diff --git a/sprout/range/algorithm/equal_range.hpp b/sprout/range/algorithm/equal_range.hpp
index 9a7662b2..8f5f10a6 100644
--- a/sprout/range/algorithm/equal_range.hpp
+++ b/sprout/range/algorithm/equal_range.hpp
@@ -4,14 +4,14 @@
 #include <sprout/config.hpp>
 #include <sprout/container/functions.hpp>
 #include <sprout/utility/operation.hpp>
-#include <sprout/range/lvref_range.hpp>
+#include <sprout/range/lvalue_range.hpp>
 #include <sprout/algorithm/equal_range.hpp>
 
 namespace sprout {
 	namespace range {
 		namespace detail {
 			template<typename Range, typename Pair>
-			inline SPROUT_CONSTEXPR typename sprout::range::lvref_range<Range>::type
+			inline SPROUT_CONSTEXPR typename sprout::range::lvalue_range<Range>::type
 			pair_to_range(Pair const& pair) {
 				return {pair.first, pair.second};
 			}
@@ -21,7 +21,7 @@ namespace sprout {
 
 		// 25.4.3.3 equal_range
 		template<typename Range, typename T>
-		inline SPROUT_CONSTEXPR typename sprout::range::lvref_range<Range>::type
+		inline SPROUT_CONSTEXPR typename sprout::range::lvalue_range<Range>::type
 		equal_range(Range&& range, T const& value) {
 			return sprout::range::detail::pair_to_range<Range>(
 				sprout::equal_range(
@@ -33,7 +33,7 @@ namespace sprout {
 		}
 
 		template<typename Range, typename T, typename Compare>
-		inline SPROUT_CONSTEXPR typename sprout::range::lvref_range<Range>::type
+		inline SPROUT_CONSTEXPR typename sprout::range::lvalue_range<Range>::type
 		equal_range(Range&& range, T const& value, Compare comp) {
 			return sprout::range::detail::pair_to_range<Range>(
 				sprout::equal_range(
diff --git a/sprout/range/algorithm/mismatch.hpp b/sprout/range/algorithm/mismatch.hpp
index 9dae09dd..4dc7edbd 100644
--- a/sprout/range/algorithm/mismatch.hpp
+++ b/sprout/range/algorithm/mismatch.hpp
@@ -5,7 +5,7 @@
 #include <sprout/container/functions.hpp>
 #include <sprout/utility/operation.hpp>
 #include <sprout/utility/pair.hpp>
-#include <sprout/range/lvref_iterator.hpp>
+#include <sprout/range/lvalue_iterator.hpp>
 #include <sprout/algorithm/mismatch.hpp>
 
 namespace sprout {
@@ -15,8 +15,8 @@ namespace sprout {
 		// 25.2.10 Mismatch
 		template<typename Range1, typename Range2>
 		inline SPROUT_CONSTEXPR sprout::pair<
-			typename sprout::range::lvref_iterator<Range1>::type,
-			typename sprout::range::lvref_iterator<Range2>::type
+			typename sprout::range::lvalue_iterator<Range1>::type,
+			typename sprout::range::lvalue_iterator<Range2>::type
 		>
 		mismatch(Range1&& range1, Range2&& range2) {
 			return sprout::mismatch(
@@ -28,8 +28,8 @@ namespace sprout {
 
 		template<typename Range1, typename Range2, typename BinaryPredicate>
 		inline SPROUT_CONSTEXPR sprout::pair<
-			typename sprout::range::lvref_iterator<Range1>::type,
-			typename sprout::range::lvref_iterator<Range2>::type
+			typename sprout::range::lvalue_iterator<Range1>::type,
+			typename sprout::range::lvalue_iterator<Range2>::type
 		>
 		mismatch(Range1&& range1, Range2&& range2, BinaryPredicate pred) {
 			return sprout::mismatch(
diff --git a/sprout/range/lvalue_iterator.hpp b/sprout/range/lvalue_iterator.hpp
new file mode 100644
index 00000000..817f20ae
--- /dev/null
+++ b/sprout/range/lvalue_iterator.hpp
@@ -0,0 +1,24 @@
+#ifndef SPROUT_RANGE_LVALUE_ITERATOR_HPP
+#define SPROUT_RANGE_LVALUE_ITERATOR_HPP
+
+#include <type_traits>
+#include <sprout/config.hpp>
+#include <sprout/container/traits.hpp>
+#include <sprout/type_traits/lvalue_reference.hpp>
+
+namespace sprout {
+	namespace range {
+		//
+		// lvalue_iterator
+		//
+		template<typename Range>
+		struct lvalue_iterator {
+		public:
+			typedef typename sprout::container_traits<
+				typename std::remove_reference<typename sprout::lvalue_reference<Range>::type>::type
+			>::iterator type;
+		};
+	}	// namespace range
+}	// namespace sprout
+
+#endif	// #ifndef SPROUT_RANGE_LVALUE_ITERATOR_HPP
diff --git a/sprout/range/lvref_range.hpp b/sprout/range/lvalue_range.hpp
similarity index 50%
rename from sprout/range/lvref_range.hpp
rename to sprout/range/lvalue_range.hpp
index ec7b3302..05cbd36f 100644
--- a/sprout/range/lvref_range.hpp
+++ b/sprout/range/lvalue_range.hpp
@@ -1,21 +1,21 @@
-#ifndef SPROUT_RANGE_LVREF_RANGE_HPP
-#define SPROUT_RANGE_LVREF_RANGE_HPP
+#ifndef SPROUT_RANGE_LVALUE_RANGE_HPP
+#define SPROUT_RANGE_LVALUE_RANGE_HPP
 
