sprout/container/indexes.hpp>
diff --git a/sprout/numeric/dft/fixed/phase_spectrum.hpp b/sprout/numeric/dft/fixed/phase_spectrum.hpp
index 6016a181..a4012f5c 100644
--- a/sprout/numeric/dft/fixed/phase_spectrum.hpp
+++ b/sprout/numeric/dft/fixed/phase_spectrum.hpp
@@ -4,7 +4,7 @@
 #include <iterator>
 #include <type_traits>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/container/traits.hpp>
 #include <sprout/container/functions.hpp>
 #include <sprout/container/indexes.hpp>
diff --git a/sprout/numeric/dft/fixed/sawtooth.hpp b/sprout/numeric/dft/fixed/sawtooth.hpp
index 4ce0112e..bf3c7ef7 100644
--- a/sprout/numeric/dft/fixed/sawtooth.hpp
+++ b/sprout/numeric/dft/fixed/sawtooth.hpp
@@ -2,7 +2,7 @@
 #define SPROUT_NUMERIC_DFT_FIXED_SAWTOOTH_HPP
 
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/container/traits.hpp>
 #include <sprout/container/functions.hpp>
 #include <sprout/container/indexes.hpp>
diff --git a/sprout/numeric/dft/fixed/sinusoid.hpp b/sprout/numeric/dft/fixed/sinusoid.hpp
index 92ab2901..d3112880 100644
--- a/sprout/numeric/dft/fixed/sinusoid.hpp
+++ b/sprout/numeric/dft/fixed/sinusoid.hpp
@@ -2,7 +2,7 @@
 #define SPROUT_NUMERIC_DFT_FIXED_SINUSOID_HPP
 
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/container/traits.hpp>
 #include <sprout/container/functions.hpp>
 #include <sprout/container/indexes.hpp>
diff --git a/sprout/numeric/dft/fixed/square.hpp b/sprout/numeric/dft/fixed/square.hpp
index a52b4ec8..db78497d 100644
--- a/sprout/numeric/dft/fixed/square.hpp
+++ b/sprout/numeric/dft/fixed/square.hpp
@@ -2,7 +2,7 @@
 #define SPROUT_NUMERIC_DFT_FIXED_SQUARE_HPP
 
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/container/traits.hpp>
 #include <sprout/container/functions.hpp>
 #include <sprout/container/indexes.hpp>
diff --git a/sprout/numeric/dft/fixed/triangle.hpp b/sprout/numeric/dft/fixed/triangle.hpp
index c9a5e050..b4e0bd25 100644
--- a/sprout/numeric/dft/fixed/triangle.hpp
+++ b/sprout/numeric/dft/fixed/triangle.hpp
@@ -2,7 +2,7 @@
 #define SPROUT_NUMERIC_DFT_FIXED_TRINAGLE_HPP
 
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/container/traits.hpp>
 #include <sprout/container/functions.hpp>
 #include <sprout/container/indexes.hpp>
diff --git a/sprout/numeric/fft/fixed/bitrev_table.hpp b/sprout/numeric/fft/fixed/bitrev_table.hpp
index e75ead6d..d26592fc 100644
--- a/sprout/numeric/fft/fixed/bitrev_table.hpp
+++ b/sprout/numeric/fft/fixed/bitrev_table.hpp
@@ -4,7 +4,7 @@
 #include <cstddef>
 #include <type_traits>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/container/traits.hpp>
 #include <sprout/container/functions.hpp>
 #include <sprout/container/indexes.hpp>
diff --git a/sprout/numeric/fixed/iota.hpp b/sprout/numeric/fixed/iota.hpp
index bf0ab97d..4c850be9 100644
--- a/sprout/numeric/fixed/iota.hpp
+++ b/sprout/numeric/fixed/iota.hpp
@@ -2,7 +2,7 @@
 #define SPROUT_NUMERIC_FIXED_IOTA_HPP
 
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/container/traits.hpp>
 #include <sprout/container/functions.hpp>
 #include <sprout/container/indexes.hpp>
diff --git a/sprout/operation/fixed/append.hpp b/sprout/operation/fixed/append.hpp
index fec5b797..a2dfae65 100644
--- a/sprout/operation/fixed/append.hpp
+++ b/sprout/operation/fixed/append.hpp
@@ -2,7 +2,7 @@
 #define SPROUT_OPERATION_FIXED_APPEND_HPP
 
