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/unordered/unordered_set_fwd.hpp b/ndnboost/unordered/unordered_set_fwd.hpp
new file mode 100644
index 0000000..622f837
--- /dev/null
+++ b/ndnboost/unordered/unordered_set_fwd.hpp
@@ -0,0 +1,63 @@
+
+// Copyright (C) 2008-2011 Daniel James.
+// 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)
+
+#ifndef BOOST_UNORDERED_SET_FWD_HPP_INCLUDED
+#define BOOST_UNORDERED_SET_FWD_HPP_INCLUDED
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1020)
+# pragma once
+#endif
+
+#include <ndnboost/config.hpp>
+#include <memory>
+#include <functional>
+#include <ndnboost/functional/hash_fwd.hpp>
+#include <ndnboost/unordered/detail/fwd.hpp>
+
+namespace ndnboost
+{
+    namespace unordered
+    {
+        template <class T,
+            class H = ndnboost::hash<T>,
+            class P = std::equal_to<T>,
+            class A = std::allocator<T> >
+        class unordered_set;
+
+        template <class T, class H, class P, class A>
+        inline bool operator==(unordered_set<T, H, P, A> const&,
+            unordered_set<T, H, P, A> const&);
+        template <class T, class H, class P, class A>
+        inline bool operator!=(unordered_set<T, H, P, A> const&,
+            unordered_set<T, H, P, A> const&);
+        template <class T, class H, class P, class A>
+        inline void swap(unordered_set<T, H, P, A> &m1,
+                unordered_set<T, H, P, A> &m2);
+
+        template <class T,
+            class H = ndnboost::hash<T>,
+            class P = std::equal_to<T>,
+            class A = std::allocator<T> >
+        class unordered_multiset;
+
+        template <class T, class H, class P, class A>
+        inline bool operator==(unordered_multiset<T, H, P, A> const&,
+            unordered_multiset<T, H, P, A> const&);
+        template <class T, class H, class P, class A>
+        inline bool operator!=(unordered_multiset<T, H, P, A> const&,
+            unordered_multiset<T, H, P, A> const&);
+        template <class T, class H, class P, class A>
+        inline void swap(unordered_multiset<T, H, P, A> &m1,
+                unordered_multiset<T, H, P, A> &m2);
+    }
+
+    using ndnboost::unordered::unordered_set;
+    using ndnboost::unordered::unordered_multiset;
+    using ndnboost::unordered::swap;
+    using ndnboost::unordered::operator==;
+    using ndnboost::unordered::operator!=;
+}
+
+#endif