1 files changed, 50 insertions, 0 deletions
diff --git a/boost/callable_traits/detail/polyfills/make_index_sequence.hpp b/boost/callable_traits/detail/polyfills/make_index_sequence.hpp
new file mode 100644
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+++ b/boost/callable_traits/detail/polyfills/make_index_sequence.hpp
@@ -0,0 +1,50 @@
+/*
+Copyright Barrett Adair 2016-2017
+
+Distributed under the Boost Software License, Version 1.0.
+(See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
+*/
+
+#ifndef BOOST_CLBL_TRTS_DETAIL_POLYFILLS_MAKE_INDEX_SEQUENCE_HPP
+#define BOOST_CLBL_TRTS_DETAIL_POLYFILLS_MAKE_INDEX_SEQUENCE_HPP
+
+#undef BOOST_CLBL_TRTS_IX_SEQ
+#define BOOST_CLBL_TRTS_IX_SEQ(...) \
+    ::boost::callable_traits::detail::index_sequence<__VA_ARGS__>
+
+#undef BOOST_CLBL_TRTS_MAKE_IX_SEQ
+#define BOOST_CLBL_TRTS_MAKE_IX_SEQ(...) \
+    ::boost::callable_traits::detail::make_index_sequence<__VA_ARGS__>
+
+namespace boost { namespace callable_traits { namespace detail { 
+
+template<std::size_t...>
+struct index_sequence { using type = index_sequence; };
+
+template<typename, typename>
+struct concat;
+
+template<std::size_t... I1, std::size_t... I2>
+struct concat<index_sequence<I1...>, index_sequence<I2...>>
+    : index_sequence<I1..., (sizeof...(I1)+I2)...> {};
+
+template<std::size_t N>
+    struct make_index_sequence_t;
+
+template<std::size_t N>
+struct make_index_sequence_t : concat< 
+    typename make_index_sequence_t<N/2>::type,
+    typename make_index_sequence_t<N - N/2>::type >::type {};
+
+template<>
+struct make_index_sequence_t<0> : index_sequence<> {};
+
+template<>
+struct make_index_sequence_t<1> : index_sequence<0> {};
+
+template<std::size_t... I>
+using make_index_sequence = typename make_index_sequence_t<I...>::type;
+
+}}} // namespace boost::callable_traits::detail
+
+#endif // #ifndef BOOST_CLBL_TRTS_DETAIL_POLYFILLS_MAKE_INDEX_SEQUENCE_HPP