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/container/traits.hpp>
 #include <sprout/container/functions.hpp>
 #include <sprout/container/indexes.hpp>
diff --git a/sprout/operation/fixed/append_back.hpp b/sprout/operation/fixed/append_back.hpp
index 65192567..5c7e643b 100644
--- a/sprout/operation/fixed/append_back.hpp
+++ b/sprout/operation/fixed/append_back.hpp
@@ -3,7 +3,7 @@
 
 #include <cstddef>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/container/traits.hpp>
 #include <sprout/container/functions.hpp>
 #include <sprout/container/indexes.hpp>
diff --git a/sprout/operation/fixed/append_front.hpp b/sprout/operation/fixed/append_front.hpp
index 98517766..df7b237d 100644
--- a/sprout/operation/fixed/append_front.hpp
+++ b/sprout/operation/fixed/append_front.hpp
@@ -3,7 +3,7 @@
 
 #include <cstddef>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/container/traits.hpp>
 #include <sprout/container/functions.hpp>
 #include <sprout/container/indexes.hpp>
diff --git a/sprout/operation/fixed/erase.hpp b/sprout/operation/fixed/erase.hpp
index 0c105760..a66805b1 100644
--- a/sprout/operation/fixed/erase.hpp
+++ b/sprout/operation/fixed/erase.hpp
@@ -2,7 +2,7 @@
 #define SPROUT_OPERATION_FIXED_ERASE_HPP
 
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/container/traits.hpp>
 #include <sprout/container/functions.hpp>
 #include <sprout/container/indexes.hpp>
diff --git a/sprout/operation/fixed/erase_n.hpp b/sprout/operation/fixed/erase_n.hpp
index 4dd0eb64..49b43ee6 100644
--- a/sprout/operation/fixed/erase_n.hpp
+++ b/sprout/operation/fixed/erase_n.hpp
@@ -3,7 +3,7 @@
 
 #include <cstddef>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/container/traits.hpp>
 #include <sprout/container/functions.hpp>
 #include <sprout/container/indexes.hpp>
diff --git a/sprout/operation/fixed/insert.hpp b/sprout/operation/fixed/insert.hpp
index ca6b114d..4545c63c 100644
--- a/sprout/operation/fixed/insert.hpp
+++ b/sprout/operation/fixed/insert.hpp
@@ -3,7 +3,7 @@
 
 #include <type_traits>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/container/traits.hpp>
 #include <sprout/container/functions.hpp>
 #include <sprout/container/indexes.hpp>
diff --git a/sprout/operation/fixed/insert_n.hpp b/sprout/operation/fixed/insert_n.hpp
index 6ea6e4aa..d62e0a08 100644
--- a/sprout/operation/fixed/insert_n.hpp
+++ b/sprout/operation/fixed/insert_n.hpp
@@ -4,7 +4,7 @@
 #include <cstddef>
 #include <type_traits>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/container/traits.hpp>
 #include <sprout/container/functions.hpp>
 #include <sprout/container/indexes.hpp>
diff --git a/sprout/operation/fixed/pop_back.hpp b/sprout/operation/fixed/pop_back.hpp
index dda3ef02..5642841b 100644
--- a/sprout/operation/fixed/pop_back.hpp
+++ b/sprout/operation/fixed/pop_back.hpp
@@ -3,7 +3,7 @@
 
 #include <cstddef>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/container/traits.hpp>
 #include <sprout/container/functions.hpp>
 #include <sprout/container/indexes.hpp>
diff --git a/sprout/operation/fixed/pop_back_n.hpp b/sprout/operation/fixed/pop_back_n.hpp
index 98cc0458..9f5be852 100644
--- a/sprout/operation/fixed/pop_back_n.hpp
+++ b/sprout/operation/fixed/pop_back_n.hpp
@@ -3,7 +3,7 @@
 
 #include <cstddef>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/container/traits.hpp>
 #include <sprout/container/functions.hpp>
 #include <sprout/container/indexes.hpp>
diff --git a/sprout/operation/fixed/pop_front.hpp b/sprout/operation/fixed/pop_front.hpp
index 25d24bab..639a79d0 100644
--- a/sprout/operation/fixed/pop_front.hpp
+++ b/sprout/operation/fixed/pop_front.hpp
@@ -3,7 +3,7 @@
 
