Add buffer_size

include/boost/beast/websocket/impl/stream.hpp

@@ -10,6 +10,7 @@
 #ifndef BOOST_BEAST_WEBSOCKET_IMPL_STREAM_HPP
 #define BOOST_BEAST_WEBSOCKET_IMPL_STREAM_HPP
 
+#include <boost/beast/core/buffer_size.hpp>
 #include <boost/beast/websocket/rfc6455.hpp>
 #include <boost/beast/websocket/teardown.hpp>
 #include <boost/beast/websocket/detail/hybi13.hpp>
@@ -282,7 +283,6 @@ parse_fh(
     DynamicBuffer& b,
     error_code& ec)
 {
-    using net::buffer_size;
     if(buffer_size(b.data()) < 2)
     {
         // need more bytes