From f0dfb208e0eef8394c5c0afa8ea97a104755525e Mon Sep 17 00:00:00 2001
From: bolero-MURAKAMI <bolero.murakami@gmail.com>
Date: Sun, 7 Apr 2013 21:55:55 +0900
Subject: [PATCH] add _indexes User-defined literals

---
 sprout/index_tuple/udl.hpp     | 67 ++++++++++++++++++++++++++++++++++
 sprout/index_tuple/utility.hpp |  1 +
 sprout/type/string/string.hpp  | 14 +++++++
 3 files changed, 82 insertions(+)
 create mode 100644 sprout/index_tuple/udl.hpp

diff --git a/sprout/index_tuple/udl.hpp b/sprout/index_tuple/udl.hpp
new file mode 100644
index 00000000..c33d6032
--- /dev/null
+++ b/sprout/index_tuple/udl.hpp
@@ -0,0 +1,67 @@
+#ifndef SPROUT_INDEX_TUPLE_UDL_HPP
+#define SPROUT_INDEX_TUPLE_UDL_HPP
+
+#include <sprout/config.hpp>
+#include <sprout/index_tuple/index_tuple.hpp>
+
+#if SPROUT_USE_USER_DEFINED_LITERALS
+
+#include <type_traits>
+#include <sprout/index_tuple/make_index_tuple.hpp>
+
+namespace sprout {
+	namespace detail {
+		template<typename IntType, char... Chars>
+		struct digits_to_int;
+		template<typename IntType, char C>
+		struct digits_to_int<IntType, C>
+			: public std::integral_constant<IntType, IntType(C - 48)>
+		{};
+		template<typename IntType, char Head, char... Tail>
+		struct digits_to_int<IntType, Head, Tail...>
+			: public std::integral_constant<IntType, 10 * IntType(Head - 48) + sprout::detail::digits_to_int<IntType, Tail...>::value>
+		{};
+	}	// namespace detail
+
+	//
+	// indexes_result
+	//
+	template<char... Chars>
+	struct indexes_result
+		: public sprout::make_index_tuple<sprout::detail::digits_to_int<sprout::index_t, Chars...>::value>
+	{};
+	//
+	// uindexes_result
+	//
+	template<char... Chars>
+	struct uindexes_result
+		: public sprout::make_uindex_tuple<sprout::detail::digits_to_int<sprout::uindex_t, Chars...>::value>
+	{};
+
+	namespace udl {
+		//
+		// _indexes
+		//
+		template<char... Chars>
+		SPROUT_CONSTEXPR typename sprout::indexes_result<Chars...>::type
+		operator "" _indexes() {
+			return sprout::indexes_result<Chars...>::make();
+		}
+
+		//
+		// _uindexes
+		//
+		template<char... Chars>
+		SPROUT_CONSTEXPR typename sprout::uindexes_result<Chars...>::type
+		operator "" _uindexes() {
+			return sprout::uindexes_result<Chars...>::make();
+		}
+	}	// namespace udl
+
+	using sprout::udl::operator "" _indexes;
+	using sprout::udl::operator "" _uindexes;
+}	// namespace sprout
+
+#endif	// #if SPROUT_USE_USER_DEFINED_LITERALS
+
+#endif	// #ifndef SPROUT_INDEX_TUPLE_UDL_HPP
diff --git a/sprout/index_tuple/utility.hpp b/sprout/index_tuple/utility.hpp
index 26165edd..40175c56 100644
--- a/sprout/index_tuple/utility.hpp
+++ b/sprout/index_tuple/utility.hpp
@@ -4,5 +4,6 @@
 #include <sprout/config.hpp>
 #include <sprout/index_tuple/make_indexes.hpp>
 #include <sprout/index_tuple/enable_make_indexes.hpp>
+#include <sprout/index_tuple/udl.hpp>
 
 #endif	// #ifndef SPROUT_INDEX_TUPLE_UTILITY_HPP
diff --git a/sprout/type/string/string.hpp b/sprout/type/string/string.hpp
index 884263c6..91e9eb27 100644
--- a/sprout/type/string/string.hpp
+++ b/sprout/type/string/string.hpp
@@ -6,6 +6,7 @@
 #include <sprout/config.hpp>
 #include <sprout/type/tuple.hpp>
 #include <sprout/type/integral_array.hpp>
+#include <sprout/tuple/tuple/get.hpp>
 
 namespace sprout {
 	namespace types {
@@ -47,4 +48,17 @@ namespace std {
 #endif
 }	// namespace std
 
+namespace sprout {
+	//
+	// tuple_get
+	//
+	template<std::size_t I, typename T, T... Values>
+	inline SPROUT_CONSTEXPR typename std::tuple_element<I, sprout::types::basic_string<T, Values...> >::type
+	tuple_get(sprout::types::basic_string<T, Values...>) SPROUT_NOEXCEPT {
+		static_assert(I < sizeof...(Values), "tuple_get: index out of range");
+		typedef typename std::tuple_element<I, sprout::types::basic_string<T, Values...> >::type type;
+		return type();
+	}
+}	// namespace sprout
+
 #endif	// #ifndef SPROUT_TYPE_STRING_STRING_HPP