 #include <cstddef>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/container/traits.hpp>
 #include <sprout/container/functions.hpp>
 #include <sprout/container/indexes.hpp>
diff --git a/sprout/operation/fixed/pop_front_n.hpp b/sprout/operation/fixed/pop_front_n.hpp
index bee36742..e8d788f8 100644
--- a/sprout/operation/fixed/pop_front_n.hpp
+++ b/sprout/operation/fixed/pop_front_n.hpp
@@ -3,7 +3,7 @@
 
 #include <cstddef>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/container/traits.hpp>
 #include <sprout/container/functions.hpp>
 #include <sprout/container/indexes.hpp>
diff --git a/sprout/operation/fixed/push_back.hpp b/sprout/operation/fixed/push_back.hpp
index 2cbaa0e4..ce1bd68d 100644
--- a/sprout/operation/fixed/push_back.hpp
+++ b/sprout/operation/fixed/push_back.hpp
@@ -3,7 +3,7 @@
 
 #include <cstddef>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/container/traits.hpp>
 #include <sprout/container/functions.hpp>
 #include <sprout/container/indexes.hpp>
diff --git a/sprout/operation/fixed/push_back_n.hpp b/sprout/operation/fixed/push_back_n.hpp
index 26be9e77..c0e10c19 100644
--- a/sprout/operation/fixed/push_back_n.hpp
+++ b/sprout/operation/fixed/push_back_n.hpp
@@ -3,7 +3,7 @@
 
 #include <cstddef>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/container/traits.hpp>
 #include <sprout/container/functions.hpp>
 #include <sprout/container/indexes.hpp>
diff --git a/sprout/operation/fixed/push_front.hpp b/sprout/operation/fixed/push_front.hpp
index 59f77eae..df40b360 100644
--- a/sprout/operation/fixed/push_front.hpp
+++ b/sprout/operation/fixed/push_front.hpp
@@ -3,7 +3,7 @@
 
 #include <cstddef>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/container/traits.hpp>
 #include <sprout/container/functions.hpp>
 #include <sprout/container/indexes.hpp>
diff --git a/sprout/operation/fixed/push_front_n.hpp b/sprout/operation/fixed/push_front_n.hpp
index 8666a6fd..5cf3d1da 100644
--- a/sprout/operation/fixed/push_front_n.hpp
+++ b/sprout/operation/fixed/push_front_n.hpp
@@ -3,7 +3,7 @@
 
 #include <cstddef>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/container/traits.hpp>
 #include <sprout/container/functions.hpp>
 #include <sprout/container/indexes.hpp>
diff --git a/sprout/operation/fixed/realign.hpp b/sprout/operation/fixed/realign.hpp
index 48f9cd6f..cc912891 100644
--- a/sprout/operation/fixed/realign.hpp
+++ b/sprout/operation/fixed/realign.hpp
@@ -2,7 +2,7 @@
 #define SPROUT_OPERATION_FIXED_REALIGN_HPP
 
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/container/traits.hpp>
 #include <sprout/container/functions.hpp>
 #include <sprout/container/indexes.hpp>
diff --git a/sprout/operation/fixed/realign_to.hpp b/sprout/operation/fixed/realign_to.hpp
index 6373d4b9..450622f5 100644
--- a/sprout/operation/fixed/realign_to.hpp
+++ b/sprout/operation/fixed/realign_to.hpp
@@ -3,7 +3,7 @@
 
 #include <cstddef>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/container/traits.hpp>
 #include <sprout/container/functions.hpp>
 #include <sprout/container/indexes.hpp>
diff --git a/sprout/operation/fixed/resize.hpp b/sprout/operation/fixed/resize.hpp
index 149e5585..35651214 100644
--- a/sprout/operation/fixed/resize.hpp
+++ b/sprout/operation/fixed/resize.hpp
@@ -3,7 +3,7 @@
 
 #include <cstddef>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/container/traits.hpp>
 #include <sprout/container/functions.hpp>
 #include <sprout/container/indexes.hpp>
diff --git a/sprout/operation/fixed/resize_backward.hpp b/sprout/operation/fixed/resize_backward.hpp
index 767c4380..b516af79 100644
--- a/sprout/operation/fixed/resize_backward.hpp
+++ b/sprout/operation/fixed/resize_backward.hpp
@@ -3,7 +3,7 @@
 
