diff --git a/libs/weed/example/remove_space.cpp b/libs/weed/example/remove_space.cpp
index 23600f52..e155670b 100644
--- a/libs/weed/example/remove_space.cpp
+++ b/libs/weed/example/remove_space.cpp
@@ -1,36 +1,36 @@
-//
-// Sprout C++ Library
-//
-// Copyright (c) 2012
-// bolero-MURAKAMI : http://d.hatena.ne.jp/boleros/
-// osyo-manga : http://d.hatena.ne.jp/osyo-manga/
-// 
-// Readme:
-// https://github.com/osyo-manga/cpp-half/blob/master/README
-//
-// License:
-// Boost Software License - Version 1.0
-// <http://www.boost.org/LICENSE_1_0.txt>
-//
-#include <sprout/weed.hpp>
-
-
-int
-main(){
-	namespace w = sprout::weed;
-	
-	static constexpr auto max_string_size = 32;
-	static constexpr auto space = *w::omit[ w::space ];
-	static constexpr auto remove_space = *w::lim<max_string_size>(space >> w::char_);
-	
-	static constexpr auto source = sprout::to_string("  homu  :  mami=   10 ");
-	static constexpr auto result = w::parse(
-		sprout::begin(source), sprout::end(source),
-		remove_space
-	);
-
-	static_assert(result.success(), "fail remove_space parse");
-	static_assert(result.attr() == "homu:mami=10", "");
-
-	return 0;
-}
+//
+// Sprout C++ Library
+//
+// Copyright (c) 2012
+// bolero-MURAKAMI : http://d.hatena.ne.jp/boleros/
+// osyo-manga : http://d.hatena.ne.jp/osyo-manga/
+// 
+// Readme:
+// https://github.com/osyo-manga/cpp-half/blob/master/README
+//
+// License:
+// Boost Software License - Version 1.0
+// <http://www.boost.org/LICENSE_1_0.txt>
+//
+#include <sprout/weed.hpp>
+
+
+int
+main(){
+	namespace w = sprout::weed;
+	
+	static constexpr auto max_string_size = 32;
+	static constexpr auto space = *w::omit[ w::space ];
+	static constexpr auto remove_space = *w::lim<max_string_size>(space >> w::char_);
+	
+	static constexpr auto source = sprout::to_string("  homu  :  mami=   10 ");
+	static constexpr auto result = w::parse(
+		sprout::begin(source), sprout::end(source),
+		remove_space
+	);
+
+	static_assert(result.success(), "fail remove_space parse");
+	static_assert(result.attr() == "homu:mami=10", "");
+
+	return 0;
+}
diff --git a/sprout/cmath.hpp b/sprout/cmath.hpp
new file mode 100644
index 00000000..1568cb14
--- /dev/null
+++ b/sprout/cmath.hpp
@@ -0,0 +1,7 @@
+#ifndef SPROUT_CMATH_HPP
+#define SPROUT_CMATH_HPP
+
+#include <sprout/config.hpp>
+#include <sprout/math/trigonometric.hpp>
+
+#endif	// #ifndef SPROUT_CMATH_HPP
diff --git a/sprout/config/auto_config.hpp b/sprout/config/auto_config.hpp
index b694fe93..2728c9dc 100644
--- a/sprout/config/auto_config.hpp
+++ b/sprout/config/auto_config.hpp
@@ -52,6 +52,15 @@
 // SPROUT_CONFIG_USE_SSCRISK_CEL
 //
 
+//
+// SPROUT_CONFIG_DISABLE_BUILTIN_CMATH_FUNCTION
+//
+#ifndef SPROUT_CONFIG_DISABLE_BUILTIN_CMATH_FUNCTION
+#	ifndef SPROUT_HAS_CONSTEXPR_CMATH_FUNCTION
+#		define SPROUT_CONFIG_DISABLE_BUILTIN_CMATH_FUNCTION
+#	endif	// #ifdef SPROUT_HAS_CONSTEXPR_CMATH_FUNCTION
+#endif	// #ifndef SPROUT_CONFIG_DISABLE_SUPPORT_TEMPORARY_CONTAINER_ITERATION
+
 //
 // SPROUT_CONFIG_DISABLE_SUPPORT_TEMPORARY_CONTAINER_ITERATION
 // SPROUT_CONFIG_SUPPORT_TEMPORARY_CONTAINER_ITERATION
