diff --git a/example/darkroom/two_spheres-8192x8192.png b/example/darkroom/two_spheres-8192x8192.png
new file mode 100644
index 00000000..19634c52
Binary files /dev/null and b/example/darkroom/two_spheres-8192x8192.png differ
diff --git a/sprout/algorithm/fill.hpp b/sprout/algorithm/fill.hpp
index 8f193716..b67982ff 100644
--- a/sprout/algorithm/fill.hpp
+++ b/sprout/algorithm/fill.hpp
@@ -14,9 +14,9 @@ namespace sprout {
 	//
 	// 25.3.6 Fill
 	//
-	template<typename ForwrdIterator, typename T>
+	template<typename ForwardIterator, typename T>
 	inline SPROUT_CXX14_CONSTEXPR void
-	fill(ForwrdIterator first, ForwrdIterator last, T const& value) {
+	fill(ForwardIterator first, ForwardIterator last, T const& value) {
 		while (first != last) {
 			*first++ = value;
 		}
diff --git a/sprout/algorithm/fixed/remove_copy.hpp b/sprout/algorithm/fixed/remove_copy.hpp
index 856c8fe6..80b6f869 100644
--- a/sprout/algorithm/fixed/remove_copy.hpp
+++ b/sprout/algorithm/fixed/remove_copy.hpp
@@ -14,6 +14,8 @@
 #include <sprout/container/functions.hpp>
 #include <sprout/iterator/operation.hpp>
 #include <sprout/iterator/remove_iterator.hpp>
+#include <sprout/iterator/type_traits/is_iterator_of.hpp>
+#include <sprout/type_traits/enabler_if.hpp>
 #include <sprout/algorithm/fixed/result_of.hpp>
 #include <sprout/pit/pit.hpp>
 #include <sprout/detail/container_complate.hpp>
@@ -93,7 +95,20 @@ namespace sprout {
 		}
 	}	// namespace fixed
 
-	using sprout::fixed::remove_copy;
+	template<
+		typename InputIterator, typename Result, typename T,
+		typename sprout::enabler_if<!sprout::is_output_iterator<Result>::value>::type = sprout::enabler
+	>
+	inline SPROUT_CONSTEXPR typename sprout::fixed::result_of::algorithm<Result>::type
+	remove_copy(InputIterator first, InputIterator last, Result const& result, T const& value) {
+		return sprout::fixed::remove_copy(first, last, result, value);
+	}
+
+	template<typename Result, typename InputIterator, typename T>
+	inline SPROUT_CONSTEXPR typename sprout::fixed::result_of::algorithm<Result>::type
+	remove_copy(InputIterator first, InputIterator last, T const& value) {
+		return sprout::fixed::remove_copy<Result>(first, last, value);
+	}
 }	// namespace sprout
 
 #endif	// #ifndef SPROUT_ALGORITHM_FIXED_REMOVE_COPY_HPP
diff --git a/sprout/algorithm/fixed/remove_copy_if.hpp b/sprout/algorithm/fixed/remove_copy_if.hpp
index 8c64b4c2..42be802c 100644
--- a/sprout/algorithm/fixed/remove_copy_if.hpp
+++ b/sprout/algorithm/fixed/remove_copy_if.hpp
@@ -14,6 +14,8 @@
 #include <sprout/container/functions.hpp>
 #include <sprout/iterator/operation.hpp>
 #include <sprout/iterator/remove_if_iterator.hpp>
+#include <sprout/iterator/type_traits/is_iterator_of.hpp>
+#include <sprout/type_traits/enabler_if.hpp>
 #include <sprout/algorithm/fixed/result_of.hpp>
 #include <sprout/pit/pit.hpp>
 #include <sprout/detail/container_complate.hpp>
@@ -93,7 +95,20 @@ namespace sprout {
 		}
 	}	// namespace fixed
 
-	using sprout::fixed::remove_copy_if;
+	template<
+		typename InputIterator, typename Result, typename Predicate,
+		typename sprout::enabler_if<!sprout::is_output_iterator<Result>::value>::type = sprout::enabler
+	>
+	inline SPROUT_CONSTEXPR typename sprout::fixed::result_of::algorithm<Result>::type
+	remove_copy_if(InputIterator first, InputIterator last, Result const& result, Predicate pred) {
+		return sprout::fixed::remove_copy_if(first, last, result, pred);
+	}
+
+	template<typename Result, typename InputIterator, typename Predicate>
+	inline SPROUT_CONSTEXPR typename sprout::fixed::result_of::algorithm<Result>::type
+	remove_copy_if(InputIterator first, InputIterator last, Predicate pred) {
+		return sprout::fixed::remove_copy_if<Result>(first, last, pred);
+	}
 }	// namespace sprout
 
 #endif	// #ifndef SPROUT_ALGORITHM_FIXED_REMOVE_COPY_IF_HPP
diff --git a/sprout/algorithm/fixed/reverse_copy.hpp b/sprout/algorithm/fixed/reverse_copy.hpp
index 0d4a3be7..7d7715e9 100644
--- a/sprout/algorithm/fixed/reverse_copy.hpp
+++ b/sprout/algorithm/fixed/reverse_copy.hpp
@@ -137,7 +137,20 @@ namespace sprout {
 		}
 	}	// namespace fixed
 
-	using sprout::fixed::reverse_copy;
+	template<
+		typename BidirectionalIterator, typename Result,
+		typename sprout::enabler_if<!sprout::is_output_iterator<Result>::value>::type = sprout::enabler
+	>
+	inline SPROUT_CONSTEXPR typename sprout::fixed::result_of::algorithm<Result>::type
+	reverse_copy(BidirectionalIterator first, BidirectionalIterator last, Result const& result) {
+		return sprout::fixed::reverse_copy(first, last, result);
+	}
+
+	template<typename Result, typename BidirectionalIterator>
+	inline SPROUT_CONSTEXPR typename sprout::fixed::result_of::algorithm<Result>::type
+	reverse_copy(BidirectionalIterator first, BidirectionalIterator last) {
+		return sprout::fixed::reverse_copy<Result>(first, last);
+	}
 }	// namespace sprout
 
 #endif	// #ifndef SPROUT_ALGORITHM_FIXED_REVERSE_COPY_HPP
diff --git a/sprout/algorithm/fixed/rotate_copy.hpp b/sprout/algorithm/fixed/rotate_copy.hpp
index 2a514778..d00654c9 100644
--- a/sprout/algorithm/fixed/rotate_copy.hpp
+++ b/sprout/algorithm/fixed/rotate_copy.hpp
@@ -17,6 +17,8 @@
 #include <sprout/container/indexes.hpp>
 #include <sprout/iterator/operation.hpp>
 #include <sprout/iterator/joint_iterator.hpp>
+#include <sprout/iterator/type_traits/is_iterator_of.hpp>
+#include <sprout/type_traits/enabler_if.hpp>
 #include <sprout/algorithm/fixed/result_of.hpp>
 #include <sprout/pit/pit.hpp>
 #include <sprout/detail/container_complate.hpp>
@@ -178,7 +180,20 @@ namespace sprout {
 		}
 	}	// namespace fixed
 
-	using sprout::fixed::rotate_copy;
+	template<
+		typename ForwardIterator, typename Result,
+		typename sprout::enabler_if<!sprout::is_output_iterator<Result>::value>::type = sprout::enabler
+	>
+	inline SPROUT_CONSTEXPR typename sprout::fixed::result_of::algorithm<Result>::type
+	rotate_copy(ForwardIterator first, ForwardIterator middle, ForwardIterator last, Result const& result) {
+		return sprout::fixed::rotate_copy(first, middle, last, result);
+	}
+
+	template<typename Result, typename ForwardIterator>
+	inline SPROUT_CONSTEXPR typename sprout::fixed::result_of::algorithm<Result>::type
+	rotate_copy(ForwardIterator first, ForwardIterator middle, ForwardIterator last) {
+		return sprout::fixed::rotate_copy<Result>(first, middle, last);
+	}
 }	// namespace sprout
 
 #endif	// #ifndef SPROUT_ALGORITHM_FIXED_ROTATE_COPY_HPP
diff --git a/sprout/algorithm/fixed/unique_copy.hpp b/sprout/algorithm/fixed/unique_copy.hpp
index 833d0615..5412f888 100644
--- a/sprout/algorithm/fixed/unique_copy.hpp
+++ b/sprout/algorithm/fixed/unique_copy.hpp
@@ -14,6 +14,8 @@
 #include <sprout/container/functions.hpp>
 #include <sprout/iterator/operation.hpp>
 #include <sprout/iterator/unique_iterator.hpp>
+#include <sprout/iterator/type_traits/is_iterator_of.hpp>
+#include <sprout/type_traits/enabler_if.hpp>
 #include <sprout/algorithm/fixed/result_of.hpp>
 #include <sprout/pit/pit.hpp>
 #include <sprout/detail/container_complate.hpp>
@@ -178,7 +180,38 @@ namespace sprout {
 		}
 	}	// namespace fixed
 
-	using sprout::fixed::unique_copy;
+	template<
+		typename InputIterator, typename Result,
+		typename sprout::enabler_if<!sprout::is_output_iterator<Result>::value>::type = sprout::enabler
+	>
+	inline SPROUT_CONSTEXPR typename sprout::fixed::result_of::algorithm<Result>::type
+	unique_copy(InputIterator first, InputIterator last, Result const& result) {
+		return sprout::fixed::unique_copy(first, last, result);
+	}
+
+	template<typename Result, typename InputIterator>
+	inline SPROUT_CONSTEXPR typename sprout::fixed::result_of::algorithm<Result>::type
+	unique_copy(InputIterator first, InputIterator last) {
+		return sprout::fixed::unique_copy<Result>(first, last);
+	}
+
+	template<
+		typename InputIterator, typename Result, typename BinaryPredicate,
+		typename sprout::enabler_if<!sprout::is_output_iterator<Result>::value>::type = sprout::enabler
+	>
+	inline SPROUT_CONSTEXPR typename sprout::fixed::result_of::algorithm<Result>::type
+	unique_copy(InputIterator first, InputIterator last, Result const& result, BinaryPredicate pred) {
+		return sprout::fixed::unique_copy(first, last, result, pred);
+	}
+
+	template<
+		typename Result, typename InputIterator, typename BinaryPredicate,
+		typename sprout::enabler_if<!sprout::is_output_iterator<BinaryPredicate>::value>::type = sprout::enabler
+	>
+	inline SPROUT_CONSTEXPR typename sprout::fixed::result_of::algorithm<Result>::type
+	unique_copy(InputIterator first, InputIterator last, BinaryPredicate pred) {
+		return sprout::fixed::unique_copy<Result>(first, last, pred);
+	}
 }	// namespace sprout
 
 #endif	// #ifndef SPROUT_ALGORITHM_FIXED_UNIQUE_COPY_HPP
diff --git a/sprout/algorithm/generate.hpp b/sprout/algorithm/generate.hpp
index 38fc1721..d579ec00 100644
--- a/sprout/algorithm/generate.hpp
+++ b/sprout/algorithm/generate.hpp
@@ -14,9 +14,9 @@ namespace sprout {
 	//
 	// 25.3.7 Generate
 	//
-	template<typename ForwrdIterator, typename Generator>
+	template<typename ForwardIterator, typename Generator>
 	inline SPROUT_CXX14_CONSTEXPR void
-	generate(ForwrdIterator first, ForwrdIterator last, Generator gen) {
+	generate(ForwardIterator first, ForwardIterator last, Generator gen) {
 		while (first != last) {
 			*first++ = gen();
 		}
diff --git a/sprout/algorithm/modifying.hpp b/sprout/algorithm/modifying.hpp
index 552c952d..8ecc6681 100644
--- a/sprout/algorithm/modifying.hpp
+++ b/sprout/algorithm/modifying.hpp
@@ -40,11 +40,12 @@
 #include <sprout/algorithm/reverse_copy.hpp>
 #include <sprout/algorithm/rotate.hpp>
 #include <sprout/algorithm/rotate_copy.hpp>
+#include <sprout/algorithm/random_shuffle.hpp>
 #include <sprout/algorithm/shuffle.hpp>
 #include <sprout/algorithm/shuffle_result.hpp>
 #include <sprout/algorithm/partition.hpp>
-#include <sprout/algorithm/partition_copy.hpp>
 #include <sprout/algorithm/stable_partition.hpp>
+#include <sprout/algorithm/partition_copy.hpp>
 #include <sprout/algorithm/stable_partition_copy.hpp>
 #include <sprout/algorithm/sort.hpp>
 #include <sprout/algorithm/stable_sort.hpp>
diff --git a/sprout/algorithm/partition.hpp b/sprout/algorithm/partition.hpp
index db0308a6..3275454d 100644
--- a/sprout/algorithm/partition.hpp
+++ b/sprout/algorithm/partition.hpp
@@ -9,6 +9,28 @@
 #define SPROUT_ALGORITHM_PARTITION_HPP
 
 #include <sprout/config.hpp>
+#include <sprout/algorithm/iter_swap.hpp>
+#include <sprout/algorithm/find_if.hpp>
+#include <sprout/algorithm/find_if_not.hpp>
+
+namespace sprout {
+	//
+	// 25.3.13 Partitions
+	//
+	template<typename ForwardIterator, typename Predicate>
+	inline SPROUT_CXX14_CONSTEXPR ForwardIterator
+	partition(ForwardIterator first, ForwardIterator last, Predicate pred) {
+		first = sprout::find_if_not(first, last, pred);
+		ForwardIterator it = sprout::find_if(first, last, pred);
+		while (it != last) {
+			sprout::iter_swap(first, it);
+			first = sprout::find_if_not(first, last, pred);
+			it = sprout::find_if(it, last, pred);
+		}
+		return first;
+	}
+}	// namespace sprout
+
 #include <sprout/algorithm/fixed/partition.hpp>
 #include <sprout/algorithm/fit/partition.hpp>
 
diff --git a/sprout/algorithm/partition_copy.hpp b/sprout/algorithm/partition_copy.hpp
index fae72760..0a89b5a7 100644
--- a/sprout/algorithm/partition_copy.hpp
+++ b/sprout/algorithm/partition_copy.hpp
@@ -9,6 +9,17 @@
 #define SPROUT_ALGORITHM_PARTITION_COPY_HPP
 
 #include <sprout/config.hpp>
+#include <sprout/utility/pair.hpp>
+
+namespace sprout {
+	//
+	// 25.3.13 Partitions
+	//
+	template<typename InputIterator, typename OutputIterator1, typename OutputIterator2, typename Predicate>
+	inline SPROUT_CXX14_CONSTEXPR sprout::pair<OutputIterator1, OutputIterator2>
+	partition_copy(InputIterator first, InputIterator last, OutputIterator1 out_true, OutputIterator2 out_false, Predicate pred); // !!!
+}	// namespace sprout
+
 #include <sprout/algorithm/fixed/partition_copy.hpp>
 #include <sprout/algorithm/fit/partition_copy.hpp>
 
diff --git a/sprout/algorithm/random_shuffle.hpp b/sprout/algorithm/random_shuffle.hpp
new file mode 100644
index 00000000..7c9ad98e
--- /dev/null
+++ b/sprout/algorithm/random_shuffle.hpp
@@ -0,0 +1,30 @@
+/*=============================================================================
+  Copyright (c) 2011-2013 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_ALGORITHM_RANDOM_SHUFFLE_HPP
+#define SPROUT_ALGORITHM_RANDOM_SHUFFLE_HPP
+
+#include <sprout/config.hpp>
+#include <sprout/algorithm/iter_swap.hpp>
+
+namespace sprout {
+	//
+	// 25.3.12 Random shuffle
+	//
+	template<typename RandomAccessIterator, typename RandomNumberGenerator>
+	inline SPROUT_CXX14_CONSTEXPR void
+	random_shuffle(RandomAccessIterator first, RandomAccessIterator last, RandomNumberGenerator&& rand) {
+		if (first == last) {
+			return;
+		}
+		for (auto it = first + 1; it != last; ++it) {
+			sprout::iter_swap(it, first + rand(it - first + 1));
+		}
+	}
+}	// namespace sprout
+
+#endif	// #ifndef SPROUT_ALGORITHM_RANDOM_SHUFFLE_HPP
diff --git a/sprout/algorithm/remove.hpp b/sprout/algorithm/remove.hpp
index f429bf50..48e5c884 100644
--- a/sprout/algorithm/remove.hpp
+++ b/sprout/algorithm/remove.hpp
@@ -9,6 +9,25 @@
 #define SPROUT_ALGORITHM_REMOVE_HPP
 
 #include <sprout/config.hpp>
+#include <sprout/utility/move.hpp>
+
+namespace sprout {
+	//
+	// 25.3.8 Remove
+	//
+	template<typename ForwardIterator, typename T>
+	inline SPROUT_CXX14_CONSTEXPR ForwardIterator
+	remove(ForwardIterator first, ForwardIterator last, T const& value) {
+		ForwardIterator result = first;
+		for (; first != last; ++first) {
+			if (!(*first == value)) {
+				*result++ = sprout::move(*first);
+			}
+		}
+		return result;
+	}
+}	// namespace sprout
+
 #include <sprout/algorithm/fixed/remove.hpp>
 #include <sprout/algorithm/fit/remove.hpp>
 
diff --git a/sprout/algorithm/remove_copy.hpp b/sprout/algorithm/remove_copy.hpp
index 11385026..e84e627e 100644
--- a/sprout/algorithm/remove_copy.hpp
+++ b/sprout/algorithm/remove_copy.hpp
@@ -9,6 +9,28 @@
 #define SPROUT_ALGORITHM_REMOVE_COPY_HPP
 
 #include <sprout/config.hpp>
+#include <sprout/iterator/type_traits/is_iterator_of.hpp>
+#include <sprout/type_traits/enabler_if.hpp>
+
+namespace sprout {
+	//
+	// 25.3.8 Remove
+	//
+	template<
+		typename InputIterator, typename OutputIterator, typename T,
+		typename sprout::enabler_if<sprout::is_output_iterator<OutputIterator>::value>::type = sprout::enabler
+	>
+	inline SPROUT_CXX14_CONSTEXPR OutputIterator
+	remove_copy(InputIterator first, InputIterator last, OutputIterator result, T const& value) {
+		for (; first != last; ++first) {
+			if (!(*first == value)) {
+				*result++ = *first;
+			}
+		}
+		return result;
+	}
+}	// namespace sprout
+
 #include <sprout/algorithm/fixed/remove_copy.hpp>
 #include <sprout/algorithm/fit/remove_copy.hpp>
 
diff --git a/sprout/algorithm/remove_copy_if.hpp b/sprout/algorithm/remove_copy_if.hpp
index 9b218ba2..b1f3e124 100644
--- a/sprout/algorithm/remove_copy_if.hpp
+++ b/sprout/algorithm/remove_copy_if.hpp
@@ -9,6 +9,28 @@
 #define SPROUT_ALGORITHM_REMOVE_COPY_IF_HPP
 
 #include <sprout/config.hpp>
+#include <sprout/iterator/type_traits/is_iterator_of.hpp>
+#include <sprout/type_traits/enabler_if.hpp>
+
+namespace sprout {
+	//
+	// 25.3.8 Remove
+	//
+	template<
+		typename InputIterator, typename OutputIterator, typename Predicate,
+		typename sprout::enabler_if<sprout::is_output_iterator<OutputIterator>::value>::type = sprout::enabler
+	>
+	inline SPROUT_CXX14_CONSTEXPR OutputIterator
+	remove_copy_if(InputIterator first, InputIterator last, OutputIterator result, Predicate pred) {
+		for (; first != last; ++first) {
+			if (!pred(*first)) {
+				*result++ = *first;
+			}
+		}
+		return result;
+	}
+}	// namespace sprout
+
 #include <sprout/algorithm/fixed/remove_copy_if.hpp>
 #include <sprout/algorithm/fit/remove_copy_if.hpp>
 
diff --git a/sprout/algorithm/remove_if.hpp b/sprout/algorithm/remove_if.hpp
index 6c398756..e7570548 100644
--- a/sprout/algorithm/remove_if.hpp
+++ b/sprout/algorithm/remove_if.hpp
@@ -9,6 +9,25 @@
 #define SPROUT_ALGORITHM_REMOVE_IF_HPP
 
 #include <sprout/config.hpp>
+#include <sprout/utility/move.hpp>
+
+namespace sprout {
+	//
+	// 25.3.8 Remove
+	//
+	template<typename ForwardIterator, typename Predicate>
+	inline SPROUT_CXX14_CONSTEXPR ForwardIterator
+	remove_if(ForwardIterator first, ForwardIterator last, Predicate pred) {
+		ForwardIterator result = first;
+		for (; first != last; ++first) {
+			if (!pred(*first)) {
+				*result++ = sprout::move(*first);
+			}
+		}
+		return result;
+	}
+}	// namespace sprout
+
 #include <sprout/algorithm/fixed/remove_if.hpp>
 #include <sprout/algorithm/fit/remove_if.hpp>
 
diff --git a/sprout/algorithm/replace.hpp b/sprout/algorithm/replace.hpp
index ca196c25..b918a9d1 100644
--- a/sprout/algorithm/replace.hpp
+++ b/sprout/algorithm/replace.hpp
@@ -14,9 +14,9 @@ namespace sprout {
 	//
 	// 25.3.5 Replace
 	//
-	template<typename ForwrdIterator, typename T>
+	template<typename ForwardIterator, typename T>
 	inline SPROUT_CXX14_CONSTEXPR void
-	replace(ForwrdIterator first, ForwrdIterator last, T const& old_value, T const& new_value) {
+	replace(ForwardIterator first, ForwardIterator last, T const& old_value, T const& new_value) {
 		for (; first != last; ++first) {
 			if (*first == old_value) {
 				*first = new_value;
diff --git a/sprout/algorithm/replace_if.hpp b/sprout/algorithm/replace_if.hpp
index 75689137..53e772c5 100644
--- a/sprout/algorithm/replace_if.hpp
+++ b/sprout/algorithm/replace_if.hpp
@@ -14,9 +14,9 @@ namespace sprout {
 	//
 	// 25.3.5 Replace
 	//
-	template<typename ForwrdIterator, typename Predicate, typename T>
+	template<typename ForwardIterator, typename Predicate, typename T>
 	inline SPROUT_CXX14_CONSTEXPR void
-	replace_if(ForwrdIterator first, ForwrdIterator last, Predicate pred, T const& new_value) {
+	replace_if(ForwardIterator first, ForwardIterator last, Predicate pred, T const& new_value) {
 		for (; first != last; ++first) {
 			if (pred(*first)) {
 				*first = new_value;
diff --git a/sprout/algorithm/reverse.hpp b/sprout/algorithm/reverse.hpp
index 0c923438..899731aa 100644
--- a/sprout/algorithm/reverse.hpp
+++ b/sprout/algorithm/reverse.hpp
@@ -9,6 +9,21 @@
 #define SPROUT_ALGORITHM_REVERSE_HPP
 
 #include <sprout/config.hpp>
+#include <sprout/algorithm/iter_swap.hpp>
+
+namespace sprout {
+	//
+	// 25.3.10 Reverse
+	//
+	template<typename BidirectionalIterator>
+	inline SPROUT_CXX14_CONSTEXPR void
+	reverse(BidirectionalIterator first, BidirectionalIterator last) {
+		for (; first != last && first != --last; ++first) {
+			sprout::iter_swap(first, last);
+		}
+	}
+}	// namespace sprout
+
 #include <sprout/algorithm/fixed/reverse.hpp>
 #include <sprout/algorithm/fit/reverse.hpp>
 
diff --git a/sprout/algorithm/reverse_copy.hpp b/sprout/algorithm/reverse_copy.hpp
index bd66d098..c45f0d3d 100644
--- a/sprout/algorithm/reverse_copy.hpp
+++ b/sprout/algorithm/reverse_copy.hpp
@@ -9,6 +9,26 @@
 #define SPROUT_ALGORITHM_REVERSE_COPY_HPP
 
 #include <sprout/config.hpp>
+#include <sprout/iterator/type_traits/is_iterator_of.hpp>
+#include <sprout/type_traits/enabler_if.hpp>
+
+namespace sprout {
+	//
+	// 25.3.10 Reverse
+	//
+	template<
+		typename BidirectionalIterator, typename OutputIterator,
+		typename sprout::enabler_if<sprout::is_output_iterator<OutputIterator>::value>::type = sprout::enabler
+	>
+	inline SPROUT_CXX14_CONSTEXPR OutputIterator
+	reverse_copy(BidirectionalIterator first, BidirectionalIterator last, OutputIterator result) {
+		while (first != last) {
+			*result++ = *--last;
+		}
+		return result;
+	}
+}	// namespace sprout
+
 #include <sprout/algorithm/fixed/reverse_copy.hpp>
 #include <sprout/algorithm/fit/reverse_copy.hpp>
 
diff --git a/sprout/algorithm/rotate.hpp b/sprout/algorithm/rotate.hpp
index 1180a9ce..4023e05f 100644
--- a/sprout/algorithm/rotate.hpp
+++ b/sprout/algorithm/rotate.hpp
@@ -8,7 +8,53 @@
 #ifndef SPROUT_ALGORITHM_ROTATE_HPP
 #define SPROUT_ALGORITHM_ROTATE_HPP
 
+#include <iterator>
 #include <sprout/config.hpp>
+#include <sprout/algorithm/iter_swap.hpp>
+
+namespace sprout {
+	//
+	// 25.3.11 Rotate
+	//
+	template<typename ForwardIterator>
+	inline SPROUT_CXX14_CONSTEXPR ForwardIterator
+	rotate(ForwardIterator first, ForwardIterator middle, ForwardIterator last) {
+		if (first == middle) {
+			return last;
+		} else if (middle == last) {
+			return first;
+		}
+		ForwardIterator first2 = middle;
+		while (true) {
+			sprout::iter_swap(first, first2);
+			++first;
+			if (++first2 == last) {
+				break;
+			}
+			if (first == middle) {
+				middle = first2;
+			}
+		}
+		ForwardIterator result = first;
+		if (first != middle) {
+			first2 = middle;
+			while (true) {
+				sprout::iter_swap(first, first2);
+				++first;
+				if (++first2 == last) {
+					if (first == middle) {
+						break;
+					}
+					first2 = middle;
+				} else if (first == middle) {
+					middle = first2;
+				}
+			}
+		}
+		return result;
+	}
+}	// namespace sprout
+
 #include <sprout/algorithm/fixed/rotate.hpp>
 #include <sprout/algorithm/fit/rotate.hpp>
 
diff --git a/sprout/algorithm/rotate_copy.hpp b/sprout/algorithm/rotate_copy.hpp
index e268f5cb..dac4f483 100644
--- a/sprout/algorithm/rotate_copy.hpp
+++ b/sprout/algorithm/rotate_copy.hpp
@@ -9,6 +9,24 @@
 #define SPROUT_ALGORITHM_ROTATE_COPY_HPP
 