 #include <cstddef>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/container/traits.hpp>
 #include <sprout/container/functions.hpp>
 #include <sprout/container/indexes.hpp>
diff --git a/sprout/operation/fixed/set.hpp b/sprout/operation/fixed/set.hpp
index afa4df8f..90a1969b 100644
--- a/sprout/operation/fixed/set.hpp
+++ b/sprout/operation/fixed/set.hpp
@@ -2,7 +2,7 @@
 #define SPROUT_OPERATION_FIXED_SET_HPP
 
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/container/traits.hpp>
 #include <sprout/container/functions.hpp>
 #include <sprout/container/indexes.hpp>
diff --git a/sprout/range/adaptor/piped.hpp b/sprout/range/adaptor/piped.hpp
index 91ef8b69..9bff1a79 100644
--- a/sprout/range/adaptor/piped.hpp
+++ b/sprout/range/adaptor/piped.hpp
@@ -4,7 +4,7 @@
 #include <type_traits>
 #include <utility>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/utility/forward.hpp>
 #include <sprout/utility/lvalue_forward.hpp>
 #include <sprout/tuple/tuple/tuple.hpp>
diff --git a/sprout/string/concat.hpp b/sprout/string/concat.hpp
index 1b2c64a7..281b1508 100644
--- a/sprout/string/concat.hpp
+++ b/sprout/string/concat.hpp
@@ -4,7 +4,7 @@
 #include <cstddef>
 #include <type_traits>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/string/char_traits.hpp>
 #include <sprout/string/string.hpp>
 
diff --git a/sprout/string/float_to_string.hpp b/sprout/string/float_to_string.hpp
index ecfbe461..52073d81 100644
--- a/sprout/string/float_to_string.hpp
+++ b/sprout/string/float_to_string.hpp
@@ -5,7 +5,7 @@
 #include <limits>
 #include <type_traits>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/string/string.hpp>
 #include <sprout/type_traits/enabler_if.hpp>
 #include <sprout/math/floor.hpp>
diff --git a/sprout/string/int_to_string.hpp b/sprout/string/int_to_string.hpp
index 23277615..48c30abd 100644
--- a/sprout/string/int_to_string.hpp
+++ b/sprout/string/int_to_string.hpp
@@ -4,7 +4,7 @@
 #include <cstddef>
 #include <type_traits>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/string/string.hpp>
 #include <sprout/integer/integer_digits.hpp>
 #include <sprout/type_traits/enabler_if.hpp>
diff --git a/sprout/string/shrink.hpp b/sprout/string/shrink.hpp
index 57cd9ddc..effc333e 100644
--- a/sprout/string/shrink.hpp
+++ b/sprout/string/shrink.hpp
@@ -3,7 +3,7 @@
 
 #include <cstddef>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/string/char_traits.hpp>
 #include <sprout/string/string.hpp>
 #include <sprout/utility/value_holder/value_holder.hpp>
diff --git a/sprout/string/string.hpp b/sprout/string/string.hpp
index 4daa13f5..244e526d 100644
--- a/sprout/string/string.hpp
+++ b/sprout/string/string.hpp
@@ -8,7 +8,7 @@
 #include <stdexcept>
 #include <type_traits>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/array/array.hpp>
 #include <sprout/array/make_array.hpp>
 #include <sprout/iterator/reverse_iterator.hpp>
diff --git a/sprout/sub_array/sub_array.hpp b/sprout/sub_array/sub_array.hpp
index e702224f..c36b6304 100644
--- a/sprout/sub_array/sub_array.hpp
+++ b/sprout/sub_array/sub_array.hpp
@@ -6,7 +6,7 @@
 #include <stdexcept>
 #include <type_traits>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/container/traits.hpp>
 #include <sprout/container/functions.hpp>
 #include <sprout/iterator/operation.hpp>
diff --git a/sprout/tuple/algorithm/copy.hpp b/sprout/tuple/algorithm/copy.hpp
index 34d05fff..51b6450d 100644
--- a/sprout/tuple/algorithm/copy.hpp
+++ b/sprout/tuple/algorithm/copy.hpp
@@ -3,7 +3,7 @@
 
