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/preprocessor/expr_if.hpp b/ndnboost/preprocessor/expr_if.hpp
new file mode 100644
index 0000000..6fedfb3
--- /dev/null
+++ b/ndnboost/preprocessor/expr_if.hpp
@@ -0,0 +1,17 @@
+# /* **************************************************************************
+# * *
+# * (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_EXPR_IF_HPP
+# define BOOST_PREPROCESSOR_EXPR_IF_HPP
+#
+# include <ndnboost/preprocessor/control/expr_if.hpp>
+#
+# endif