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diff --git a/boost/hana/detail/variadic/split_at.hpp b/boost/hana/detail/variadic/split_at.hpp
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+++ b/boost/hana/detail/variadic/split_at.hpp
@@ -0,0 +1,153 @@
+/*!
+@file
+Defines `boost::hana::detail::variadic::split_at`.
+
+@copyright Louis Dionne 2013-2016
+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_HANA_DETAIL_VARIADIC_SPLIT_AT_HPP
+#define BOOST_HANA_DETAIL_VARIADIC_SPLIT_AT_HPP
+
+#include <boost/hana/config.hpp>
+#include <boost/hana/functional/partial.hpp>
+#include <boost/hana/functional/reverse_partial.hpp>
+
+#include <cstddef>
+
+
+BOOST_HANA_NAMESPACE_BEGIN namespace detail { namespace variadic {
+    template <std::size_t n>
+    struct split_at_t {
+        template <typename F, typename X1, typename X2, typename X3, typename X4, typename X5, typename X6, typename X7, typename X8, typename ...Xs>
+        constexpr decltype(auto) operator()(F&& f, X1&& x1, X2&& x2, X3&& x3, X4&& x4, X5&& x5, X6&& x6, X7&& x7, X8&& x8, Xs&& ...xs) const {
+            return split_at_t<n - 8>{}(
+                hana::partial(static_cast<F&&>(f),
+                    static_cast<X1&&>(x1),
+                    static_cast<X2&&>(x2),
+                    static_cast<X3&&>(x3),
+                    static_cast<X4&&>(x4),
+                    static_cast<X5&&>(x5),
+                    static_cast<X6&&>(x6),
+                    static_cast<X7&&>(x7),
+                    static_cast<X8&&>(x8)
+                ),
+                static_cast<Xs&&>(xs)...
+            );
+        }
+    };
+
+    template <>
+    struct split_at_t<0> {
+        template <typename F, typename ...Xs>
+        constexpr decltype(auto) operator()(F&& f, Xs&& ...xs) const {
+            return static_cast<F&&>(f)()(static_cast<Xs&&>(xs)...);
+        }
+    };
+
+    template <>
+    struct split_at_t<1> {
+        template <typename F, typename X1, typename ...Xs>
+        constexpr decltype(auto) operator()(F&& f, X1&& x1, Xs&& ...xs) const {
+            return static_cast<F&&>(f)(
+                static_cast<X1&&>(x1)
+            )(static_cast<Xs&&>(xs)...);
+        }
+    };
+
+    template <>
+    struct split_at_t<2> {
+        template <typename F, typename X1, typename X2, typename ...Xs>
+        constexpr decltype(auto) operator()(F&& f, X1&& x1, X2&& x2, Xs&& ...xs) const {
+            return static_cast<F&&>(f)(
+                static_cast<X1&&>(x1),
+                static_cast<X2&&>(x2)
+            )(static_cast<Xs&&>(xs)...);
+        }
+    };
+
+    template <>
+    struct split_at_t<3> {
+        template <typename F, typename X1, typename X2, typename X3, typename ...Xs>
+        constexpr decltype(auto) operator()(F&& f, X1&& x1, X2&& x2, X3&& x3, Xs&& ...xs) const {
+            return static_cast<F&&>(f)(
+                static_cast<X1&&>(x1),
+                static_cast<X2&&>(x2),
+                static_cast<X3&&>(x3)
+            )(static_cast<Xs&&>(xs)...);
+        }
+    };
+
+    template <>
+    struct split_at_t<4> {
+        template <typename F, typename X1, typename X2, typename X3, typename X4, typename ...Xs>
+        constexpr decltype(auto) operator()(F&& f, X1&& x1, X2&& x2, X3&& x3, X4&& x4, Xs&& ...xs) const {
+            return static_cast<F&&>(f)(
+                static_cast<X1&&>(x1),
+                static_cast<X2&&>(x2),
+                static_cast<X3&&>(x3),
+                static_cast<X4&&>(x4)
+            )(static_cast<Xs&&>(xs)...);
+        }
+    };
+
+    template <>
+    struct split_at_t<5> {
+        template <typename F, typename X1, typename X2, typename X3, typename X4, typename X5, typename ...Xs>
+        constexpr decltype(auto) operator()(F&& f, X1&& x1, X2&& x2, X3&& x3, X4&& x4, X5&& x5, Xs&& ...xs) const {
+            return static_cast<F&&>(f)(
+                static_cast<X1&&>(x1),
+                static_cast<X2&&>(x2),
+                static_cast<X3&&>(x3),
+                static_cast<X4&&>(x4),
+                static_cast<X5&&>(x5)
+            )(static_cast<Xs&&>(xs)...);
+        }
+    };
+
+    template <>
+    struct split_at_t<6> {
+        template <typename F, typename X1, typename X2, typename X3, typename X4, typename X5, typename X6, typename ...Xs>
+        constexpr decltype(auto) operator()(F&& f, X1&& x1, X2&& x2, X3&& x3, X4&& x4, X5&& x5, X6&& x6, Xs&& ...xs) const {
+            return static_cast<F&&>(f)(
+                static_cast<X1&&>(x1),
+                static_cast<X2&&>(x2),
+                static_cast<X3&&>(x3),
+                static_cast<X4&&>(x4),
+                static_cast<X5&&>(x5),
+                static_cast<X6&&>(x6)
+            )(static_cast<Xs&&>(xs)...);
+        }
+    };
+
+    template <>
+    struct split_at_t<7> {
+        template <typename F, typename X1, typename X2, typename X3, typename X4, typename X5, typename X6, typename X7, typename ...Xs>
+        constexpr decltype(auto) operator()(F&& f, X1&& x1, X2&& x2, X3&& x3, X4&& x4, X5&& x5, X6&& x6, X7&& x7, Xs&& ...xs) const {
+            return static_cast<F&&>(f)(
+                static_cast<X1&&>(x1),
+                static_cast<X2&&>(x2),
+                static_cast<X3&&>(x3),
+                static_cast<X4&&>(x4),
+                static_cast<X5&&>(x5),
+                static_cast<X6&&>(x6),
+                static_cast<X7&&>(x7)
+            )(static_cast<Xs&&>(xs)...);
+        }
+    };
+
+    template <std::size_t n>
+    struct _makesplit_at_t {
+        template <typename ...Xs>
+        constexpr decltype(auto) operator()(Xs&& ...xs) const {
+            return hana::reverse_partial(split_at_t<n>{},
+                                         static_cast<Xs&&>(xs)...);
+        }
+    };
+
+    template <std::size_t n>
+    constexpr _makesplit_at_t<n> split_at{};
+}} BOOST_HANA_NAMESPACE_END
+
+#endif // !BOOST_HANA_DETAIL_VARIADIC_SPLIT_AT_HPP