add boost on mac

macx64/include/boost/beast/websocket/stream_fwd.hpp

@@ -0,0 +1,32 @@
+//
+// Copyright (c) 2016-2019 Vinnie Falco (vinnie dot falco at gmail dot com)
+//
+// 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)
+//
+// Official repository: https://github.com/boostorg/beast
+//
+
+#ifndef BOOST_BEAST_WEBSOCKET_STREAM_FWD_HPP
+#define BOOST_BEAST_WEBSOCKET_STREAM_FWD_HPP
+
+#include <boost/beast/core/detail/config.hpp>
+
+//[code_websocket_1h
+
+namespace boost {
+namespace beast {
+namespace websocket {
+
+template<
+    class NextLayer,
+    bool deflateSupported = true>
+class stream;
+
+} // websocket
+} // beast
+} // boost
+
+//]
+
+#endif