ndnboost: Include boost::iostreams for internal use.
diff --git a/include/ndnboost/iostreams/detail/default_arg.hpp b/include/ndnboost/iostreams/detail/default_arg.hpp
new file mode 100644
index 0000000..c85aae6
--- /dev/null
+++ b/include/ndnboost/iostreams/detail/default_arg.hpp
@@ -0,0 +1,25 @@
+// (C) Copyright 2008 CodeRage, LLC (turkanis at coderage dot com)
+// (C) Copyright 2005-2007 Jonathan Turkanis
+// 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/libs/iostreams for documentation.
+
+#ifndef NDNBOOST_IOSTREAMS_DETAIL_DEFAULT_ARG_HPP_INCLUDED
+#define NDNBOOST_IOSTREAMS_DETAIL_DEFAULT_ARG_HPP_INCLUDED
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1020)
+# pragma once
+#endif
+
+#include <ndnboost/config.hpp>
+#include <ndnboost/detail/workaround.hpp>
+
+#if NDNBOOST_WORKAROUND(NDNBOOST_MSVC, < 1300)
+# include <ndnboost/mpl/identity.hpp>
+# define NDNBOOST_IOSTREAMS_DEFAULT_ARG(arg) mpl::identity< arg >::type
+#else
+# define NDNBOOST_IOSTREAMS_DEFAULT_ARG(arg) arg
+#endif
+
+#endif // #ifndef NDNBOOST_IOSTREAMS_DETAIL_DEFAULT_ARG_HPP_INCLUDED