Include bind in ndnboost.
diff --git a/ndnboost/optional/optional_fwd.hpp b/ndnboost/optional/optional_fwd.hpp
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+++ b/ndnboost/optional/optional_fwd.hpp
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+// Copyright (C) 2003, 2008 Fernando Luis Cacciola Carballal.
+//
+// Use, modification, and distribution is 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/optional for documentation.
+//
+// You are welcome to contact the author at:
+// fernando_cacciola@hotmail.com
+//
+// Revisions:
+// 10 May 2008 (added swap related forward declaration) Niels Dekker
+//
+#ifndef BOOST_OPTIONAL_OPTIONAL_FWD_FLC_19NOV2002_HPP
+#define BOOST_OPTIONAL_OPTIONAL_FWD_FLC_19NOV2002_HPP
+
+namespace ndnboost {
+
+template<class T> class optional ;
+
+template<class T> void swap ( optional<T>& , optional<T>& ) ;
+
+template<class T> struct optional_swap_should_use_default_constructor ;
+
+} // namespace ndnboost
+
+#endif
+