Since the protocol is line-based, implementing a client for the chat is straightforward:
Lines read from stdin should be sent over the socket.
Lines read from the socket should be echoed to stdout.
Although async does not significantly affect client performance (as unlike the server, the client interacts solely with one user and only needs limited concurrency), async is still useful for managing concurrency!
The client has to read from stdin and the socket simultaneously.
Programming this with threads is cumbersome, especially when implementing a clean shutdown.
With async, the select! macro is all that is needed.