 #include <type_traits>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/tuple/traits.hpp>
 #include <sprout/tuple/functions.hpp>
 #include <sprout/tuple/indexes.hpp>
diff --git a/sprout/tuple/fused.hpp b/sprout/tuple/fused.hpp
index 8d2f7fe1..466b9443 100644
--- a/sprout/tuple/fused.hpp
+++ b/sprout/tuple/fused.hpp
@@ -4,7 +4,7 @@
 #include <utility>
 #include <type_traits>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/tuple/tuple/tuple.hpp>
 #include <sprout/tuple/tuple/get.hpp>
 #include <sprout/tuple/indexes.hpp>
diff --git a/sprout/tuple/indexes.hpp b/sprout/tuple/indexes.hpp
index 5648483d..fba325a1 100644
--- a/sprout/tuple/indexes.hpp
+++ b/sprout/tuple/indexes.hpp
@@ -2,8 +2,8 @@
 #define SPROUT_TUPLE_INDEXES_HPP
 
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
-#include <sprout/index_tuple/detail/make_indexes_helper.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
+#include <sprout/index_tuple/enable_make_indexes.hpp>
 #include <sprout/tuple/tuple/tuple.hpp>
 #include <sprout/tuple/tuple/get.hpp>
 
@@ -14,7 +14,7 @@ namespace sprout {
 		//
 		template<typename Tuple>
 		struct tuple_indexes
-			: public sprout::detail::make_indexes_helper<
+			: public sprout::enable_make_indexes<
 				sprout::make_index_tuple<sprout::tuples::tuple_size<Tuple>::value>
 			>
 		{};
diff --git a/sprout/tuple/operation/append_back.hpp b/sprout/tuple/operation/append_back.hpp
index c72a8a09..398b4479 100644
--- a/sprout/tuple/operation/append_back.hpp
+++ b/sprout/tuple/operation/append_back.hpp
@@ -2,7 +2,7 @@
 #define SPROUT_TUPLE_OPERATION_APPEND_BACK_HPP
 
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/tuple/tuple.hpp>
 #include <sprout/tuple/functions.hpp>
 #include <sprout/tuple/indexes.hpp>
diff --git a/sprout/tuple/operation/append_front.hpp b/sprout/tuple/operation/append_front.hpp
index 3e2bb140..10a6e167 100644
--- a/sprout/tuple/operation/append_front.hpp
+++ b/sprout/tuple/operation/append_front.hpp
@@ -2,7 +2,7 @@
 #define SPROUT_TUPLE_OPERATION_APPEND_FRONT_HPP
 
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/tuple/tuple.hpp>
 #include <sprout/tuple/functions.hpp>
 #include <sprout/tuple/indexes.hpp>
diff --git a/sprout/tuple/operation/pop_back.hpp b/sprout/tuple/operation/pop_back.hpp
index 485f9d57..875eaa9d 100644
--- a/sprout/tuple/operation/pop_back.hpp
+++ b/sprout/tuple/operation/pop_back.hpp
@@ -2,7 +2,7 @@
 #define SPROUT_TUPLE_OPERATION_POP_BACK_HPP
 
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/tuple/tuple.hpp>
 #include <sprout/tuple/functions.hpp>
 #include <sprout/type/operation/pop_back.hpp>
diff --git a/sprout/tuple/operation/pop_front.hpp b/sprout/tuple/operation/pop_front.hpp
index 7aa525b7..191c84e4 100644
--- a/sprout/tuple/operation/pop_front.hpp
+++ b/sprout/tuple/operation/pop_front.hpp
@@ -2,7 +2,7 @@
 #define SPROUT_TUPLE_OPERATION_POP_FRONT_HPP
 
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/tuple/tuple.hpp>
 #include <sprout/tuple/functions.hpp>
 #include <sprout/type/operation/pop_front.hpp>
diff --git a/sprout/tuple/operation/push_back.hpp b/sprout/tuple/operation/push_back.hpp
index 9e450d4c..40f0e4ec 100644
--- a/sprout/tuple/operation/push_back.hpp
+++ b/sprout/tuple/operation/push_back.hpp
@@ -2,7 +2,7 @@
 #define SPROUT_TUPLE_OPERATION_PUSH_BACK_HPP
 
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/tuple/tuple.hpp>
 #include <sprout/tuple/functions.hpp>
 #include <sprout/tuple/indexes.hpp>
diff --git a/sprout/tuple/operation/push_front.hpp b/sprout/tuple/operation/push_front.hpp
index 1478a197..1fba0e4e 100644
--- a/sprout/tuple/operation/push_front.hpp
+++ b/sprout/tuple/operation/push_front.hpp
@@ -2,7 +2,7 @@
 #define SPROUT_TUPLE_OPERATION_PUSH_FRONT_HPP
 
