diff --git a/sprout/type/algorithm/detail/find_index_result.hpp b/sprout/type/algorithm/detail/find_index_result.hpp
new file mode 100644
index 00000000..68ad19db
--- /dev/null
+++ b/sprout/type/algorithm/detail/find_index_result.hpp
@@ -0,0 +1,30 @@
+/*=============================================================================
+  Copyright (c) 2011-2015 Bolero MURAKAMI
+  https://github.com/bolero-MURAKAMI/Sprout
+
+  Distributed under the Boost Software License, Version 1.0. (See accompanying
+  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+=============================================================================*/
+#ifndef SPROUT_TYPE_ALGORITHM_DETAIL_FIND_INDEX_RESULT_HPP
+#define SPROUT_TYPE_ALGORITHM_DETAIL_FIND_INDEX_RESULT_HPP
+
+#include <sprout/config.hpp>
+#include <sprout/workaround/std/cstddef.hpp>
+#include <sprout/type/tuple.hpp>
+#include <sprout/type_traits/integral_constant.hpp>
+
+namespace sprout {
+	namespace types {
+		namespace detail {
+			template<typename Tuple, std::size_t Found>
+			struct find_index_result
+				: public sprout::integral_constant<std::size_t, Found>
+			{
+			public:
+				typedef sprout::bool_constant<Found != sprout::types::tuple_size<Tuple>::value> found;
+			};
+		}	// namespace detail
+	}	// namespace types
+}	// namespace sprout
+
+#endif	// #ifndef SPROUT_TYPE_ALGORITHM_DETAIL_FIND_INDEX_RESULT_HPP
diff --git a/sprout/type/algorithm/find_index.hpp b/sprout/type/algorithm/find_index.hpp
index ba9e50fd..a021a02d 100644
--- a/sprout/type/algorithm/find_index.hpp
+++ b/sprout/type/algorithm/find_index.hpp
@@ -12,48 +12,56 @@
 #include <sprout/config.hpp>
 #include <sprout/workaround/std/cstddef.hpp>
 #include <sprout/type/tuple.hpp>
-#include <sprout/type_traits/integral_constant.hpp>
+#include <sprout/type/algorithm/detail/find_index_result.hpp>
 
 namespace sprout {
 	namespace types {
 		namespace detail {
 			template<
-				typename Tuple, typename T, std::size_t I,
-				bool Valid = (I != sprout::types::tuple_size<Tuple>::value),
-				typename Enable = void
+				typename Tuple, typename T, std::size_t First, std::size_t Last,
+				std::size_t Pivot, std::size_t Found,
+				bool C0 = (Found != First), bool C1 = (Pivot == 0)
 			>
 			struct find_index_impl;
-			template<typename Tuple, typename T, std::size_t I>
-			struct find_index_impl<
-				Tuple, T, I, false,
-				void
+			template<
+				typename Tuple, typename T, std::size_t First, std::size_t Last,
+				std::size_t Pivot, std::size_t Found,
+				bool C1
 			>
-				: public sprout::integral_constant<std::size_t, I>
-			{
-			public:
-				typedef sprout::false_type found;
-			};
-			template<typename Tuple, typename T, std::size_t I>
-			struct find_index_impl<
-				Tuple, T, I, true,
-				typename std::enable_if<
-					std::is_same<typename sprout::types::tuple_element<I, Tuple>::type, T>::value
-				>::type
+			struct find_index_impl<Tuple, T, First, Last, Pivot, Found, true, C1>
+				: public sprout::types::detail::find_index_result<Tuple, Found>
+			{};
+			template<
+				typename Tuple, typename T, std::size_t First, std::size_t Last,
+				std::size_t Pivot, std::size_t Found
 			>
-				: public sprout::integral_constant<std::size_t, I>
-			{
-			public:
-				typedef sprout::true_type found;
-				typedef typename sprout::types::tuple_element<I, Tuple>::type element;
-			};
-			template<typename Tuple, typename T, std::size_t I>
-			struct find_index_impl<
-				Tuple, T, I, true,
-				typename std::enable_if<
-					!std::is_same<typename sprout::types::tuple_element<I, Tuple>::type, T>::value
-				>::type
+			struct find_index_impl<Tuple, T, First, Last, Pivot, Found, false, true>
+				: public sprout::types::detail::find_index_result<
+					Tuple, (std::is_same<typename sprout::types::tuple_element<First, Tuple>::type, T>::value ? First : Last)
+				>
+			{};
+			template<
+				typename Tuple, typename T, std::size_t First, std::size_t Last,
+				std::size_t Pivot, std::size_t Found
 			>
-				: public sprout::types::detail::find_index_impl<Tuple, T, I + 1>
+			struct find_index_impl<Tuple, T, First, Last, Pivot, Found, false, false>
+				: public sprout::types::detail::find_index_impl<
+					Tuple, T, First + Pivot, Last,
+					(Last - First - Pivot) / 2,
+					sprout::types::detail::find_index_impl<
+						Tuple, T, First, First + Pivot,
+						Pivot / 2,
+						First
+					>::value
+				>
+			{};
+			template<typename Tuple, typename T, std::size_t Size = sprout::types::tuple_size<Tuple>::value>
+			struct find_index
+				: public sprout::types::detail::find_index_impl<Tuple, T, 0, Size, Size / 2, 0>
+			{};
+			template<typename Tuple, typename T>
+			struct find_index<Tuple, T, 0>
+				: public sprout::types::detail::find_index_result<Tuple, 0>
 			{};
 		}	// namespace detail
 		//
@@ -61,7 +69,7 @@ namespace sprout {
 		//
 		template<typename Tuple, typename T>
 		struct find_index
-			: public sprout::types::detail::find_index_impl<Tuple, T, 0>
+			: public sprout::types::detail::find_index<Tuple, T>
 		{};
 
