diff --git a/sprout/algorithm/fit/partition_copy.hpp b/sprout/algorithm/fit/partition_copy.hpp
index e3a48820..90fc4644 100644
--- a/sprout/algorithm/fit/partition_copy.hpp
+++ b/sprout/algorithm/fit/partition_copy.hpp
@@ -7,7 +7,7 @@
 #include <sprout/algorithm/fixed/partition_copy.hpp>
 #include <sprout/algorithm/fit/result_of.hpp>
 #include <sprout/sub_array.hpp>
-#include <sprout/detail/count_n_if.hpp>
+#include <sprout/detail/algorithm/count_n_if.hpp>
 #include HDR_ALGORITHM_SSCRISK_CEL_OR_SPROUT
 #include HDR_FUNCTIONAL_SSCRISK_CEL_OR_SPROUT
 
diff --git a/sprout/algorithm/fit/set_difference.hpp b/sprout/algorithm/fit/set_difference.hpp
index 4be4d0a9..a7d83ae7 100644
--- a/sprout/algorithm/fit/set_difference.hpp
+++ b/sprout/algorithm/fit/set_difference.hpp
@@ -7,7 +7,7 @@
 #include <sprout/algorithm/fixed/set_difference.hpp>
 #include <sprout/algorithm/fit/result_of.hpp>
 #include <sprout/sub_array.hpp>
-#include <sprout/detail/set_overlap_count.hpp>
+#include <sprout/detail/algorithm/set_overlap_count.hpp>
 #include HDR_ALGORITHM_SSCRISK_CEL_OR_SPROUT
 #include HDR_ITERATOR_SSCRISK_CEL_OR_SPROUT
 
diff --git a/sprout/algorithm/fit/set_intersection.hpp b/sprout/algorithm/fit/set_intersection.hpp
index 072d3f06..66c84891 100644
--- a/sprout/algorithm/fit/set_intersection.hpp
+++ b/sprout/algorithm/fit/set_intersection.hpp
@@ -7,7 +7,7 @@
 #include <sprout/algorithm/fixed/set_intersection.hpp>
 #include <sprout/algorithm/fit/result_of.hpp>
 #include <sprout/sub_array.hpp>
-#include <sprout/detail/set_overlap_count.hpp>
+#include <sprout/detail/algorithm/set_overlap_count.hpp>
 #include HDR_ALGORITHM_SSCRISK_CEL_OR_SPROUT
 
 namespace sprout {
diff --git a/sprout/algorithm/fit/set_symmetric_difference.hpp b/sprout/algorithm/fit/set_symmetric_difference.hpp
index b564e19a..15a22875 100644
--- a/sprout/algorithm/fit/set_symmetric_difference.hpp
+++ b/sprout/algorithm/fit/set_symmetric_difference.hpp
@@ -7,7 +7,7 @@
 #include <sprout/algorithm/fixed/set_symmetric_difference.hpp>
 #include <sprout/algorithm/fit/result_of.hpp>
 #include <sprout/sub_array.hpp>
-#include <sprout/detail/set_overlap_count.hpp>
+#include <sprout/detail/algorithm/set_overlap_count.hpp>
 #include HDR_ALGORITHM_SSCRISK_CEL_OR_SPROUT
 #include HDR_ITERATOR_SSCRISK_CEL_OR_SPROUT
 
diff --git a/sprout/algorithm/fit/set_union.hpp b/sprout/algorithm/fit/set_union.hpp
index 9d85423b..4e838f44 100644
--- a/sprout/algorithm/fit/set_union.hpp
+++ b/sprout/algorithm/fit/set_union.hpp
@@ -7,7 +7,7 @@
 #include <sprout/algorithm/fixed/set_union.hpp>
 #include <sprout/algorithm/fit/result_of.hpp>
 #include <sprout/sub_array.hpp>
-#include <sprout/detail/set_overlap_count.hpp>
+#include <sprout/detail/algorithm/set_overlap_count.hpp>
 #include HDR_ALGORITHM_SSCRISK_CEL_OR_SPROUT
 #include HDR_ITERATOR_SSCRISK_CEL_OR_SPROUT
 
