diff --git a/sprout/ctime.hpp b/sprout/ctime.hpp
new file mode 100644
index 00000000..652b40f8
--- /dev/null
+++ b/sprout/ctime.hpp
@@ -0,0 +1,15 @@
+/*=============================================================================
+  Copyright (c) 2011-2014 Bolero MURAKAMI
+  https://github.com/bolero-MURAKAMI/Sprout
+
+  Distributed under the Boost Software License, Version 1.0. (See accompanying
+  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+=============================================================================*/
+#ifndef SPROUT_CTIME_HPP
+#define SPROUT_CTIME_HPP
+
+#include <sprout/config.hpp>
+#include <sprout/ctime/difftime.hpp>
+#include <sprout/ctime/to_time_t.hpp>
+
+#endif	// #ifndef SPROUT_CTIME_HPP
diff --git a/sprout/ctime/difftime.hpp b/sprout/ctime/difftime.hpp
new file mode 100644
index 00000000..472f2752
--- /dev/null
+++ b/sprout/ctime/difftime.hpp
@@ -0,0 +1,24 @@
+/*=============================================================================
+  Copyright (c) 2011-2014 Bolero MURAKAMI
+  https://github.com/bolero-MURAKAMI/Sprout
+
+  Distributed under the Boost Software License, Version 1.0. (See accompanying
+  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+=============================================================================*/
+#ifndef SPROUT_CTIME_DIFFTIME_HPP
+#define SPROUT_CTIME_DIFFTIME_HPP
+
+#include <ctime>
+#include <sprout/config.hpp>
+
+namespace sprout {
+	//
+	// 7.23.2.2 The difftime function
+	//
+	inline SPROUT_CONSTEXPR double
+	difftime(std::time_t time1, std::time_t time0) {
+		return static_cast<double>(time1) - static_cast<double>(time0);
+	}
+}	// namespace sprout
+
+#endif	// #ifndef SPROUT_CTIME_DIFFTIME_HPP
diff --git a/sprout/ctime/to_time_t.hpp b/sprout/ctime/to_time_t.hpp
new file mode 100644
index 00000000..df9ec6f8
--- /dev/null
+++ b/sprout/ctime/to_time_t.hpp
@@ -0,0 +1,111 @@
+/*=============================================================================
+  Copyright (c) 2011-2014 Bolero MURAKAMI
+  https://github.com/bolero-MURAKAMI/Sprout
+
+  Distributed under the Boost Software License, Version 1.0. (See accompanying
+  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+=============================================================================*/
+#ifndef SPROUT_CTIME_TO_TIME_T_HPP
+#define SPROUT_CTIME_TO_TIME_T_HPP
+
+#include <ctime>
+#include <sprout/config.hpp>
+#include <sprout/ctype/ascii.hpp>
+#include <sprout/algorithm/equal.hpp>
+#include <sprout/iterator/ptr_index_iterator.hpp>
+
+namespace sprout {
+	namespace detail {
+		inline SPROUT_CONSTEXPR std::time_t
+		to_time_t_impl(int year, int mon, int day, int hour, int min, int sec) {
+			return (((
+							std::time_t(year / 4 - year / 100 + year / 400 + 367 * mon / 12 + day) + year * 365 - 719499
+						) * 24 + hour
+					) * 60 + min
+				) * 60 + sec
+				;
+		}
+	}	// namespace detail
+	//
+	// to_time_t
+	//
+	inline SPROUT_CONSTEXPR std::time_t
+	to_time_t(int year, int mon, int day, int hour, int min, int sec) {
+		return mon <= 2
+			? sprout::detail::to_time_t_impl(year - 1, mon + 10, day, hour, min, sec)
+			: sprout::detail::to_time_t_impl(year, mon - 2, day, hour, min, sec)
+			;
+	}
+	inline SPROUT_CONSTEXPR std::time_t
+	to_time_t(std::tm const& t) {
+		return sprout::to_time_t(t.tm_year + 1900, t.tm_mon + 1, t.tm_mday, t.tm_hour, t.tm_min, t.tm_sec);
+	}
+
+	namespace detail {
+		template<typename Elem>
+		inline SPROUT_CONSTEXPR int
+		get_num(Elem e) {
+			return !sprout::isdigit(e) ? 0
+				: e - static_cast<Elem>('0')
+				;
+		}
+		template<typename InputIterator>
+		inline SPROUT_CONSTEXPR int
+		get_month(InputIterator const& date) {
+			return sprout::equal(sprout::ptr_index(date), sprout::ptr_index(date, 3), sprout::ptr_index("Jan")) ? 1
+				: sprout::equal(sprout::ptr_index(date), sprout::ptr_index(date, 3), sprout::ptr_index("Feb")) ? 2
+				: sprout::equal(sprout::ptr_index(date), sprout::ptr_index(date, 3), sprout::ptr_index("Mar")) ? 3
+				: sprout::equal(sprout::ptr_index(date), sprout::ptr_index(date, 3), sprout::ptr_index("Apr")) ? 4