 #include <sprout/config.hpp>
+#include <sprout/iterator/type_traits/is_iterator_of.hpp>
+#include <sprout/type_traits/enabler_if.hpp>
+#include <sprout/algorithm/copy.hpp>
+
+namespace sprout {
+	//
+	// 25.3.11 Rotate
+	//
+	template<
+		typename ForwardIterator, typename OutputIterator,
+		typename sprout::enabler_if<sprout::is_output_iterator<OutputIterator>::value>::type = sprout::enabler
+	>
+	inline SPROUT_CXX14_CONSTEXPR OutputIterator
+	rotate_copy(ForwardIterator first, ForwardIterator middle, ForwardIterator last, OutputIterator result) {
+		return sprout::copy(first, middle, sprout::copy(middle, last, result));
+	}
+}	// namespace sprout
+
 #include <sprout/algorithm/fixed/rotate_copy.hpp>
 #include <sprout/algorithm/fit/rotate_copy.hpp>
 
diff --git a/sprout/algorithm/shuffle.hpp b/sprout/algorithm/shuffle.hpp
index 2cc943e3..41bb628e 100644
--- a/sprout/algorithm/shuffle.hpp
+++ b/sprout/algorithm/shuffle.hpp
@@ -9,6 +9,16 @@
 #define SPROUT_ALGORITHM_SHUFFLE_HPP
 
 #include <sprout/config.hpp>
+
+namespace sprout {
+	//
+	// 25.3.12 Random shuffle
+	//
+	template<typename RandomAccessIterator, typename UniformRandomNumberGenerator>
+	inline SPROUT_CXX14_CONSTEXPR void
+	shuffle(RandomAccessIterator first, RandomAccessIterator last, UniformRandomNumberGenerator&& g); // !!!
+}	// namespace sprout
+
 #include <sprout/algorithm/fixed/shuffle.hpp>
 #include <sprout/algorithm/fit/shuffle.hpp>
 
diff --git a/sprout/algorithm/stable_partition.hpp b/sprout/algorithm/stable_partition.hpp
index 86e95b3e..b2a03b7e 100644
--- a/sprout/algorithm/stable_partition.hpp
+++ b/sprout/algorithm/stable_partition.hpp
@@ -9,6 +9,17 @@
 #define SPROUT_ALGORITHM_STABLE_PARTITION_HPP
 
 #include <sprout/config.hpp>
+
+
+namespace sprout {
+	//
+	// 25.3.13 Partitions
+	//
+	template<typename BidirectionalIterator, typename Predicate>
+	inline SPROUT_CXX14_CONSTEXPR BidirectionalIterator
+	stable_partition(BidirectionalIterator first, BidirectionalIterator last, Predicate pred); // !!!
+}	// namespace sprout
+
 #include <sprout/algorithm/fixed/stable_partition.hpp>
 #include <sprout/algorithm/fit/stable_partition.hpp>
 
diff --git a/sprout/algorithm/unique.hpp b/sprout/algorithm/unique.hpp
index 0ba1ff2d..38c88ec9 100644
--- a/sprout/algorithm/unique.hpp
+++ b/sprout/algorithm/unique.hpp
@@ -8,7 +8,50 @@
 #ifndef SPROUT_ALGORITHM_UNIQUE_HPP
 #define SPROUT_ALGORITHM_UNIQUE_HPP
 
+#include <iterator>
 #include <sprout/config.hpp>
+#include <sprout/utility/move.hpp>
+
+namespace sprout {
+	//
+	// 25.3.9 Unique
+	//
+	template<typename ForwardIterator>
+	inline SPROUT_CXX14_CONSTEXPR ForwardIterator
+	unique(ForwardIterator first, ForwardIterator last) {
+		if (first == last) {
+			return first;
+		}
+		ForwardIterator result = first;
+		typename std::iterator_traits<ForwardIterator>::value_type value = sprout::move(*first++);
+		for (; first != last; ++first) {
+			if (!(value == *first)) {
+				*result++ = sprout::move(value);
+				value = sprout::move(*first);
+			}
+		}
+		*result++ = sprout::move(value);
+		return result;
+	}
+	template<typename ForwardIterator, typename BinaryPredicate>
+	inline SPROUT_CXX14_CONSTEXPR ForwardIterator
+	unique(ForwardIterator first, ForwardIterator last, BinaryPredicate pred) {
+		if (first == last) {
+			return first;
+		}
+		ForwardIterator result = first;
+		typename std::iterator_traits<ForwardIterator>::value_type value = sprout::move(*first++);
+		for (; first != last; ++first) {
+			if (!pred(value, *first)) {
+				*result++ = sprout::move(value);
+				value = sprout::move(*first);
+			}
+		}
+		*result++ = sprout::move(value);
+		return result;
+	}
+}	// namespace sprout
+
 #include <sprout/algorithm/fixed/unique.hpp>
 #include <sprout/algorithm/fit/unique.hpp>
 
diff --git a/sprout/algorithm/unique_copy.hpp b/sprout/algorithm/unique_copy.hpp
index d6c0b4dd..57e79532 100644
--- a/sprout/algorithm/unique_copy.hpp
+++ b/sprout/algorithm/unique_copy.hpp
@@ -1,14 +1,63 @@
 /*=============================================================================
-  Copyright (c) 2011-2013 Bolero MURAKAMI
-  https://github.com/bolero-MURAKAMI/Sprout
+	Copyright (c) 2011-2013 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)
+	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_ALGORITHM_UNIQUE_COPY_HPP
 #define SPROUT_ALGORITHM_UNIQUE_COPY_HPP
 
+#include <iterator>
 #include <sprout/config.hpp>
+#include <sprout/iterator/type_traits/is_iterator_of.hpp>
+#include <sprout/type_traits/enabler_if.hpp>
+
+namespace sprout {
+	//
+	// 25.3.9 Unique
+	//
+	template<
+		typename InputIterator, typename OutputIterator,
+		typename sprout::enabler_if<sprout::is_output_iterator<OutputIterator>::value>::type = sprout::enabler
+	>
+	inline SPROUT_CXX14_CONSTEXPR OutputIterator
+	unique_copy(InputIterator first, InputIterator last, OutputIterator result) {
+		if (first == last) {
+			return result;
+		}
+		typename std::iterator_traits<InputIterator>::value_type value = *first++;
+		*result++ = value;
+		for (; first != last; ++first) {
+			if (!(value == *first)) {
+				value = *first;
+				*result++ = value;
+			}
+		}
+		return result;
+	}
+
+	template<
+		typename InputIterator, typename OutputIterator, typename BinaryPredicate,
+		typename sprout::enabler_if<sprout::is_output_iterator<OutputIterator>::value>::type = sprout::enabler
+	>
+	inline SPROUT_CXX14_CONSTEXPR OutputIterator
+	unique_copy(InputIterator first, InputIterator last, OutputIterator result, BinaryPredicate pred) {
+		if (first == last) {
+			return result;
+		}
+		typename std::iterator_traits<InputIterator>::value_type value = *first++;
+		*result++ = value;
+		for (; first != last; ++first) {
+			if (!pred(value, *first)) {
+				value = *first;
+				*result++ = value;
+			}
+		}
+		return result;
+	}
+}	// namespace sprout
+
 #include <sprout/algorithm/fixed/unique_copy.hpp>
 #include <sprout/algorithm/fit/unique_copy.hpp>
 
diff --git a/sprout/array/make_array.hpp b/sprout/array/make_array.hpp
index a443f250..51f06664 100644
--- a/sprout/array/make_array.hpp
+++ b/sprout/array/make_array.hpp
@@ -25,6 +25,15 @@ namespace sprout {
 	make_array(Types&&... args) {
 		return sprout::array<T, sizeof...(Types)>{{T(sprout::forward<Types>(args))...}};
 	}
+//	template<typename... Types>
+//	inline SPROUT_CONSTEXPR sprout::array<typename sprout::common_decay<Types&&...>::type, sizeof...(Types)>
+//	make_array(Types&&... args) {
+//		typedef sprout::array<
+//			typename sprout::common_decay<Types&&...>::type,
+//			sizeof...(Types)
+//		> type;
+//		return type{{typename sprout::common_decay<Types&&...>::type(sprout::forward<Types>(args))...}};
+//	}
 
 	//
 	// make_common_array
diff --git a/sprout/math/abs.hpp b/sprout/math/abs.hpp
index 72f3311c..90062e21 100644
--- a/sprout/math/abs.hpp
+++ b/sprout/math/abs.hpp
@@ -16,24 +16,16 @@
 
 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
-			abs(FloatType x) {
-				return sprout::math::fabs(x);
-			}
-		}	// namespace detail
-
+		//
+		// abs
+		//
 		template<
 			typename FloatType,
 			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
 		>
 		inline SPROUT_CONSTEXPR FloatType
 		abs(FloatType x) {
-			return NS_SPROUT_MATH_DETAIL::abs(x);
+				return sprout::math::fabs(x);
 		}
 	}	// namespace math
 
diff --git a/sprout/math/acos.hpp b/sprout/math/acos.hpp
index b3ab5cdf..0b87ab51 100644
--- a/sprout/math/acos.hpp
+++ b/sprout/math/acos.hpp
@@ -22,39 +22,54 @@
 namespace sprout {
 	namespace math {
 		namespace detail {
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+			inline SPROUT_CONSTEXPR float
+			builtin_acos(float x) {
+				return __builtin_acosf(x);
+			}
+			inline SPROUT_CONSTEXPR double
+			builtin_acos(double x) {
+				return __builtin_acos(x);
+			}
+			inline SPROUT_CONSTEXPR long double
+			builtin_acos(long double x) {
+				return __builtin_acosl(x);
+			}
+#endif
+
 			template<typename T>
 			inline SPROUT_CONSTEXPR T
 			acos_impl(T x) {
 				return sprout::math::half_pi<T>() - sprout::math::asin(x);
 			}
-
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR FloatType
-			acos(FloatType x) {
-				return sprout::math::isnan(x) ? x
-					: sprout::math::fabs(x) > 1 ? sprout::numeric_limits<FloatType>::quiet_NaN()
-#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
-					: std::acos(x)
-#else
-					: x == 1 ? FloatType(0)
-					: static_cast<FloatType>(sprout::math::detail::acos_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
-#endif
-					;
-			}
-			template<
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR double
-			acos(IntType x) {
-				return sprout::math::detail::acos(static_cast<double>(x));
-			}
 		}	// namespace detail
-
-		using sprout::math::detail::acos;
+		//
+		// acos
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR FloatType
+		acos(FloatType x) {
+			return sprout::math::isnan(x) ? x
+				: sprout::math::fabs(x) > 1 ? sprout::numeric_limits<FloatType>::quiet_NaN()
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				: sprout::math::detail::builtin_acos(x)
+#else
+				: x == 1 ? FloatType(0)
+				: static_cast<FloatType>(sprout::math::detail::acos_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
+#endif
+				;
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR double
+		acos(IntType x) {
+			return sprout::math::acos(static_cast<double>(x));
+		}
 	}	// namespace math
 
 	using sprout::math::acos;
diff --git a/sprout/math/acosh.hpp b/sprout/math/acosh.hpp
index ac62f4e6..b66e9fed 100644
--- a/sprout/math/acosh.hpp
+++ b/sprout/math/acosh.hpp
@@ -21,40 +21,55 @@
 namespace sprout {
 	namespace math {
 		namespace detail {
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+			inline SPROUT_CONSTEXPR float
+			builtin_acosh(float x) {
+				return __builtin_acoshf(x);
+			}
+			inline SPROUT_CONSTEXPR double
+			builtin_acosh(double x) {
+				return __builtin_acosh(x);
+			}
+			inline SPROUT_CONSTEXPR long double
+			builtin_acosh(long double x) {
+				return __builtin_acoshl(x);
+			}
+#endif
+
 			template<typename T>
 			inline SPROUT_CONSTEXPR T
 			acosh_impl(T x) {
 				return sprout::math::log(x + sprout::math::sqrt(x * x - 1));
 			}
-
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR FloatType
-			acosh(FloatType x) {
-				return sprout::math::isnan(x) ? x
-					: x < 1 ? -sprout::numeric_limits<FloatType>::quiet_NaN()
-					: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
-#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
-					: std::acosh(x)
-#else
-					: x == 1 ? FloatType(0)
-					: static_cast<FloatType>(sprout::math::detail::acosh_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
-#endif
-					;
-			}
-			template<
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR double
-			acosh(IntType x) {
-				return sprout::math::detail::acosh(static_cast<double>(x));
-			}
 		}	// namespace detail
-
-		using sprout::math::detail::acosh;
+		//
+		// acosh
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR FloatType
+		acosh(FloatType x) {
+			return sprout::math::isnan(x) ? x
+				: x < 1 ? -sprout::numeric_limits<FloatType>::quiet_NaN()
+				: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				: sprout::math::detail::builtin_acosh(x)
+#else
+				: x == 1 ? FloatType(0)
+				: static_cast<FloatType>(sprout::math::detail::acosh_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
+#endif
+				;
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR double
+		acosh(IntType x) {
+			return sprout::math::acosh(static_cast<double>(x));
+		}
 	}	// namespace math
 
 	using sprout::math::acosh;
diff --git a/sprout/math/asin.hpp b/sprout/math/asin.hpp
index fcd45c87..6afd3d13 100644
--- a/sprout/math/asin.hpp
+++ b/sprout/math/asin.hpp
@@ -24,6 +24,21 @@
 namespace sprout {
 	namespace math {
 		namespace detail {
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+			inline SPROUT_CONSTEXPR float
+			builtin_asin(float x) {
+				return __builtin_asinf(x);
+			}
+			inline SPROUT_CONSTEXPR double
+			builtin_asin(double x) {
+				return __builtin_asin(x);
+			}
+			inline SPROUT_CONSTEXPR long double
+			builtin_asin(long double x) {
+				return __builtin_asinl(x);
+			}
+#endif
+
 			template<typename T>
 			inline SPROUT_CONSTEXPR T
 			asin_impl_center_1(T x, T x2) {
@@ -76,37 +91,37 @@ namespace sprout {
 					: sprout::math::detail::asin_impl_center(x)
 					;
 			}
-
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR FloatType
-			asin(FloatType x) {
-				return sprout::math::isnan(x) ? x
-					: sprout::math::fabs(x) > 1 ? sprout::numeric_limits<FloatType>::quiet_NaN()
-#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
-					: std::asin(x)
-#else
-					: x == 0 ? x
-					: static_cast<FloatType>(
-						x < 0 ? -sprout::math::detail::asin_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(-x))
-							: sprout::math::detail::asin_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x))
-						)
-#endif
-					;
-			}
-			template<
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR double
-			asin(IntType x) {
-				return sprout::math::detail::asin(static_cast<double>(x));
-			}
 		}	// namespace detail
-
-		using sprout::math::detail::asin;
+		//
+		// asin
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR FloatType
+		asin(FloatType x) {
+			return sprout::math::isnan(x) ? x
+				: sprout::math::fabs(x) > 1 ? sprout::numeric_limits<FloatType>::quiet_NaN()
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				: sprout::math::detail::builtin_asin(x)
+#else
+				: x == 0 ? x
+				: static_cast<FloatType>(
+					x < 0 ? -sprout::math::detail::asin_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(-x))
+						: sprout::math::detail::asin_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x))
+					)
+#endif
+				;
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR double
+		asin(IntType x) {
+			return sprout::math::asin(static_cast<double>(x));
+		}
 	}	// namespace math
 
 	using sprout::math::asin;
diff --git a/sprout/math/asinh.hpp b/sprout/math/asinh.hpp
index 890ea664..d23df972 100644
--- a/sprout/math/asinh.hpp
+++ b/sprout/math/asinh.hpp
@@ -21,40 +21,55 @@
 namespace sprout {
 	namespace math {
 		namespace detail {
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+			inline SPROUT_CONSTEXPR float
+			builtin_asinh(float x) {
+				return __builtin_asinhf(x);
+			}
+			inline SPROUT_CONSTEXPR double
+			builtin_asinh(double x) {
+				return __builtin_asinh(x);
+			}
+			inline SPROUT_CONSTEXPR long double
+			builtin_asinh(long double x) {
+				return __builtin_asinhl(x);
+			}
+#endif
+
 			template<typename T>
 			inline SPROUT_CONSTEXPR T
 			asinh_impl(T x) {
 				return sprout::math::log(x + sprout::math::sqrt(x * x + 1));
 			}
-
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR FloatType
-			asinh(FloatType x) {
-				return sprout::math::isnan(x) ? x
-					: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
-					: x == -sprout::numeric_limits<FloatType>::infinity() ? -sprout::numeric_limits<FloatType>::infinity()
-#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
-					: std::asinh(x)
-#else
-					: x == 0 ? x
-					: static_cast<FloatType>(sprout::math::detail::asinh_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
-#endif
-					;
-			}
-			template<
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR double
-			asinh(IntType x) {
-				return sprout::math::detail::asinh(static_cast<double>(x));
-			}
 		}	// namespace detail
-
-		using sprout::math::detail::asinh;
+		//
+		// asinh
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR FloatType
+		asinh(FloatType x) {
+			return sprout::math::isnan(x) ? x
+				: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
+				: x == -sprout::numeric_limits<FloatType>::infinity() ? -sprout::numeric_limits<FloatType>::infinity()
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				: sprout::math::detail::builtin_asinh(x)
+#else
+				: x == 0 ? x
+				: static_cast<FloatType>(sprout::math::detail::asinh_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
+#endif
+				;
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR double
+		asinh(IntType x) {
+			return sprout::math::asinh(static_cast<double>(x));
+		}
 	}	// namespace math
 
 	using sprout::math::asinh;
diff --git a/sprout/math/atan.hpp b/sprout/math/atan.hpp
index 399e3e03..c910c6d8 100644
--- a/sprout/math/atan.hpp
+++ b/sprout/math/atan.hpp
@@ -23,6 +23,21 @@
 namespace sprout {
 	namespace math {
 		namespace detail {
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+			inline SPROUT_CONSTEXPR float
+			builtin_atan(float x) {
+				return __builtin_atanf(x);
+			}
+			inline SPROUT_CONSTEXPR double
+			builtin_atan(double x) {
+				return __builtin_atan(x);
+			}
+			inline SPROUT_CONSTEXPR long double
+			builtin_atan(long double x) {
+				return __builtin_atanl(x);
+			}
+#endif
+
 			template<typename T>
 			inline SPROUT_CONSTEXPR T
 			atan_impl_1(T x, std::size_t n, std::size_t last) {
@@ -43,37 +58,38 @@ namespace sprout {
 					;
 			}
 
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR FloatType
-			atan(FloatType x) {
-				return sprout::math::isnan(x) ? x
-					: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::math::half_pi<FloatType>()
-					: x == -sprout::numeric_limits<FloatType>::infinity() ? -sprout::math::half_pi<FloatType>()
-#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
-					: std::atan(x)
-#else
-					: x == 0 ? x
-					: static_cast<FloatType>(
-						x < 0 ? -sprout::math::detail::atan_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(-x))
-							: sprout::math::detail::atan_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x))
-						)
-#endif
-					;
-			}
-			template<
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR double
-			atan(IntType x) {
-				return sprout::math::detail::atan(static_cast<double>(x));
-			}
 		}	// namespace detail
-
-		using sprout::math::detail::atan;
+		//
+		// atan
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR FloatType
+		atan(FloatType x) {
+			return sprout::math::isnan(x) ? x
+				: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::math::half_pi<FloatType>()
+				: x == -sprout::numeric_limits<FloatType>::infinity() ? -sprout::math::half_pi<FloatType>()
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				: sprout::math::detail::builtin_atan(x)
+#else
+				: x == 0 ? x
+				: static_cast<FloatType>(
+					x < 0 ? -sprout::math::detail::atan_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(-x))
+						: sprout::math::detail::atan_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x))
+					)
+#endif
+				;
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR double
+		atan(IntType x) {
+			return sprout::math::atan(static_cast<double>(x));
+		}
 	}	// namespace math
 
 	using sprout::math::atan;
diff --git a/sprout/math/atan2.hpp b/sprout/math/atan2.hpp
index a6595b5a..8953cb8c 100644
--- a/sprout/math/atan2.hpp
+++ b/sprout/math/atan2.hpp
@@ -25,6 +25,21 @@
 namespace sprout {
 	namespace math {
 		namespace detail {
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+			inline SPROUT_CONSTEXPR float
+			builtin_atan2(float y, float x) {
+				return __builtin_atan2f(y, x);
+			}
+			inline SPROUT_CONSTEXPR double
+			builtin_atan2(double y, double x) {
+				return __builtin_atan2(y, x);
+			}
+			inline SPROUT_CONSTEXPR long double
+			builtin_atan2(long double y, long double x) {
+				return __builtin_atan2l(y, x);
+			}
+#endif
+
 			template<typename T>
 			inline SPROUT_CONSTEXPR T
 			atan2_impl(T y, T x) {
@@ -35,63 +50,10 @@ namespace sprout {
 					: sprout::math::atan(y / x)
 					;
 			}
-
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR FloatType
-			atan2(FloatType y, FloatType x) {
-				return sprout::math::isnan(y)
-						? sprout::math::isnan(x)
-							? sprout::math::signbit(y) && sprout::math::signbit(x) ? -sprout::numeric_limits<FloatType>::quiet_NaN()
-								: sprout::numeric_limits<FloatType>::quiet_NaN()
-							: y
-					: sprout::math::isnan(x) ? x
-					: x == -sprout::numeric_limits<FloatType>::infinity()
-						? y == sprout::numeric_limits<FloatType>::infinity() ? sprout::math::three_quarters_pi<FloatType>()
-							: y == -sprout::numeric_limits<FloatType>::infinity() ? -sprout::math::three_quarters_pi<FloatType>()
-							: sprout::math::copysign(sprout::math::pi<FloatType>(), y)
-					: x == sprout::numeric_limits<FloatType>::infinity()
-						? y == sprout::numeric_limits<FloatType>::infinity() ? sprout::math::quarter_pi<FloatType>()
-							: y == -sprout::numeric_limits<FloatType>::infinity() ? -sprout::math::quarter_pi<FloatType>()
-							: FloatType(0) * y
-					: y == sprout::numeric_limits<FloatType>::infinity() ? sprout::math::half_pi<FloatType>()
-					: y == -sprout::numeric_limits<FloatType>::infinity() ? -sprout::math::half_pi<FloatType>()
-#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
-					: std::atan2(y, x)
-#else
-					: y == 0
-						? x < 0 ? sprout::math::copysign(sprout::math::pi<FloatType>(), y)
-							: x > 0 ? FloatType(0) * y
-							: sprout::math::signbit(x) ? sprout::math::copysign(sprout::math::pi<FloatType>(), y)
-							: FloatType(0) * y
-					: x == 0
-						? y < 0 ? -sprout::math::half_pi<FloatType>()
-							: sprout::math::half_pi<FloatType>()
-					: static_cast<FloatType>(
-						sprout::math::detail::atan2_impl(
-							static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(y),
-							static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)
-							)
-						)
-#endif
-					;
-			}
-			template<
-				typename ArithmeticType1,
-				typename ArithmeticType2,
-				typename sprout::enabler_if<
-					std::is_arithmetic<ArithmeticType1>::value && std::is_arithmetic<ArithmeticType2>::value
-				>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type
-			atan2(ArithmeticType1 y, ArithmeticType2 x) {
-				typedef typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type type;
-				return sprout::math::detail::atan2(static_cast<type>(y), static_cast<type>(x));
-			}
 		}	// namespace detail
 		//
+		// atan2
+		//
 		// issue:
 		//	[ !SPROUT_USE_BUILTIN_CMATH_FUNCTION ]
 		//	atan2(�}0, -0) returns �}�� .
@@ -101,7 +63,60 @@ namespace sprout {
 		//	atan2(-NaN, -NaN) returns -NaN .
 		//		# returns +NaN . ( same as atan2(+NaN, +NaN) )
 		//
-		using sprout::math::detail::atan2;
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR FloatType
+		atan2(FloatType y, FloatType x) {
+			return sprout::math::isnan(y)
+					? sprout::math::isnan(x)
+						? sprout::math::signbit(y) && sprout::math::signbit(x) ? -sprout::numeric_limits<FloatType>::quiet_NaN()
+							: sprout::numeric_limits<FloatType>::quiet_NaN()
+						: y
+				: sprout::math::isnan(x) ? x
+				: x == -sprout::numeric_limits<FloatType>::infinity()
+					? y == sprout::numeric_limits<FloatType>::infinity() ? sprout::math::three_quarters_pi<FloatType>()
+						: y == -sprout::numeric_limits<FloatType>::infinity() ? -sprout::math::three_quarters_pi<FloatType>()
+						: sprout::math::copysign(sprout::math::pi<FloatType>(), y)
+				: x == sprout::numeric_limits<FloatType>::infinity()
+					? y == sprout::numeric_limits<FloatType>::infinity() ? sprout::math::quarter_pi<FloatType>()
+						: y == -sprout::numeric_limits<FloatType>::infinity() ? -sprout::math::quarter_pi<FloatType>()
+						: FloatType(0) * y
+				: y == sprout::numeric_limits<FloatType>::infinity() ? sprout::math::half_pi<FloatType>()
+				: y == -sprout::numeric_limits<FloatType>::infinity() ? -sprout::math::half_pi<FloatType>()
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				: sprout::math::detail::builtin_atan2(y, x)
+#else
+				: y == 0
+					? x < 0 ? sprout::math::copysign(sprout::math::pi<FloatType>(), y)
+						: x > 0 ? FloatType(0) * y
+						: sprout::math::signbit(x) ? sprout::math::copysign(sprout::math::pi<FloatType>(), y)
+						: FloatType(0) * y
+				: x == 0
+					? y < 0 ? -sprout::math::half_pi<FloatType>()
+						: sprout::math::half_pi<FloatType>()
+				: static_cast<FloatType>(
+					sprout::math::detail::atan2_impl(
+						static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(y),
+						static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)
+						)
+					)
+#endif
+				;
+		}
+		template<
+			typename ArithmeticType1,
+			typename ArithmeticType2,
+			typename sprout::enabler_if<
+				std::is_arithmetic<ArithmeticType1>::value && std::is_arithmetic<ArithmeticType2>::value
+			>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type
+		atan2(ArithmeticType1 y, ArithmeticType2 x) {
+			typedef typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type type;
+			return sprout::math::atan2(static_cast<type>(y), static_cast<type>(x));
+		}
 	}	// namespace math
 
 	using sprout::math::atan2;
diff --git a/sprout/math/atanh.hpp b/sprout/math/atanh.hpp
index bae28cae..fba2f50d 100644
--- a/sprout/math/atanh.hpp
+++ b/sprout/math/atanh.hpp
@@ -21,41 +21,56 @@
 namespace sprout {
 	namespace math {
 		namespace detail {
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+			inline SPROUT_CONSTEXPR float
+			builtin_atanh(float x) {
+				return __builtin_atanhf(x);
+			}
+			inline SPROUT_CONSTEXPR double
+			builtin_atanh(double x) {
+				return __builtin_atanh(x);
+			}
+			inline SPROUT_CONSTEXPR long double
+			builtin_atanh(long double x) {
+				return __builtin_atanhl(x);
+			}
+#endif
+
 			template<typename T>
 			inline SPROUT_CONSTEXPR T
 			atanh_impl(T x) {
 				return sprout::math::log((1 + x) / (1 - x)) / 2;
 			}
-
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR FloatType
-			atanh(FloatType x) {
-				return sprout::math::isnan(x) ? x
-					: x == 1 ? sprout::numeric_limits<FloatType>::infinity()
-					: x == -1 ? -sprout::numeric_limits<FloatType>::infinity()
-					: sprout::math::fabs(x) > 1 ? -sprout::numeric_limits<FloatType>::quiet_NaN()
-#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
-					: std::atanh(x)
-#else
-					: x == 0 ? x
-					: static_cast<FloatType>(sprout::math::detail::atanh_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
-#endif
-					;
-			}
-			template<
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR double
-			atanh(IntType x) {
-				return sprout::math::detail::atanh(static_cast<double>(x));
-			}
 		}	// namespace detail
-
-		using sprout::math::detail::atanh;
+		//
+		// atanh
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR FloatType
+		atanh(FloatType x) {
+			return sprout::math::isnan(x) ? x
+				: x == 1 ? sprout::numeric_limits<FloatType>::infinity()
+				: x == -1 ? -sprout::numeric_limits<FloatType>::infinity()
+				: sprout::math::fabs(x) > 1 ? -sprout::numeric_limits<FloatType>::quiet_NaN()
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				: sprout::math::detail::builtin_atanh(x)
+#else
+				: x == 0 ? x
+				: static_cast<FloatType>(sprout::math::detail::atanh_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
+#endif
+				;
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR double
+		atanh(IntType x) {
+			return sprout::math::atanh(static_cast<double>(x));
+		}
 	}	// namespace math
 
 	using sprout::math::atanh;
diff --git a/sprout/math/cbrt.hpp b/sprout/math/cbrt.hpp
index 2f639f30..b8fd360c 100644
--- a/sprout/math/cbrt.hpp
+++ b/sprout/math/cbrt.hpp
@@ -21,6 +21,21 @@
 namespace sprout {
 	namespace math {
 		namespace detail {
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+			inline SPROUT_CONSTEXPR float
+			builtin_cbrt(float x) {
+				return __builtin_cbrtf(x);
+			}
+			inline SPROUT_CONSTEXPR double
+			builtin_cbrt(double x) {
+				return __builtin_cbrt(x);
+			}
+			inline SPROUT_CONSTEXPR long double
+			builtin_cbrt(long double x) {
+				return __builtin_cbrtl(x);
+			}
+#endif
+
 			template<typename T>
 			inline SPROUT_CONSTEXPR T
 			cbrt_impl(T x) {
@@ -28,36 +43,36 @@ namespace sprout {
 					: sprout::pow(x, sprout::math::third<T>())
 					;
 			}
-
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR FloatType
-			cbrt(FloatType x) {
-				return sprout::math::isnan(x) ? x
-					: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
-					: x == -sprout::numeric_limits<FloatType>::infinity() ? -sprout::numeric_limits<FloatType>::infinity()
-#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
-					: std::cbrt(x)
-#else
-					: x == 0 ? x
-					: static_cast<FloatType>(sprout::math::detail::cbrt_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
-#endif
-					;
-			}
-
-			template<
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR double
-			cbrt(IntType x) {
-				return sprout::math::detail::cbrt(static_cast<double>(x));
-			}
 		}	// namespace detail
+		//
+		// cbrt
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR FloatType
+		cbrt(FloatType x) {
+			return sprout::math::isnan(x) ? x
+				: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
+				: x == -sprout::numeric_limits<FloatType>::infinity() ? -sprout::numeric_limits<FloatType>::infinity()
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				: sprout::math::detail::builtin_cbrt(x)
+#else
+				: x == 0 ? x
+				: static_cast<FloatType>(sprout::math::detail::cbrt_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
+#endif
+				;
+		}
 
