diff --git a/ndnboost/preprocessor/detail/is_unary.hpp b/ndnboost/preprocessor/detail/is_unary.hpp
new file mode 100644
index 0000000..c12f008
--- /dev/null
+++ b/ndnboost/preprocessor/detail/is_unary.hpp
@@ -0,0 +1,30 @@
+# /* **************************************************************************
+#  *                                                                          *
+#  *     (C) Copyright Paul Mensonides 2002.
+#  *     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)
+#  *                                                                          *
+#  ************************************************************************** */
+#
+# /* See http://www.boost.org for most recent version. */
+#
+# ifndef BOOST_PREPROCESSOR_DETAIL_IS_UNARY_HPP
+# define BOOST_PREPROCESSOR_DETAIL_IS_UNARY_HPP
+#
+# include <ndnboost/preprocessor/config/config.hpp>
+# include <ndnboost/preprocessor/detail/check.hpp>
+#
+# /* BOOST_PP_IS_UNARY */
+#
+# if ~BOOST_PP_CONFIG_FLAGS() & BOOST_PP_CONFIG_EDG()
+#    define BOOST_PP_IS_UNARY(x) BOOST_PP_CHECK(x, BOOST_PP_IS_UNARY_CHECK)
+# else
+#    define BOOST_PP_IS_UNARY(x) BOOST_PP_IS_UNARY_I(x)
+#    define BOOST_PP_IS_UNARY_I(x) BOOST_PP_CHECK(x, BOOST_PP_IS_UNARY_CHECK)
+# endif
+#
+# define BOOST_PP_IS_UNARY_CHECK(a) 1
+# define BOOST_PP_CHECK_RESULT_BOOST_PP_IS_UNARY_CHECK 0, BOOST_PP_NIL
+#
+# endif