 #include <sprout/config.hpp>
 #include <sprout/range/range_container.hpp>
-#include <sprout/range/lvref_iterator.hpp>
+#include <sprout/range/lvalue_iterator.hpp>
 
 namespace sprout {
 	namespace range {
 		//
-		// lvref_range
+		// lvalue_range
 		//
 		template<typename Range>
-		struct lvref_range {
+		struct lvalue_range {
 		public:
-			typedef sprout::range::range_container<typename sprout::range::lvref_iterator<Range>::type> type;
+			typedef sprout::range::range_container<typename sprout::range::lvalue_iterator<Range>::type> type;
 		};
 	}	// namespace range
 }	// namespace sprout
 
-#endif	// #ifndef SPROUT_RANGE_LVREF_RANGE_HPP
+#endif	// #ifndef SPROUT_RANGE_LVALUE_RANGE_HPP
diff --git a/sprout/range/lvref_iterator.hpp b/sprout/range/lvref_iterator.hpp
deleted file mode 100644
index ce09aec6..00000000
--- a/sprout/range/lvref_iterator.hpp
+++ /dev/null
@@ -1,24 +0,0 @@
-#ifndef SPROUT_RANGE_LVREF_ITERATOR_HPP
-#define SPROUT_RANGE_LVREF_ITERATOR_HPP
-
-#include <type_traits>
-#include <sprout/config.hpp>
-#include <sprout/container/traits.hpp>
-#include <sprout/utility/operation_ext.hpp>
-
-namespace sprout {
-	namespace range {
-		//
-		// lvref_iterator
-		//
-		template<typename Range>
-		struct lvref_iterator {
-		public:
-			typedef typename sprout::container_traits<
-				typename std::remove_reference<typename sprout::lvref<Range>::type>::type
-			>::iterator type;
-		};
-	}	// namespace range
-}	// namespace sprout
-
-#endif	// #ifndef SPROUT_RANGE_LVREF_ITERATOR_HPP
diff --git a/sprout/range/range_return.hpp b/sprout/range/range_return.hpp
index b1fea3ea..b680be59 100644
--- a/sprout/range/range_return.hpp
+++ b/sprout/range/range_return.hpp
@@ -5,8 +5,8 @@
 #include <sprout/container/traits.hpp>
 #include <sprout/container/functions.hpp>
 #include <sprout/utility/operation.hpp>
-#include <sprout/range/lvref_iterator.hpp>
-#include <sprout/range/lvref_range.hpp>
+#include <sprout/range/lvalue_iterator.hpp>
+#include <sprout/range/lvalue_range.hpp>
 