-		using sprout::math::detail::cbrt;
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR double
+		cbrt(IntType x) {
+			return sprout::math::cbrt(static_cast<double>(x));
+		}
 	}	// namespace math
 
 	using sprout::math::cbrt;
diff --git a/sprout/math/ceil.hpp b/sprout/math/ceil.hpp
index a8384fbc..1a457d5e 100644
--- a/sprout/math/ceil.hpp
+++ b/sprout/math/ceil.hpp
@@ -22,6 +22,21 @@
 namespace sprout {
 	namespace math {
 		namespace detail {
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+			inline SPROUT_CONSTEXPR float
+			builtin_ceil(float x) {
+				return __builtin_ceilf(x);
+			}
+			inline SPROUT_CONSTEXPR double
+			builtin_ceil(double x) {
+				return __builtin_ceil(x);
+			}
+			inline SPROUT_CONSTEXPR long double
+			builtin_ceil(long double x) {
+				return __builtin_ceill(x);
+			}
+#endif
+
 			template<typename T>
 			inline SPROUT_CONSTEXPR T
 			ceil_impl_1(T x, T x0) {
@@ -36,37 +51,37 @@ namespace sprout {
 					: sprout::math::detail::ceil_impl_1(x, static_cast<T>(static_cast<std::uintmax_t>(x)))
 					;
 			}
-
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR FloatType
-			ceil(FloatType x) {
-				return sprout::math::isnan(x) ? x
-					: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
-					: x == -sprout::numeric_limits<FloatType>::infinity() ? -sprout::numeric_limits<FloatType>::infinity()
-#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
-					: std::ceil(x)
-#else
-					: x == 0 ? x
-					: sprout::numeric_limits<std::uintmax_t>::max() < x || sprout::numeric_limits<std::uintmax_t>::max() < -x
-						? SPROUT_MATH_THROW_LARGE_FLOAT_ROUNDING(std::runtime_error("ceil: large float rounding."), x)
-					: static_cast<FloatType>(sprout::math::detail::ceil_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
-#endif
-					;
-			}
-			template<
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR double
-			ceil(IntType x) {
-				return sprout::math::detail::ceil(static_cast<double>(x));
-			}
 		}	// namespace detail
-
-		using sprout::math::detail::ceil;
+		//
+		// ceil
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR FloatType
+		ceil(FloatType x) {
+			return sprout::math::isnan(x) ? x
+				: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
+				: x == -sprout::numeric_limits<FloatType>::infinity() ? -sprout::numeric_limits<FloatType>::infinity()
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				: sprout::math::detail::builtin_ceil(x)
+#else
+				: x == 0 ? x
+				: sprout::numeric_limits<std::uintmax_t>::max() < x || sprout::numeric_limits<std::uintmax_t>::max() < -x
+					? SPROUT_MATH_THROW_LARGE_FLOAT_ROUNDING(std::runtime_error("ceil: large float rounding."), x)
+				: static_cast<FloatType>(sprout::math::detail::ceil_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
+#endif
+				;
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR double
+		ceil(IntType x) {
+			return sprout::math::ceil(static_cast<double>(x));
+		}
 	}	// namespace math
 
 	using sprout::math::ceil;
diff --git a/sprout/math/copysign.hpp b/sprout/math/copysign.hpp
index 497cf9d7..311b69bf 100644
--- a/sprout/math/copysign.hpp
+++ b/sprout/math/copysign.hpp
@@ -20,38 +20,24 @@
 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
-			copysign(FloatType x, FloatType y) {
-				return x == 0
-						? y == 0 ? y
-							: sprout::math::signbit(y) ? -FloatType(0)
-							: FloatType(0)
-					: sprout::math::isnan(x)
-						? sprout::math::isnan(y) ? y
-							: sprout::math::signbit(y) ? -sprout::numeric_limits<FloatType>::quiet_NaN()
-							: sprout::numeric_limits<FloatType>::quiet_NaN()
-					: sprout::math::signbit(y) != sprout::math::signbit(x) ? -x
-					: x
-					;
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+			inline SPROUT_CONSTEXPR float
+			builtin_copysign(float x, float y) {
+				return __builtin_copysignf(x, y);
 			}
-			template<
-				typename ArithmeticType1,
-				typename ArithmeticType2,
-				typename sprout::enabler_if<
-					std::is_arithmetic<ArithmeticType1>::value && std::is_arithmetic<ArithmeticType2>::value
-				>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type
-			copysign(ArithmeticType1 x, ArithmeticType2 y) {
-				typedef typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type type;
-				return sprout::math::detail::copysign(static_cast<type>(x), static_cast<type>(y));
+			inline SPROUT_CONSTEXPR double
+			builtin_copysign(double x, double y) {
+				return __builtin_copysign(x, y);
 			}
+			inline SPROUT_CONSTEXPR long double
+			builtin_copysign(long double x, long double y) {
+				return __builtin_copysignl(x, y);
+			}
+#endif
 		}	// namespace detail
 		//
+		// copysign
+		//
 		// issue:
 		//	[ !SPROUT_USE_BUILTIN_CMATH_FUNCTION ]
 		//	copysign(�}x, -0) returns -x for |x| is not 0 .
@@ -59,7 +45,42 @@ namespace sprout {
 		//	copysign(�}x, -NaN) returns -x for |x| is not NaN .
 		//		# returns +x . ( same as copysign(�}x, +NaN) )
 		//
-		using NS_SPROUT_MATH_DETAIL::copysign;
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR FloatType
+		copysign(FloatType x, FloatType y) {
+			return
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				sprout::math::detail::builtin_copysign(x, y)
+#else
+				x == 0
+					? y == 0 ? y
+						: sprout::math::signbit(y) ? -FloatType(0)
+						: FloatType(0)
+				: sprout::math::isnan(x)
+					? sprout::math::isnan(y) ? y
+						: sprout::math::signbit(y) ? -sprout::numeric_limits<FloatType>::quiet_NaN()
+						: sprout::numeric_limits<FloatType>::quiet_NaN()
+				: sprout::math::signbit(y) != sprout::math::signbit(x) ? -x
+				: x
+#endif
+				;
+		}
+
+		template<
+			typename ArithmeticType1,
+			typename ArithmeticType2,
+			typename sprout::enabler_if<
+				std::is_arithmetic<ArithmeticType1>::value && std::is_arithmetic<ArithmeticType2>::value
+			>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type
+		copysign(ArithmeticType1 x, ArithmeticType2 y) {
+			typedef typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type type;
+			return sprout::math::copysign(static_cast<type>(x), static_cast<type>(y));
+		}
 	}	// namespace math
 
 	using sprout::math::copysign;
diff --git a/sprout/math/cos.hpp b/sprout/math/cos.hpp
index c27e58a7..5cf528dd 100644
--- a/sprout/math/cos.hpp
+++ b/sprout/math/cos.hpp
@@ -27,6 +27,21 @@
 namespace sprout {
 	namespace math {
 		namespace detail {
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+			inline SPROUT_CONSTEXPR float
+			builtin_cos(float x) {
+				return __builtin_cosf(x);
+			}
+			inline SPROUT_CONSTEXPR double
+			builtin_cos(double x) {
+				return __builtin_cos(x);
+			}
+			inline SPROUT_CONSTEXPR long double
+			builtin_cos(long double x) {
+				return __builtin_cosl(x);
+			}
+#endif
+
 			template<typename T>
 			inline SPROUT_CONSTEXPR T
 			cos_impl_1(T x2, std::size_t n, std::size_t last) {
@@ -70,35 +85,35 @@ namespace sprout {
 //			cos_impl(T x) {
 //				return sprout::math::detail::cos_impl_1(sprout::math::fmod(sprout::math::fabs(x), sprout::math::two_pi<T>()));
 //			}
-
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR FloatType
-			cos(FloatType x) {
-				return sprout::math::isnan(x) ? x
-					: x == sprout::numeric_limits<FloatType>::infinity() || x == -sprout::numeric_limits<FloatType>::infinity()
-						? -sprout::numeric_limits<FloatType>::quiet_NaN()
-#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
-					: std::cos(x)
-#else
-					: x == 0 ? FloatType(1)
-					: static_cast<FloatType>(sprout::math::detail::cos_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
-#endif
-					;
-			}
-			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
-
-		using sprout::math::detail::cos;
+		//
+		// cos
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR FloatType
+		cos(FloatType x) {
+			return sprout::math::isnan(x) ? x
+				: x == sprout::numeric_limits<FloatType>::infinity() || x == -sprout::numeric_limits<FloatType>::infinity()
+					? -sprout::numeric_limits<FloatType>::quiet_NaN()
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				: sprout::math::detail::builtin_cos(x)
+#else
+				: x == 0 ? FloatType(1)
+				: static_cast<FloatType>(sprout::math::detail::cos_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
+#endif
+				;
+		}
+		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::cos(static_cast<double>(x));
+		}
 	}	// namespace math
 
 	using sprout::math::cos;
diff --git a/sprout/math/cosh.hpp b/sprout/math/cosh.hpp
index f9f1516a..ef98e2ac 100644
--- a/sprout/math/cosh.hpp
+++ b/sprout/math/cosh.hpp
@@ -21,6 +21,21 @@
 namespace sprout {
 	namespace math {
 		namespace detail {
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+			inline SPROUT_CONSTEXPR float
+			builtin_cosh(float x) {
+				return __builtin_coshf(x);
+			}
+			inline SPROUT_CONSTEXPR double
+			builtin_cosh(double x) {
+				return __builtin_cosh(x);
+			}
+			inline SPROUT_CONSTEXPR long double
+			builtin_cosh(long double x) {
+				return __builtin_coshl(x);
+			}
+#endif
+
 			template<typename T>
 			inline SPROUT_CONSTEXPR T
 			cosh_impl_1(T t) {
@@ -31,35 +46,35 @@ namespace sprout {
 			cosh_impl(T x) {
 				return sprout::math::detail::cosh_impl_1(sprout::math::exp(x));
 			}
-
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR FloatType
-			cosh(FloatType x) {
-				return sprout::math::isnan(x) ? x
-					: x == sprout::numeric_limits<FloatType>::infinity() || x == -sprout::numeric_limits<FloatType>::infinity()
-						? sprout::numeric_limits<FloatType>::infinity()
-#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
-					: std::cosh(x)
-#else
-					: x == 0 ? FloatType(1)
-					: static_cast<FloatType>(sprout::math::detail::cosh_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
-#endif
-					;
-			}
-			template<
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR double
-			cosh(IntType x) {
-				return sprout::math::detail::cosh(static_cast<double>(x));
-			}
 		}	// namespace detail
-
-		using sprout::math::detail::cosh;
+		//
+		// cosh
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR FloatType
+		cosh(FloatType x) {
+			return sprout::math::isnan(x) ? x
+				: x == sprout::numeric_limits<FloatType>::infinity() || x == -sprout::numeric_limits<FloatType>::infinity()
+					? sprout::numeric_limits<FloatType>::infinity()
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				: sprout::math::detail::builtin_cosh(x)
+#else
+				: x == 0 ? FloatType(1)
+				: static_cast<FloatType>(sprout::math::detail::cosh_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
+#endif
+				;
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR double
+		cosh(IntType x) {
+			return sprout::math::cosh(static_cast<double>(x));
+		}
 	}	// namespace math
 
 	using sprout::math::cosh;
diff --git a/sprout/math/detail/config.hpp b/sprout/math/detail/config.hpp
index d15f0f2c..46f5bb19 100644
--- a/sprout/math/detail/config.hpp
+++ b/sprout/math/detail/config.hpp
@@ -14,12 +14,6 @@
 #	include <cmath>
 #endif
 
-#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
-#	define NS_SPROUT_MATH_DETAIL std
-#else	// #ifndef SPROUT_USE_BUILTIN_CMATH_FUNCTION
-#	define NS_SPROUT_MATH_DETAIL sprout::math::detail
-#endif	// #ifndef SPROUT_USE_BUILTIN_CMATH_FUNCTION
-
 #if (FLT_RADIX == 2)
 #	define SPROUT_FLT_RADIX_IS_2 1
 #else
diff --git a/sprout/math/erf.hpp b/sprout/math/erf.hpp
index 7620a66a..2d3a08e2 100644
--- a/sprout/math/erf.hpp
+++ b/sprout/math/erf.hpp
@@ -22,6 +22,21 @@
 namespace sprout {
 	namespace math {
 		namespace detail {
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+			inline SPROUT_CONSTEXPR float
+			builtin_erf(float x) {
+				return __builtin_erff(x);
+			}
+			inline SPROUT_CONSTEXPR double
+			builtin_erf(double x) {
+				return __builtin_erf(x);
+			}
+			inline SPROUT_CONSTEXPR long double
+			builtin_erf(long double x) {
+				return __builtin_erfl(x);
+			}
+#endif
+
 			template<typename T>
 			inline SPROUT_CONSTEXPR T
 			erf_impl_3(T x, T y) {
@@ -125,35 +140,35 @@ namespace sprout {
 			erf_impl(T x) {
 				return sprout::math::detail::erf_impl_1(x, x < 0 ? -x : x);
 			}
-
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR FloatType
-			erf(FloatType x) {
-				return sprout::math::isnan(x) ? x
-					: x == sprout::numeric_limits<FloatType>::infinity() ? FloatType(1)
-					: x == -sprout::numeric_limits<FloatType>::infinity() ? FloatType(-1)
-#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
-					: std::erf(x)
-#else
-					: x == 0 ? x
-					: static_cast<FloatType>(sprout::math::detail::erf_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
-#endif
-					;
-			}
-			template<
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR double
-			erf(IntType x) {
-				return sprout::math::detail::erf(static_cast<double>(x));
-			}
 		}	// namespace detail
-
-		using sprout::math::detail::erf;
+		//
+		// erf
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR FloatType
+		erf(FloatType x) {
+			return sprout::math::isnan(x) ? x
+				: x == sprout::numeric_limits<FloatType>::infinity() ? FloatType(1)
+				: x == -sprout::numeric_limits<FloatType>::infinity() ? FloatType(-1)
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				: sprout::math::detail::builtin_erf(x)
+#else
+				: x == 0 ? x
+				: static_cast<FloatType>(sprout::math::detail::erf_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
+#endif
+				;
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR double
+		erf(IntType x) {
+			return sprout::math::erf(static_cast<double>(x));
+		}
 	}	// namespace math
 
 	using sprout::math::erf;
diff --git a/sprout/math/erfc.hpp b/sprout/math/erfc.hpp
index f09165e9..44cdd3a9 100644
--- a/sprout/math/erfc.hpp
+++ b/sprout/math/erfc.hpp
@@ -19,39 +19,54 @@
 namespace sprout {
 	namespace math {
 		namespace detail {
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+			inline SPROUT_CONSTEXPR float
+			builtin_erfc(float x) {
+				return __builtin_erfcf(x);
+			}
+			inline SPROUT_CONSTEXPR double
+			builtin_erfc(double x) {
+				return __builtin_erfc(x);
+			}
+			inline SPROUT_CONSTEXPR long double
+			builtin_erfc(long double x) {
+				return __builtin_erfcl(x);
+			}
+#endif
+
 			template<typename T>
 			inline SPROUT_CONSTEXPR T
 			erfc_impl(T x) {
 				return T(1) - sprout::math::erf(x);
 			}
-
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR FloatType
-			erfc(FloatType x) {
-				return sprout::math::isnan(x) ? x
-					: x == sprout::numeric_limits<FloatType>::infinity() ? FloatType(0)
-					: x == -sprout::numeric_limits<FloatType>::infinity() ? FloatType(2)
-#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
-					: std::erfc(x)
-#else
-					: static_cast<FloatType>(sprout::math::detail::erfc_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
-#endif
-					;
-			}
-			template<
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR double
-			erfc(IntType x) {
-				return sprout::math::detail::erfc(static_cast<double>(x));
-			}
 		}	// namespace detail
-
-		using sprout::math::detail::erfc;
+		//
+		// erfc
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR FloatType
+		erfc(FloatType x) {
+			return sprout::math::isnan(x) ? x
+				: x == sprout::numeric_limits<FloatType>::infinity() ? FloatType(0)
+				: x == -sprout::numeric_limits<FloatType>::infinity() ? FloatType(2)
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				: sprout::math::detail::builtin_erfc(x)
+#else
+				: static_cast<FloatType>(sprout::math::detail::erfc_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
+#endif
+				;
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR double
+		erfc(IntType x) {
+			return sprout::math::erfc(static_cast<double>(x));
+		}
 	}	// namespace math
 
 	using sprout::math::erfc;
diff --git a/sprout/math/exp.hpp b/sprout/math/exp.hpp
index 8d8d6286..0546734d 100644
--- a/sprout/math/exp.hpp
+++ b/sprout/math/exp.hpp
@@ -22,6 +22,21 @@
 namespace sprout {
 	namespace math {
 		namespace detail {
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+			inline SPROUT_CONSTEXPR float
+			builtin_exp(float x) {
+				return __builtin_expf(x);
+			}
+			inline SPROUT_CONSTEXPR double
+			builtin_exp(double x) {
+				return __builtin_exp(x);
+			}
+			inline SPROUT_CONSTEXPR long double
+			builtin_exp(long double x) {
+				return __builtin_expl(x);
+			}
+#endif
+
 			template<typename T>
 			inline SPROUT_CONSTEXPR T
 			exp_impl_1(T x, std::size_t n, std::size_t last) {
@@ -38,35 +53,35 @@ namespace sprout {
 					: T(1) + sprout::math::detail::exp_impl_1(x, 1, sprout::math::factorial_limit<T>() / 2 + 1)
 					;
 			}
-
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR FloatType
-			exp(FloatType x) {
-				return sprout::math::isnan(x) ? x
-					: x == -sprout::numeric_limits<FloatType>::infinity() ? FloatType(0)
-					: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
-#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
-					: std::exp(x)
-#else
-					: x == 0 ? FloatType(1)
-					: static_cast<FloatType>(sprout::math::detail::exp_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
-#endif
-					;
-			}
-			template<
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR double
-			exp(IntType x) {
-				return sprout::math::detail::exp(static_cast<double>(x));
-			}
 		}	// namespace detail
-
-		using sprout::math::detail::exp;
+		//
+		// exp
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR FloatType
+		exp(FloatType x) {
+			return sprout::math::isnan(x) ? x
+				: x == -sprout::numeric_limits<FloatType>::infinity() ? FloatType(0)
+				: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				: sprout::math::detail::builtin_exp(x)
+#else
+				: x == 0 ? FloatType(1)
+				: static_cast<FloatType>(sprout::math::detail::exp_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
+#endif
+				;
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR double
+		exp(IntType x) {
+			return sprout::math::exp(static_cast<double>(x));
+		}
 	}	// namespace math
 
 	using sprout::math::exp;
diff --git a/sprout/math/exp10.hpp b/sprout/math/exp10.hpp
index 93a1ab59..805567df 100644
--- a/sprout/math/exp10.hpp
+++ b/sprout/math/exp10.hpp
@@ -26,31 +26,31 @@ namespace sprout {
 			exp10_impl(T x) {
 				return sprout::math::exp(x * sprout::math::ln_ten<T>());
 			}
-
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR FloatType
-			exp10(FloatType x) {
-				return sprout::math::isnan(x) ? x
-					: x == -sprout::numeric_limits<FloatType>::infinity() ? FloatType(0)
-					: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
-					: x == 0 ? FloatType(1)
-					: static_cast<FloatType>(sprout::math::detail::exp10_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
-					;
-			}
-			template<
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR double
-			exp10(IntType x) {
-				return sprout::math::detail::exp10(static_cast<double>(x));
-			}
 		}	// namespace detail
-
-		using sprout::math::detail::exp10;
+		//
+		// exp10
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR FloatType
+		exp10(FloatType x) {
+			return sprout::math::isnan(x) ? x
+				: x == -sprout::numeric_limits<FloatType>::infinity() ? FloatType(0)
+				: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
+				: x == 0 ? FloatType(1)
+				: static_cast<FloatType>(sprout::math::detail::exp10_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
+				;
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR double
+		exp10(IntType x) {
+			return sprout::math::exp10(static_cast<double>(x));
+		}
 	}	// namespace math
 
 	using sprout::math::exp10;
diff --git a/sprout/math/exp2.hpp b/sprout/math/exp2.hpp
index c02196d8..008b0aaf 100644
--- a/sprout/math/exp2.hpp
+++ b/sprout/math/exp2.hpp
@@ -21,40 +21,56 @@
 namespace sprout {
 	namespace math {
 		namespace detail {
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+			inline SPROUT_CONSTEXPR float
+			builtin_exp2(float x) {
+				return __builtin_exp2f(x);
+			}
+			inline SPROUT_CONSTEXPR double
+			builtin_exp2(double x) {
+				return __builtin_exp2(x);
+			}
+			inline SPROUT_CONSTEXPR long double
+			builtin_exp2(long double x) {
+				return __builtin_exp2l(x);
+			}
+#endif
+
 			template<typename T>
 			inline SPROUT_CONSTEXPR T
 			exp2_impl(T x) {
 				return sprout::math::exp(x * sprout::math::ln_two<T>());
 			}
 
