diff --git a/sprout/detail/literal_def.hpp b/sprout/detail/literal_def.hpp
index 39dea32a..1a5bc341 100644
--- a/sprout/detail/literal_def.hpp
+++ b/sprout/detail/literal_def.hpp
@@ -18,33 +18,34 @@
 //
 #if SPROUT_USE_UNICODE_LITERALS
 #	define SPROUT_LITERAL_STRING_DEF(NAME, STRING, LENGTH) \
-		template<typename Elem> \
+		template<typename Elem, typename X = void> \
 		struct NAME; \
 		SPROUT_LITERAL_STRING_DEF_IMPL(NAME, STRING, LENGTH, char); \
 		SPROUT_LITERAL_STRING_DEF_IMPL(NAME, SPROUT_PP_CAT(L, STRING), LENGTH, wchar_t); \
 		SPROUT_LITERAL_STRING_DEF_IMPL(NAME, SPROUT_PP_CAT(u, STRING), LENGTH, char16_t); \
 		SPROUT_LITERAL_STRING_DEF_IMPL(NAME, SPROUT_PP_CAT(U, STRING), LENGTH, char32_t); \
-		template<typename Elem> \
+		template<typename Elem, typename X> \
 		struct NAME {}
 #else
 #	define SPROUT_LITERAL_STRING_DEF(NAME, STRING, LENGTH) \
-		template<typename Elem> \
+		template<typename Elem, typename X = void> \
 		struct NAME; \
 		SPROUT_LITERAL_STRING_DEF_IMPL(NAME, STRING, LENGTH, char); \
 		SPROUT_LITERAL_STRING_DEF_IMPL(NAME, SPROUT_PP_CAT(L, STRING), LENGTH, wchar_t); \
-		template<typename Elem> \
+		template<typename Elem, typename X> \
 		struct NAME {}
 #endif
 #define SPROUT_LITERAL_STRING_DEF_IMPL(NAME, STRING, LENGTH, ELEM) \
-	template<> \
-	struct NAME<ELEM> { \
+	template<typename X> \
+	struct NAME<ELEM, X> { \
 	public: \
 		SPROUT_STATIC_CONSTEXPR sprout::basic_string<ELEM, LENGTH> value \
-			SPROUT_STATIC_CONSTEXPR_DATA_MEMBER_INNER(STRING) \
+			SPROUT_STATIC_CONSTEXPR_DATA_MEMBER_INNER(sprout::to_string(STRING)) \
 			; \
 	}; \
-	SPROUT_CONSTEXPR_OR_CONST sprout::basic_string<ELEM, LENGTH> NAME<ELEM>::value \
-		SPROUT_STATIC_CONSTEXPR_DATA_MEMBER_OUTER(STRING)
+	template<typename X> \
+	SPROUT_CONSTEXPR_OR_CONST sprout::basic_string<ELEM, LENGTH> NAME<ELEM, X>::value \
+		SPROUT_STATIC_CONSTEXPR_DATA_MEMBER_OUTER(sprout::to_string(STRING))
 