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/tuple/tuple.hpp>
 #include <sprout/tuple/functions.hpp>
 #include <sprout/tuple/indexes.hpp>
diff --git a/sprout/tuple/traits.hpp b/sprout/tuple/traits.hpp
index 12283377..c6c47622 100644
--- a/sprout/tuple/traits.hpp
+++ b/sprout/tuple/traits.hpp
@@ -2,7 +2,7 @@
 #define SPROUT_TUPLE_TRAITS_HPP
 
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/tuple/tuple.hpp>
 #include <sprout/tuple/indexes.hpp>
 #include <sprout/type/rebind_types.hpp>
diff --git a/sprout/tuple/tuple/hash.hpp b/sprout/tuple/tuple/hash.hpp
index 32c54b00..4edc7bcd 100644
--- a/sprout/tuple/tuple/hash.hpp
+++ b/sprout/tuple/tuple/hash.hpp
@@ -4,7 +4,7 @@
 #include <cstddef>
 #include <functional>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/functional/hash.hpp>
 #include <sprout/tuple/tuple/tuple.hpp>
 #include <sprout/tuple/tuple/get.hpp>
diff --git a/sprout/tuple/tuple/make_tuple.hpp b/sprout/tuple/tuple/make_tuple.hpp
index 55817d1b..51ecf7e4 100644
--- a/sprout/tuple/tuple/make_tuple.hpp
+++ b/sprout/tuple/tuple/make_tuple.hpp
@@ -3,7 +3,7 @@
 
 #include <type_traits>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/utility/forward.hpp>
 #include <sprout/tuple/tuple/tuple.hpp>
 #include <sprout/tuple/tuple/get.hpp>
diff --git a/sprout/tuple/tuple/tuple_decl.hpp b/sprout/tuple/tuple/tuple_decl.hpp
index c4882e0d..ff802f4e 100644
--- a/sprout/tuple/tuple/tuple_decl.hpp
+++ b/sprout/tuple/tuple/tuple_decl.hpp
@@ -6,7 +6,7 @@
 #include <type_traits>
 #include <tuple>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/utility/forward.hpp>
 #include <sprout/utility/move.hpp>
 #include <sprout/utility/swap.hpp>
diff --git a/sprout/type/integral_array.hpp b/sprout/type/integral_array.hpp
index 5d78e797..5cdc24d2 100644
--- a/sprout/type/integral_array.hpp
+++ b/sprout/type/integral_array.hpp
@@ -7,6 +7,7 @@
 #include <sprout/config.hpp>
 #include <sprout/type/tuple.hpp>
 #include <sprout/type/type_tuple.hpp>
+#include <sprout/tuple/tuple/get.hpp>
 
 namespace sprout {
 	namespace types {
@@ -49,4 +50,17 @@ namespace std {
 #endif
 }	// namespace std
 
+namespace sprout {
+	//
+	// tuple_get
+	//
+	template<std::size_t I, typename T, T... Values>
+	inline SPROUT_CONSTEXPR typename std::tuple_element<I, sprout::types::integral_array<T, Values...> >::type
+	tuple_get(sprout::types::integral_array<T, Values...>) SPROUT_NOEXCEPT {
+		static_assert(I < sizeof...(Values), "tuple_get: index out of range");
+		typedef typename std::tuple_element<I, sprout::types::integral_array<T, Values...> >::type type;
+		return type();
+	}
+}	// namespace sprout
+
 #endif	// #ifndef SPROUT_TYPE_INTEGRAL_ARRAY_HPP
diff --git a/sprout/type/operation/append_back.hpp b/sprout/type/operation/append_back.hpp
index 2ba30298..f813b568 100644
--- a/sprout/type/operation/append_back.hpp
+++ b/sprout/type/operation/append_back.hpp
@@ -2,7 +2,7 @@
 #define SPROUT_TYPE_OPERATION_APPEND_BACK_HPP
 
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/type/tuple.hpp>
 #include <sprout/type/rebind_types.hpp>
 #include <sprout/tuple/indexes.hpp>
diff --git a/sprout/type/operation/append_front.hpp b/sprout/type/operation/append_front.hpp
index ef2675b4..0694ec06 100644
--- a/sprout/type/operation/append_front.hpp
+++ b/sprout/type/operation/append_front.hpp
@@ -2,7 +2,7 @@
 #define SPROUT_TYPE_OPERATION_APPEND_FRONT_HPP
 