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR FloatType
-			exp2(FloatType x) {
-				return sprout::math::isnan(x) ? x
-					: x == -sprout::numeric_limits<FloatType>::infinity() ? FloatType(0)
-					: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
-#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
-					: std::exp2(x)
-#else
-					: x == 0 ? FloatType(1)
-					: static_cast<FloatType>(sprout::math::detail::exp2_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
-#endif
-					;
-			}
-			template<
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR double
-			exp2(IntType x) {
-				return sprout::math::detail::exp2(static_cast<double>(x));
-			}
 		}	// namespace detail
-
-		using sprout::math::detail::exp2;
+		//
+		// exp2
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR FloatType
+		exp2(FloatType x) {
+			return sprout::math::isnan(x) ? x
+				: x == -sprout::numeric_limits<FloatType>::infinity() ? FloatType(0)
+				: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				: sprout::math::detail::builtin_exp2(x)
+#else
+				: x == 0 ? FloatType(1)
+				: static_cast<FloatType>(sprout::math::detail::exp2_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
+#endif
+				;
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR double
+		exp2(IntType x) {
+			return sprout::math::exp2(static_cast<double>(x));
+		}
 	}	// namespace math
 
 	using sprout::math::exp2;
diff --git a/sprout/math/expm1.hpp b/sprout/math/expm1.hpp
index 86446a12..a610e62a 100644
--- a/sprout/math/expm1.hpp
+++ b/sprout/math/expm1.hpp
@@ -22,40 +22,55 @@
 namespace sprout {
 	namespace math {
 		namespace detail {
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+			inline SPROUT_CONSTEXPR float
+			builtin_expm1(float x) {
+				return __builtin_expm1f(x);
+			}
+			inline SPROUT_CONSTEXPR double
+			builtin_expm1(double x) {
+				return __builtin_expm1(x);
+			}
+			inline SPROUT_CONSTEXPR long double
+			builtin_expm1(long double x) {
+				return __builtin_expm1l(x);
+			}
+#endif
+
 			template<typename T>
 			inline SPROUT_CONSTEXPR T
 			expm1_impl(T x) {
 				return sprout::math::exp(x) - T(1);
 			}
-
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR FloatType
-			expm1(FloatType x) {
-				return sprout::math::isnan(x) ? x
-					: x == -sprout::numeric_limits<FloatType>::infinity() ? FloatType(-1)
-					: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
-#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
-					: std::expm1(x)
-#else
-					: x == 0 ? x
-					: static_cast<FloatType>(sprout::math::detail::expm1_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
-#endif
-					;
-			}
-			template<
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR double
-			expm1(IntType x) {
-				return sprout::math::detail::expm1(static_cast<double>(x));
-			}
 		}	// namespace detail
-
-		using sprout::math::detail::expm1;
+		//
+		// expm1
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR FloatType
+		expm1(FloatType x) {
+			return sprout::math::isnan(x) ? x
+				: x == -sprout::numeric_limits<FloatType>::infinity() ? FloatType(-1)
+				: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				: sprout::math::detail::builtin_expm1(x)
+#else
+				: x == 0 ? x
+				: static_cast<FloatType>(sprout::math::detail::expm1_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
+#endif
+				;
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR double
+		expm1(IntType x) {
+			return sprout::math::expm1(static_cast<double>(x));
+		}
 	}	// namespace math
 
 	using sprout::math::expm1;
diff --git a/sprout/math/fabs.hpp b/sprout/math/fabs.hpp
index c7da5eee..de6d42e2 100644
--- a/sprout/math/fabs.hpp
+++ b/sprout/math/fabs.hpp
@@ -18,28 +18,48 @@
 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
-			fabs(FloatType x) {
-				return sprout::math::isnan(x) ? sprout::numeric_limits<FloatType>::quiet_NaN()
-					: x == 0 ? FloatType(0)
-					: sprout::math::copysign(x, FloatType(0))
-					;
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+			inline SPROUT_CONSTEXPR float
+			builtin_fabs(float x) {
+				return __builtin_fabsf(x);
 			}
-			template<
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
-			>
 			inline SPROUT_CONSTEXPR double
-			fabs(IntType x) {
-				return sprout::math::detail::fabs(static_cast<double>(x));
+			builtin_fabs(double x) {
+				return __builtin_fabs(x);
 			}
+			inline SPROUT_CONSTEXPR long double
+			builtin_fabs(long double x) {
+				return __builtin_fabsl(x);
+			}
+#endif
 		}	// namespace detail
-
-		using NS_SPROUT_MATH_DETAIL::fabs;
+		//
+		// fabs
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR FloatType
+		fabs(FloatType x) {
+			return
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				sprout::math::detail::builtin_fabs(x)
+#else
+				sprout::math::isnan(x) ? sprout::numeric_limits<FloatType>::quiet_NaN()
+				: x == 0 ? FloatType(0)
+				: sprout::math::copysign(x, FloatType(0))
+#endif
+				;
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR double
+		fabs(IntType x) {
+			return sprout::math::fabs(static_cast<double>(x));
+		}
 	}	// namespace math
 
 	using sprout::math::fabs;
diff --git a/sprout/math/fdim.hpp b/sprout/math/fdim.hpp
index 018a8607..babd7c5e 100644
--- a/sprout/math/fdim.hpp
+++ b/sprout/math/fdim.hpp
@@ -19,40 +19,55 @@
 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
-			fdim(FloatType x, FloatType y) {
-				return sprout::math::isnan(y) ? y
-					: sprout::math::isnan(x) ? x
-					: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
-					: x == -sprout::numeric_limits<FloatType>::infinity() ? FloatType(0)
-					: y == sprout::numeric_limits<FloatType>::infinity() ? FloatType(0)
-					: y == -sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
 #if SPROUT_USE_BUILTIN_CMATH_FUNCTION
-					: std::fdim(x, y)
-#else
-					: x > y ? x - y : FloatType(0)
+			inline SPROUT_CONSTEXPR float
+			builtin_fdim(float x, float y) {
+				return __builtin_fdimf(x, y);
+			}
+			inline SPROUT_CONSTEXPR double
+			builtin_fdim(double x, double y) {
+				return __builtin_fdim(x, y);
+			}
+			inline SPROUT_CONSTEXPR long double
+			builtin_fdim(long double x, long double y) {
+				return __builtin_fdiml(x, y);
+			}
 #endif
-					;
-			}
-			template<
-				typename ArithmeticType1,
-				typename ArithmeticType2,
-				typename sprout::enabler_if<
-					std::is_arithmetic<ArithmeticType1>::value && std::is_arithmetic<ArithmeticType2>::value
-				>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type
-			fdim(ArithmeticType1 x, ArithmeticType2 y) {
-				typedef typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type type;
-				return sprout::math::detail::fdim(static_cast<type>(x), static_cast<type>(y));
-			}
 		}	// namespace detail
-
-		using sprout::math::detail::fdim;
+		//
+		// fdim
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR FloatType
+		fdim(FloatType x, FloatType y) {
+			return sprout::math::isnan(y) ? y
+				: sprout::math::isnan(x) ? x
+				: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
+				: x == -sprout::numeric_limits<FloatType>::infinity() ? FloatType(0)
+				: y == sprout::numeric_limits<FloatType>::infinity() ? FloatType(0)
+				: y == -sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				: sprout::math::detail::builtin_fdim(x, y)
+#else
+				: x > y ? x - y : FloatType(0)
+#endif
+				;
+		}
+		template<
+			typename ArithmeticType1,
+			typename ArithmeticType2,
+			typename sprout::enabler_if<
+				std::is_arithmetic<ArithmeticType1>::value && std::is_arithmetic<ArithmeticType2>::value
+			>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type
+		fdim(ArithmeticType1 x, ArithmeticType2 y) {
+			typedef typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type type;
+			return sprout::math::fdim(static_cast<type>(x), static_cast<type>(y));
+		}
 	}	// namespace math
 
 	using sprout::math::fdim;
diff --git a/sprout/math/float2_exponent.hpp b/sprout/math/float2_exponent.hpp
index a21d88ce..46b8d035 100644
--- a/sprout/math/float2_exponent.hpp
+++ b/sprout/math/float2_exponent.hpp
@@ -18,30 +18,29 @@
 
 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 int
-			float2_exponent(FloatType x) {
-				return sprout::math::isnan(x) ? 0
-					: x == 0 ? 0
-					: x == sprout::numeric_limits<FloatType>::infinity() || x == -sprout::numeric_limits<FloatType>::infinity() ? 0
-					: sprout::math::ilogb2(x) + 1
-					;
-			}
-			template<
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR int
-			float2_exponent(IntType x) {
-				return sprout::math::detail::float2_exponent(static_cast<double>(x));
-			}
-		}	// namespace detail
-
-		using sprout::math::detail::float2_exponent;
+		//
+		// float2_exponent
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR int
+		float2_exponent(FloatType x) {
+			return sprout::math::isnan(x) ? 0
+				: x == 0 ? 0
+				: x == sprout::numeric_limits<FloatType>::infinity() || x == -sprout::numeric_limits<FloatType>::infinity() ? 0
+				: sprout::math::ilogb2(x) + 1
+				;
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR int
+		float2_exponent(IntType x) {
+			return sprout::math::float2_exponent(static_cast<double>(x));
+		}
 	}	// namespace math
 
 	using sprout::math::float2_exponent;
diff --git a/sprout/math/float2_sig_exp.hpp b/sprout/math/float2_sig_exp.hpp
index 4529fd01..5628f791 100644
--- a/sprout/math/float2_sig_exp.hpp
+++ b/sprout/math/float2_sig_exp.hpp
@@ -27,32 +27,32 @@ namespace sprout {
 				typedef sprout::pair<T, int> type;
 				return type(x / sprout::detail::pow_n(T(2), exp), exp);
 			}
-
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR sprout::pair<FloatType, int>
-			float2_sig_exp(FloatType x) {
-				typedef sprout::pair<FloatType, int> type;
-				return sprout::math::isnan(x) ? type(x, 0)
-					: x == sprout::numeric_limits<FloatType>::infinity() ? type(sprout::numeric_limits<FloatType>::infinity(), 0)
-					: x == -sprout::numeric_limits<FloatType>::infinity() ? type(-sprout::numeric_limits<FloatType>::infinity(), 0)
-					: x == 0 ? type(x, 0)
-					: sprout::math::detail::float2_sig_exp_impl(x, sprout::math::ilogb2(x) + 1)
-					;
-			}
-			template<
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR sprout::pair<double, int>
-			float2_sig_exp(IntType x) {
-				return sprout::math::detail::float2_sig_exp(static_cast<double>(x));
-			}
 		}	// namespace detail
-
-		using sprout::math::detail::float2_sig_exp;
+		//
+		// float2_sig_exp
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR sprout::pair<FloatType, int>
+		float2_sig_exp(FloatType x) {
+			typedef sprout::pair<FloatType, int> type;
+			return sprout::math::isnan(x) ? type(x, 0)
+				: x == sprout::numeric_limits<FloatType>::infinity() ? type(sprout::numeric_limits<FloatType>::infinity(), 0)
+				: x == -sprout::numeric_limits<FloatType>::infinity() ? type(-sprout::numeric_limits<FloatType>::infinity(), 0)
+				: x == 0 ? type(x, 0)
+				: sprout::math::detail::float2_sig_exp_impl(x, sprout::math::ilogb2(x) + 1)
+				;
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR sprout::pair<double, int>
+		float2_sig_exp(IntType x) {
+			return sprout::math::float2_sig_exp(static_cast<double>(x));
+		}
 	}	// namespace math
 
 	using sprout::math::float2_sig_exp;
diff --git a/sprout/math/float2_significand.hpp b/sprout/math/float2_significand.hpp
index 462d99f4..38ac9250 100644
--- a/sprout/math/float2_significand.hpp
+++ b/sprout/math/float2_significand.hpp
@@ -19,31 +19,30 @@
 
 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
-			float2_significand(FloatType x) {
-				return sprout::math::isnan(x) ? x
-					: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
-					: x == -sprout::numeric_limits<FloatType>::infinity() ? -sprout::numeric_limits<FloatType>::infinity()
-					: x == 0 ? x
-					: x / sprout::detail::pow_n(FloatType(2), sprout::float2_exponent(x))
-					;
-			}
-			template<
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR double
-			float2_significand(IntType x) {
-				return sprout::math::detail::float_significand(static_cast<double>(x));
-			}
-		}	// namespace detail
-
-		using sprout::math::detail::float2_significand;
+		//
+		// float2_significand
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR FloatType
+		float2_significand(FloatType x) {
+			return sprout::math::isnan(x) ? x
+				: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
+				: x == -sprout::numeric_limits<FloatType>::infinity() ? -sprout::numeric_limits<FloatType>::infinity()
+				: x == 0 ? x
+				: x / sprout::detail::pow_n(FloatType(2), sprout::float2_exponent(x))
+				;
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR double
+		float2_significand(IntType x) {
+			return sprout::math::float_significand(static_cast<double>(x));
+		}
 	}	// namespace math
 
 	using sprout::math::float2_significand;
diff --git a/sprout/math/float_exponent.hpp b/sprout/math/float_exponent.hpp
index b36cbf2c..0c8392ea 100644
--- a/sprout/math/float_exponent.hpp
+++ b/sprout/math/float_exponent.hpp
@@ -18,30 +18,29 @@
 
 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 int
-			float_exponent(FloatType x) {
-				return sprout::math::isnan(x) ? 0
-					: x == 0 ? 0
-					: x == sprout::numeric_limits<FloatType>::infinity() || x == -sprout::numeric_limits<FloatType>::infinity() ? 0
-					: sprout::math::ilogb(x) + 1
-					;
-			}
-			template<
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR int
-			float_exponent(IntType x) {
-				return sprout::math::detail::float_exponent(static_cast<double>(x));
-			}
-		}	// namespace detail
-
-		using sprout::math::detail::float_exponent;
+		//
+		// float_exponent
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR int
+		float_exponent(FloatType x) {
+			return sprout::math::isnan(x) ? 0
+				: x == 0 ? 0
+				: x == sprout::numeric_limits<FloatType>::infinity() || x == -sprout::numeric_limits<FloatType>::infinity() ? 0
+				: sprout::math::ilogb(x) + 1
+				;
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR int
+		float_exponent(IntType x) {
+			return sprout::math::float_exponent(static_cast<double>(x));
+		}
 	}	// namespace math
 
 	using sprout::math::float_exponent;
diff --git a/sprout/math/float_sig_exp.hpp b/sprout/math/float_sig_exp.hpp
index 20be698c..833a12ff 100644
--- a/sprout/math/float_sig_exp.hpp
+++ b/sprout/math/float_sig_exp.hpp
@@ -27,32 +27,32 @@ namespace sprout {
 				typedef sprout::pair<T, int> type;
 				return type(x / sprout::detail::pow_n(T(sprout::numeric_limits<T>::radix), exp), exp);
 			}
-
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR sprout::pair<FloatType, int>
-			float_sig_exp(FloatType x) {
-				typedef sprout::pair<FloatType, int> type;
-				return sprout::math::isnan(x) ? type(x, 0)
-					: x == sprout::numeric_limits<FloatType>::infinity() ? type(sprout::numeric_limits<FloatType>::infinity(), 0)
-					: x == -sprout::numeric_limits<FloatType>::infinity() ? type(-sprout::numeric_limits<FloatType>::infinity(), 0)
-					: x == 0 ? type(x, 0)
-					: sprout::math::detail::float_sig_exp_impl(x, sprout::math::ilogb(x) + 1)
-					;
-			}
-			template<
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR sprout::pair<double, int>
-			float_sig_exp(IntType x) {
-				return sprout::math::detail::float_sig_exp(static_cast<double>(x));
-			}
 		}	// namespace detail
-
-		using sprout::math::detail::float_sig_exp;
+		//
+		// float_sig_exp
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR sprout::pair<FloatType, int>
+		float_sig_exp(FloatType x) {
+			typedef sprout::pair<FloatType, int> type;
+			return sprout::math::isnan(x) ? type(x, 0)
+				: x == sprout::numeric_limits<FloatType>::infinity() ? type(sprout::numeric_limits<FloatType>::infinity(), 0)
+				: x == -sprout::numeric_limits<FloatType>::infinity() ? type(-sprout::numeric_limits<FloatType>::infinity(), 0)
+				: x == 0 ? type(x, 0)
+				: sprout::math::detail::float_sig_exp_impl(x, sprout::math::ilogb(x) + 1)
+				;
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR sprout::pair<double, int>
+		float_sig_exp(IntType x) {
+			return sprout::math::float_sig_exp(static_cast<double>(x));
+		}
 	}	// namespace math
 
 	using sprout::math::float_sig_exp;
diff --git a/sprout/math/float_significand.hpp b/sprout/math/float_significand.hpp
index 677d8c00..61dfda06 100644
--- a/sprout/math/float_significand.hpp
+++ b/sprout/math/float_significand.hpp
@@ -19,31 +19,30 @@
 
 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
-			float_significand(FloatType x) {
-				return sprout::math::isnan(x) ? x
-					: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
-					: x == -sprout::numeric_limits<FloatType>::infinity() ? -sprout::numeric_limits<FloatType>::infinity()
-					: x == 0 ? x
-					: x / sprout::detail::pow_n(FloatType(sprout::numeric_limits<FloatType>::radix), sprout::float_exponent(x))
-					;
-			}
-			template<
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR double
-			float_significand(IntType x) {
-				return sprout::math::detail::float_significand(static_cast<double>(x));
-			}
-		}	// namespace detail
-
-		using sprout::math::detail::float_significand;
+		//
+		// float_significand
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR FloatType
+		float_significand(FloatType x) {
+			return sprout::math::isnan(x) ? x
+				: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
+				: x == -sprout::numeric_limits<FloatType>::infinity() ? -sprout::numeric_limits<FloatType>::infinity()
+				: x == 0 ? x
+				: x / sprout::detail::pow_n(FloatType(sprout::numeric_limits<FloatType>::radix), sprout::float_exponent(x))
+				;
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR double
+		float_significand(IntType x) {
+			return sprout::math::float_significand(static_cast<double>(x));
+		}
 	}	// namespace math
 
 	using sprout::math::float_significand;
diff --git a/sprout/math/floor.hpp b/sprout/math/floor.hpp
index fe6969cc..47738ad5 100644
--- a/sprout/math/floor.hpp
+++ b/sprout/math/floor.hpp
@@ -22,6 +22,21 @@
 namespace sprout {
 	namespace math {
 		namespace detail {
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+			inline SPROUT_CONSTEXPR float
+			builtin_floor(float x) {
+				return __builtin_floorf(x);
+			}
+			inline SPROUT_CONSTEXPR double
+			builtin_floor(double x) {
+				return __builtin_floor(x);
+			}
+			inline SPROUT_CONSTEXPR long double
+			builtin_floor(long double x) {
+				return __builtin_floorl(x);
+			}
+#endif
+
 			template<typename T>
 			inline SPROUT_CONSTEXPR T
 			floor_impl_1(T x, T x0) {
@@ -36,37 +51,37 @@ namespace sprout {
 					: static_cast<T>(static_cast<std::uintmax_t>(x))
 					;
 			}
-
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR FloatType
-			floor(FloatType x) {
-				return sprout::math::isnan(x) ? x
-					: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
-					: x == -sprout::numeric_limits<FloatType>::infinity() ? -sprout::numeric_limits<FloatType>::infinity()
-#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
-					: std::floor(x)
-#else
-					: x == 0 ? x
-					: sprout::numeric_limits<std::uintmax_t>::max() < x || sprout::numeric_limits<std::uintmax_t>::max() < -x
-						? SPROUT_MATH_THROW_LARGE_FLOAT_ROUNDING(std::runtime_error("floor: large float rounding."), x)
-					: static_cast<FloatType>(sprout::math::detail::floor_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
-#endif
-					;
-			}
-			template<
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR double
-			floor(IntType x) {
-				return sprout::math::detail::floor(static_cast<double>(x));
-			}
 		}	// namespace detail
-
-		using sprout::math::detail::floor;
+		//
+		// floor
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR FloatType
+		floor(FloatType x) {
+			return sprout::math::isnan(x) ? x
+				: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
+				: x == -sprout::numeric_limits<FloatType>::infinity() ? -sprout::numeric_limits<FloatType>::infinity()
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				: sprout::math::detail::builtin_floor(x)
+#else
+				: x == 0 ? x
+				: sprout::numeric_limits<std::uintmax_t>::max() < x || sprout::numeric_limits<std::uintmax_t>::max() < -x
+					? SPROUT_MATH_THROW_LARGE_FLOAT_ROUNDING(std::runtime_error("floor: large float rounding."), x)
+				: static_cast<FloatType>(sprout::math::detail::floor_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
+#endif
+				;
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR double
+		floor(IntType x) {
+			return sprout::math::floor(static_cast<double>(x));
+		}
 	}	// namespace math
 
 	using sprout::math::floor;
diff --git a/sprout/math/fma.hpp b/sprout/math/fma.hpp
index d693aa90..39da79dc 100644
--- a/sprout/math/fma.hpp
+++ b/sprout/math/fma.hpp
@@ -21,48 +21,63 @@
 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
-			fma(FloatType x, FloatType y, FloatType z) {
-				return sprout::math::isnan(x) ? x
-					: sprout::math::isnan(y) ? y
-					: sprout::math::isnan(z) ? z
-					: sprout::math::isinf(x) && y == 0 ? sprout::numeric_limits<FloatType>::quiet_NaN()
-					: sprout::math::isinf(y) && x == 0 ? sprout::numeric_limits<FloatType>::quiet_NaN()
-					: (sprout::math::isinf(x) || sprout::math::isinf(y)) && sprout::math::isinf(z) && (sprout::math::signbit(x) ^ sprout::math::signbit(y) ^ sprout::math::signbit(z))
-						? sprout::numeric_limits<FloatType>::quiet_NaN()
 #if SPROUT_USE_BUILTIN_CMATH_FUNCTION
-					: std::fma(x, y, z)
-#else
-					: x * y + z
+			inline SPROUT_CONSTEXPR float
+			builtin_fma(float x, float y, float z) {
+				return __builtin_fmaf(x, y, z);
+			}
+			inline SPROUT_CONSTEXPR double
+			builtin_fma(double x, double y, double z) {
+				return __builtin_fma(x, y, z);
+			}
+			inline SPROUT_CONSTEXPR long double
+			builtin_fma(long double x, long double y, long double z) {
+				return __builtin_fmal(x, y, z);
+			}
 #endif
-					;
-			}
-			template<
-				typename ArithmeticType1,
-				typename ArithmeticType2,
-				typename ArithmeticType3,
-				typename sprout::enabler_if<
-					std::is_arithmetic<ArithmeticType1>::value
-						&& std::is_arithmetic<ArithmeticType2>::value
-						&& std::is_arithmetic<ArithmeticType3>::value
-				>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR typename sprout::float_promote<
-				ArithmeticType1, ArithmeticType2, ArithmeticType3
-			>::type
-			fma(ArithmeticType1 x, ArithmeticType2 y, ArithmeticType3 z) {
-				typedef typename sprout::float_promote<
-					ArithmeticType1, ArithmeticType2, ArithmeticType3
-				>::type type;
-				return sprout::math::detail::fma(static_cast<type>(x), static_cast<type>(y), static_cast<type>(z));
-			}
 		}	// namespace detail
-
-		using sprout::math::detail::fma;
+		//
+		// fma
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR FloatType
+		fma(FloatType x, FloatType y, FloatType z) {
+			return sprout::math::isnan(x) ? x
+				: sprout::math::isnan(y) ? y
+				: sprout::math::isnan(z) ? z
+				: sprout::math::isinf(x) && y == 0 ? sprout::numeric_limits<FloatType>::quiet_NaN()
+				: sprout::math::isinf(y) && x == 0 ? sprout::numeric_limits<FloatType>::quiet_NaN()
+				: (sprout::math::isinf(x) || sprout::math::isinf(y)) && sprout::math::isinf(z) && (sprout::math::signbit(x) ^ sprout::math::signbit(y) ^ sprout::math::signbit(z))
+					? sprout::numeric_limits<FloatType>::quiet_NaN()
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				: sprout::math::detail::builtin_fma(x, y, z)
+#else
+				: x * y + z
+#endif
+				;
+		}
+		template<
+			typename ArithmeticType1,
+			typename ArithmeticType2,
+			typename ArithmeticType3,
+			typename sprout::enabler_if<
+				std::is_arithmetic<ArithmeticType1>::value
+					&& std::is_arithmetic<ArithmeticType2>::value
+					&& std::is_arithmetic<ArithmeticType3>::value
+			>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR typename sprout::float_promote<
+			ArithmeticType1, ArithmeticType2, ArithmeticType3
+		>::type
+		fma(ArithmeticType1 x, ArithmeticType2 y, ArithmeticType3 z) {
+			typedef typename sprout::float_promote<
+				ArithmeticType1, ArithmeticType2, ArithmeticType3
+			>::type type;
+			return sprout::math::fma(static_cast<type>(x), static_cast<type>(y), static_cast<type>(z));
+		}
 	}	// namespace math
 
 	using sprout::math::fma;
diff --git a/sprout/math/fmax.hpp b/sprout/math/fmax.hpp
index bfe68780..b6dc5831 100644
--- a/sprout/math/fmax.hpp
+++ b/sprout/math/fmax.hpp
@@ -19,41 +19,56 @@
 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
-			fmax(FloatType x, FloatType y) {
-				return sprout::math::isnan(y) ? x
-					: sprout::math::isnan(x) ? y
-					: y == -sprout::numeric_limits<FloatType>::infinity() ? x
-					: x == sprout::numeric_limits<FloatType>::infinity() ? x
-					: x == -sprout::numeric_limits<FloatType>::infinity() ? y
-					: y == sprout::numeric_limits<FloatType>::infinity() ? y
 #if SPROUT_USE_BUILTIN_CMATH_FUNCTION
-					: x == 0 && y == 0 ? x
-					: std::fmax(x, y)
-#else
-					: x < y ? y : x
+			inline SPROUT_CONSTEXPR float
+			builtin_fmax(float x, float y) {
+				return __builtin_fmaxf(x, y);
+			}
+			inline SPROUT_CONSTEXPR double
+			builtin_fmax(double x, double y) {
+				return __builtin_fmax(x, y);
+			}
+			inline SPROUT_CONSTEXPR long double
+			builtin_fmax(long double x, long double y) {
+				return __builtin_fmaxl(x, y);
+			}
 #endif
-					;
-			}
-			template<
-				typename ArithmeticType1,
-				typename ArithmeticType2,
-				typename sprout::enabler_if<
-					std::is_arithmetic<ArithmeticType1>::value && std::is_arithmetic<ArithmeticType2>::value
-				>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type
-			fmax(ArithmeticType1 x, ArithmeticType2 y) {
-				typedef typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type type;
-				return sprout::math::detail::fmax(static_cast<type>(x), static_cast<type>(y));
-			}
 		}	// namespace detail
-
-		using sprout::math::detail::fmax;
+		//
+		// fmax
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR FloatType
+		fmax(FloatType x, FloatType y) {
+			return sprout::math::isnan(y) ? x
+				: sprout::math::isnan(x) ? y
+				: y == -sprout::numeric_limits<FloatType>::infinity() ? x
+				: x == sprout::numeric_limits<FloatType>::infinity() ? x
+				: x == -sprout::numeric_limits<FloatType>::infinity() ? y
+				: y == sprout::numeric_limits<FloatType>::infinity() ? y
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				: x == 0 && y == 0 ? x
+				: sprout::math::detail::builtin_fmax(x, y)
+#else
+				: x < y ? y : x
+#endif
+				;
+		}
+		template<
+			typename ArithmeticType1,
+			typename ArithmeticType2,
+			typename sprout::enabler_if<
+				std::is_arithmetic<ArithmeticType1>::value && std::is_arithmetic<ArithmeticType2>::value
+			>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type
+		fmax(ArithmeticType1 x, ArithmeticType2 y) {
+			typedef typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type type;
+			return sprout::math::fmax(static_cast<type>(x), static_cast<type>(y));
+		}
 	}	// namespace math
 
 	using sprout::math::fmax;
diff --git a/sprout/math/fmin.hpp b/sprout/math/fmin.hpp
index 1c529505..7eeb6bf9 100644
--- a/sprout/math/fmin.hpp
+++ b/sprout/math/fmin.hpp
@@ -19,41 +19,56 @@
 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
-			fmin(FloatType x, FloatType y) {
-				return sprout::math::isnan(y) ? x
-					: sprout::math::isnan(x) ? y
-					: x == -sprout::numeric_limits<FloatType>::infinity() ? x
-					: y == sprout::numeric_limits<FloatType>::infinity() ? x
-					: y == -sprout::numeric_limits<FloatType>::infinity() ? y
-					: x == sprout::numeric_limits<FloatType>::infinity() ? y
 #if SPROUT_USE_BUILTIN_CMATH_FUNCTION
-					: x == 0 && y == 0 ? x
-					: std::fmin(x, y)
-#else
-					: y < x ? y : x
+			inline SPROUT_CONSTEXPR float
+			builtin_fmin(float x, float y) {
+				return __builtin_fminf(x, y);
+			}
+			inline SPROUT_CONSTEXPR double
+			builtin_fmin(double x, double y) {
+				return __builtin_fmin(x, y);
+			}
+			inline SPROUT_CONSTEXPR long double
+			builtin_fmin(long double x, long double y) {
+				return __builtin_fminl(x, y);
+			}
 #endif
-					;
-			}
-			template<
-				typename ArithmeticType1,
-				typename ArithmeticType2,
-				typename sprout::enabler_if<
-					std::is_arithmetic<ArithmeticType1>::value && std::is_arithmetic<ArithmeticType2>::value
-				>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type
-			fmin(ArithmeticType1 x, ArithmeticType2 y) {
-				typedef typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type type;
-				return sprout::math::detail::fmin(static_cast<type>(x), static_cast<type>(y));
-			}
 		}	// namespace detail
-
-		using sprout::math::detail::fmin;
+		//
+		// fmin
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR FloatType
+		fmin(FloatType x, FloatType y) {
+			return sprout::math::isnan(y) ? x
+				: sprout::math::isnan(x) ? y
+				: x == -sprout::numeric_limits<FloatType>::infinity() ? x
+				: y == sprout::numeric_limits<FloatType>::infinity() ? x
+				: y == -sprout::numeric_limits<FloatType>::infinity() ? y
+				: x == sprout::numeric_limits<FloatType>::infinity() ? y
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				: x == 0 && y == 0 ? x
+				: sprout::math::detail::builtin_fmin(x, y)
+#else
+				: y < x ? y : x
+#endif
+				;
+		}
+		template<
+			typename ArithmeticType1,
+			typename ArithmeticType2,
+			typename sprout::enabler_if<
+				std::is_arithmetic<ArithmeticType1>::value && std::is_arithmetic<ArithmeticType2>::value
+			>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type
+		fmin(ArithmeticType1 x, ArithmeticType2 y) {
+			typedef typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type type;
+			return sprout::math::fmin(static_cast<type>(x), static_cast<type>(y));
+		}
 	}	// namespace math
 
