role_type is in boost/beast/core/role.hpp (API Change):

This enumeration is now part of the library core and
not specific to websocket.

include/boost/beast/ssl/ssl_stream.hpp

@@ -658,7 +658,7 @@ public:
 template<class SyncStream>
 void
 teardown(
-    boost::beast::websocket::role_type role,
+    boost::beast::role_type role,
     ssl_stream<SyncStream>& stream,
     boost::system::error_code& ec)
 {
@@ -670,7 +670,7 @@ teardown(
 template<class AsyncStream, class TeardownHandler>
 void
 async_teardown(
-    boost::beast::websocket::role_type role,
+    boost::beast::role_type role,
     ssl_stream<AsyncStream>& stream,
     TeardownHandler&& handler)
 {