+				: sprout::equal(sprout::ptr_index(date), sprout::ptr_index(date, 3), sprout::ptr_index("May")) ? 5
+				: sprout::equal(sprout::ptr_index(date), sprout::ptr_index(date, 3), sprout::ptr_index("Jun")) ? 6
+				: sprout::equal(sprout::ptr_index(date), sprout::ptr_index(date, 3), sprout::ptr_index("Jul")) ? 7
+				: sprout::equal(sprout::ptr_index(date), sprout::ptr_index(date, 3), sprout::ptr_index("Aug")) ? 8
+				: sprout::equal(sprout::ptr_index(date), sprout::ptr_index(date, 3), sprout::ptr_index("Sep")) ? 9
+				: sprout::equal(sprout::ptr_index(date), sprout::ptr_index(date, 3), sprout::ptr_index("Oct")) ? 10
+				: sprout::equal(sprout::ptr_index(date), sprout::ptr_index(date, 3), sprout::ptr_index("Nov")) ? 11
+				: sprout::equal(sprout::ptr_index(date), sprout::ptr_index(date, 3), sprout::ptr_index("Dec")) ? 12
+				: 0
+				;
+		}
+		template<typename RandomAccessIterator>
+		inline SPROUT_CONSTEXPR int
+		get_day(RandomAccessIterator const& date) {
+			return sprout::detail::get_num(date[0]) * 10
+				+ sprout::detail::get_num(date[1])
+				;
+		}
+		template<typename RandomAccessIterator>
+		inline SPROUT_CONSTEXPR int
+		get_year(RandomAccessIterator const& date) {
+			return sprout::detail::get_num(date[0]) * 1000
+				+ sprout::detail::get_num(date[1]) * 100
+				+ sprout::detail::get_num(date[2]) * 10
+				+ sprout::detail::get_num(date[3])
+				;
+		}
+		template<typename RandomAccessIterator>
+		inline SPROUT_CONSTEXPR int
+		get_time(RandomAccessIterator const& time) {
+			return sprout::detail::get_num(time[0]) * 10
+				+ sprout::detail::get_num(time[1])
+				;
+		}
+	}	// namespace detail
+	//
+	// to_time_t
+	//
+	template<typename RandomAccessIterator1, typename RandomAccessIterator2>
+	inline SPROUT_CONSTEXPR std::time_t
+	to_time_t(RandomAccessIterator1 const& date, RandomAccessIterator2 const& time) {
+		return sprout::to_time_t(
+			sprout::detail::get_year(date + 7),
+			sprout::detail::get_month(date + 0),
+			sprout::detail::get_day(date + 4),
+			sprout::detail::get_time(time + 0),
+			sprout::detail::get_time(time + 3),
+			sprout::detail::get_time(time + 6)
+			);
+	}
+}	// namespace sprout
+
+#endif	// #ifndef SPROUT_CTIME_TO_TIME_T_HPP
diff --git a/sprout/type.hpp b/sprout/type.hpp
index d0437103..2340f16a 100644
--- a/sprout/type.hpp
+++ b/sprout/type.hpp
@@ -17,6 +17,7 @@
 #include <sprout/type/integral_array.hpp>
 #include <sprout/type/string.hpp>
 #include <sprout/type/uniform_types.hpp>
+#include <sprout/type/packer.hpp>
 #include <sprout/type/rebind_types.hpp>
 #include <sprout/type/map_types.hpp>
 #include <sprout/type/joint_types.hpp>
diff --git a/sprout/type/packer.hpp b/sprout/type/packer.hpp
new file mode 100644
index 00000000..7cd9c175
--- /dev/null
+++ b/sprout/type/packer.hpp
@@ -0,0 +1,139 @@
+/*=============================================================================
+  Copyright (c) 2011-2014 Bolero MURAKAMI
+  https://github.com/bolero-MURAKAMI/Sprout
+
+  Distributed under the Boost Software License, Version 1.0. (See accompanying
+  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+=============================================================================*/
+#ifndef SPROUT_TYPE_PACKER_HPP
+#define SPROUT_TYPE_PACKER_HPP
+
+#include <tuple>
+#include <sprout/config.hpp>
+#include <sprout/type/type_tuple.hpp>
+#include <sprout/type/tuple.hpp>
+
+namespace sprout {
+	namespace types {
+		//
+		// packer
+		//
+#if SPROUT_USE_TEMPLATE_ALIASES
+		template<typename... Types>
+		using packer = sprout::types::type_tuple<Types...>;
+#else	// #if SPROUT_USE_TEMPLATE_ALIASES
+		template<typename... Types>
+		struct packer
+			: public sprout::types::type_tuple<Types...>
+		{};
+#endif	// #if SPROUT_USE_TEMPLATE_ALIASES
+	}	// namespace types
+
+	using sprout::types::packer;
+}	// namespace sprout
+
+#if !SPROUT_USE_TEMPLATE_ALIASES
+
+namespace std {
+#if defined(__clang__)
+#	pragma clang diagnostic push
+#	pragma clang diagnostic ignored "-Wmismatched-tags"
+#endif