 	using sprout::math::fmin;
diff --git a/sprout/math/fmod.hpp b/sprout/math/fmod.hpp
index 5c4b2b1b..bb406fc6 100644
--- a/sprout/math/fmod.hpp
+++ b/sprout/math/fmod.hpp
@@ -71,49 +71,49 @@ namespace sprout {
 			fmod_impl(T x, T y) {
 				return sprout::math::detail::fmod_impl_1(x, sprout::math::fabs(y), sprout::math::fabs(x));
 			}
-
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR FloatType
-			fmod(FloatType x, FloatType y) {
-				return sprout::math::isnan(y)
-						? sprout::math::isnan(x)
-							? sprout::math::signbit(y) || sprout::math::signbit(x) ? -sprout::numeric_limits<FloatType>::quiet_NaN()
-								: sprout::numeric_limits<FloatType>::quiet_NaN()
-							: y
-					: sprout::math::isnan(x) ? x
-					: x == sprout::numeric_limits<FloatType>::infinity() || x == -sprout::numeric_limits<FloatType>::infinity() || y == 0
-						? -sprout::numeric_limits<FloatType>::quiet_NaN()
-					: x == 0 ? x
-					: y == sprout::numeric_limits<FloatType>::infinity() || y == -sprout::numeric_limits<FloatType>::infinity() ? x
-					: static_cast<FloatType>(sprout::math::detail::fmod_impl(
-						static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x),
-						static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(y)
-						))
-					;
-			}
-
-			template<
-				typename ArithmeticType1,
-				typename ArithmeticType2,
-				typename sprout::enabler_if<
-					std::is_arithmetic<ArithmeticType1>::value && std::is_arithmetic<ArithmeticType2>::value
-				>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type
-			fmod(ArithmeticType1 x, ArithmeticType2 y) {
-				typedef typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type type;
-				return sprout::math::detail::fmod(static_cast<type>(x), static_cast<type>(y));
-			}
 		}	// namespace detail
 		//
+		// fmod
+		//
 		// issue:
 		//	fmod(-NaN, -NaN) returns -NaN .
 		//		# returns +NaN . ( same as fmod(+NaN, +NaN) )
 		//
-		using sprout::math::detail::fmod;
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR FloatType
+		fmod(FloatType x, FloatType y) {
+			return sprout::math::isnan(y)
+					? sprout::math::isnan(x)
+						? sprout::math::signbit(y) || sprout::math::signbit(x) ? -sprout::numeric_limits<FloatType>::quiet_NaN()
+							: sprout::numeric_limits<FloatType>::quiet_NaN()
+						: y
+				: sprout::math::isnan(x) ? x
+				: x == sprout::numeric_limits<FloatType>::infinity() || x == -sprout::numeric_limits<FloatType>::infinity() || y == 0
+					? -sprout::numeric_limits<FloatType>::quiet_NaN()
+				: x == 0 ? x
+				: y == sprout::numeric_limits<FloatType>::infinity() || y == -sprout::numeric_limits<FloatType>::infinity() ? x
+				: static_cast<FloatType>(sprout::math::detail::fmod_impl(
+					static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x),
+					static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(y)
+					))
+				;
+		}
+
+		template<
+			typename ArithmeticType1,
+			typename ArithmeticType2,
+			typename sprout::enabler_if<
+				std::is_arithmetic<ArithmeticType1>::value && std::is_arithmetic<ArithmeticType2>::value
+			>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type
+		fmod(ArithmeticType1 x, ArithmeticType2 y) {
+			typedef typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type type;
+			return sprout::math::fmod(static_cast<type>(x), static_cast<type>(y));
+		}
 	}	// namespace math
 
 	using sprout::math::fmod;
diff --git a/sprout/math/fpclassify.hpp b/sprout/math/fpclassify.hpp
index 9303ca82..537a0a79 100644
--- a/sprout/math/fpclassify.hpp
+++ b/sprout/math/fpclassify.hpp
@@ -21,22 +21,45 @@
 namespace sprout {
 	namespace math {
 		namespace detail {
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+			template<typename FloatType>
 			inline SPROUT_CONSTEXPR int
-			fpclassify(FloatType x) {
-				return sprout::math::isnan(x) ? FP_NAN
-					: sprout::math::isinf(x) ? FP_INFINITE
-					: sprout::math::iszero(x) ? FP_ZERO
-					: sprout::math::detail::issubnormal_or_zero(x) ? FP_SUBNORMAL
-					: FP_NORMAL
-					;
+			builtin_fpclassify(FloatType x) {
+				return __builtin_fpclassify(FP_NAN, FP_INFINITE, FP_NORMAL, FP_SUBNORMAL, FP_ZERO, x);
 			}
+#endif
 		}	// namespace detail
-
-		using NS_SPROUT_MATH_DETAIL::fpclassify;
+		//
+		// fpclassify
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR int
+		fpclassify(FloatType x) {
+			return
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				sprout::math::detail::builtin_fpclassify(x)
+#else
+				sprout::math::isnan(x) ? FP_NAN
+				: sprout::math::isinf(x) ? FP_INFINITE
+				: sprout::math::iszero(x) ? FP_ZERO
+				: sprout::math::detail::issubnormal_or_zero(x) ? FP_SUBNORMAL
+				: FP_NORMAL
+#endif
+				;
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR int
+		fpclassify(IntType x) {
+			return x ? FP_NORMAL
+				: FP_ZERO
+				;
+		}
 	}	// namespace math
 
 	using sprout::math::fpclassify;
diff --git a/sprout/math/frac_int.hpp b/sprout/math/frac_int.hpp
index 8f6e71ce..09fe90ca 100644
--- a/sprout/math/frac_int.hpp
+++ b/sprout/math/frac_int.hpp
@@ -32,26 +32,26 @@ namespace sprout {
 					: type(sprout::math::copysign(x - ipart, x), ipart)
 					;
 			}
-
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR sprout::pair<FloatType, FloatType>
-			frac_int(FloatType x) {
-				return sprout::math::detail::frac_int_impl(x, sprout::integer_part(x));
-			}
-			template<
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR sprout::pair<double, double>
-			frac_int(IntType x) {
-				return sprout::math::detail::frac_int(static_cast<double>(x));
-			}
 		}	// namespace detail
-
-		using sprout::math::detail::frac_int;
+		//
+		// frac_int
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR sprout::pair<FloatType, FloatType>
+		frac_int(FloatType x) {
+			return sprout::math::detail::frac_int_impl(x, sprout::integer_part(x));
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR sprout::pair<double, double>
+		frac_int(IntType x) {
+			return sprout::math::frac_int(static_cast<double>(x));
+		}
 	}	// namespace math
 
 	using sprout::math::frac_int;
diff --git a/sprout/math/fractional_part.hpp b/sprout/math/fractional_part.hpp
index e8e7e898..4f4382fb 100644
--- a/sprout/math/fractional_part.hpp
+++ b/sprout/math/fractional_part.hpp
@@ -27,30 +27,30 @@ namespace sprout {
 					: sprout::math::copysign(x - ipart, x)
 					;
 			}
-
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR FloatType
-			fractional_part(FloatType x) {
-				return sprout::math::isnan(x) ? x
-					: x == sprout::numeric_limits<FloatType>::infinity() || x == -sprout::numeric_limits<FloatType>::infinity() ? sprout::math::copysign(FloatType(0), x)
-					: x == 0 ? x
-					: sprout::math::detail::fractional_part_impl(x, sprout::integer_part(x))
-					;
-			}
-			template<
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR double
-			fractional_part(IntType x) {
-				return sprout::math::detail::fractional_part(static_cast<double>(x));
-			}
 		}	// namespace detail
-
-		using sprout::math::detail::fractional_part;
+		//
+		// fractional_part
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR FloatType
+		fractional_part(FloatType x) {
+			return sprout::math::isnan(x) ? x
+				: x == sprout::numeric_limits<FloatType>::infinity() || x == -sprout::numeric_limits<FloatType>::infinity() ? sprout::math::copysign(FloatType(0), x)
+				: x == 0 ? x
+				: sprout::math::detail::fractional_part_impl(x, sprout::integer_part(x))
+				;
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR double
+		fractional_part(IntType x) {
+			return sprout::math::fractional_part(static_cast<double>(x));
+		}
 	}	// namespace math
 
 	using sprout::math::fractional_part;
diff --git a/sprout/math/hypot.hpp b/sprout/math/hypot.hpp
index a1aa7c9e..93e0d064 100644
--- a/sprout/math/hypot.hpp
+++ b/sprout/math/hypot.hpp
@@ -23,6 +23,21 @@
 namespace sprout {
 	namespace math {
 		namespace detail {
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+			inline SPROUT_CONSTEXPR float
+			builtin_hypot(float x, float y) {
+				return __builtin_hypotf(x, y);
+			}
+			inline SPROUT_CONSTEXPR double
+			builtin_hypot(double x, double y) {
+				return __builtin_hypot(x, y);
+			}
+			inline SPROUT_CONSTEXPR long double
+			builtin_hypot(long double x, long double y) {
+				return __builtin_hypotl(x, y);
+			}
+#endif
+
 			template<typename T>
 			inline SPROUT_CONSTEXPR T
 			hypot_impl_2(T t, T w) {
@@ -41,47 +56,47 @@ namespace sprout {
 			hypot_impl(T x, T y) {
 				return sprout::math::detail::hypot_impl_1(sprout::math::fabs(x), sprout::math::fabs(y));
 			}
-
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR FloatType
-			hypot(FloatType x, FloatType y) {
-				return y == sprout::numeric_limits<FloatType>::infinity() || y == -sprout::numeric_limits<FloatType>::infinity()
-						? sprout::numeric_limits<FloatType>::infinity()
-					: x == sprout::numeric_limits<FloatType>::infinity() || x == -sprout::numeric_limits<FloatType>::infinity()
-						? sprout::numeric_limits<FloatType>::infinity()
-					: sprout::math::isnan(y) ? y
-					: sprout::math::isnan(x) ? x
-#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
-					: std::hypot(x, y)
-#else
-					: y == 0 ? sprout::math::fabs(x)
-					: x == 0 ? sprout::math::fabs(y)
-					: static_cast<FloatType>(sprout::math::detail::hypot_impl(
-						static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x),
-						static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(y)
-						))
-#endif
-					;
-			}
-
-			template<
-				typename ArithmeticType1,
-				typename ArithmeticType2,
-				typename sprout::enabler_if<
-					std::is_arithmetic<ArithmeticType1>::value && std::is_arithmetic<ArithmeticType2>::value
-				>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type
-			hypot(ArithmeticType1 x, ArithmeticType2 y) {
-				typedef typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type type;
-				return sprout::math::detail::hypot(static_cast<type>(x), static_cast<type>(y));
-			}
 		}	// namespace detail
+		//
+		// hypot
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR FloatType
+		hypot(FloatType x, FloatType y) {
+			return y == sprout::numeric_limits<FloatType>::infinity() || y == -sprout::numeric_limits<FloatType>::infinity()
+					? sprout::numeric_limits<FloatType>::infinity()
+				: x == sprout::numeric_limits<FloatType>::infinity() || x == -sprout::numeric_limits<FloatType>::infinity()
+					? sprout::numeric_limits<FloatType>::infinity()
+				: sprout::math::isnan(y) ? y
+				: sprout::math::isnan(x) ? x
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				: sprout::math::detail::builtin_hypot(x, y)
+#else
+				: y == 0 ? sprout::math::fabs(x)
+				: x == 0 ? sprout::math::fabs(y)
+				: static_cast<FloatType>(sprout::math::detail::hypot_impl(
+					static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x),
+					static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(y)
+					))
+#endif
+				;
+		}
 
-		using sprout::math::detail::hypot;
+		template<
+			typename ArithmeticType1,
+			typename ArithmeticType2,
+			typename sprout::enabler_if<
+				std::is_arithmetic<ArithmeticType1>::value && std::is_arithmetic<ArithmeticType2>::value
+			>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type
+		hypot(ArithmeticType1 x, ArithmeticType2 y) {
+			typedef typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type type;
+			return sprout::math::hypot(static_cast<type>(x), static_cast<type>(y));
+		}
 	}	// namespace math
 
 	using sprout::math::hypot;
diff --git a/sprout/math/iceil.hpp b/sprout/math/iceil.hpp
index 2e0bc73a..e0c96d5f 100644
--- a/sprout/math/iceil.hpp
+++ b/sprout/math/iceil.hpp
@@ -24,8 +24,8 @@
 
 namespace sprout {
 	namespace math {
-		namespace detail {
 #if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+		namespace detail {
 			template<typename To, typename FloatType>
 			inline SPROUT_CONSTEXPR To
 			iceil_impl(FloatType x) {
@@ -34,18 +34,23 @@ namespace sprout {
 					: static_cast<To>(x)
 					;
 			}
-			template<
-				typename To = int,
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value && std::is_integral<To>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR To
-			iceil(FloatType x) {
-				return sprout::math::isnan(x) || sprout::math::isinf(x) ? sprout::numeric_limits<To>::min()
-					: sprout::math::detail::iceil_impl<To>(sprout::math::ceil(x))
-					;
-			}
+		}	// namespace detail
+		//
+		// iceil
+		//
+		template<
+			typename To = int,
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value && std::is_integral<To>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR To
+		iceil(FloatType x) {
+			return sprout::math::isnan(x) || sprout::math::isinf(x) ? sprout::numeric_limits<To>::min()
+				: sprout::math::detail::iceil_impl<To>(sprout::math::ceil(x))
+				;
+		}
 #else
+		namespace detail {
 			template<typename To, typename FloatType>
 			inline SPROUT_CONSTEXPR To
 			iceil_impl(FloatType x, To x0) {
@@ -53,33 +58,34 @@ namespace sprout {
 					: x0 + 1
 					;
 			}
-			template<
-				typename To = int,
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value && std::is_integral<To>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR To
-			iceil(FloatType x) {
-				return sprout::math::isnan(x) || sprout::math::isinf(x) ? sprout::numeric_limits<To>::min()
-					: x == 0 ? To(0)
-					: sprout::numeric_limits<To>::max() < x || sprout::numeric_limits<To>::min() > x
-						? SPROUT_MATH_THROW_LARGE_FLOAT_ROUNDING(std::runtime_error("iceil: large float rounding."), static_cast<To>(x))
-					: sprout::math::detail::iceil_impl(x, static_cast<To>(x))
-					;
-			}
-#endif
-			template<
-				typename To = int,
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value && std::is_integral<To>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR To
-			iceil(IntType x) {
-				return sprout::math::detail::iceil<To>(static_cast<double>(x));
-			}
 		}	// namespace detail
-
-		using sprout::math::detail::iceil;
+		//
+		// iceil
+		//
+		template<
+			typename To = int,
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value && std::is_integral<To>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR To
+		iceil(FloatType x) {
+			return sprout::math::isnan(x) || sprout::math::isinf(x) ? sprout::numeric_limits<To>::min()
+				: x == 0 ? To(0)
+				: sprout::numeric_limits<To>::max() < x || sprout::numeric_limits<To>::min() > x
+					? SPROUT_MATH_THROW_LARGE_FLOAT_ROUNDING(std::runtime_error("iceil: large float rounding."), static_cast<To>(x))
+				: sprout::math::detail::iceil_impl(x, static_cast<To>(x))
+				;
+		}
+#endif
+		template<
+			typename To = int,
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value && std::is_integral<To>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR To
+		iceil(IntType x) {
+			return sprout::math::iceil<To>(static_cast<double>(x));
+		}
 	}	// namespace math
 
 	using sprout::math::iceil;
diff --git a/sprout/math/ifloor.hpp b/sprout/math/ifloor.hpp
index d994d19b..71d93bd9 100644
--- a/sprout/math/ifloor.hpp
+++ b/sprout/math/ifloor.hpp
@@ -24,8 +24,8 @@
 
 namespace sprout {
 	namespace math {
-		namespace detail {
 #if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+		namespace detail {
 			template<typename To, typename FloatType>
 			inline SPROUT_CONSTEXPR To
 			ifloor_impl(FloatType x) {
@@ -34,18 +34,23 @@ namespace sprout {
 					: static_cast<To>(x)
 					;
 			}
-			template<
-				typename To = int,
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value && std::is_integral<To>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR To
-			ifloor(FloatType x) {
-				return sprout::math::isnan(x) || sprout::math::isinf(x) ? sprout::numeric_limits<To>::min()
-					: sprout::math::detail::ifloor_impl<To>(sprout::math::floor(x))
-					;
-			}
+		}	// namespace detail
+		//
+		// ifloor
+		//
+		template<
+			typename To = int,
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value && std::is_integral<To>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR To
+		ifloor(FloatType x) {
+			return sprout::math::isnan(x) || sprout::math::isinf(x) ? sprout::numeric_limits<To>::min()
+				: sprout::math::detail::ifloor_impl<To>(sprout::math::floor(x))
+				;
+		}
 #else
+		namespace detail {
 			template<typename To, typename FloatType>
 			inline SPROUT_CONSTEXPR To
 			ifloor_impl(FloatType x, To x0) {
@@ -53,33 +58,34 @@ namespace sprout {
 					: x0 - 1
 					;
 			}
-			template<
-				typename To = int,
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value && std::is_integral<To>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR To
-			ifloor(FloatType x) {
-				return sprout::math::isnan(x) || sprout::math::isinf(x) ? sprout::numeric_limits<To>::min()
-					: x == 0 ? To(0)
-					: sprout::numeric_limits<To>::max() < x || sprout::numeric_limits<To>::min() > x
-						? SPROUT_MATH_THROW_LARGE_FLOAT_ROUNDING(std::runtime_error("ifloor: large float rounding."), static_cast<To>(x))
-					: sprout::math::detail::ifloor_impl(x, static_cast<To>(x))
-					;
-			}
-#endif
-			template<
-				typename To = int,
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value && std::is_integral<To>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR To
-			ifloor(IntType x) {
-				return sprout::math::detail::ifloor<To>(static_cast<double>(x));
-			}
 		}	// namespace detail
-
-		using sprout::math::detail::ifloor;
+		//
+		// ifloor
+		//
+		template<
+			typename To = int,
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value && std::is_integral<To>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR To
+		ifloor(FloatType x) {
+			return sprout::math::isnan(x) || sprout::math::isinf(x) ? sprout::numeric_limits<To>::min()
+				: x == 0 ? To(0)
+				: sprout::numeric_limits<To>::max() < x || sprout::numeric_limits<To>::min() > x
+					? SPROUT_MATH_THROW_LARGE_FLOAT_ROUNDING(std::runtime_error("ifloor: large float rounding."), static_cast<To>(x))
+				: sprout::math::detail::ifloor_impl(x, static_cast<To>(x))
+				;
+		}
+#endif
+		template<
+			typename To = int,
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value && std::is_integral<To>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR To
+		ifloor(IntType x) {
+			return sprout::math::ifloor<To>(static_cast<double>(x));
+		}
 	}	// namespace math
 
 	using sprout::math::ifloor;
diff --git a/sprout/math/ilogb.hpp b/sprout/math/ilogb.hpp
index 7073f49b..6d47fa00 100644
--- a/sprout/math/ilogb.hpp
+++ b/sprout/math/ilogb.hpp
@@ -22,33 +22,48 @@
 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 int
-			ilogb(FloatType x) {
-				return sprout::math::iszero(x) ? FP_ILOGB0
-					: sprout::math::isinf(x) ? INT_MAX
-					: sprout::math::isnan(x) ? FP_ILOGBNAN
 #if SPROUT_USE_BUILTIN_CMATH_FUNCTION
-					: std::ilogb(x)
-#else
-					: static_cast<int>(sprout::math::logb(x))
-#endif
-					;
-			}
-			template<
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
-			>
 			inline SPROUT_CONSTEXPR int
-			ilogb(IntType x) {
-				return sprout::math::detail::ilogb(static_cast<double>(x));
+			builtin_ilogb(float x) {
+				return __builtin_ilogbf(x);
 			}
+			inline SPROUT_CONSTEXPR int
+			builtin_ilogb(double x) {
+				return __builtin_ilogb(x);
+			}
+			inline SPROUT_CONSTEXPR int
+			builtin_ilogb(long double x) {
+				return __builtin_ilogbl(x);
+			}
+#endif
 		}	// namespace detail
-
-		using sprout::math::detail::ilogb;
+		//
+		// ilogb
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR int
+		ilogb(FloatType x) {
+			return sprout::math::iszero(x) ? FP_ILOGB0
+				: sprout::math::isinf(x) ? INT_MAX
+				: sprout::math::isnan(x) ? FP_ILOGBNAN
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				: sprout::math::detail::builtin_ilogb(x)
+#else
+				: static_cast<int>(sprout::math::logb(x))
+#endif
+				;
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR int
+		ilogb(IntType x) {
+			return sprout::math::ilogb(static_cast<double>(x));
+		}
 	}	// namespace math
 
 	using sprout::math::ilogb;
diff --git a/sprout/math/ilogb2.hpp b/sprout/math/ilogb2.hpp
index 8132d25e..b7c591ec 100644
--- a/sprout/math/ilogb2.hpp
+++ b/sprout/math/ilogb2.hpp
@@ -25,49 +25,45 @@
 
 namespace sprout {
 	namespace math {
-		namespace detail {
 #if SPROUT_FLT_RADIX_IS_2
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR int
-			ilogb2(FloatType x) {
-				return sprout::math::ilogb(x);
-			}
-			template<
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR int
-			ilogb2(IntType x) {
-				return sprout::math::ilogb(x);
-			}
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR int
+		ilogb2(FloatType x) {
+			return sprout::math::ilogb(x);
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR int
+		ilogb2(IntType x) {
+			return sprout::math::ilogb(x);
+		}
 #else
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR int
-			ilogb2(FloatType x) {
-				return sprout::math::iszero(x) ? FP_ILOGB0
-					: sprout::math::isinf(x) ? INT_MAX
-					: sprout::math::isnan(x) ? FP_ILOGBNAN
-					: static_cast<int>(sprout::math::logb2(x))
-					;
-			}
-			template<
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR int
-			ilogb2(IntType x) {
-				return sprout::math::detail::ilogb2(static_cast<double>(x));
-			}
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR int
+		ilogb2(FloatType x) {
+			return sprout::math::iszero(x) ? FP_ILOGB0
+				: sprout::math::isinf(x) ? INT_MAX
+				: sprout::math::isnan(x) ? FP_ILOGBNAN
+				: static_cast<int>(sprout::math::logb2(x))
+				;
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR int
+		ilogb2(IntType x) {
+			return sprout::math::ilogb2(static_cast<double>(x));
+		}
 #endif
-		}	// namespace detail
-
-		using sprout::math::detail::ilogb2;
 	}	// namespace math
 
 	using sprout::math::ilogb2;
diff --git a/sprout/math/integer_part.hpp b/sprout/math/integer_part.hpp
index 36c69784..f5a0c583 100644
--- a/sprout/math/integer_part.hpp
+++ b/sprout/math/integer_part.hpp
@@ -18,31 +18,30 @@
 