diff --git a/sprout/config/compiler/gcc.hpp b/sprout/config/compiler/gcc.hpp
index 701757eb..6df80508 100644
--- a/sprout/config/compiler/gcc.hpp
+++ b/sprout/config/compiler/gcc.hpp
@@ -21,4 +21,8 @@
 #	define SPROUT_NO_DELEGATING_CONSTRUCTORS
 #endif
 
+#if ((__GNUC__ >= 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 6)) && defined(__GXX_EXPERIMENTAL_CXX0X__))
+#	define SPROUT_HAS_CONSTEXPR_CMATH_FUNCTION
+#endif
+
 #endif	// #ifndef SPROUT_CONFIG_COMPILER_GCC_HPP
diff --git a/sprout/config/config.hpp b/sprout/config/config.hpp
index 889ba4ea..7afacb47 100644
--- a/sprout/config/config.hpp
+++ b/sprout/config/config.hpp
@@ -55,6 +55,12 @@
 #	define NS_SSCRISK_CEL_OR_SPROUT sscrisk::cel
 #endif	// #ifndef SPROUT_CONFIG_USE_SSCRISK_CEL
 
+#ifndef SPROUT_CONFIG_DISABLE_BUILTIN_CMATH_FUNCTION
+#	define SPROUT_USE_BUILTIN_CMATH_FUNCTION 1
+#else	// #ifndef SPROUT_CONFIG_DISABLE_BUILTIN_CMATH_FUNCTION
+#	define SPROUT_USE_BUILTIN_CMATH_FUNCTION 0
+#endif	// #ifndef SPROUT_CONFIG_DISABLE_BUILTIN_CMATH_FUNCTION
+
 #ifndef SPROUT_CONFIG_DISABLE_SUPPORT_TEMPORARY_CONTAINER_ITERATION
 #	define SPROUT_USE_INDEX_ITERATOR_IMPLEMENTATION 1
 #else	// #ifndef SPROUT_CONFIG_DISABLE_SUPPORT_TEMPORARY_CONTAINER_ITERATION
diff --git a/sprout/math/cos.hpp b/sprout/math/cos.hpp
new file mode 100644
index 00000000..3b0443b8
--- /dev/null
+++ b/sprout/math/cos.hpp
@@ -0,0 +1,64 @@
+#ifndef SPROUT_MATH_COS_HPP
+#define SPROUT_MATH_COS_HPP
+
+#include <cstddef>
+#include <type_traits>
+#include <sprout/config.hpp>
+#include <sprout/math/factorial.hpp>
+#include <sprout/utility/enabler_if.hpp>
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+#	include <cmath>
+#endif
+
+namespace sprout {
+	namespace math {
+		namespace detail {
+			template<typename T>
+			inline SPROUT_CONSTEXPR T
+			cos_impl(T x, T tmp, std::size_t n, T x2n) {
+				return 2 * n > sprout::math::factorial_limit<T>() ? tmp
+					: sprout::math::detail::cos_impl(
+						x,
+						tmp + (n % 2 ? -1 : 1) / sprout::math::factorial<T>(2 * n) * x2n,
+						n + 1,
+						x2n * x * x
+						)
+					;
+			}
+
+			template<
+				typename FloatType,
+				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+			>
+			inline SPROUT_CONSTEXPR FloatType
+			cos(FloatType x) {
+				typedef double type;
+				return static_cast<FloatType>(sprout::math::detail::cos_impl(
+					static_cast<type>(x),
+					type(1),
+					1,
+					static_cast<type>(x) * static_cast<type>(x)
+					));
+			}
+
+			template<
+				typename IntType,
+				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+			>
+			inline SPROUT_CONSTEXPR double
+			cos(IntType x) {
+				return sprout::math::detail::cos(static_cast<double>(x));
+			}
+		}	// namespace detail
+
+#	if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+		using std::cos;
+#	else
+		using sprout::math::detail::cos;
+#	endif
+	}	// namespace math
+
+	using sprout::math::cos;
+}	// namespace sprout
+
+#endif	// #ifndef SPROUT_MATH_COS_HPP
diff --git a/sprout/math/factorial.hpp b/sprout/math/factorial.hpp
index ed2239e0..109aed89 100644
--- a/sprout/math/factorial.hpp