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/type/tuple.hpp>
 #include <sprout/type/rebind_types.hpp>
 #include <sprout/tuple/indexes.hpp>
diff --git a/sprout/type/operation/pop_back.hpp b/sprout/type/operation/pop_back.hpp
index 4894c65a..5daa2f7a 100644
--- a/sprout/type/operation/pop_back.hpp
+++ b/sprout/type/operation/pop_back.hpp
@@ -2,7 +2,7 @@
 #define SPROUT_TYPE_OPERATION_POP_BACK_HPP
 
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/type/tuple.hpp>
 #include <sprout/type/rebind_types.hpp>
 
diff --git a/sprout/type/operation/pop_front.hpp b/sprout/type/operation/pop_front.hpp
index 976ccb46..32c49839 100644
--- a/sprout/type/operation/pop_front.hpp
+++ b/sprout/type/operation/pop_front.hpp
@@ -2,7 +2,7 @@
 #define SPROUT_TYPE_OPERATION_POP_FRONT_HPP
 
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/type/tuple.hpp>
 #include <sprout/type/rebind_types.hpp>
 
diff --git a/sprout/type/operation/push_back.hpp b/sprout/type/operation/push_back.hpp
index 9e327a5a..21eafef7 100644
--- a/sprout/type/operation/push_back.hpp
+++ b/sprout/type/operation/push_back.hpp
@@ -2,7 +2,7 @@
 #define SPROUT_TYPE_OPERATION_PUSH_BACK_HPP
 
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/type/tuple.hpp>
 #include <sprout/type/rebind_types.hpp>
 #include <sprout/tuple/indexes.hpp>
diff --git a/sprout/type/operation/push_front.hpp b/sprout/type/operation/push_front.hpp
index a772b594..920540dd 100644
--- a/sprout/type/operation/push_front.hpp
+++ b/sprout/type/operation/push_front.hpp
@@ -2,7 +2,7 @@
 #define SPROUT_TYPE_OPERATION_PUSH_FRONT_HPP
 
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/type/tuple.hpp>
 #include <sprout/type/rebind_types.hpp>
 #include <sprout/tuple/indexes.hpp>
diff --git a/sprout/type/string/to_string.hpp b/sprout/type/string/to_string.hpp
index ca8fe324..194b7989 100644
--- a/sprout/type/string/to_string.hpp
+++ b/sprout/type/string/to_string.hpp
@@ -6,7 +6,7 @@
 #include <sprout/config.hpp>
 #include <sprout/string.hpp>
 #include <sprout/type/string/string.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/container/traits.hpp>
 #include <sprout/container/size.hpp>
 #include <sprout/container/begin.hpp>
diff --git a/sprout/type/string/to_string_constant.hpp b/sprout/type/string/to_string_constant.hpp
index 9f504c56..aa127e75 100644
--- a/sprout/type/string/to_string_constant.hpp
+++ b/sprout/type/string/to_string_constant.hpp
@@ -3,7 +3,7 @@
 
 #include <type_traits>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/string.hpp>
 #include <sprout/type/string/string.hpp>
 #include <sprout/type/tuple.hpp>
diff --git a/sprout/utility/pack.hpp b/sprout/utility/pack.hpp
index aa2d5586..19dc84c5 100644
--- a/sprout/utility/pack.hpp
+++ b/sprout/utility/pack.hpp
@@ -12,25 +12,33 @@ namespace sprout {
 	// tppack_at
 	//
 	namespace detail {
-		template<std::size_t N, typename Head, typename... Tail>
+		template<std::size_t I, typename Head, typename... Tail>
 		struct tppack_at_impl_1
-			: public sprout::detail::tppack_at_impl_1<N - 1, Tail...>
+			: public sprout::detail::tppack_at_impl_1<I - 1, Tail...>
 		{};
 		template<typename Head, typename... Tail>
 		struct tppack_at_impl_1<0, Head, Tail...> {
 		public:
 			typedef Head type;
 		};
-		template<std::size_t N, typename... Args>
+		template<std::size_t I, typename... Args>
 		struct tppack_at_impl
-			: public sprout::detail::tppack_at_impl_1<N, Args...>
+			: public sprout::detail::tppack_at_impl_1<I, Args...>
 		{
-			static_assert(N < sizeof...(Args), "N < sizeof...(Args)");
+			static_assert(I < sizeof...(Args), "I < sizeof...(Args)");
 		};
 	}	// namespace detail
-	template<std::size_t N, typename... Args>
+	template<std::size_t I, typename... Args>
 	struct tppack_at
-		: public sprout::detail::tppack_at_impl<N, Args...>
+		: public sprout::detail::tppack_at_impl<I, Args...>
+	{};
+
+	//
+	// tppack_c_at
+	//
+	template<std::size_t I, typename T, T... Args>
+	struct tppack_c_at
+		: public sprout::tppack_at<I, std::integral_constant<T, Args>...>::type
 	{};
 
