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diff --git a/boost/hana/ext/std/integral_constant.hpp b/boost/hana/ext/std/integral_constant.hpp
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+/*!
+@file
+Adapts `std::integral_constant` for use with Hana.
+
+@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_EXT_STD_INTEGRAL_CONSTANT_HPP
+#define BOOST_HANA_EXT_STD_INTEGRAL_CONSTANT_HPP
+
+#include <boost/hana/concept/integral_constant.hpp>
+#include <boost/hana/config.hpp>
+#include <boost/hana/core/when.hpp>
+#include <boost/hana/fwd/core/to.hpp>
+#include <boost/hana/fwd/core/tag_of.hpp>
+#include <boost/hana/fwd/integral_constant.hpp>
+
+#include <type_traits>
+
+
+#ifdef BOOST_HANA_DOXYGEN_INVOKED
+namespace std {
+    //! @ingroup group-ext-std
+    //! Adapter for `std::integral_constant`s.
+    //!
+    //! Provided models
+    //! ---------------
+    //! 1. `Constant` and `IntegralConstant`\n
+    //! A `std::integral_constant` is a model of the `IntegralConstant` and
+    //! `Constant` concepts, just like `hana::integral_constant`s are. As a
+    //! consequence, they are also implicitly a model of the concepts provided
+    //! for all models of `Constant`.
+    //! @include example/ext/std/integral_constant.cpp
+    template <typename T, T v>
+    struct integral_constant { };
+}
+#endif
+
+
+BOOST_HANA_NAMESPACE_BEGIN
+    namespace ext { namespace std {
+        template <typename T>
+        struct integral_constant_tag { using value_type = T; };
+    }}
+
+    namespace detail {
+        template <typename T, T v>
+        constexpr bool
+        is_std_integral_constant(std::integral_constant<T, v>*)
+        { return true; }
+
+        constexpr bool is_std_integral_constant(...)
+        { return false; }
+
+
+        template <typename T, T v>
+        constexpr bool
+        is_hana_integral_constant(hana::integral_constant<T, v>*)
+        { return true; }
+
+        constexpr bool is_hana_integral_constant(...)
+        { return false; }
+    }
+
+    template <typename T>
+    struct tag_of<T, when<
+        detail::is_std_integral_constant((T*)0) &&
+        !detail::is_hana_integral_constant((T*)0)
+    >> {
+        using type = ext::std::integral_constant_tag<
+            typename hana::tag_of<typename T::value_type>::type
+        >;
+    };
+
+    //////////////////////////////////////////////////////////////////////////
+    // Constant/IntegralConstant
+    //////////////////////////////////////////////////////////////////////////
+    template <typename T>
+    struct IntegralConstant<ext::std::integral_constant_tag<T>> {
+        static constexpr bool value = true;
+    };
+
+    template <typename T, typename C>
+    struct to_impl<ext::std::integral_constant_tag<T>, C, when<
+        hana::IntegralConstant<C>::value
+    >> : embedding<is_embedded<typename C::value_type, T>{}> {
+        template <typename N>
+        static constexpr auto apply(N const&) {
+            return std::integral_constant<T, N::value>{};
+        }
+    };
+BOOST_HANA_NAMESPACE_END
+
+#endif // !BOOST_HANA_EXT_STD_INTEGRAL_CONSTANT_HPP