diff --git a/sprout/algorithm/fit/unique.hpp b/sprout/algorithm/fit/unique.hpp
index f0b61130..8541176e 100644
--- a/sprout/algorithm/fit/unique.hpp
+++ b/sprout/algorithm/fit/unique.hpp
@@ -7,7 +7,7 @@
 #include <sprout/algorithm/fixed/unique.hpp>
 #include <sprout/algorithm/fit/result_of.hpp>
 #include <sprout/sub_array.hpp>
-#include <sprout/detail/overlap_count.hpp>
+#include <sprout/detail/algorithm/overlap_count.hpp>
 
 namespace sprout {
 	namespace fit {
diff --git a/sprout/algorithm/fit/unique_copy.hpp b/sprout/algorithm/fit/unique_copy.hpp
index 3a7fb1aa..0e112281 100644
--- a/sprout/algorithm/fit/unique_copy.hpp
+++ b/sprout/algorithm/fit/unique_copy.hpp
@@ -7,7 +7,7 @@
 #include <sprout/algorithm/fixed/unique_copy.hpp>
 #include <sprout/algorithm/fit/result_of.hpp>
 #include <sprout/sub_array.hpp>
-#include <sprout/detail/overlap_count.hpp>
+#include <sprout/detail/algorithm/overlap_count.hpp>
 #include HDR_ALGORITHM_SSCRISK_CEL_OR_SPROUT
 #include HDR_ITERATOR_SSCRISK_CEL_OR_SPROUT
 
diff --git a/sprout/detail/count_n.hpp b/sprout/detail/algorithm/count_n.hpp
similarity index 76%
rename from sprout/detail/count_n.hpp
rename to sprout/detail/algorithm/count_n.hpp
index 224719c6..13cd3a29 100644
--- a/sprout/detail/count_n.hpp
+++ b/sprout/detail/algorithm/count_n.hpp
@@ -1,5 +1,5 @@
-#ifndef SPROUT_DETAIL_COUNT_N_HPP
-#define SPROUT_DETAIL_COUNT_N_HPP
+#ifndef SPROUT_DETAIL_ALGORITHM_COUNT_N_HPP
+#define SPROUT_DETAIL_ALGORITHM_COUNT_N_HPP
 
 #include <iterator>
 #include <sprout/config.hpp>
@@ -24,4 +24,4 @@ namespace sprout {
 	}	// namespace detail
 }	// namespace sprout
 
-#endif	// #ifndef SPROUT_DETAIL_COUNT_N_HPP
+#endif	// #ifndef SPROUT_DETAIL_ALGORITHM_COUNT_N_HPP
diff --git a/sprout/detail/count_n_if.hpp b/sprout/detail/algorithm/count_n_if.hpp
similarity index 75%
rename from sprout/detail/count_n_if.hpp
rename to sprout/detail/algorithm/count_n_if.hpp
index 9d117a9c..54071879 100644
--- a/sprout/detail/count_n_if.hpp
+++ b/sprout/detail/algorithm/count_n_if.hpp
@@ -1,5 +1,5 @@
-#ifndef SPROUT_DETAIL_COUNT_N_IF_HPP
-#define SPROUT_DETAIL_COUNT_N_IF_HPP
+#ifndef SPROUT_DETAIL_ALGORITHM_COUNT_N_IF_HPP
+#define SPROUT_DETAIL_ALGORITHM_COUNT_N_IF_HPP
 
 #include <iterator>
 #include <sprout/config.hpp>
@@ -24,4 +24,4 @@ namespace sprout {
 	}	// namespace detail
 }	// namespace sprout
 
-#endif	// #ifndef SPROUT_DETAIL_COUNT_N_IF_HPP
+#endif	// #ifndef SPROUT_DETAIL_ALGORITHM_COUNT_N_IF_HPP
diff --git a/sprout/detail/overlap_count.hpp b/sprout/detail/algorithm/overlap_count.hpp
similarity index 89%
rename from sprout/detail/overlap_count.hpp
rename to sprout/detail/algorithm/overlap_count.hpp
index d926a632..582f8f0c 100644
--- a/sprout/detail/overlap_count.hpp
+++ b/sprout/detail/algorithm/overlap_count.hpp
@@ -1,5 +1,5 @@
-#ifndef SPROUT_DETAIL_OVERLAP_COUNT_HPP
-#define SPROUT_DETAIL_OVERLAP_COUNT_HPP
+#ifndef SPROUT_DETAIL_ALGORITHM_OVERLAP_COUNT_HPP
+#define SPROUT_DETAIL_ALGORITHM_OVERLAP_COUNT_HPP
 
