ndnboost: Include boost::iostreams for internal use.
diff --git a/include/ndnboost/iostreams/detail/enable_if_stream.hpp b/include/ndnboost/iostreams/detail/enable_if_stream.hpp
new file mode 100644
index 0000000..a96dfe0
--- /dev/null
+++ b/include/ndnboost/iostreams/detail/enable_if_stream.hpp
@@ -0,0 +1,32 @@
+// (C) Copyright 2008 CodeRage, LLC (turkanis at coderage dot com)
+// (C) Copyright 2003-2007 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_ENABLE_IF_STREAM_HPP_INCLUDED
+#define NDNBOOST_IOSTREAMS_DETAIL_ENABLE_IF_STREAM_HPP_INCLUDED
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1020)
+# pragma once
+#endif
+
+#include <ndnboost/config.hpp> // NDNBOOST_NO_SFINAE.
+#include <ndnboost/utility/enable_if.hpp>
+#include <ndnboost/iostreams/traits_fwd.hpp> // is_std_io.
+
+#if !defined(NDNBOOST_NO_SFINAE) && \
+ !NDNBOOST_WORKAROUND(__BORLANDC__, NDNBOOST_TESTED_AT(0x592))
+# define NDNBOOST_IOSTREAMS_ENABLE_IF_STREAM(T) \
+ , typename ndnboost::enable_if< ndnboost::iostreams::is_std_io<T> >::type* = 0 \
+ /**/
+# define NDNBOOST_IOSTREAMS_DISABLE_IF_STREAM(T) \
+ , typename ndnboost::disable_if< ndnboost::iostreams::is_std_io<T> >::type* = 0 \
+ /**/
+#else
+# define NDNBOOST_IOSTREAMS_ENABLE_IF_STREAM(T)
+# define NDNBOOST_IOSTREAMS_DISABLE_IF_STREAM(T)
+#endif
+
+#endif // #ifndef NDNBOOST_IOSTREAMS_DETAIL_ENABLE_IF_STREAM_HPP_INCLUDED