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/type_traits/conditional.hpp b/ndnboost/type_traits/conditional.hpp
new file mode 100644
index 0000000..6d2f45c
--- /dev/null
+++ b/ndnboost/type_traits/conditional.hpp
@@ -0,0 +1,25 @@
+
+// (C) Copyright John Maddock 2010.
+// Use, modification and distribution are subject to 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/type_traits for most recent version including documentation.
+
+
+#ifndef BOOST_TT_CONDITIONAL_HPP_INCLUDED
+#define BOOST_TT_CONDITIONAL_HPP_INCLUDED
+
+#include <ndnboost/mpl/if.hpp>
+
+namespace ndnboost {
+
+template <bool b, class T, class U>
+struct conditional : public mpl::if_c<b, T, U>
+{
+};
+
+} // namespace ndnboost
+
+
+#endif // BOOST_TT_CONDITIONAL_HPP_INCLUDED