WebSocket Decorator is a socket option (API Change):

This changes the interface used to apply a decorator to the HTTP
request or response messages used to perform the WebSocket handshake
as follows:

* Add the `stream_base::decorator` option object

* Add `stream::set_option` overload to set the decorator from
  the option

* The decorator applies to all client and server handshakes
  performed on the stream after the option is set.

* Overloads of the following functions which accept a Decorator
  are deprecated:
  - accept, accept_ex
  - handshake, handshake_ex
  - async_accept, async_accept_ex
  - async_handshake, async_handshake_ex

Actions Required:

* Code which passes decorator to any `websocket::stream` member
  function should call `stream::set_option` instead with a newly
  constructed `stream_base::decorator` object containing the
  decorator. Alternatively, the macro `BOOST_BEAST_ALLOW_DEPRECATED`
  may be defined to 1.

test/beast/websocket/stream.cpp

@@ -28,6 +28,20 @@ public:
         net::io_context ioc;
         stream<test::stream> ws(ioc);
 
+        {
+            ws.set_option(
+                stream_base::decorator(
+                    [](request_type&)
+                    {
+                    }));
+
+            ws.set_option(
+                stream_base::decorator(
+                    [](response_type&)
+                    {
+                    }));
+        }
+
         {
             ws.set_option(
                 stream_base::suggested_settings(