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diff --git a/boost/parameter/aux_/is_tagged_argument.hpp b/boost/parameter/aux_/is_tagged_argument.hpp
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+++ b/boost/parameter/aux_/is_tagged_argument.hpp
@@ -0,0 +1,95 @@
+// Copyright Daniel Wallin, David Abrahams 2005.
+// Copyright Cromwell D. Enage 2017.
+// Distributed under the Boost Software License, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at
+// http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_PARAMETER_IS_TAGGED_ARGUMENT_HPP
+#define BOOST_PARAMETER_IS_TAGGED_ARGUMENT_HPP
+
+namespace boost { namespace parameter { namespace aux {
+
+    struct tagged_argument_base
+    {
+    };
+}}} // namespace boost::parameter::aux
+
+#include <boost/parameter/config.hpp>
+#include <boost/mpl/bool.hpp>
+#include <boost/mpl/if.hpp>
+
+#if defined(BOOST_PARAMETER_HAS_PERFECT_FORWARDING) || \
+    (0 < BOOST_PARAMETER_EXPONENTIAL_OVERLOAD_THRESHOLD_ARITY)
+#include <boost/type_traits/is_base_of.hpp>
+#include <boost/type_traits/remove_const.hpp>
+#include <boost/type_traits/remove_reference.hpp>
+
+namespace boost { namespace parameter { namespace aux {
+
+    // This metafunction identifies tagged_argument specializations
+    // and their derived classes.
+    template <typename T>
+    struct is_tagged_argument
+      : ::boost::mpl::if_<
+            // Cannot use is_convertible<> to check if T is derived from
+            // tagged_argument_base. -- Cromwell D. Enage
+            ::boost::is_base_of<
+                ::boost::parameter::aux::tagged_argument_base
+              , typename ::boost::remove_const<
+                    typename ::boost::remove_reference<T>::type
+                >::type
+            >
+          , ::boost::mpl::true_
+          , ::boost::mpl::false_
+        >::type
+    {
+    };
+}}} // namespace boost::parameter::aux
+
+#else   // no perfect forwarding support and no exponential overloads
+#include <boost/type_traits/is_convertible.hpp>
+#include <boost/type_traits/is_lvalue_reference.hpp>
+
+namespace boost { namespace parameter { namespace aux {
+
+    template <typename T>
+    struct is_tagged_argument_aux
+      : ::boost::is_convertible<
+            T*
+          , ::boost::parameter::aux::tagged_argument_base const*
+        >
+    {
+    };
+
+    // This metafunction identifies tagged_argument specializations
+    // and their derived classes.
+    template <typename T>
+    struct is_tagged_argument
+      : ::boost::mpl::if_<
+            ::boost::is_lvalue_reference<T>
+          , ::boost::mpl::false_
+          , ::boost::parameter::aux::is_tagged_argument_aux<T>
+        >::type
+    {
+    };
+}}} // namespace boost::parameter::aux
+
+#endif  // perfect forwarding support, or exponential overloads
+
+#if defined(BOOST_PARAMETER_CAN_USE_MP11)
+#include <type_traits>
+
+namespace boost { namespace parameter { namespace aux {
+
+    template <typename T>
+    using is_tagged_argument_mp11 = ::std::is_base_of<
+        ::boost::parameter::aux::tagged_argument_base
+      , typename ::std::remove_const<
+            typename ::std::remove_reference<T>::type
+        >::type
+    >;
+}}} // namespace boost::parameter::aux
+
+#endif  // BOOST_PARAMETER_CAN_USE_MP11
+#endif  // include guard
+