 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
-			integer_part(FloatType x) {
-				return sprout::math::isnan(x) ? x
-					: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
-					: x == -sprout::numeric_limits<FloatType>::infinity() ? -sprout::numeric_limits<FloatType>::infinity()
-					: x == 0 ? x
-					: sprout::math::trunc(x)
-					;
-			}
-			template<
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR double
-			integer_part(IntType x) {
-				return sprout::math::detail::integer_part(static_cast<double>(x));
-			}
-		}	// namespace detail
-
-		using sprout::math::detail::integer_part;
+		//
+		// integer_part
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR FloatType
+		integer_part(FloatType x) {
+			return sprout::math::isnan(x) ? x
+				: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
+				: x == -sprout::numeric_limits<FloatType>::infinity() ? -sprout::numeric_limits<FloatType>::infinity()
+				: x == 0 ? x
+				: sprout::math::trunc(x)
+				;
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR double
+		integer_part(IntType x) {
+			return sprout::math::integer_part(static_cast<double>(x));
+		}
 	}	// namespace math
 
 	using sprout::math::integer_part;
diff --git a/sprout/math/iround.hpp b/sprout/math/iround.hpp
index be294ec4..4ecc035e 100644
--- a/sprout/math/iround.hpp
+++ b/sprout/math/iround.hpp
@@ -24,8 +24,8 @@
 
 namespace sprout {
 	namespace math {
-		namespace detail {
 #if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+		namespace detail {
 			template<typename To, typename FloatType>
 			inline SPROUT_CONSTEXPR To
 			iround_impl(FloatType x) {
@@ -34,18 +34,23 @@ namespace sprout {
 					: static_cast<To>(x)
 					;
 			}
-			template<
-				typename To = int,
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value && std::is_integral<To>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR To
-			iround(FloatType x) {
-				return sprout::math::isnan(x) || sprout::math::isinf(x) ? sprout::numeric_limits<To>::min()
-					: sprout::math::detail::iround_impl<To>(sprout::math::round(x))
-					;
-			}
+		}	// namespace detail
+		//
+		// iround
+		//
+		template<
+			typename To = int,
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value && std::is_integral<To>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR To
+		iround(FloatType x) {
+			return sprout::math::isnan(x) || sprout::math::isinf(x) ? sprout::numeric_limits<To>::min()
+				: sprout::math::detail::iround_impl<To>(sprout::math::round(x))
+				;
+		}
 #else
+		namespace detail {
 			template<typename To, typename FloatType>
 			inline SPROUT_CONSTEXPR To
 			iround_impl_positive(FloatType x, To x0) {
@@ -60,34 +65,35 @@ namespace sprout {
 					: x0 - 1
 					;
 			}
-			template<
-				typename To = int,
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value && std::is_integral<To>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR To
-			iround(FloatType x) {
-				return sprout::math::isnan(x) || sprout::math::isinf(x) ? sprout::numeric_limits<To>::min()
-					: x == 0 ? To(0)
-					: sprout::numeric_limits<To>::max() < x || sprout::numeric_limits<To>::min() > x
-						? SPROUT_MATH_THROW_LARGE_FLOAT_ROUNDING(std::runtime_error("iround: large float irounding."), x)
-					: x < 0 ? sprout::math::detail::iround_impl_nagative(x, static_cast<To>(x))
-					: sprout::math::detail::iround_impl_positive(x, static_cast<To>(x))
-					;
-			}
-#endif
-			template<
-				typename To = int,
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value && std::is_integral<To>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR To
-			iround(IntType x) {
-				return sprout::math::detail::iround(static_cast<double>(x));
-			}
 		}	// namespace detail
-
-		using sprout::math::detail::iround;
+		//
+		// iround
+		//
+		template<
+			typename To = int,
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value && std::is_integral<To>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR To
+		iround(FloatType x) {
+			return sprout::math::isnan(x) || sprout::math::isinf(x) ? sprout::numeric_limits<To>::min()
+				: x == 0 ? To(0)
+				: sprout::numeric_limits<To>::max() < x || sprout::numeric_limits<To>::min() > x
+					? SPROUT_MATH_THROW_LARGE_FLOAT_ROUNDING(std::runtime_error("iround: large float irounding."), x)
+				: x < 0 ? sprout::math::detail::iround_impl_nagative(x, static_cast<To>(x))
+				: sprout::math::detail::iround_impl_positive(x, static_cast<To>(x))
+				;
+		}
+#endif
+		template<
+			typename To = int,
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value && std::is_integral<To>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR To
+		iround(IntType x) {
+			return sprout::math::iround(static_cast<double>(x));
+		}
 	}	// namespace math
 
 	using sprout::math::iround;
diff --git a/sprout/math/is_even.hpp b/sprout/math/is_even.hpp
index c80ff08d..d4bc5d14 100644
--- a/sprout/math/is_even.hpp
+++ b/sprout/math/is_even.hpp
@@ -22,20 +22,20 @@ namespace sprout {
 			is_even_unchecked(T x) {
 				return sprout::math::fmod(x, T(2)) == T(0);
 			}
-
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR bool
-			is_even(FloatType x) {
-				return sprout::math::isfinite(x)
-					&& sprout::math::detail::is_even_unchecked(x)
-					;
-			}
 		}	// namespace detail
-
-		using sprout::math::detail::is_even;
+		//
+		// is_even
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR bool
+		is_even(FloatType x) {
+			return sprout::math::isfinite(x)
+				&& sprout::math::detail::is_even_unchecked(x)
+				;
+		}
 	}	// namespace math
 
 	using sprout::math::is_even;
diff --git a/sprout/math/is_integer.hpp b/sprout/math/is_integer.hpp
index ac8b1c54..8a37349c 100644
--- a/sprout/math/is_integer.hpp
+++ b/sprout/math/is_integer.hpp
@@ -22,20 +22,20 @@ namespace sprout {
 			is_integer_unchecked(T x) {
 				return x == sprout::math::trunc(x);
 			}
-
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR bool
-			is_integer(FloatType x) {
-				return sprout::math::isfinite(x)
-					&& sprout::math::detail::is_integer_unchecked(x)
-					;
-			}
 		}	// namespace detail
-
-		using sprout::math::detail::is_integer;
+		//
+		// is_integer
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR bool
+		is_integer(FloatType x) {
+			return sprout::math::isfinite(x)
+				&& sprout::math::detail::is_integer_unchecked(x)
+				;
+		}
 	}	// namespace math
 
 	using sprout::math::is_integer;
diff --git a/sprout/math/is_odd.hpp b/sprout/math/is_odd.hpp
index c790907d..3a03c772 100644
--- a/sprout/math/is_odd.hpp
+++ b/sprout/math/is_odd.hpp
@@ -22,20 +22,20 @@ namespace sprout {
 			is_odd_unchecked(T x) {
 				return sprout::math::fmod(x, T(2)) == T(1);
 			}
-
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR bool
-			is_odd(FloatType x) {
-				return sprout::math::isfinite(x)
-					&& sprout::math::detail::is_odd_unchecked(x)
-					;
-			}
 		}	// namespace detail
-
-		using sprout::math::detail::is_odd;
+		//
+		// is_odd
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR bool
+		is_odd(FloatType x) {
+			return sprout::math::isfinite(x)
+				&& sprout::math::detail::is_odd_unchecked(x)
+				;
+		}
 	}	// namespace math
 
 	using sprout::math::is_odd;
diff --git a/sprout/math/isfinite.hpp b/sprout/math/isfinite.hpp
index 4f5dcf5f..8f70cf46 100644
--- a/sprout/math/isfinite.hpp
+++ b/sprout/math/isfinite.hpp
@@ -18,19 +18,39 @@
 namespace sprout {
 	namespace math {
 		namespace detail {
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+			template<typename FloatType>
 			inline SPROUT_CONSTEXPR bool
-			isfinite(FloatType x) {
-				return !sprout::math::isnan(x)
-					&& !sprout::math::isinf(x)
-					;
+			builtin_isfinite(FloatType x) {
+				return __builtin_isfinite(x);
 			}
+#endif
 		}	// namespace detail
-
-		using NS_SPROUT_MATH_DETAIL::isfinite;
+		//
+		// isfinite
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR bool
+		isfinite(FloatType x) {
+			return
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				sprout::math::detail::builtin_isfinite(x)
+#else
+				!(sprout::math::isnan(x) || sprout::math::isinf(x))
+#endif
+				;
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR bool
+		isfinite(IntType x) {
+			return true;
+		}
 	}	// namespace math
 
 	using sprout::math::isfinite;
diff --git a/sprout/math/isinf.hpp b/sprout/math/isinf.hpp
index 66ebce95..39092966 100644
--- a/sprout/math/isinf.hpp
+++ b/sprout/math/isinf.hpp
@@ -17,19 +17,40 @@
 namespace sprout {
 	namespace math {
 		namespace detail {
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+			template<typename FloatType>
 			inline SPROUT_CONSTEXPR bool
-			isinf(FloatType x) {
-				return x == sprout::numeric_limits<FloatType>::infinity()
-					|| x == -sprout::numeric_limits<FloatType>::infinity()
-					;
+			builtin_isinf(FloatType x) {
+				return __builtin_isinf(x);
 			}
+#endif
 		}	// namespace detail
-
-		using NS_SPROUT_MATH_DETAIL::isinf;
+		//
+		// isinf
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR bool
+		isinf(FloatType x) {
+			return
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				sprout::math::detail::builtin_isinf(x)
+#else
+				x == sprout::numeric_limits<FloatType>::infinity()
+				|| x == -sprout::numeric_limits<FloatType>::infinity()
+#endif
+				;
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR bool
+		isinf(IntType x) {
+			return false;
+		}
 	}	// namespace math
 
 	using sprout::math::isinf;
diff --git a/sprout/math/isnan.hpp b/sprout/math/isnan.hpp
index 185107e0..e58ab5ae 100644
--- a/sprout/math/isnan.hpp
+++ b/sprout/math/isnan.hpp
@@ -16,17 +16,39 @@
 namespace sprout {
 	namespace math {
 		namespace detail {
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+			template<typename FloatType>
 			inline SPROUT_CONSTEXPR bool
-			isnan(FloatType x) {
-				return !(x == x);
+			builtin_isnan(FloatType x) {
+				return __builtin_isnan(x);
 			}
+#endif
 		}	// namespace detail
-
-		using NS_SPROUT_MATH_DETAIL::isnan;
+		//
+		// isnan
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR bool
+		isnan(FloatType x) {
+			return
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				sprout::math::detail::builtin_isnan(x)
+#else
+				!(x == x)
+#endif
+				;
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR bool
+		isnan(IntType x) {
+			return false;
+		}
 	}	// namespace math
 
 	using sprout::math::isnan;
diff --git a/sprout/math/isnormal.hpp b/sprout/math/isnormal.hpp
index 106f1f55..bbe001de 100644
--- a/sprout/math/isnormal.hpp
+++ b/sprout/math/isnormal.hpp
@@ -19,20 +19,41 @@
 namespace sprout {
 	namespace math {
 		namespace detail {
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+			template<typename FloatType>
 			inline SPROUT_CONSTEXPR bool
-			isnormal(FloatType x) {
-				return !sprout::math::isnan(x)
-					&& !sprout::math::isinf(x)
-					&& !sprout::math::detail::issubnormal_or_zero(x)
-					;
+			builtin_isnormal(FloatType x) {
+				return __builtin_isnormal(x);
 			}
+#endif
 		}	// namespace detail
-
-		using NS_SPROUT_MATH_DETAIL::isnormal;
+		//
+		// isnormal
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR bool
+		isnormal(FloatType x) {
+			return
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				sprout::math::detail::builtin_isnormal(x)
+#else
+				!sprout::math::isnan(x)
+				&& !sprout::math::isinf(x)
+				&& !sprout::math::detail::issubnormal_or_zero(x)
+#endif
+				;
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR bool
+		isnormal(IntType x) {
+			return x != 0;
+		}
 	}	// namespace math
 
 	using sprout::math::isnormal;
diff --git a/sprout/math/issubnormal.hpp b/sprout/math/issubnormal.hpp
index b3476f7b..3b26026b 100644
--- a/sprout/math/issubnormal.hpp
+++ b/sprout/math/issubnormal.hpp
@@ -18,6 +18,9 @@
 namespace sprout {
 	namespace math {
 		namespace detail {
+			//
+			// issubnormal_or_zero
+			//
 			template<
 				typename FloatType,
 				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
@@ -29,21 +32,21 @@ namespace sprout {
 					: x > -sprout::numeric_limits<double>::min()
 					;
 			}
-
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR bool
-			issubnormal(FloatType x) {
-				return !sprout::math::isnan(x)
-					&& !sprout::math::iszero(x)
-					&& sprout::math::detail::issubnormal_or_zero(x)
-					;
-			}
 		}	// namespace detail
-
-		using sprout::math::detail::issubnormal;
+		//
+		// issubnormal
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR bool
+		issubnormal(FloatType x) {
+			return !sprout::math::isnan(x)
+				&& !sprout::math::iszero(x)
+				&& sprout::math::detail::issubnormal_or_zero(x)
+				;
+		}
 	}	// namespace math
 
 	using sprout::math::issubnormal;
diff --git a/sprout/math/iszero.hpp b/sprout/math/iszero.hpp
index cc401b94..96efc3ac 100644
--- a/sprout/math/iszero.hpp
+++ b/sprout/math/iszero.hpp
@@ -14,18 +14,25 @@
 
 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 bool
-			iszero(FloatType x) {
-				return x == 0;
-			}
-		}	// namespace detail
-
-		using sprout::math::detail::iszero;
+		//
+		// iszero
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR bool
+		iszero(FloatType x) {
+			return x == 0;
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR bool
+		iszero(IntType x) {
+			return x == 0;
+		}
 	}	// namespace math
 
 	using sprout::math::iszero;
diff --git a/sprout/math/itrunc.hpp b/sprout/math/itrunc.hpp
index 009e9bc3..f5a8d1d7 100644
--- a/sprout/math/itrunc.hpp
+++ b/sprout/math/itrunc.hpp
@@ -22,8 +22,8 @@
 
 namespace sprout {
 	namespace math {
-		namespace detail {
 #if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+		namespace detail {
 			template<typename To, typename FloatType>
 			inline SPROUT_CONSTEXPR To
 			itrunc_impl(FloatType x) {
@@ -32,45 +32,49 @@ namespace sprout {
 					: static_cast<To>(x)
 					;
 			}
-			template<
-				typename To = int,
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value && std::is_integral<To>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR To
-			itrunc(FloatType x) {
-				return sprout::math::isnan(x) || sprout::math::isinf(x) ? sprout::numeric_limits<To>::min()
-					: sprout::math::detail::itrunc_impl<To>(sprout::math::trunc(x))
-					;
-			}
-#else
-			template<
-				typename To = int,
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value && std::is_integral<To>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR To
-			itrunc(FloatType x) {
-				return sprout::math::isnan(x) || sprout::math::isinf(x) ? sprout::numeric_limits<To>::min()
-					: x == 0 ? To(0)
-					: sprout::numeric_limits<To>::max() < x || sprout::numeric_limits<To>::min() > x
-						? SPROUT_MATH_THROW_LARGE_FLOAT_ROUNDING(std::runtime_error("itrunc: large float rounding."), static_cast<To>(x))
-					: static_cast<To>(x)
-					;
-			}
-#endif
-			template<
-				typename To = int,
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value && std::is_integral<To>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR To
-			itrunc(IntType x) {
-				return sprout::math::detail::itrunc<To>(static_cast<double>(x));
-			}
 		}	// namespace detail
-
-		using sprout::math::detail::itrunc;
+		//
+		// itrunc
+		//
+		template<
+			typename To = int,
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value && std::is_integral<To>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR To
+		itrunc(FloatType x) {
+			return sprout::math::isnan(x) || sprout::math::isinf(x) ? sprout::numeric_limits<To>::min()
+				: sprout::math::detail::itrunc_impl<To>(sprout::math::trunc(x))
+				;
+		}
+#else
+		//
+		// itrunc
+		//
+		template<
+			typename To = int,
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value && std::is_integral<To>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR To
+		itrunc(FloatType x) {
+			return sprout::math::isnan(x) || sprout::math::isinf(x) ? sprout::numeric_limits<To>::min()
+				: x == 0 ? To(0)
+				: sprout::numeric_limits<To>::max() < x || sprout::numeric_limits<To>::min() > x
+					? SPROUT_MATH_THROW_LARGE_FLOAT_ROUNDING(std::runtime_error("itrunc: large float rounding."), static_cast<To>(x))
+				: static_cast<To>(x)
+				;
+		}
+#endif
+		template<
+			typename To = int,
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value && std::is_integral<To>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR To
+		itrunc(IntType x) {
+			return sprout::math::itrunc<To>(static_cast<double>(x));
+		}
 	}	// namespace math
 
 	using sprout::math::itrunc;
diff --git a/sprout/math/ldexp.hpp b/sprout/math/ldexp.hpp
index 51507f31..be73d7c7 100644
--- a/sprout/math/ldexp.hpp
+++ b/sprout/math/ldexp.hpp
@@ -20,37 +20,57 @@
 namespace sprout {
 	namespace math {
 		namespace detail {
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+			inline SPROUT_CONSTEXPR float
+			builtin_ldexp(float x, int exp) {
+				return __builtin_ldexpf(x, exp);
+			}
+			inline SPROUT_CONSTEXPR double
+			builtin_ldexp(double x, int exp) {
+				return __builtin_ldexp(x, exp);
+			}
+			inline SPROUT_CONSTEXPR long double
+			builtin_ldexp(long double x, int exp) {
+				return __builtin_ldexpl(x, exp);
+			}
+#endif
+
 			template<typename T>
 			inline SPROUT_CONSTEXPR T
 			ldexp_impl(T x, int exp) {
 				return x * sprout::detail::pow_n(T(2), exp);
 			}
-
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR FloatType
-			ldexp(FloatType x, int exp) {
-				return sprout::math::isnan(x) ? x
-					: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
-					: x == -sprout::numeric_limits<FloatType>::infinity() ? -sprout::numeric_limits<FloatType>::infinity()
-					: exp == 0 ? x
-					: x == 0 ? x
-					: static_cast<FloatType>(sprout::math::detail::ldexp_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x), exp))
-					;
-			}
-			template<
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR double
-			ldexp(IntType x, int exp) {
-				return sprout::math::detail::ldexp(static_cast<double>(x), exp);
-			}
 		}	// namespace detail
-
-		using NS_SPROUT_MATH_DETAIL::ldexp;
+		//
+		// ldexp
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR FloatType
+		ldexp(FloatType x, int exp) {
+			return
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				sprout::math::detail::builtin_ldexp(x, exp)
+#else
+				sprout::math::isnan(x) ? x
+				: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
+				: x == -sprout::numeric_limits<FloatType>::infinity() ? -sprout::numeric_limits<FloatType>::infinity()
+				: exp == 0 ? x
+				: x == 0 ? x
+				: static_cast<FloatType>(sprout::math::detail::ldexp_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x), exp))
+#endif
+				;
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR double
+		ldexp(IntType x, int exp) {
+			return sprout::math::ldexp(static_cast<double>(x), exp);
+		}
 	}	// namespace math
 
 	using sprout::math::ldexp;
diff --git a/sprout/math/lgamma.hpp b/sprout/math/lgamma.hpp
index 1d1bc17b..c4d53069 100644
--- a/sprout/math/lgamma.hpp
+++ b/sprout/math/lgamma.hpp
@@ -26,6 +26,21 @@
 namespace sprout {
 	namespace math {
 		namespace detail {
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+			inline SPROUT_CONSTEXPR float
+			builtin_lgamma(float x) {
+				return __builtin_lgammaf(x);
+			}
+			inline SPROUT_CONSTEXPR double
+			builtin_lgamma(double x) {
+				return __builtin_lgamma(x);
+			}
+			inline SPROUT_CONSTEXPR long double
+			builtin_lgamma(long double x) {
+				return __builtin_lgammal(x);
+			}
+#endif
+
 			template<typename T>
 			inline SPROUT_CONSTEXPR T
 			lgamma_impl_3(T x, T y) {
@@ -183,38 +198,38 @@ namespace sprout {
 			lgamma_impl(T x) {
 				return sprout::math::detail::lgamma_impl_1(x, x < 0 ? -x : x);
 			}
-
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR FloatType
-			lgamma(FloatType x) {
-				return sprout::math::isnan(x) ? x
-					: x <= 0 && sprout::math::is_integer(x) ? sprout::numeric_limits<FloatType>::infinity()
-					: x == -sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
-					: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
-//#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
-//					: std::lgamma(x)
-//#else
-					: x == 1 ? FloatType(0)
-					: x == 2 ? FloatType(0)
-					: static_cast<FloatType>(sprout::math::detail::lgamma_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
-//#endif
-					;
-			}
-
-			template<
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR double
-			lgamma(IntType x) {
-				return sprout::math::detail::lgamma(static_cast<double>(x));
-			}
 		}	// namespace detail
+		//
+		// lgamma
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR FloatType
+		lgamma(FloatType x) {
+			return sprout::math::isnan(x) ? x
+				: x <= 0 && sprout::math::is_integer(x) ? sprout::numeric_limits<FloatType>::infinity()
+				: x == -sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
+				: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
+//#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+//				: sprout::math::detail::builtin_lgamma(x)
+//#else
+				: x == 1 ? FloatType(0)
+				: x == 2 ? FloatType(0)
+				: static_cast<FloatType>(sprout::math::detail::lgamma_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
+//#endif
+				;
+		}
 
-		using sprout::math::detail::lgamma;
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR double
+		lgamma(IntType x) {
+			return sprout::math::lgamma(static_cast<double>(x));
+		}
 	}	// namespace math
 
 	using sprout::math::lgamma;
diff --git a/sprout/math/llround.hpp b/sprout/math/llround.hpp
index cf41abb8..4b8e762a 100644
--- a/sprout/math/llround.hpp
+++ b/sprout/math/llround.hpp
@@ -20,35 +20,52 @@
 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 long long
-			llround(FloatType x) {
-				return sprout::math::isnan(x) || sprout::math::isinf(x) ? sprout::numeric_limits<long long>::min()
 #if SPROUT_USE_BUILTIN_CMATH_FUNCTION
-					: std::llround(x)
-#else
-					: sprout::math::iround<long long>(x);
-#endif
-					;
-			}
-			template<
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
-			>
 			inline SPROUT_CONSTEXPR long long
-			llround(IntType x) {
-#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
-				return std::llround(x);
-#else
-				return sprout::math::iround<long long>(x);
-#endif
+			builtin_llround(float x) {
+				return __builtin_llroundf(x);
 			}
+			inline SPROUT_CONSTEXPR long long
+			builtin_llround(double x) {
+				return __builtin_llround(x);
+			}
+			inline SPROUT_CONSTEXPR long long
+			builtin_llround(long double x) {
+				return __builtin_llroundl(x);
+			}
+#endif
 		}	// namespace detail
-
-		using sprout::math::detail::llround;
+		//
+		// llround
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR long long
+		llround(FloatType x) {
+			return sprout::math::isnan(x) || sprout::math::isinf(x) ? sprout::numeric_limits<long long>::min()
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				: sprout::math::detail::builtin_llround(x)
+#else
+				: sprout::math::iround<long long>(x);
+#endif
+				;
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR long long
+		llround(IntType x) {
+			return
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				sprout::math::detail::builtin_llround(x)
+#else
+				sprout::math::iround<long long>(x)
+#endif
+				;
+		}
 	}	// namespace math
 
 	using sprout::math::llround;
diff --git a/sprout/math/log.hpp b/sprout/math/log.hpp
index 5ee55d0f..3dc1c158 100644
--- a/sprout/math/log.hpp
+++ b/sprout/math/log.hpp
@@ -24,6 +24,21 @@
 namespace sprout {
 	namespace math {
 		namespace detail {
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+			inline SPROUT_CONSTEXPR float
+			builtin_log(float x) {
+				return __builtin_logf(x);
+			}
+			inline SPROUT_CONSTEXPR double
+			builtin_log(double x) {
+				return __builtin_log(x);
+			}
+			inline SPROUT_CONSTEXPR long double
+			builtin_log(long double x) {
+				return __builtin_logl(x);
+			}
+#endif
+
 			template<typename T>
 			inline SPROUT_CONSTEXPR T
 			log_impl_2(T x, std::size_t n, std::size_t last) {
@@ -48,36 +63,36 @@ namespace sprout {
 					: sprout::math::detail::log_impl_1(x)
 					;
 			}
-
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR FloatType
-			log(FloatType x) {
-				return sprout::math::isnan(x) ? x
-					: x == 0 ? -sprout::numeric_limits<FloatType>::infinity()
-					: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
-					: x < 0 ? sprout::numeric_limits<FloatType>::quiet_NaN()
-#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
-					: std::log(x)
-#else
-					: x == 1 ? FloatType(0)
-					: static_cast<FloatType>(sprout::math::detail::log_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
-#endif
-					;
-			}
-			template<
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR double
-			log(IntType x) {
-				return sprout::math::detail::log(static_cast<double>(x));
-			}
 		}	// namespace detail
-
-		using sprout::math::detail::log;
+		//
+		// log
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR FloatType
+		log(FloatType x) {
+			return sprout::math::isnan(x) ? x
+				: x == 0 ? -sprout::numeric_limits<FloatType>::infinity()
+				: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
+				: x < 0 ? sprout::numeric_limits<FloatType>::quiet_NaN()
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				: sprout::math::detail::builtin_log(x)
+#else
+				: x == 1 ? FloatType(0)
+				: static_cast<FloatType>(sprout::math::detail::log_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
+#endif
+				;
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR double
+		log(IntType x) {
+			return sprout::math::log(static_cast<double>(x));
+		}
 	}	// namespace math
 
 	using sprout::math::log;
diff --git a/sprout/math/log10.hpp b/sprout/math/log10.hpp
index 4fddd7bf..d4795f18 100644
--- a/sprout/math/log10.hpp
+++ b/sprout/math/log10.hpp
@@ -21,41 +21,56 @@
 namespace sprout {
 	namespace math {
 		namespace detail {
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+			inline SPROUT_CONSTEXPR float
+			builtin_log10(float x) {
+				return __builtin_log10f(x);
+			}
+			inline SPROUT_CONSTEXPR double
+			builtin_log10(double x) {
+				return __builtin_log10(x);
+			}
+			inline SPROUT_CONSTEXPR long double
+			builtin_log10(long double x) {
+				return __builtin_log10l(x);
+			}
+#endif
+
 			template<typename T>
 			inline SPROUT_CONSTEXPR T
 			log10_impl(T x) {
 				return sprout::math::log(x) / sprout::math::ln_ten<T>();
 			}
-
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR FloatType
-			log10(FloatType x) {
-				return sprout::math::isnan(x) ? x
-					: x == 0 ? -sprout::numeric_limits<FloatType>::infinity()
-					: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
-					: x < 0 ? sprout::numeric_limits<FloatType>::quiet_NaN()
-#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
-					: std::log10(x)
-#else
-					: x == 1 ? FloatType(0)
-					: static_cast<FloatType>(sprout::math::detail::log10_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
-#endif
-					;
-			}
-			template<
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR double
-			log10(IntType x) {
-				return sprout::math::detail::log10(static_cast<double>(x));
-			}
 		}	// namespace detail
-
-		using sprout::math::detail::log10;
+		//
+		// log10
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR FloatType
+		log10(FloatType x) {
+			return sprout::math::isnan(x) ? x
+				: x == 0 ? -sprout::numeric_limits<FloatType>::infinity()
+				: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
+				: x < 0 ? sprout::numeric_limits<FloatType>::quiet_NaN()
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				: sprout::math::detail::builtin_log10(x)
+#else
+				: x == 1 ? FloatType(0)
+				: static_cast<FloatType>(sprout::math::detail::log10_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
+#endif
+				;
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR double
+		log10(IntType x) {
+			return sprout::math::log10(static_cast<double>(x));
+		}
 	}	// namespace math
 
 	using sprout::math::log10;
diff --git a/sprout/math/log1p.hpp b/sprout/math/log1p.hpp
index ad52caf4..3684f3b6 100644
--- a/sprout/math/log1p.hpp
+++ b/sprout/math/log1p.hpp
@@ -20,41 +20,56 @@
 namespace sprout {
 	namespace math {
 		namespace detail {
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+			inline SPROUT_CONSTEXPR float
+			builtin_log1p(float x) {
+				return __builtin_log1pf(x);
+			}
+			inline SPROUT_CONSTEXPR double
+			builtin_log1p(double x) {
+				return __builtin_log1p(x);
+			}
+			inline SPROUT_CONSTEXPR long double
+			builtin_log1p(long double x) {
+				return __builtin_log1pl(x);
+			}
+#endif
+
 			template<typename T>
 			inline SPROUT_CONSTEXPR T
 			log1p_impl(T x) {
 				return sprout::math::log(T(1) + x);
 			}
-
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR FloatType
-			log1p(FloatType x) {
-				return sprout::math::isnan(x) ? x
-					: x == -1 ? -sprout::numeric_limits<FloatType>::infinity()
-					: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
-					: x < -1 ? -sprout::numeric_limits<FloatType>::quiet_NaN()
-#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
-					: std::log1p(x)
-#else
-					: x == 0 ? x
-					: static_cast<FloatType>(sprout::math::detail::log1p_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
-#endif
-					;
-			}
-			template<
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR double
-			log1p(IntType x) {
-				return sprout::math::detail::log1p(static_cast<double>(x));
-			}
 		}	// namespace detail
-
-		using sprout::math::detail::log1p;
+		//
+		// log1p
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR FloatType
+		log1p(FloatType x) {
+			return sprout::math::isnan(x) ? x
+				: x == -1 ? -sprout::numeric_limits<FloatType>::infinity()
+				: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
+				: x < -1 ? -sprout::numeric_limits<FloatType>::quiet_NaN()
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				: sprout::math::detail::builtin_log1p(x)
+#else
+				: x == 0 ? x
+				: static_cast<FloatType>(sprout::math::detail::log1p_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
+#endif
+				;
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR double
+		log1p(IntType x) {
+			return sprout::math::log1p(static_cast<double>(x));
+		}
 	}	// namespace math
 
 	using sprout::math::log1p;
diff --git a/sprout/math/log2.hpp b/sprout/math/log2.hpp
index 61fcd999..1f155c5c 100644
--- a/sprout/math/log2.hpp
+++ b/sprout/math/log2.hpp
@@ -21,41 +21,56 @@
 namespace sprout {
 	namespace math {
 		namespace detail {
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+			inline SPROUT_CONSTEXPR float
+			builtin_log2(float x) {
+				return __builtin_log2f(x);
+			}
+			inline SPROUT_CONSTEXPR double
+			builtin_log2(double x) {
+				return __builtin_log2(x);
+			}
+			inline SPROUT_CONSTEXPR long double
+			builtin_log2(long double x) {
+				return __builtin_log2l(x);
+			}
+#endif
+
 			template<typename T>
 			inline SPROUT_CONSTEXPR T
 			log2_impl(T x) {
 				return sprout::math::log(x) / sprout::math::ln_two<T>();
 			}
-
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR FloatType
-			log2(FloatType x) {
-				return sprout::math::isnan(x) ? x
-					: x == 0 ? -sprout::numeric_limits<FloatType>::infinity()
-					: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
-					: x < 0 ? sprout::numeric_limits<FloatType>::quiet_NaN()
-#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
-					: std::log2(x)
-#else
-					: x == 1 ? FloatType(0)
-					: static_cast<FloatType>(sprout::math::detail::log2_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
-#endif
-					;
-			}
-			template<
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR double
-			log2(IntType x) {
-				return sprout::math::detail::log2(static_cast<double>(x));
-			}
 		}	// namespace detail
-
-		using sprout::math::detail::log2;
+		//
+		// log2
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR FloatType
+		log2(FloatType x) {
+			return sprout::math::isnan(x) ? x
+				: x == 0 ? -sprout::numeric_limits<FloatType>::infinity()
+				: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
+				: x < 0 ? sprout::numeric_limits<FloatType>::quiet_NaN()
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				: sprout::math::detail::builtin_log2(x)
+#else
+				: x == 1 ? FloatType(0)
+				: static_cast<FloatType>(sprout::math::detail::log2_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
+#endif
+				;
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR double
+		log2(IntType x) {
+			return sprout::math::log2(static_cast<double>(x));
+		}
 	}	// namespace math
 
 	using sprout::math::log2;
diff --git a/sprout/math/log_a.hpp b/sprout/math/log_a.hpp
index c0c9f5f0..240bb2b4 100644
--- a/sprout/math/log_a.hpp
+++ b/sprout/math/log_a.hpp
@@ -28,34 +28,34 @@ namespace sprout {
 					: sprout::math::log(y) / sprout::math::log(x)
 					;
 			}
-
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR FloatType
-			log_a(FloatType x, FloatType y) {
-				return static_cast<FloatType>(sprout::math::detail::log_a_impl(
-					static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x),
-					static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(y)
-					));
-			}
-
-			template<
-				typename ArithmeticType1,
-				typename ArithmeticType2,
-				typename sprout::enabler_if<
-					std::is_arithmetic<ArithmeticType1>::value && std::is_arithmetic<ArithmeticType2>::value
-				>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type
-			log_a(ArithmeticType1 x, ArithmeticType2 y) {
-				typedef typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type type;
-				return sprout::math::detail::log_a(static_cast<type>(x), static_cast<type>(y));
-			}
 		}	// namespace detail
+		//
+		// log_a
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR FloatType
+		log_a(FloatType x, FloatType y) {
+			return static_cast<FloatType>(sprout::math::detail::log_a_impl(
+				static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x),
+				static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(y)
+				));
+		}
 