 #if SPROUT_USE_TEMPLATE_ALIASES
diff --git a/sprout/type/algorithm/find_index_if.hpp b/sprout/type/algorithm/find_index_if.hpp
index 5707bdf1..4a108db3 100644
--- a/sprout/type/algorithm/find_index_if.hpp
+++ b/sprout/type/algorithm/find_index_if.hpp
@@ -13,48 +13,56 @@
 #include <sprout/workaround/std/cstddef.hpp>
 #include <sprout/type/apply.hpp>
 #include <sprout/type/tuple.hpp>
-#include <sprout/type_traits/integral_constant.hpp>
+#include <sprout/type/algorithm/detail/find_index_result.hpp>
 
 namespace sprout {
 	namespace types {
 		namespace detail {
 			template<
-				typename Tuple, typename Predicate, std::size_t I,
-				bool Valid = (I != sprout::types::tuple_size<Tuple>::value),
-				typename Enable = void
+				typename Tuple, typename Predicate, std::size_t First, std::size_t Last,
+				std::size_t Pivot, std::size_t Found,
+				bool C0 = (Found != First), bool C1 = (Pivot == 0)
 			>
 			struct find_index_if_impl;
-			template<typename Tuple, typename Predicate, std::size_t I>
-			struct find_index_if_impl<
-				Tuple, Predicate, I, false,
-				void
+			template<
+				typename Tuple, typename Predicate, std::size_t First, std::size_t Last,
+				std::size_t Pivot, std::size_t Found,
+				bool C1
 			>
-				: public sprout::integral_constant<std::size_t, I>
-			{
-			public:
-				typedef sprout::false_type found;
-			};
-			template<typename Tuple, typename Predicate, std::size_t I>
-			struct find_index_if_impl<
-				Tuple, Predicate, I, true,
-				typename std::enable_if<
-					sprout::types::apply<Predicate, typename sprout::types::tuple_element<I, Tuple>::type>::type::value
-				>::type
+			struct find_index_if_impl<Tuple, Predicate, First, Last, Pivot, Found, true, C1>
+				: public sprout::types::detail::find_index_result<Tuple, Found>
+			{};
+			template<
+				typename Tuple, typename Predicate, std::size_t First, std::size_t Last,
+				std::size_t Pivot, std::size_t Found
 			>
-				: public sprout::integral_constant<std::size_t, I>
-			{
-			public:
-				typedef sprout::true_type found;
-				typedef typename sprout::types::tuple_element<I, Tuple>::type element;
-			};
-			template<typename Tuple, typename Predicate, std::size_t I>
-			struct find_index_if_impl<
-				Tuple, Predicate, I, true,
-				typename std::enable_if<
-					!sprout::types::apply<Predicate, typename sprout::types::tuple_element<I, Tuple>::type>::type::value
-				>::type
+			struct find_index_if_impl<Tuple, Predicate, First, Last, Pivot, Found, false, true>
+				: public sprout::types::detail::find_index_result<
+					Tuple, (sprout::types::apply<Predicate, typename sprout::types::tuple_element<First, Tuple>::type>::type::value ? First : Last)
+				>
+			{};
+			template<
+				typename Tuple, typename Predicate, std::size_t First, std::size_t Last,
+				std::size_t Pivot, std::size_t Found
 			>
-				: public sprout::types::detail::find_index_if_impl<Tuple, Predicate, I + 1>
+			struct find_index_if_impl<Tuple, Predicate, First, Last, Pivot, Found, false, false>
+				: public sprout::types::detail::find_index_if_impl<
+					Tuple, Predicate, First + Pivot, Last,
+					(Last - First - Pivot) / 2,
+					sprout::types::detail::find_index_if_impl<
+						Tuple, Predicate, First, First + Pivot,
+						Pivot / 2,
+						First
+					>::value
+				>
+			{};
+			template<typename Tuple, typename Predicate, std::size_t Size = sprout::types::tuple_size<Tuple>::value>
+			struct find_index_if
+				: public sprout::types::detail::find_index_if_impl<Tuple, Predicate, 0, Size, Size / 2, 0>
+			{};
+			template<typename Tuple, typename Predicate>
+			struct find_index_if<Tuple, Predicate, 0>
+				: public sprout::types::detail::find_index_result<Tuple, 0>
 			{};
 		}	// namespace detail
 		//
@@ -62,7 +70,7 @@ namespace sprout {
 		//
 		template<typename Tuple, typename Predicate>
 		struct find_index_if
-			: public sprout::types::detail::find_index_if_impl<Tuple, Predicate, 0>
+			: public sprout::types::detail::find_index_if<Tuple, Predicate>
 		{};
 
 #if SPROUT_USE_TEMPLATE_ALIASES