 //
 // SPROUT_LITERAL_CHAR_DEF
diff --git a/sprout/math/bernoulli.hpp b/sprout/math/bernoulli.hpp
index 413c9d2a..14e843ce 100644
--- a/sprout/math/bernoulli.hpp
+++ b/sprout/math/bernoulli.hpp
@@ -179,6 +179,10 @@ namespace sprout {
 					;
 			};
 			template<typename X>
+			SPROUT_CONSTEXPR_OR_CONST std::size_t sprout::math::detail::bernoulli_numbers<
+				float, X
+			>::limit;
+			template<typename X>
 			SPROUT_CONSTEXPR_OR_CONST typename sprout::math::detail::bernoulli_numbers<
 				float, X
 			>::table_type sprout::math::detail::bernoulli_numbers<
@@ -199,6 +203,10 @@ namespace sprout {
 					;
 			};
 			template<typename X>
+			SPROUT_CONSTEXPR_OR_CONST std::size_t sprout::math::detail::bernoulli_numbers<
+				double, X
+			>::limit;
+			template<typename X>
 			SPROUT_CONSTEXPR_OR_CONST typename sprout::math::detail::bernoulli_numbers<
 				double, X
 			>::table_type sprout::math::detail::bernoulli_numbers<
@@ -219,6 +227,10 @@ namespace sprout {
 					;
 			};
 			template<typename X>
+			SPROUT_CONSTEXPR_OR_CONST std::size_t sprout::math::detail::bernoulli_numbers<
+				long double, X
+			>::limit;
+			template<typename X>
 			SPROUT_CONSTEXPR_OR_CONST typename sprout::math::detail::bernoulli_numbers<
 				long double, X
 			>::table_type sprout::math::detail::bernoulli_numbers<
diff --git a/sprout/tuple/tuple/tuple_decl.hpp b/sprout/tuple/tuple/tuple_decl.hpp
index 99c96a96..bdab7f13 100644
--- a/sprout/tuple/tuple/tuple_decl.hpp
+++ b/sprout/tuple/tuple/tuple_decl.hpp
@@ -301,7 +301,7 @@ namespace sprout {
 			}
 			template<sprout::index_t... Indexes>
 			SPROUT_CONSTEXPR std::tuple<Types...>
-			to_std_tuple(sprout::index_tuple<Indexes...>) {
+			to_std_tuple(sprout::index_tuple<Indexes...>) const {
 				return std::tuple<Types...>(base_type::template get<Indexes>(*this)...);
 			}
 		public:
diff --git a/sprout/weed/detail/bdigits.hpp b/sprout/weed/detail/bdigits.hpp
index ea47ba3e..ea404f43 100644
--- a/sprout/weed/detail/bdigits.hpp
+++ b/sprout/weed/detail/bdigits.hpp
@@ -22,14 +22,14 @@ namespace sprout {
 		namespace detail {
 			SPROUT_LITERAL_STRING_DEF(bdigits, "01", 2);
 
-			template<typename Dummy>
+			template<typename Dummy, typename X = void>
 			struct bvalues;
 
 #		define SPROUT_WEED_BDIGITS_TABLE_DEF \
 			{{0, 1}}
 
-			template<>
-			struct bvalues<void> {
+			template<typename X>
+			struct bvalues<void, X> {
 			public:
 				typedef sprout::array<std::uint8_t, 2> value_type;
 			public:
@@ -37,8 +37,9 @@ namespace sprout {
 					SPROUT_STATIC_CONSTEXPR_DATA_MEMBER_INNER(SPROUT_WEED_BDIGITS_TABLE_DEF)
 					;
 			};
-			SPROUT_CONSTEXPR_OR_CONST sprout::weed::detail::bvalues<void>::value_type
-			sprout::weed::detail::bvalues<void>::value
+			template<typename X>
+			SPROUT_CONSTEXPR_OR_CONST typename sprout::weed::detail::bvalues<void, X>::value_type
+			sprout::weed::detail::bvalues<void, X>::value
 				SPROUT_STATIC_CONSTEXPR_DATA_MEMBER_OUTER(SPROUT_WEED_BDIGITS_TABLE_DEF)
 				;
 
diff --git a/sprout/weed/detail/digits.hpp b/sprout/weed/detail/digits.hpp
index 8b5755e0..0078b900 100644
--- a/sprout/weed/detail/digits.hpp
+++ b/sprout/weed/detail/digits.hpp
@@ -22,14 +22,14 @@ namespace sprout {
 		namespace detail {
 			SPROUT_LITERAL_STRING_DEF(digits, "0123456789", 10);
 
-			template<typename Dummy>
+			template<typename Dummy, typename X = void>
 			struct values;
 