-		using sprout::math::detail::log_a;
+		template<
+			typename ArithmeticType1,
+			typename ArithmeticType2,
+			typename sprout::enabler_if<
+				std::is_arithmetic<ArithmeticType1>::value && std::is_arithmetic<ArithmeticType2>::value
+			>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type
+		log_a(ArithmeticType1 x, ArithmeticType2 y) {
+			typedef typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type type;
+			return sprout::math::log_a(static_cast<type>(x), static_cast<type>(y));
+		}
 	}	// namespace math
 
 	using sprout::math::log_a;
diff --git a/sprout/math/logb.hpp b/sprout/math/logb.hpp
index 20ce7c72..508fab38 100644
--- a/sprout/math/logb.hpp
+++ b/sprout/math/logb.hpp
@@ -25,6 +25,21 @@
 namespace sprout {
 	namespace math {
 		namespace detail {
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+			inline SPROUT_CONSTEXPR float
+			builtin_logb(float x) {
+				return __builtin_logbf(x);
+			}
+			inline SPROUT_CONSTEXPR double
+			builtin_logb(double x) {
+				return __builtin_logb(x);
+			}
+			inline SPROUT_CONSTEXPR long double
+			builtin_logb(long double x) {
+				return __builtin_logbl(x);
+			}
+#endif
+
 			template<typename T>
 			inline SPROUT_CONSTEXPR T
 			logb_impl_3_neg_lo(T x, T x0, T base, T exp) {
@@ -100,39 +115,39 @@ namespace sprout {
 					: sprout::math::detail::logb_impl_1(x, sprout::math::trunc(sprout::math::log_a(T(sprout::numeric_limits<T>::radix), x)))
 					;
 			}
-
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR FloatType
-			logb(FloatType x) {
-				return sprout::math::isnan(x) ? x
-					: x == 0 ? -sprout::numeric_limits<FloatType>::infinity()
+		}	// namespace detail
+		//
+		// logb
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR FloatType
+		logb(FloatType x) {
+			return sprout::math::isnan(x) ? x
+				: x == 0 ? -sprout::numeric_limits<FloatType>::infinity()
 #if SPROUT_USE_BUILTIN_CMATH_FUNCTION
 #	if defined(__GNUC__)
-					: x == -sprout::numeric_limits<FloatType>::infinity()
-						? sprout::numeric_limits<FloatType>::infinity()
+				: x == -sprout::numeric_limits<FloatType>::infinity()
+					? sprout::numeric_limits<FloatType>::infinity()
 #	endif
-					: std::logb(x)
+				: sprout::math::detail::builtin_logb(x)
 #else
-					: x == sprout::numeric_limits<FloatType>::infinity() || x == -sprout::numeric_limits<FloatType>::infinity()
-						? sprout::numeric_limits<FloatType>::infinity()
-					: static_cast<FloatType>(sprout::math::detail::logb_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
+				: x == sprout::numeric_limits<FloatType>::infinity() || x == -sprout::numeric_limits<FloatType>::infinity()
+					? sprout::numeric_limits<FloatType>::infinity()
+				: static_cast<FloatType>(sprout::math::detail::logb_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
 #endif
-					;
-			}
-			template<
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR double
-			logb(IntType x) {
-				return sprout::math::detail::logb(static_cast<double>(x));
-			}
-		}	// namespace detail
-
-		using sprout::math::detail::logb;
+				;
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR double
+		logb(IntType x) {
+			return sprout::math::logb(static_cast<double>(x));
+		}
 	}	// namespace math
 
 	using sprout::math::logb;
diff --git a/sprout/math/logb2.hpp b/sprout/math/logb2.hpp
index 5c14a189..3b239dcd 100644
--- a/sprout/math/logb2.hpp
+++ b/sprout/math/logb2.hpp
@@ -28,25 +28,28 @@
 
 namespace sprout {
 	namespace math {
-		namespace detail {
 #if SPROUT_FLT_RADIX_IS_2
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR FloatType
-			logb2(FloatType x) {
-				return sprout::math::logb(x);
-			}
-			template<
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR double
-			logb2(IntType x) {
-				return sprout::math::logb(x);
-			}
+		//
+		// logb2
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR FloatType
+		logb2(FloatType x) {
+			return sprout::math::logb(x);
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR double
+		logb2(IntType x) {
+			return sprout::math::logb(x);
+		}
 #else
+		namespace detail {
 			template<typename T>
 			inline SPROUT_CONSTEXPR T
 			logb2_impl_3_neg_lo(T x, T x0, T base, T exp) {
@@ -122,32 +125,32 @@ namespace sprout {
 					: sprout::math::detail::logb2_impl_1(x, sprout::math::trunc(sprout::math::log_a(T(2), x)))
 					;
 			}
-
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR FloatType
-			logb2(FloatType x) {
-				return sprout::math::isnan(x) ? x
-					: x == 0 ? -sprout::numeric_limits<FloatType>::infinity()
-					: x == sprout::numeric_limits<FloatType>::infinity() || x == -sprout::numeric_limits<FloatType>::infinity()
-						? sprout::numeric_limits<FloatType>::infinity()
-					: static_cast<FloatType>(sprout::math::detail::logb2_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
-					;
-			}
-			template<
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR double
-			logb2(IntType x) {
-				return sprout::math::detail::logb2(static_cast<double>(x));
-			}
-#endif
 		}	// namespace detail
-
-		using sprout::math::detail::logb2;
+		//
+		// logb2
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR FloatType
+		logb2(FloatType x) {
+			return sprout::math::isnan(x) ? x
+				: x == 0 ? -sprout::numeric_limits<FloatType>::infinity()
+				: x == sprout::numeric_limits<FloatType>::infinity() || x == -sprout::numeric_limits<FloatType>::infinity()
+					? sprout::numeric_limits<FloatType>::infinity()
+				: static_cast<FloatType>(sprout::math::detail::logb2_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
+				;
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR double
+		logb2(IntType x) {
+			return sprout::math::logb2(static_cast<double>(x));
+		}
+#endif
 	}	// namespace math
 
 	using sprout::math::logb2;
diff --git a/sprout/math/lround.hpp b/sprout/math/lround.hpp
index c128c7d7..89c21761 100644
--- a/sprout/math/lround.hpp
+++ b/sprout/math/lround.hpp
@@ -20,35 +20,52 @@
 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 long
-			lround(FloatType x) {
-				return sprout::math::isnan(x) || sprout::math::isinf(x) ? sprout::numeric_limits<long>::min()
 #if SPROUT_USE_BUILTIN_CMATH_FUNCTION
-					: std::lround(x)
-#else
-					: sprout::math::iround<long>(x);
-#endif
-					;
-			}
-			template<
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
-			>
 			inline SPROUT_CONSTEXPR long
-			lround(IntType x) {
-#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
-				return std::lround(x);
-#else
-				return sprout::math::iround<long>(x);
-#endif
+			builtin_lround(float x) {
+				return __builtin_lroundf(x);
 			}
+			inline SPROUT_CONSTEXPR long
+			builtin_lround(double x) {
+				return __builtin_lround(x);
+			}
+			inline SPROUT_CONSTEXPR long
+			builtin_lround(long double x) {
+				return __builtin_lroundl(x);
+			}
+#endif
 		}	// namespace detail
-
-		using sprout::math::detail::lround;
+		//
+		// lround
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR long
+		lround(FloatType x) {
+			return sprout::math::isnan(x) || sprout::math::isinf(x) ? sprout::numeric_limits<long>::min()
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				: sprout::math::detail::builtin_lround(x)
+#else
+				: sprout::math::iround<long>(x);
+#endif
+				;
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR long
+		lround(IntType x) {
+			return
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				sprout::math::detail::builtin_lround(x)
+#else
+				sprout::math::iround<long>(x)
+#endif
+				;
+		}
 	}	// namespace math
 
 	using sprout::math::lround;
diff --git a/sprout/math/pow.hpp b/sprout/math/pow.hpp
index b61efef6..977718bf 100644
--- a/sprout/math/pow.hpp
+++ b/sprout/math/pow.hpp
@@ -26,76 +26,91 @@
 namespace sprout {
 	namespace math {
 		namespace detail {
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+			inline SPROUT_CONSTEXPR float
+			builtin_pow(float x, float y) {
+				return __builtin_powf(x, y);
+			}
+			inline SPROUT_CONSTEXPR double
+			builtin_pow(double x, double y) {
+				return __builtin_pow(x, y);
+			}
+			inline SPROUT_CONSTEXPR long double
+			builtin_pow(long double x, long double y) {
+				return __builtin_powl(x, y);
+			}
+#endif
+
 			template<typename T>
 			inline SPROUT_CONSTEXPR T
 			pow_impl(T x, T y) {
 				return sprout::math::exp(y * sprout::math::log(x));
 			}
-
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR FloatType
-			pow(FloatType x, FloatType y) {
-				return x == 1 ? FloatType(1)
-					: y == 0 ? FloatType(1)
-					: sprout::math::isnan(y) ? y
-					: sprout::math::isnan(x) ? x
-					: x == 0
-						? y < 0
-							? sprout::math::is_odd(y) ? sprout::math::copysign(sprout::numeric_limits<FloatType>::infinity(), x)
-							: sprout::numeric_limits<FloatType>::infinity()
-						: sprout::math::is_odd(y) ? x
-						: FloatType(0)
-					: x == -1 && (y == sprout::numeric_limits<FloatType>::infinity() || y == -sprout::numeric_limits<FloatType>::infinity()) ? FloatType(1)
-					: y == -sprout::numeric_limits<FloatType>::infinity()
-						? sprout::math::fabs(x) < 1 ? sprout::numeric_limits<FloatType>::infinity()
-						: FloatType(0)
-					: y == sprout::numeric_limits<FloatType>::infinity()
-						? sprout::math::fabs(x) < 1 ? FloatType(0)
-						: sprout::numeric_limits<FloatType>::infinity()
-					: x == -sprout::numeric_limits<FloatType>::infinity()
-						? y < 0
-							? sprout::math::is_odd(y) ? -FloatType(0)
-							: FloatType(0)
-						: sprout::math::is_odd(y) ? -sprout::numeric_limits<FloatType>::infinity()
-						: sprout::numeric_limits<FloatType>::infinity()
-					: x == sprout::numeric_limits<FloatType>::infinity()
-						? y < 0 ? FloatType(0)
-						: sprout::numeric_limits<FloatType>::infinity()
-					: x < 0 && !sprout::math::is_integer(y) ? sprout::numeric_limits<FloatType>::quiet_NaN()
-#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
-					: std::pow(x, y)
-#else
-					: static_cast<FloatType>(sprout::math::detail::pow_impl(
-						static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x),
-						static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(y)
-						))
-#endif
-					;
-			}
-
-			template<
-				typename ArithmeticType1,
-				typename ArithmeticType2,
-				typename sprout::enabler_if<
-					std::is_arithmetic<ArithmeticType1>::value && std::is_arithmetic<ArithmeticType2>::value
-				>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type
-			pow(ArithmeticType1 x, ArithmeticType2 y) {
-				typedef typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type type;
-				return sprout::math::detail::pow(static_cast<type>(x), static_cast<type>(y));
-			}
 		}	// namespace detail
 		//
+		// pow
+		//
 		// issue:
 		//	[ !SPROUT_USE_BUILTIN_CMATH_FUNCTION ]
 		//	pow(-0, y) returns -�� for y an odd integer < 0.
 		//		# returns +�� . ( same as pow(+0, y) )
 		//
-		using sprout::math::detail::pow;
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR FloatType
+		pow(FloatType x, FloatType y) {
+			return x == 1 ? FloatType(1)
+				: y == 0 ? FloatType(1)
+				: sprout::math::isnan(y) ? y
+				: sprout::math::isnan(x) ? x
+				: x == 0
+					? y < 0
+						? sprout::math::is_odd(y) ? sprout::math::copysign(sprout::numeric_limits<FloatType>::infinity(), x)
+						: sprout::numeric_limits<FloatType>::infinity()
+					: sprout::math::is_odd(y) ? x
+					: FloatType(0)
+				: x == -1 && (y == sprout::numeric_limits<FloatType>::infinity() || y == -sprout::numeric_limits<FloatType>::infinity()) ? FloatType(1)
+				: y == -sprout::numeric_limits<FloatType>::infinity()
+					? sprout::math::fabs(x) < 1 ? sprout::numeric_limits<FloatType>::infinity()
+					: FloatType(0)
+				: y == sprout::numeric_limits<FloatType>::infinity()
+					? sprout::math::fabs(x) < 1 ? FloatType(0)
+					: sprout::numeric_limits<FloatType>::infinity()
+				: x == -sprout::numeric_limits<FloatType>::infinity()
+					? y < 0
+						? sprout::math::is_odd(y) ? -FloatType(0)
+						: FloatType(0)
+					: sprout::math::is_odd(y) ? -sprout::numeric_limits<FloatType>::infinity()
+					: sprout::numeric_limits<FloatType>::infinity()
+				: x == sprout::numeric_limits<FloatType>::infinity()
+					? y < 0 ? FloatType(0)
+					: sprout::numeric_limits<FloatType>::infinity()
+				: x < 0 && !sprout::math::is_integer(y) ? sprout::numeric_limits<FloatType>::quiet_NaN()
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				: sprout::math::detail::builtin_pow(x, y)
+#else
+				: static_cast<FloatType>(sprout::math::detail::pow_impl(
+					static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x),
+					static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(y)
+					))
+#endif
+				;
+		}
+
+		template<
+			typename ArithmeticType1,
+			typename ArithmeticType2,
+			typename sprout::enabler_if<
+				std::is_arithmetic<ArithmeticType1>::value && std::is_arithmetic<ArithmeticType2>::value
+			>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type
+		pow(ArithmeticType1 x, ArithmeticType2 y) {
+			typedef typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type type;
+			return sprout::math::pow(static_cast<type>(x), static_cast<type>(y));
+		}
 	}	// namespace math
 
 	using sprout::math::pow;
diff --git a/sprout/math/quotient.hpp b/sprout/math/quotient.hpp
index 2d0ab884..89fa3c17 100644
--- a/sprout/math/quotient.hpp
+++ b/sprout/math/quotient.hpp
@@ -20,39 +20,38 @@
 
 namespace sprout {
 	namespace math {
-		namespace detail {
-			template<
-				typename R = int,
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value && std::is_integral<R>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR R
-			quotient(FloatType x, FloatType y) {
-				return y == 0 ? R(0)
-					: sprout::math::isnan(y) || sprout::math::isnan(x) ? R(0)
-					: x == sprout::numeric_limits<FloatType>::infinity() || x == -sprout::numeric_limits<FloatType>::infinity()
-						? R(0)
-					: x == 0 ? R(0)
-					: y == sprout::numeric_limits<FloatType>::infinity() || y == -sprout::numeric_limits<FloatType>::infinity() ? R(0)
-					: sprout::math::rem_quo<R>(x, y).second
-					;
-			}
-			template<
-				typename R = int,
-				typename ArithmeticType1,
-				typename ArithmeticType2,
-				typename sprout::enabler_if<
-					std::is_arithmetic<ArithmeticType1>::value && std::is_arithmetic<ArithmeticType2>::value && std::is_integral<R>::value
-				>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR R
-			quotient(ArithmeticType1 x, ArithmeticType2 y) {
-				typedef typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type type;
-				return sprout::math::detail::quotient(static_cast<type>(x), static_cast<type>(y));
-			}
-		}	// namespace detail
-
-		using sprout::math::detail::quotient;
+		//
+		// quotient
+		//
+		template<
+			typename R = int,
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value && std::is_integral<R>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR R
+		quotient(FloatType x, FloatType y) {
+			return y == 0 ? R(0)
+				: sprout::math::isnan(y) || sprout::math::isnan(x) ? R(0)
+				: x == sprout::numeric_limits<FloatType>::infinity() || x == -sprout::numeric_limits<FloatType>::infinity()
+					? R(0)
+				: x == 0 ? R(0)
+				: y == sprout::numeric_limits<FloatType>::infinity() || y == -sprout::numeric_limits<FloatType>::infinity() ? R(0)
+				: sprout::math::rem_quo<R>(x, y).second
+				;
+		}
+		template<
+			typename R = int,
+			typename ArithmeticType1,
+			typename ArithmeticType2,
+			typename sprout::enabler_if<
+				std::is_arithmetic<ArithmeticType1>::value && std::is_arithmetic<ArithmeticType2>::value && std::is_integral<R>::value
+			>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR R
+		quotient(ArithmeticType1 x, ArithmeticType2 y) {
+			typedef typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type type;
+			return sprout::math::quotient(static_cast<type>(x), static_cast<type>(y));
+		}
 	}	// namespace math
 
 	using sprout::math::quotient;
diff --git a/sprout/math/rem_quo.hpp b/sprout/math/rem_quo.hpp
index a4f0e2f6..44fc0c56 100644
--- a/sprout/math/rem_quo.hpp
+++ b/sprout/math/rem_quo.hpp
@@ -87,55 +87,56 @@ namespace sprout {
 			rem_quo_impl(T x, T y, R iquo) {
 				return sprout::math::detail::rem_quo_impl_1(x, sprout::math::fabs(y), (sprout::math::signbit(x) ^ sprout::math::signbit(y) ? -1 : 1), iquo, sprout::math::fabs(x));
 			}
-
-			template<
-				typename R = int,
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value && std::is_integral<R>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR sprout::pair<FloatType, R>
-			rem_quo(FloatType x, FloatType y) {
-				typedef sprout::pair<FloatType, R> type;
-				return y == 0 ? type(-sprout::numeric_limits<FloatType>::quiet_NaN(), R(0))
-					: sprout::math::isnan(y)
-						? sprout::math::isnan(x)
-							? type(sprout::math::signbit(y) && sprout::math::signbit(x) ? -sprout::numeric_limits<FloatType>::quiet_NaN() : sprout::numeric_limits<FloatType>::quiet_NaN(), R(0))
-							: type(y, R(0))
-					: sprout::math::isnan(x) ? type(x, R(0))
-					: x == sprout::numeric_limits<FloatType>::infinity() || x == -sprout::numeric_limits<FloatType>::infinity()
-						? type(-sprout::numeric_limits<FloatType>::quiet_NaN(), R(0))
-					: x == 0 ? type(x, R(0))
-					: y == sprout::numeric_limits<FloatType>::infinity() || y == -sprout::numeric_limits<FloatType>::infinity() ? type(x, R(0))
-					: sprout::math::detail::rem_quo_ret<R, FloatType>(sprout::math::detail::rem_quo_impl(
-						static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x),
-						static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(y),
-						R(0)
-						))
-					;
-			}
-			template<
-				typename R = int,
-				typename ArithmeticType1,
-				typename ArithmeticType2,
-				typename sprout::enabler_if<
-					std::is_arithmetic<ArithmeticType1>::value && std::is_arithmetic<ArithmeticType2>::value && std::is_integral<R>::value
-				>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR sprout::pair<
-				typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type,
-				R
-			>
-			rem_quo(ArithmeticType1 x, ArithmeticType2 y) {
-				typedef typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type type;
-				return sprout::math::detail::rem_quo(static_cast<type>(x), static_cast<type>(y));
-			}
 		}	// namespace detail
 		//
+		// rem_quo
+		//
+		//
 		// issue:
 		//	rem_quo(-NaN, -NaN) returns {-NaN, _} .
 		//		# returns {+NaN, _} . ( same as rem_quo(+NaN, +NaN) )
 		//
-		using sprout::math::detail::rem_quo;
+		template<
+			typename R = int,
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value && std::is_integral<R>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR sprout::pair<FloatType, R>
+		rem_quo(FloatType x, FloatType y) {
+			typedef sprout::pair<FloatType, R> type;
+			return y == 0 ? type(-sprout::numeric_limits<FloatType>::quiet_NaN(), R(0))
+				: sprout::math::isnan(y)
+					? sprout::math::isnan(x)
+						? type(sprout::math::signbit(y) && sprout::math::signbit(x) ? -sprout::numeric_limits<FloatType>::quiet_NaN() : sprout::numeric_limits<FloatType>::quiet_NaN(), R(0))
+						: type(y, R(0))
+				: sprout::math::isnan(x) ? type(x, R(0))
+				: x == sprout::numeric_limits<FloatType>::infinity() || x == -sprout::numeric_limits<FloatType>::infinity()
+					? type(-sprout::numeric_limits<FloatType>::quiet_NaN(), R(0))
+				: x == 0 ? type(x, R(0))
+				: y == sprout::numeric_limits<FloatType>::infinity() || y == -sprout::numeric_limits<FloatType>::infinity() ? type(x, R(0))
+				: sprout::math::detail::rem_quo_ret<R, FloatType>(sprout::math::detail::rem_quo_impl(
+					static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x),
+					static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(y),
+					R(0)
+					))
+				;
+		}
+		template<
+			typename R = int,
+			typename ArithmeticType1,
+			typename ArithmeticType2,
+			typename sprout::enabler_if<
+				std::is_arithmetic<ArithmeticType1>::value && std::is_arithmetic<ArithmeticType2>::value && std::is_integral<R>::value
+			>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR sprout::pair<
+			typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type,
+			R
+		>
+		rem_quo(ArithmeticType1 x, ArithmeticType2 y) {
+			typedef typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type type;
+			return sprout::math::rem_quo(static_cast<type>(x), static_cast<type>(y));
+		}
 	}	// namespace math
 
 	using sprout::math::rem_quo;
diff --git a/sprout/math/remainder.hpp b/sprout/math/remainder.hpp
index 3d34ec8c..7b00300d 100644
--- a/sprout/math/remainder.hpp
+++ b/sprout/math/remainder.hpp
@@ -21,49 +21,64 @@
 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
-			remainder(FloatType x, FloatType y) {
-				return y == 0 ? -sprout::numeric_limits<FloatType>::quiet_NaN()
-					: sprout::math::isnan(y)
-						? sprout::math::isnan(x)
-							? sprout::math::signbit(y) && sprout::math::signbit(x) ? -sprout::numeric_limits<FloatType>::quiet_NaN()
-								: sprout::numeric_limits<FloatType>::quiet_NaN()
-							: y
-					: sprout::math::isnan(x) ? x
-					: x == sprout::numeric_limits<FloatType>::infinity() || x == -sprout::numeric_limits<FloatType>::infinity()
-						? -sprout::numeric_limits<FloatType>::quiet_NaN()
-					: x == 0 ? x
-					: y == sprout::numeric_limits<FloatType>::infinity() || y == -sprout::numeric_limits<FloatType>::infinity() ? x
 #if SPROUT_USE_BUILTIN_CMATH_FUNCTION
-					: std::remainder(x, y)
-#else
-					: sprout::math::rem_quo(x, y).first
+			inline SPROUT_CONSTEXPR float
+			builtin_remainder(float x, float y) {
+				return __builtin_remainderf(x, y);
+			}
+			inline SPROUT_CONSTEXPR double
+			builtin_remainder(double x, double y) {
+				return __builtin_remainder(x, y);
+			}
+			inline SPROUT_CONSTEXPR long double 
+			builtin_remainder(long double x, long double y) {
+				return __builtin_remainderl(x, y);
+			}
 #endif
-					;
-			}
-			template<
-				typename ArithmeticType1,
-				typename ArithmeticType2,
-				typename sprout::enabler_if<
-					std::is_arithmetic<ArithmeticType1>::value && std::is_arithmetic<ArithmeticType2>::value
-				>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type
-			remainder(ArithmeticType1 x, ArithmeticType2 y) {
-				typedef typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type type;
-				return sprout::math::detail::remainder(static_cast<type>(x), static_cast<type>(y));
-			}
 		}	// namespace detail
 		//
+		// remainder
+		//
 		// issue:
 		//	remainder(-NaN, -NaN) returns -NaN .
 		//		# returns +NaN . ( same as remainder(+NaN, +NaN) )
 		//
-		using sprout::math::detail::remainder;
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR FloatType
+		remainder(FloatType x, FloatType y) {
+			return y == 0 ? -sprout::numeric_limits<FloatType>::quiet_NaN()
+				: sprout::math::isnan(y)
+					? sprout::math::isnan(x)
+						? sprout::math::signbit(y) && sprout::math::signbit(x) ? -sprout::numeric_limits<FloatType>::quiet_NaN()
+							: sprout::numeric_limits<FloatType>::quiet_NaN()
+						: y
+				: sprout::math::isnan(x) ? x
+				: x == sprout::numeric_limits<FloatType>::infinity() || x == -sprout::numeric_limits<FloatType>::infinity()
+					? -sprout::numeric_limits<FloatType>::quiet_NaN()
+				: x == 0 ? x
+				: y == sprout::numeric_limits<FloatType>::infinity() || y == -sprout::numeric_limits<FloatType>::infinity() ? x
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				: sprout::math::detail::builtin_remainder(x, y)
+#else
+				: sprout::math::rem_quo(x, y).first
+#endif
+				;
+		}
+		template<
+			typename ArithmeticType1,
+			typename ArithmeticType2,
+			typename sprout::enabler_if<
+				std::is_arithmetic<ArithmeticType1>::value && std::is_arithmetic<ArithmeticType2>::value
+			>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type
+		remainder(ArithmeticType1 x, ArithmeticType2 y) {
+			typedef typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type type;
+			return sprout::math::remainder(static_cast<type>(x), static_cast<type>(y));
+		}
 	}	// namespace math
 
