diff --git a/boost/mpl/aux_/arity.hpp b/boost/mpl/aux_/arity.hpp
new file mode 100644
index 0000000..32104ed
--- /dev/null
+++ b/boost/mpl/aux_/arity.hpp
@@ -0,0 +1,39 @@
+
+#ifndef BOOST_MPL_AUX_ARITY_HPP_INCLUDED
+#define BOOST_MPL_AUX_ARITY_HPP_INCLUDED
+
+// Copyright Aleksey Gurtovoy 2001-2004
+//
+// 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/libs/mpl for documentation.
+
+// $Id: arity.hpp 49267 2008-10-11 06:19:02Z agurtovoy $
+// $Date: 2008-10-10 23:19:02 -0700 (Fri, 10 Oct 2008) $
+// $Revision: 49267 $
+
+#include <boost/mpl/aux_/config/dtp.hpp>
+
+#if defined(BOOST_MPL_CFG_BROKEN_DEFAULT_PARAMETERS_IN_NESTED_TEMPLATES)
+
+#   include <boost/mpl/aux_/nttp_decl.hpp>
+#   include <boost/mpl/aux_/config/static_constant.hpp>
+
+namespace ndnboost { namespace mpl { namespace aux {
+
+// agurt, 15/mar/02: it's possible to implement the template so that it will 
+// "just work" and do not require any specialization, but not on the compilers
+// that require the arity workaround in the first place
+template< typename F, BOOST_MPL_AUX_NTTP_DECL(int, N) >
+struct arity
+{
+    BOOST_STATIC_CONSTANT(int, value = N);
+};
+
+}}}
+
+#endif // BOOST_MPL_CFG_BROKEN_DEFAULT_PARAMETERS_IN_NESTED_TEMPLATES
+
+#endif // BOOST_MPL_AUX_ARITY_HPP_INCLUDED