 #include <iterator>
 #include <sprout/config.hpp>
@@ -70,4 +70,4 @@ namespace sprout {
 	}	// namespace detail
 }	// namespace sprout
 
-#endif	// #ifndef SPROUT_DETAIL_OVERLAP_COUNT_HPP
+#endif	// #ifndef SPROUT_DETAIL_ALGORITHM_OVERLAP_COUNT_HPP
diff --git a/sprout/detail/set_overlap_count.hpp b/sprout/detail/algorithm/set_overlap_count.hpp
similarity index 87%
rename from sprout/detail/set_overlap_count.hpp
rename to sprout/detail/algorithm/set_overlap_count.hpp
index 29553809..bbe77d87 100644
--- a/sprout/detail/set_overlap_count.hpp
+++ b/sprout/detail/algorithm/set_overlap_count.hpp
@@ -1,5 +1,5 @@
-#ifndef SPROUT_DETAIL_SET_OVERLAP_COUNT_HPP
-#define SPROUT_DETAIL_SET_OVERLAP_COUNT_HPP
+#ifndef SPROUT_DETAIL_ALGORITHM_SET_OVERLAP_COUNT_HPP
+#define SPROUT_DETAIL_ALGORITHM_SET_OVERLAP_COUNT_HPP
 
 #include <iterator>
 #include <sprout/config.hpp>
@@ -51,4 +51,4 @@ namespace sprout {
 	}	// namespace detail
 }	// namespace sprout
 
-#endif	// #ifndef SPROUT_DETAIL_SET_OVERLAP_COUNT_HPP
+#endif	// #ifndef SPROUT_DETAIL_ALGORITHM_SET_OVERLAP_COUNT_HPP
diff --git a/sprout/detail/float.hpp b/sprout/detail/math/float.hpp
similarity index 100%
rename from sprout/detail/float.hpp
rename to sprout/detail/math/float.hpp
diff --git a/sprout/detail/int.hpp b/sprout/detail/math/int.hpp
similarity index 100%
rename from sprout/detail/int.hpp
rename to sprout/detail/math/int.hpp
diff --git a/sprout/functional/bind/bind.hpp b/sprout/functional/bind/bind.hpp
index 349e32a3..f8a8f6fc 100644
--- a/sprout/functional/bind/bind.hpp
+++ b/sprout/functional/bind/bind.hpp
@@ -269,7 +269,7 @@ namespace sprout {
 	// binder
 	//
 	template<typename Signature>
-	struct binder;
+	class binder;
 	template<typename Functor, typename... BoundArgs>
 	class binder<Functor(BoundArgs...)>
 		: public sprout::weak_result_type<Functor>
@@ -379,7 +379,7 @@ namespace sprout {
 	// bind_result
 	//
 	template<typename Result, typename Signature>
-	struct bind_result;
+	class bind_result;
 	template<typename Result, typename Functor, typename... BoundArgs>
 	class bind_result<Result, Functor(BoundArgs...)> {
 	private:
diff --git a/sprout/string/float_to_string.hpp b/sprout/string/float_to_string.hpp
index 7da293da..c313b31e 100644
--- a/sprout/string/float_to_string.hpp
+++ b/sprout/string/float_to_string.hpp
@@ -9,8 +9,8 @@
 #include <sprout/string/string.hpp>
 #include <sprout/type_traits/enabler_if.hpp>
 #include <sprout/detail/char_conversion.hpp>
-#include <sprout/detail/int.hpp>
-#include <sprout/detail/float.hpp>
+#include <sprout/detail/math/int.hpp>
+#include <sprout/detail/math/float.hpp>
 #include HDR_ALGORITHM_SSCRISK_CEL_OR_SPROUT
 
 namespace sprout {
diff --git a/sprout/string/int_to_string.hpp b/sprout/string/int_to_string.hpp
index af50f100..4be37f4d 100644
--- a/sprout/string/int_to_string.hpp
+++ b/sprout/string/int_to_string.hpp
@@ -9,7 +9,7 @@
 #include <sprout/integer/integer_digits.hpp>
 #include <sprout/type_traits/enabler_if.hpp>
 #include <sprout/detail/char_conversion.hpp>
-#include <sprout/detail/int.hpp>
+#include <sprout/detail/math/int.hpp>
 
 namespace sprout {
 	//