diff --git a/ndnboost/unordered/detail/fwd.hpp b/ndnboost/unordered/detail/fwd.hpp
new file mode 100644
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+++ b/ndnboost/unordered/detail/fwd.hpp
@@ -0,0 +1,23 @@
+
+// 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_FWD_HPP_INCLUDED
+#define BOOST_UNORDERED_FWD_HPP_INCLUDED
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1020)
+# pragma once
+#endif
+
+
+namespace ndnboost
+{
+namespace unordered
+{
+    struct piecewise_construct_t {};
+    const piecewise_construct_t piecewise_construct = piecewise_construct_t();
+}
+}
+
+#endif