 #		define SPROUT_WEED_DIGITS_TABLE_DEF \
 			{{0, 1, 2, 3, 4, 5, 6, 7, 8, 9}}
 
-			template<>
-			struct values<void> {
+			template<typename X>
+			struct values<void, X> {
 			public:
 				typedef sprout::array<std::uint8_t, 10> value_type;
 			public:
@@ -37,8 +37,9 @@ namespace sprout {
 					SPROUT_STATIC_CONSTEXPR_DATA_MEMBER_INNER(SPROUT_WEED_DIGITS_TABLE_DEF)
 					;
 			};
-			SPROUT_CONSTEXPR_OR_CONST sprout::weed::detail::values<void>::value_type
-			sprout::weed::detail::values<void>::value
+			template<typename X>
+			SPROUT_CONSTEXPR_OR_CONST typename sprout::weed::detail::values<void, X>::value_type
+			sprout::weed::detail::values<void, X>::value
 				SPROUT_STATIC_CONSTEXPR_DATA_MEMBER_OUTER(SPROUT_WEED_DIGITS_TABLE_DEF)
 				;
 
diff --git a/sprout/weed/detail/odigits.hpp b/sprout/weed/detail/odigits.hpp
index edcf0dc0..d94d7831 100644
--- a/sprout/weed/detail/odigits.hpp
+++ b/sprout/weed/detail/odigits.hpp
@@ -22,14 +22,14 @@ namespace sprout {
 		namespace detail {
 			SPROUT_LITERAL_STRING_DEF(odigits, "01234567", 8);
 
-			template<typename Dummy>
+			template<typename Dummy, typename X = void>
 			struct ovalues;
 
 #		define SPROUT_WEED_ODIGITS_TABLE_DEF \
 			{{0, 1, 2, 3, 4, 5, 6, 7}}
 
-			template<>
-			struct ovalues<void> {
+			template<typename X>
+			struct ovalues<void, X> {
 			public:
 				typedef sprout::array<std::uint8_t, 8> value_type;
 			public:
@@ -37,8 +37,9 @@ namespace sprout {
 					SPROUT_STATIC_CONSTEXPR_DATA_MEMBER_INNER(SPROUT_WEED_ODIGITS_TABLE_DEF)
 					;
 			};
-			SPROUT_CONSTEXPR_OR_CONST sprout::weed::detail::ovalues<void>::value_type
-			sprout::weed::detail::ovalues<void>::value
+			template<typename X>
+			SPROUT_CONSTEXPR_OR_CONST typename sprout::weed::detail::ovalues<void, X>::value_type
+			sprout::weed::detail::ovalues<void, X>::value
 				SPROUT_STATIC_CONSTEXPR_DATA_MEMBER_OUTER(SPROUT_WEED_ODIGITS_TABLE_DEF)
 				;
 
diff --git a/sprout/weed/detail/xdigits.hpp b/sprout/weed/detail/xdigits.hpp
index 6caa1007..52c6c41d 100644
--- a/sprout/weed/detail/xdigits.hpp
+++ b/sprout/weed/detail/xdigits.hpp
@@ -22,14 +22,14 @@ namespace sprout {
 		namespace detail {
 			SPROUT_LITERAL_STRING_DEF(xdigits, "0123456789abcdefABCDEF", 22);
 
-			template<typename Dummy>
+			template<typename Dummy, typename X = void>
 			struct xvalues;
 
 #		define SPROUT_WEED_XDIGITS_TABLE_DEF \
 			{{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 10, 11, 12, 13, 14, 15}}
 
-			template<>
-			struct xvalues<void> {
+			template<typename X>
+			struct xvalues<void, X> {
 			public:
 				typedef sprout::array<std::uint8_t, 22> value_type;
 			public:
@@ -37,8 +37,9 @@ namespace sprout {
 					SPROUT_STATIC_CONSTEXPR_DATA_MEMBER_INNER(SPROUT_WEED_XDIGITS_TABLE_DEF)
 					;
 			};
-			SPROUT_CONSTEXPR_OR_CONST sprout::weed::detail::xvalues<void>::value_type
-			sprout::weed::detail::xvalues<void>::value
+			template<typename X>
+			SPROUT_CONSTEXPR_OR_CONST typename sprout::weed::detail::xvalues<void, X>::value_type
+			sprout::weed::detail::xvalues<void, X>::value
 				SPROUT_STATIC_CONSTEXPR_DATA_MEMBER_OUTER(SPROUT_WEED_XDIGITS_TABLE_DEF)
 				;