+	//
+	// tuple_size
+	//
+	template<typename... Types>
+	struct tuple_size<sprout::types::packer<Types...> >
+		: public std::tuple_size<sprout::types::type_tuple<Types...> >
+	{};
+
+	//
+	// tuple_element
+	//
+	template<std::size_t I, typename... Types>
+	struct tuple_element<I, sprout::types::packer<Types...> >
+		: public sprout::types::tuple_element<I, sprout::types::packer<Types...> >
+	{};
+#if defined(__clang__)
+#	pragma clang diagnostic pop
+#endif
+}	// namespace std
+
+namespace sprout {
+	//
+	// tuple_get
+	//
+	template<std::size_t I, typename... Types>
+	inline SPROUT_CONSTEXPR typename std::tuple_element<I, sprout::types::packer<Types...> >::type
+	tuple_get(sprout::types::packer<Types...>) SPROUT_NOEXCEPT {
+		static_assert(I < sizeof...(Values), "tuple_get: index out of range");
+		typedef typename std::tuple_element<I, sprout::types::packer<Types...> >::type type;
+		return type();
+	}
+}	// namespace sprout
+
+#endif	// #if !SPROUT_USE_TEMPLATE_ALIASES
+
+#include <sprout/index_tuple/metafunction.hpp>
+#include <sprout/type/algorithm/contains.hpp>
+#include <sprout/tpp/algorithm/all_of.hpp>
+
+namespace sprout {
+	namespace types {
+		//
+		// is_contained_in
+		//
+		template<typename T, typename... Types>
+		struct is_contained_in
+			: public sprout::types::contains<sprout::types::type_tuple<Types...>, T>
+		{};
+
+		//
+		// contains_types
+		//
+		namespace detail {
+			template<typename T, typename U, typename IndexTuple>
+			struct contains_types_impl;
+			template<typename T, typename U, sprout::index_t... Indexes>
+			struct contains_types_impl<T, U, sprout::index_tuple<Indexes...> >
+				: public sprout::tpp::all_of<sprout::types::is_contained_in<typename sprout::types::tuple_element<Indexes, U>::type, T>...>
+			{};
+		}	// namespace detail
+		template<typename T, typename U>
+		struct contains_types
+			: public sprout::types::detail::contains_types_impl<T, U, typename sprout::make_index_tuple<sprout::types::tuple_size<U>::value>::type>
+		{};
+
+#if SPROUT_USE_TEMPLATE_ALIASES
+		template<typename T, typename... Types>
+		using is_contained_in_t = typename sprout::types::is_contained_in<T, Types...>::type;
+
+		template<typename T, typename U>
+		using contains_types_t = typename sprout::types::contains_types<T, U>::type;
+#endif	// #if SPROUT_USE_TEMPLATE_ALIASES
+
+#if SPROUT_USE_VARIABLE_TEMPLATES
+		template<typename T, typename... Types>
+		SPROUT_STATIC_CONSTEXPR bool is_contained_in_v = sprout::types::is_contained_in<T, Types...>::value;
+
+		template<typename T, typename U>
+		SPROUT_STATIC_CONSTEXPR bool contains_types_v = sprout::types::contains_types<T, U>::value;
+#endif	// #if SPROUT_USE_VARIABLE_TEMPLATES
+
+	}	// namespace types
+
+	using sprout::types::is_contained_in;
+	using sprout::types::contains_types;
+
+#if SPROUT_USE_TEMPLATE_ALIASES
+	using sprout::types::is_contained_in_t;
+	using sprout::types::contains_types_t;
+#endif	// #if SPROUT_USE_TEMPLATE_ALIASES
+
+#if SPROUT_USE_VARIABLE_TEMPLATES
+	using sprout::types::is_contained_in_v;
+	using sprout::types::contains_types_v;
+#endif	// #if SPROUT_USE_VARIABLE_TEMPLATES
+}	// namespace sprout
+
+#endif	// #ifndef SPROUT_TYPE_PACKER_HPP
diff --git a/sprout/type/type_tuple.hpp b/sprout/type/type_tuple.hpp
index 6680051c..2f6d7854 100644
--- a/sprout/type/type_tuple.hpp
+++ b/sprout/type/type_tuple.hpp
@@ -37,6 +37,8 @@ namespace sprout {
 		template<typename... Types>
 		SPROUT_CONSTEXPR_OR_CONST std::size_t sprout::types::type_tuple<Types...>::static_size;
 	}	// namespace types
+
+	using sprout::types::type_tuple;
 }	// namespace sprout
 
 #endif	// #ifndef SPROUT_TYPE_TYPE_TUPLE_HPP
diff --git a/testspr/header_all.hpp b/testspr/header_all.hpp
index 83a20f72..a5d3b17d 100644
--- a/testspr/header_all.hpp
+++ b/testspr/header_all.hpp
@@ -30,6 +30,7 @@
 #include <sprout/cstdint.hpp>
 #include <sprout/cstdlib.hpp>
 #include <sprout/cstring.hpp>
+#include <sprout/ctime.hpp>
 #include <sprout/ctype.hpp>
 #include <sprout/current_function.hpp>
 #include <sprout/cwchar.hpp>