In common.h, define func_lib for function objects. In configure.ac, define HAVE_STD_FUNCTION and HAVE_BOOST_FUNCTION. Include function headers in ndnboost.
diff --git a/ndnboost/mpl/tag.hpp b/ndnboost/mpl/tag.hpp
new file mode 100644
index 0000000..56b9fb4
--- /dev/null
+++ b/ndnboost/mpl/tag.hpp
@@ -0,0 +1,52 @@
+
+#ifndef BOOST_MPL_TAG_HPP_INCLUDED
+#define BOOST_MPL_TAG_HPP_INCLUDED
+
+// Copyright Aleksey Gurtovoy 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: tag.hpp 49267 2008-10-11 06:19:02Z agurtovoy $
+// $Date: 2008-10-10 23:19:02 -0700 (Fri, 10 Oct 2008) $
+// $Revision: 49267 $
+
+#include <ndnboost/mpl/eval_if.hpp>
+#include <ndnboost/mpl/void.hpp>
+#include <ndnboost/mpl/aux_/has_tag.hpp>
+#include <ndnboost/mpl/aux_/config/eti.hpp>
+
+namespace ndnboost { namespace mpl {
+
+namespace aux {
+template< typename T > struct tag_impl
+{
+ typedef typename T::tag type;
+};
+}
+
+template< typename T, typename Default = void_ > struct tag
+#if !defined(BOOST_MPL_CFG_MSVC_ETI_BUG)
+ : if_<
+ aux::has_tag<T>
+ , aux::tag_impl<T>
+ , Default
+ >::type
+{
+#else
+{
+ typedef typename eval_if<
+ aux::has_tag<T>
+ , aux::tag_impl<T>
+ , Default
+ >::type type;
+
+#endif
+};
+
+}}
+
+#endif // BOOST_MPL_TAG_HPP_INCLUDED