 namespace sprout {
 	namespace range {
@@ -28,7 +28,7 @@ namespace sprout {
 		template<typename Range>
 		struct range_return<Range, sprout::range::return_found> {
 		public:
-			typedef typename sprout::range::lvref_iterator<Range>::type type;
+			typedef typename sprout::range::lvalue_iterator<Range>::type type;
 		public:
 			static SPROUT_CONSTEXPR type pack(
 				typename sprout::container_traits<Range>::iterator found,
@@ -41,7 +41,7 @@ namespace sprout {
 		template<typename Range>
 		struct range_return<Range, sprout::range::return_found_end> {
 		public:
-			typedef typename sprout::range::lvref_range<Range>::type type;
+			typedef typename sprout::range::lvalue_range<Range>::type type;
 		public:
 			static SPROUT_CONSTEXPR type pack(
 				typename sprout::container_traits<Range>::iterator found,
@@ -54,7 +54,7 @@ namespace sprout {
 		template<typename Range>
 		struct range_return<Range, sprout::range::return_begin_found> {
 		public:
-			typedef typename sprout::range::lvref_range<Range>::type type;
+			typedef typename sprout::range::lvalue_range<Range>::type type;
 		public:
 			static SPROUT_CONSTEXPR type pack(
 				typename sprout::container_traits<Range>::iterator found,
diff --git a/sprout/type_traits.hpp b/sprout/type_traits.hpp
new file mode 100644
index 00000000..51df19f4
--- /dev/null
+++ b/sprout/type_traits.hpp
@@ -0,0 +1,8 @@
+#ifndef SPROUT_TYPE_TRAITS_HPP
+#define SPROUT_TYPE_TRAITS_HPP
+
+#include <sprout/config.hpp>
+#include <sprout/type_traits/lvalue_reference.hpp>
+#include <sprout/type_traits/const_reference.hpp>
+
+#endif	// #ifndef SPROUT_TYPE_TRAITS_HPP
diff --git a/sprout/type_traits/const_reference.hpp b/sprout/type_traits/const_reference.hpp
new file mode 100644
index 00000000..ecb17aa5
--- /dev/null
+++ b/sprout/type_traits/const_reference.hpp
@@ -0,0 +1,19 @@
+#ifndef SPROUT_TYPE_TRAITS_CONST_REFERENCE_HPP
+#define SPROUT_TYPE_TRAITS_CONST_REFERENCE_HPP
+
+#include <utility>
+#include <sprout/config.hpp>
+#include <sprout/utility/as_const.hpp>
+
+namespace sprout {
+	//
+	// const_reference
+	//
+	template<typename T>
+	struct const_reference {
+	public:
+		typedef decltype(sprout::as_const(std::declval<T&&>())) type;
+	};
+}	// namespace sprout
+
+#endif	// #ifndef SPROUT_TYPE_TRAITS_CONST_REFERENCE_HPP
diff --git a/sprout/type_traits/lvalue_reference.hpp b/sprout/type_traits/lvalue_reference.hpp
new file mode 100644
index 00000000..7a0b1c62
--- /dev/null
+++ b/sprout/type_traits/lvalue_reference.hpp
@@ -0,0 +1,19 @@
+#ifndef SPROUT_TYPE_TRAITS_LVALUE_REFERENCE_HPP
+#define SPROUT_TYPE_TRAITS_LVALUE_REFERENCE_HPP
+
+#include <utility>
+#include <sprout/config.hpp>
+#include <sprout/utility/as_lvalue.hpp>
+
+namespace sprout {
+	//
+	// lvalue_reference
+	//
+	template<typename T>
+	struct lvalue_reference {
+	public:
+		typedef decltype(sprout::as_lvalue(std::declval<T&&>())) type;
+	};
+}	// namespace sprout
+
+#endif	// #ifndef SPROUT_TYPE_TRAITS_LVALUE_REFERENCE_HPP
diff --git a/sprout/utility.hpp b/sprout/utility.hpp
index 9bacae00..f0f83a14 100644
--- a/sprout/utility.hpp
+++ b/sprout/utility.hpp
@@ -2,7 +2,8 @@
 #define SPROUT_UTILITY_HPP
 
 #include <sprout/config.hpp>
-#include <sprout/utility/operation.hpp>
 #include <sprout/utility/pair.hpp>
+#include <sprout/utility/operation.hpp>
+#include <sprout/utility/operation_ext.hpp>
 
 #endif	// #ifndef SPROUT_UTILITY_HPP
diff --git a/sprout/utility/as_lvalue.hpp b/sprout/utility/as_lvalue.hpp
new file mode 100644
index 00000000..7f316f12
--- /dev/null
+++ b/sprout/utility/as_lvalue.hpp
@@ -0,0 +1,20 @@
+#ifndef SPROUT_UTILITY_AS_LVALUE_HPP
+#define SPROUT_UTILITY_AS_LVALUE_HPP
+
+#include <sprout/config.hpp>
+
+namespace sprout {
+	//
+	// as_lvalue
+	//
+	template<typename T>
+	inline T& as_lvalue(T& t) {
+		return t;
+	}
+	template<typename T>
+	inline SPROUT_CONSTEXPR T const& as_lvalue(T const& t) {
+		return t;
+	}
+}	// namespace sprout
+
+#endif	// #ifndef SPROUT_UTILITY_AS_LVALUE_HPP
diff --git a/sprout/utility/as_lvref.hpp b/sprout/utility/as_lvref.hpp
deleted file mode 100644
index e2bada45..00000000
--- a/sprout/utility/as_lvref.hpp
+++ /dev/null
@@ -1,29 +0,0 @@
-#ifndef SPROUT_UTILITY_AS_LVREF_HPP
-#define SPROUT_UTILITY_AS_LVREF_HPP
-
-#include <sprout/config.hpp>
-
-namespace sprout {
-	//
-	// as_lvref
-	//
-	template<typename T>
-	inline T& as_lvref(T& t) {
-		return t;
-	}
-	template<typename T>
-	inline SPROUT_CONSTEXPR T const& as_lvref(T const& t) {
-		return t;
-	}
-
-	//
-	// lvref
-	//
-	template<typename T>
-	struct lvref {
-	public:
-		typedef decltype(sprout::as_lvref(std::declval<T&&>())) type;
-	};
-}	// namespace sprout
-
-#endif	// #ifndef SPROUT_UTILITY_AS_LVREF_HPP
diff --git a/sprout/utility/operation_ext.hpp b/sprout/utility/operation_ext.hpp
index 037c2cc1..ad064555 100644
--- a/sprout/utility/operation_ext.hpp
+++ b/sprout/utility/operation_ext.hpp
@@ -2,7 +2,7 @@
 #define SPROUT_UTILITY_OPERATION_EXT_HPP
 
 #include <sprout/config.hpp>
-#include <sprout/utility/as_lvref.hpp>
+#include <sprout/utility/as_lvalue.hpp>
 #include <sprout/utility/as_const.hpp>
 
 #endif	// #ifndef SPROUT_UTILITY_OPERATION_EXT_HPP