+++ b/sprout/math/factorial.hpp
@@ -651,4 +651,3 @@ namespace sprout {
 }	// namespace sprout
 
 #endif	// #ifndef SPROUT_MATH_FACTORIAL_HPP
-
diff --git a/sprout/math/sin.hpp b/sprout/math/sin.hpp
new file mode 100644
index 00000000..2c13ce44
--- /dev/null
+++ b/sprout/math/sin.hpp
@@ -0,0 +1,45 @@
+#ifndef SPROUT_MATH_SIN_HPP
+#define SPROUT_MATH_SIN_HPP
+
+#include <type_traits>
+#include <sprout/config.hpp>
+#include <sprout/math/cos.hpp>
+#include <sprout/math/constants.hpp>
+#include <sprout/utility/enabler_if.hpp>
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+#	include <cmath>
+#endif
+
+namespace sprout {
+	namespace math {
+		namespace detail {
+			template<
+				typename FloatType,
+				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+			>
+			inline SPROUT_CONSTEXPR FloatType
+			sin(FloatType x) {
+				return -sprout::math::detail::cos(x + sprout::math::pi_div_two<FloatType>());
+			}
+
+			template<
+				typename IntType,
+				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+			>
+			inline SPROUT_CONSTEXPR double
+			sin(IntType x) {
+				return sprout::math::detail::sin(static_cast<double>(x));
+			}
+		}	// namespace detail
+
+#	if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+		using std::sin;
+#	else
+		using sprout::math::detail::sin;
+#	endif
+	}	// namespace math
+
+	using sprout::math::sin;
+}	// namespace sprout
+
+#endif	// #ifndef SPROUT_MATH_SIN_HPP
diff --git a/sprout/math/tan.hpp b/sprout/math/tan.hpp
new file mode 100644
index 00000000..e6593917
--- /dev/null
+++ b/sprout/math/tan.hpp
@@ -0,0 +1,45 @@
+#ifndef SPROUT_MATH_TAN_HPP
+#define SPROUT_MATH_TAN_HPP
+
+#include <type_traits>
+#include <sprout/config.hpp>
+#include <sprout/math/sin.hpp>
+#include <sprout/math/cos.hpp>
+#include <sprout/utility/enabler_if.hpp>
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+#	include <cmath>
+#endif
+
+namespace sprout {
+	namespace math {
+		namespace detail {
+			template<
+				typename FloatType,
+				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+			>
+			inline SPROUT_CONSTEXPR FloatType
+			tan(FloatType x) {
+				return sprout::math::detail::sin(x) / sprout::math::detail::cos(x);
+			}
+
+			template<
+				typename IntType,
+				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+			>
+			inline SPROUT_CONSTEXPR double
+			tan(IntType x) {
+				return sprout::math::detail::tan(static_cast<double>(x));
+			}
+		}	// namespace detail
+
+#	if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+		using std::tan;
+#	else
+		using sprout::math::detail::tan;
+#	endif
+	}	// namespace math
+
+	using sprout::math::tan;
+}	// namespace sprout
+
+#endif	// #ifndef SPROUT_MATH_TAN_HPP
diff --git a/sprout/math/trigonometric.hpp b/sprout/math/trigonometric.hpp
new file mode 100644
index 00000000..78e0130c
--- /dev/null
+++ b/sprout/math/trigonometric.hpp
@@ -0,0 +1,8 @@
+#ifndef SPROUT_MATH_TRIGONOMETRIC_HPP
+#define SPROUT_MATH_TRIGONOMETRIC_HPP
+
+#include <sprout/math/sin.hpp>
+#include <sprout/math/cos.hpp>
+#include <sprout/math/tan.hpp>
+
+#endif	// #ifndef SPROUT_MATH_TRIGONOMETRIC_HPP