 	//
@@ -38,28 +46,28 @@ namespace sprout {
 	//
 	namespace detail {
 		template<
-			std::size_t N, typename R, typename Head, typename... Tail,
-			typename sprout::enabler_if<N == 0>::type = sprout::enabler
+			std::size_t I, typename R, typename Head, typename... Tail,
+			typename sprout::enabler_if<I == 0>::type = sprout::enabler
 		>
 		inline SPROUT_CONSTEXPR R
 		fppack_at_impl(Head&& head, Tail&&... tail) {
 			return sprout::forward<Head>(head);
 		}
 		template<
-			std::size_t N, typename R, typename Head, typename... Tail,
-			typename sprout::enabler_if<N != 0>::type = sprout::enabler
+			std::size_t I, typename R, typename Head, typename... Tail,
+			typename sprout::enabler_if<I != 0>::type = sprout::enabler
 		>
 		inline SPROUT_CONSTEXPR R
 		fppack_at_impl(Head&& head, Tail&&... tail) {
-			return sprout::detail::fppack_at_impl<N - 1, R>(sprout::forward<Tail>(tail)...);
+			return sprout::detail::fppack_at_impl<I - 1, R>(sprout::forward<Tail>(tail)...);
 		}
 	}	// namespace detail
-	template<std::size_t N, typename... Args>
-	inline SPROUT_CONSTEXPR typename sprout::tppack_at<N, Args&&...>::type
+	template<std::size_t I, typename... Args>
+	inline SPROUT_CONSTEXPR typename sprout::tppack_at<I, Args&&...>::type
 	fppack_at(Args&&... args) {
 		return sprout::detail::fppack_at_impl<
-			N,
-			typename sprout::tppack_at<N, Args&&...>::type
+			I,
+			typename sprout::tppack_at<I, Args&&...>::type
 		>(sprout::forward<Args>(args)...);
 	}
 }	// namespace sprout
diff --git a/sprout/utility/pair/pair.hpp b/sprout/utility/pair/pair.hpp
index 2f13d19d..cc640725 100644
--- a/sprout/utility/pair/pair.hpp
+++ b/sprout/utility/pair/pair.hpp
@@ -4,7 +4,7 @@
 #include <utility>
 #include <type_traits>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/utility/forward.hpp>
 #include <sprout/utility/swap.hpp>
 #include <sprout/utility/pair/pair_decl.hpp>
diff --git a/sprout/utility/pair/pair_decl.hpp b/sprout/utility/pair/pair_decl.hpp
index 07cb5192..88a8cfa4 100644
--- a/sprout/utility/pair/pair_decl.hpp
+++ b/sprout/utility/pair/pair_decl.hpp
@@ -4,7 +4,7 @@
 #include <utility>
 #include <type_traits>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/utility/forward.hpp>
 #include <sprout/utility/swap.hpp>
 #include <sprout/utility/pair/pair_fwd.hpp>
diff --git a/sprout/variant/variant.hpp b/sprout/variant/variant.hpp
index b83d50f6..33bc7c40 100644
--- a/sprout/variant/variant.hpp
+++ b/sprout/variant/variant.hpp
@@ -6,7 +6,7 @@
 #include <stdexcept>
 #include <type_traits>
 #include <sprout/config.hpp>
-#include <sprout/index_tuple.hpp>
+#include <sprout/index_tuple/metafunction.hpp>
 #include <sprout/utility/forward.hpp>
 #include <sprout/utility/move.hpp>
 #include <sprout/utility/swap.hpp>