 	using sprout::math::remainder;
diff --git a/sprout/math/round.hpp b/sprout/math/round.hpp
index 21882cc5..8e496a7e 100644
--- a/sprout/math/round.hpp
+++ b/sprout/math/round.hpp
@@ -21,6 +21,21 @@
 namespace sprout {
 	namespace math {
 		namespace detail {
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+			inline SPROUT_CONSTEXPR float
+			builtin_round(float x) {
+				return __builtin_roundf(x);
+			}
+			inline SPROUT_CONSTEXPR double
+			builtin_round(double x) {
+				return __builtin_round(x);
+			}
+			inline SPROUT_CONSTEXPR long double
+			builtin_round(long double x) {
+				return __builtin_roundl(x);
+			}
+#endif
+
 			template<typename T>
 			inline SPROUT_CONSTEXPR T
 			round_impl_positive(T x, T x0) {
@@ -42,37 +57,37 @@ namespace sprout {
 					: sprout::math::detail::round_impl_positive(x, static_cast<T>(static_cast<std::uintmax_t>(x)))
 					;
 			}
-
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR FloatType
-			round(FloatType x) {
-				return sprout::math::isnan(x) ? x
-					: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
-					: x == -sprout::numeric_limits<FloatType>::infinity() ? -sprout::numeric_limits<FloatType>::infinity()
-#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
-					: std::round(x)
-#else
-					: x == 0 ? x
-					: sprout::numeric_limits<std::uintmax_t>::max() < x || sprout::numeric_limits<std::uintmax_t>::max() < -x
-						? SPROUT_MATH_THROW_LARGE_FLOAT_ROUNDING(std::runtime_error("round: large float rounding."), x)
-					: static_cast<FloatType>(sprout::math::detail::round_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
-#endif
-					;
-			}
-			template<
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR double
-			round(IntType x) {
-				return sprout::math::detail::round(static_cast<double>(x));
-			}
 		}	// namespace detail
-
-		using sprout::math::detail::round;
+		//
+		// round
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR FloatType
+		round(FloatType x) {
+			return sprout::math::isnan(x) ? x
+				: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
+				: x == -sprout::numeric_limits<FloatType>::infinity() ? -sprout::numeric_limits<FloatType>::infinity()
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				: sprout::math::detail::builtin_round(x)
+#else
+				: x == 0 ? x
+				: sprout::numeric_limits<std::uintmax_t>::max() < x || sprout::numeric_limits<std::uintmax_t>::max() < -x
+					? SPROUT_MATH_THROW_LARGE_FLOAT_ROUNDING(std::runtime_error("round: large float rounding."), x)
+				: static_cast<FloatType>(sprout::math::detail::round_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
+#endif
+				;
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR double
+		round(IntType x) {
+			return sprout::math::round(static_cast<double>(x));
+		}
 	}	// namespace math
 
 	using sprout::math::round;
diff --git a/sprout/math/scalbln.hpp b/sprout/math/scalbln.hpp
index b05ffce2..0ebd07b9 100644
--- a/sprout/math/scalbln.hpp
+++ b/sprout/math/scalbln.hpp
@@ -20,37 +20,57 @@
 namespace sprout {
 	namespace math {
 		namespace detail {
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+			inline SPROUT_CONSTEXPR float
+			builtin_scalbln(float x, long exp) {
+				return __builtin_scalblnf(x, exp);
+			}
+			inline SPROUT_CONSTEXPR double
+			builtin_scalbln(double x, long exp) {
+				return __builtin_scalbln(x, exp);
+			}
+			inline SPROUT_CONSTEXPR long double
+			builtin_scalbln(long double x, long exp) {
+				return __builtin_scalblnl(x, exp);
+			}
+#endif
+
 			template<typename FloatType, typename T>
 			inline SPROUT_CONSTEXPR T
 			scalbln_impl(T x, long exp) {
 				return x * sprout::detail::pow_n(T(sprout::numeric_limits<FloatType>::radix), exp);
 			}
-
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR FloatType
-			scalbln(FloatType x, long exp) {
-				return sprout::math::isnan(x) ? x
-					: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
-					: x == -sprout::numeric_limits<FloatType>::infinity() ? -sprout::numeric_limits<FloatType>::infinity()
-					: exp == 0 ? x
-					: x == 0 ? x
-					: static_cast<FloatType>(sprout::math::detail::scalbln_impl<FloatType>(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x), exp))
-					;
-			}
-			template<
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR double
-			scalbln(IntType x, long exp) {
-				return sprout::math::detail::scalbln(static_cast<double>(x), exp);
-			}
 		}	// namespace detail
-
-		using NS_SPROUT_MATH_DETAIL::scalbln;
+		//
+		// scalbln
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR FloatType
+		scalbln(FloatType x, long exp) {
+			return
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				sprout::math::detail::builtin_scalbln(x, exp)
+#else
+				sprout::math::isnan(x) ? x
+				: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
+				: x == -sprout::numeric_limits<FloatType>::infinity() ? -sprout::numeric_limits<FloatType>::infinity()
+				: exp == 0 ? x
+				: x == 0 ? x
+				: static_cast<FloatType>(sprout::math::detail::scalbln_impl<FloatType>(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x), exp))
+#endif
+				;
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR double
+		scalbln(IntType x, long exp) {
+			return sprout::math::scalbln(static_cast<double>(x), exp);
+		}
 	}	// namespace math
 
 	using sprout::math::scalbln;
diff --git a/sprout/math/scalbn.hpp b/sprout/math/scalbn.hpp
index 2b1a3fe3..fd80993b 100644
--- a/sprout/math/scalbn.hpp
+++ b/sprout/math/scalbn.hpp
@@ -20,37 +20,57 @@
 namespace sprout {
 	namespace math {
 		namespace detail {
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+			inline SPROUT_CONSTEXPR float
+			builtin_scalbn(float x, int exp) {
+				return __builtin_scalbnf(x, exp);
+			}
+			inline SPROUT_CONSTEXPR double
+			builtin_scalbn(double x, int exp) {
+				return __builtin_scalbn(x, exp);
+			}
+			inline SPROUT_CONSTEXPR long double
+			builtin_scalbn(long double x, int exp) {
+				return __builtin_scalbnl(x, exp);
+			}
+#endif
+
 			template<typename FloatType, typename T>
 			inline SPROUT_CONSTEXPR T
 			scalbn_impl(T x, int exp) {
 				return x * sprout::detail::pow_n(T(sprout::numeric_limits<FloatType>::radix), exp);
 			}
-
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR FloatType
-			scalbn(FloatType x, int exp) {
-				return sprout::math::isnan(x) ? x
-					: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
-					: x == -sprout::numeric_limits<FloatType>::infinity() ? -sprout::numeric_limits<FloatType>::infinity()
-					: exp == 0 ? x
-					: x == 0 ? x
-					: static_cast<FloatType>(sprout::math::detail::scalbn_impl<FloatType>(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x), exp))
-					;
-			}
-			template<
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR double
-			scalbn(IntType x, int exp) {
-				return sprout::math::detail::scalbn(static_cast<double>(x), exp);
-			}
 		}	// namespace detail
-
-		using NS_SPROUT_MATH_DETAIL::scalbn;
+		//
+		// scalbn
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR FloatType
+		scalbn(FloatType x, int exp) {
+			return
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				sprout::math::detail::builtin_scalbn(x, exp)
+#else
+				sprout::math::isnan(x) ? x
+				: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
+				: x == -sprout::numeric_limits<FloatType>::infinity() ? -sprout::numeric_limits<FloatType>::infinity()
+				: exp == 0 ? x
+				: x == 0 ? x
+				: static_cast<FloatType>(sprout::math::detail::scalbn_impl<FloatType>(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x), exp))
+#endif
+				;
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR double
+		scalbn(IntType x, int exp) {
+			return sprout::math::scalbn(static_cast<double>(x), exp);
+		}
 	}	// namespace math
 
 	using sprout::math::scalbn;
diff --git a/sprout/math/signbit.hpp b/sprout/math/signbit.hpp
index f5557e5d..0bf20fd0 100644
--- a/sprout/math/signbit.hpp
+++ b/sprout/math/signbit.hpp
@@ -17,16 +17,17 @@
 namespace sprout {
 	namespace math {
 		namespace detail {
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+			template<typename FloatType>
 			inline SPROUT_CONSTEXPR bool
-			signbit(FloatType x) {
-				return !sprout::math::isnan(x) && x < 0;
+			builtin_signbit(FloatType x) {
+				return __builtin_signbit(x);
 			}
+#endif
 		}	// namespace detail
 		//
+		// signbit
+		//
 		// issue:
 		//	[ !SPROUT_USE_BUILTIN_CMATH_FUNCTION ]
 		//	signbit(-0) returns false .
@@ -34,7 +35,28 @@ namespace sprout {
 		//	signbit(-NaN) returns false .
 		//		# returns true . ( same as signbit(+NaN) )
 		//
-		using NS_SPROUT_MATH_DETAIL::signbit;
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR bool
+		signbit(FloatType x) {
+			return
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				sprout::math::detail::builtin_signbit(x)
+#else
+				!sprout::math::isnan(x) && x < 0
+#endif
+				;
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR bool
+		signbit(IntType x) {
+			return x < 0;
+		}
 	}	// namespace math
 
 	using sprout::math::signbit;
diff --git a/sprout/math/sin.hpp b/sprout/math/sin.hpp
index 38179d77..c34ac2e1 100644
--- a/sprout/math/sin.hpp
+++ b/sprout/math/sin.hpp
@@ -21,40 +21,55 @@
 namespace sprout {
 	namespace math {
 		namespace detail {
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+			inline SPROUT_CONSTEXPR float
+			builtin_sin(float x) {
+				return __builtin_sinf(x);
+			}
+			inline SPROUT_CONSTEXPR double
+			builtin_sin(double x) {
+				return __builtin_sin(x);
+			}
+			inline SPROUT_CONSTEXPR long double
+			builtin_sin(long double x) {
+				return __builtin_sinl(x);
+			}
+#endif
+
 			template<typename T>
 			inline SPROUT_CONSTEXPR T
 			sin_impl(T x) {
 				return -sprout::math::cos(x + sprout::math::half_pi<T>());
 			}
-
-			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::isnan(x) ? x
-					: x == sprout::numeric_limits<FloatType>::infinity() || x == -sprout::numeric_limits<FloatType>::infinity()
-						? -sprout::numeric_limits<FloatType>::quiet_NaN()
-#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
-					: std::sin(x)
-#else
-					: x == 0 ? x
-					: static_cast<FloatType>(sprout::math::detail::sin_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
-#endif
-					;
-			}
-			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
-
-		using sprout::math::detail::sin;
+		//
+		// sin
+		//
+		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::isnan(x) ? x
+				: x == sprout::numeric_limits<FloatType>::infinity() || x == -sprout::numeric_limits<FloatType>::infinity()
+					? -sprout::numeric_limits<FloatType>::quiet_NaN()
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				: sprout::math::detail::builtin_sin(x)
+#else
+				: x == 0 ? x
+				: static_cast<FloatType>(sprout::math::detail::sin_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
+#endif
+				;
+		}
+		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::sin(static_cast<double>(x));
+		}
 	}	// namespace math
 
 	using sprout::math::sin;
diff --git a/sprout/math/sinh.hpp b/sprout/math/sinh.hpp
index 00d56039..fe462fee 100644
--- a/sprout/math/sinh.hpp
+++ b/sprout/math/sinh.hpp
@@ -21,6 +21,21 @@
 namespace sprout {
 	namespace math {
 		namespace detail {
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+			inline SPROUT_CONSTEXPR float
+			builtin_sinh(float x) {
+				return __builtin_sinhf(x);
+			}
+			inline SPROUT_CONSTEXPR double
+			builtin_sinh(double x) {
+				return __builtin_sinh(x);
+			}
+			inline SPROUT_CONSTEXPR long double
+			builtin_sinh(long double x) {
+				return __builtin_sinhl(x);
+			}
+#endif
+
 			template<typename T>
 			inline SPROUT_CONSTEXPR T
 			sinh_impl_1(T t) {
@@ -31,35 +46,35 @@ namespace sprout {
 			sinh_impl(T x) {
 				return sprout::math::detail::sinh_impl_1(sprout::math::exp(x));
 			}
-
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR FloatType
-			sinh(FloatType x) {
-				return sprout::math::isnan(x) ? x
-					: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
-					: x == -sprout::numeric_limits<FloatType>::infinity() ? -sprout::numeric_limits<FloatType>::infinity()
-#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
-					: std::sinh(x)
-#else
-					: x == 0 ? x
-					: static_cast<FloatType>(sprout::math::detail::sinh_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
-#endif
-					;
-			}
-			template<
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR double
-			sinh(IntType x) {
-				return sprout::math::detail::sinh(static_cast<double>(x));
-			}
 		}	// namespace detail
-
-		using sprout::math::detail::sinh;
+		//
+		// sinh
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR FloatType
+		sinh(FloatType x) {
+			return sprout::math::isnan(x) ? x
+				: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
+				: x == -sprout::numeric_limits<FloatType>::infinity() ? -sprout::numeric_limits<FloatType>::infinity()
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				: sprout::math::detail::builtin_sinh(x)
+#else
+				: x == 0 ? x
+				: static_cast<FloatType>(sprout::math::detail::sinh_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
+#endif
+				;
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR double
+		sinh(IntType x) {
+			return sprout::math::sinh(static_cast<double>(x));
+		}
 	}	// namespace math
 
 	using sprout::math::sinh;
diff --git a/sprout/math/sqrt.hpp b/sprout/math/sqrt.hpp
index 12b7a4b1..ea88f4fc 100644
--- a/sprout/math/sqrt.hpp
+++ b/sprout/math/sqrt.hpp
@@ -19,6 +19,21 @@
 namespace sprout {
 	namespace math {
 		namespace detail {
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+			inline SPROUT_CONSTEXPR float
+			builtin_sqrt(float x) {
+				return __builtin_sqrtf(x);
+			}
+			inline SPROUT_CONSTEXPR double
+			builtin_sqrt(double x) {
+				return __builtin_sqrt(x);
+			}
+			inline SPROUT_CONSTEXPR long double
+			builtin_sqrt(long double x) {
+				return __builtin_sqrtl(x);
+			}
+#endif
+
 			template<typename T>
 			inline SPROUT_CONSTEXPR T
 			sqrt_impl_2(T x, T s, T s2) {
@@ -36,35 +51,35 @@ namespace sprout {
 			sqrt_impl(T x) {
 				return sprout::math::detail::sqrt_impl_1(x, x > 1 ? x : T(1));
 			}
-
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR FloatType
-			sqrt(FloatType x) {
-				return sprout::math::isnan(x) ? x
-					: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
-					: x < 0 ? -sprout::numeric_limits<FloatType>::quiet_NaN()
-#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
-					: std::sqrt(x)
-#else
-					: x == 0 ? x
-					: static_cast<FloatType>(sprout::math::detail::sqrt_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
-#endif
-					;
-			}
-			template<
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR double
-			sqrt(IntType x) {
-				return sprout::math::detail::sqrt(static_cast<double>(x));
-			}
 		}	// namespace detail
-
-		using sprout::math::detail::sqrt;
+		//
+		// sqrt
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR FloatType
+		sqrt(FloatType x) {
+			return sprout::math::isnan(x) ? x
+				: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
+				: x < 0 ? -sprout::numeric_limits<FloatType>::quiet_NaN()
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				: sprout::math::detail::builtin_sqrt(x)
+#else
+				: x == 0 ? x
+				: static_cast<FloatType>(sprout::math::detail::sqrt_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
+#endif
+				;
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR double
+		sqrt(IntType x) {
+			return sprout::math::sqrt(static_cast<double>(x));
+		}
 	}	// namespace math
 
 	using sprout::math::sqrt;
diff --git a/sprout/math/tan.hpp b/sprout/math/tan.hpp
index 6027b7ca..a7b19e6d 100644
--- a/sprout/math/tan.hpp
+++ b/sprout/math/tan.hpp
@@ -21,40 +21,55 @@
 namespace sprout {
 	namespace math {
 		namespace detail {
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+			inline SPROUT_CONSTEXPR float
+			builtin_tan(float x) {
+				return __builtin_tanf(x);
+			}
+			inline SPROUT_CONSTEXPR double
+			builtin_tan(double x) {
+				return __builtin_tan(x);
+			}
+			inline SPROUT_CONSTEXPR long double
+			builtin_tan(long double x) {
+				return __builtin_tanl(x);
+			}
+#endif
+
 			template<typename T>
 			inline SPROUT_CONSTEXPR T
 			tan_impl(T x) {
 				return sprout::math::sin(x) / sprout::math::cos(x);
 			}
-
-			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::isnan(x) ? x
-					: x == sprout::numeric_limits<FloatType>::infinity() || x == -sprout::numeric_limits<FloatType>::infinity()
-						? -sprout::numeric_limits<FloatType>::quiet_NaN()
-#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
-					: std::tan(x)
-#else
-					: x == 0 ? x
-					: static_cast<FloatType>(sprout::math::detail::tan_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
-#endif
-					;
-			}
-			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
-
-		using sprout::math::detail::tan;
+		//
+		// tan
+		//
+		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::isnan(x) ? x
+				: x == sprout::numeric_limits<FloatType>::infinity() || x == -sprout::numeric_limits<FloatType>::infinity()
+					? -sprout::numeric_limits<FloatType>::quiet_NaN()
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				: sprout::math::detail::builtin_tan(x)
+#else
+				: x == 0 ? x
+				: static_cast<FloatType>(sprout::math::detail::tan_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
+#endif
+				;
+		}
+		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::tan(static_cast<double>(x));
+		}
 	}	// namespace math
 
 	using sprout::math::tan;
diff --git a/sprout/math/tanh.hpp b/sprout/math/tanh.hpp
index 6714222c..99640a23 100644
--- a/sprout/math/tanh.hpp
+++ b/sprout/math/tanh.hpp
@@ -20,6 +20,21 @@
 namespace sprout {
 	namespace math {
 		namespace detail {
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+			inline SPROUT_CONSTEXPR float
+			builtin_tanh(float x) {
+				return __builtin_tanhf(x);
+			}
+			inline SPROUT_CONSTEXPR double
+			builtin_tanh(double x) {
+				return __builtin_tanh(x);
+			}
+			inline SPROUT_CONSTEXPR long double
+			builtin_tanh(long double x) {
+				return __builtin_tanhl(x);
+			}
+#endif
+
 			template<typename T>
 			inline SPROUT_CONSTEXPR T
 			tanh_impl_2(T t, T u) {
@@ -35,35 +50,35 @@ namespace sprout {
 			tanh_impl(T x) {
 				return sprout::math::detail::tanh_impl_1(sprout::math::exp(x));
 			}
-
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR FloatType
-			tanh(FloatType x) {
-				return sprout::math::isnan(x) ? x
-					: x == sprout::numeric_limits<FloatType>::infinity() ? FloatType(1)
-					: x == -sprout::numeric_limits<FloatType>::infinity() ? FloatType(-1)
-#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
-					: std::tanh(x)
-#else
-					: x == 0 ? x
-					: static_cast<FloatType>(sprout::math::detail::tanh_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
-#endif
-					;
-			}
-			template<
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR double
-			tanh(IntType x) {
-				return sprout::math::detail::tanh(static_cast<double>(x));
-			}
 		}	// namespace detail
-
-		using sprout::math::detail::tanh;
+		//
+		// tanh
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR FloatType
+		tanh(FloatType x) {
+			return sprout::math::isnan(x) ? x
+				: x == sprout::numeric_limits<FloatType>::infinity() ? FloatType(1)
+				: x == -sprout::numeric_limits<FloatType>::infinity() ? FloatType(-1)
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				: sprout::math::detail::builtin_tanh(x)
+#else
+				: x == 0 ? x
+				: static_cast<FloatType>(sprout::math::detail::tanh_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
+#endif
+				;
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR double
+		tanh(IntType x) {
+			return sprout::math::tanh(static_cast<double>(x));
+		}
 	}	// namespace math
 
 	using sprout::math::tanh;
diff --git a/sprout/math/tgamma.hpp b/sprout/math/tgamma.hpp
index b9996ff1..e3e54f28 100644
--- a/sprout/math/tgamma.hpp
+++ b/sprout/math/tgamma.hpp
@@ -26,6 +26,21 @@
 namespace sprout {
 	namespace math {
 		namespace detail {
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+			inline SPROUT_CONSTEXPR float
+			builtin_tgamma(float x) {
+				return __builtin_tgammaf(x);
+			}
+			inline SPROUT_CONSTEXPR double
+			builtin_tgamma(double x) {
+				return __builtin_tgamma(x);
+			}
+			inline SPROUT_CONSTEXPR long double
+			builtin_tgamma(long double x) {
+				return __builtin_tgammal(x);
+			}
+#endif
+
 			template<typename T>
 			inline SPROUT_CONSTEXPR T
 			tgamma_impl_y(T w) {
@@ -107,42 +122,42 @@ namespace sprout {
 						)
 					);
 			}
-
-			template<
-				typename FloatType,
-				typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR FloatType
-			tgamma(FloatType x) {
-				return sprout::math::isnan(x) ? x
-					: x == 0 ? sprout::math::copysign(sprout::numeric_limits<FloatType>::infinity(), x)
-					: x == -sprout::numeric_limits<FloatType>::infinity() ? -sprout::numeric_limits<FloatType>::quiet_NaN()
-					: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
-					: x < 0 && sprout::math::is_integer(x) ? sprout::numeric_limits<FloatType>::quiet_NaN()
-#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
-					: std::tgamma(x)
-#else
-					: static_cast<FloatType>(sprout::math::detail::tgamma_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
-#endif
-					;
-			}
-
-			template<
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
-			>
-			inline SPROUT_CONSTEXPR double
-			tgamma(IntType x) {
-				return sprout::math::detail::tgamma(static_cast<double>(x));
-			}
 		}	// namespace detail
 		//
+		// tgamma
+		//
 		// issue:
 		//	[ !SPROUT_USE_BUILTIN_CMATH_FUNCTION ]
 		//	tgamma(-0) returns -�� .
 		//		# returns +�� . ( same as tgamma(+0) )
 		//
-		using sprout::math::detail::tgamma;
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR FloatType
+		tgamma(FloatType x) {
+			return sprout::math::isnan(x) ? x
+				: x == 0 ? sprout::math::copysign(sprout::numeric_limits<FloatType>::infinity(), x)
+				: x == -sprout::numeric_limits<FloatType>::infinity() ? -sprout::numeric_limits<FloatType>::quiet_NaN()
+				: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
+				: x < 0 && sprout::math::is_integer(x) ? sprout::numeric_limits<FloatType>::quiet_NaN()
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				: sprout::math::detail::builtin_tgamma(x)
+#else
+				: static_cast<FloatType>(sprout::math::detail::tgamma_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
+#endif
+				;
+		}
+
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR double
+		tgamma(IntType x) {
+			return sprout::math::tgamma(static_cast<double>(x));
+		}
 	}	// namespace math
 
 	using sprout::math::tgamma;
diff --git a/sprout/math/trunc.hpp b/sprout/math/trunc.hpp
index 575ce720..a7545a8f 100644
--- a/sprout/math/trunc.hpp
+++ b/sprout/math/trunc.hpp
@@ -20,37 +20,52 @@
 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
-			trunc(FloatType x) {
-				return sprout::math::isnan(x) ? x
-					: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
-					: x == -sprout::numeric_limits<FloatType>::infinity() ? -sprout::numeric_limits<FloatType>::infinity()
 #if SPROUT_USE_BUILTIN_CMATH_FUNCTION
-					: std::trunc(x)
-#else
-					: x == 0 ? x
-					: sprout::numeric_limits<std::uintmax_t>::max() < x || sprout::numeric_limits<std::uintmax_t>::max() < -x
-						? SPROUT_MATH_THROW_LARGE_FLOAT_ROUNDING(std::runtime_error("trunc: large float rounding."), x)
-					: x < 0 ? -static_cast<FloatType>(static_cast<std::uintmax_t>(-x))
-					: static_cast<FloatType>(static_cast<std::uintmax_t>(x))
-#endif
-					;
+			inline SPROUT_CONSTEXPR float
+			builtin_trunc(float x) {
+				return __builtin_truncf(x);
 			}
-			template<
-				typename IntType,
-				typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
-			>
 			inline SPROUT_CONSTEXPR double
-			trunc(IntType x) {
-				return sprout::math::detail::trunc(static_cast<double>(x));
+			builtin_trunc(double x) {
+				return __builtin_trunc(x);
 			}
+			inline SPROUT_CONSTEXPR long double
+			builtin_trunc(long double x) {
+				return __builtin_truncl(x);
+			}
+#endif
 		}	// namespace detail
-
-		using NS_SPROUT_MATH_DETAIL::trunc;
+		//
+		// trunc
+		//
+		template<
+			typename FloatType,
+			typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR FloatType
+		trunc(FloatType x) {
+			return sprout::math::isnan(x) ? x
+				: x == sprout::numeric_limits<FloatType>::infinity() ? sprout::numeric_limits<FloatType>::infinity()
+				: x == -sprout::numeric_limits<FloatType>::infinity() ? -sprout::numeric_limits<FloatType>::infinity()
+#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
+				: sprout::math::detail::builtin_trunc(x)
+#else
+				: x == 0 ? x
+				: sprout::numeric_limits<std::uintmax_t>::max() < x || sprout::numeric_limits<std::uintmax_t>::max() < -x
+					? SPROUT_MATH_THROW_LARGE_FLOAT_ROUNDING(std::runtime_error("trunc: large float rounding."), x)
+				: x < 0 ? -static_cast<FloatType>(static_cast<std::uintmax_t>(-x))
+				: static_cast<FloatType>(static_cast<std::uintmax_t>(x))
+#endif
+				;
+		}
+		template<
+			typename IntType,
+			typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
+		>
+		inline SPROUT_CONSTEXPR double
+		trunc(IntType x) {
+			return sprout::math::trunc(static_cast<double>(x));
+		}
 	}	// namespace math
 
 	using sprout::math::trunc;