firstname.lastname@example.org (Patrick Doyle) writes:
> Can you give an example of two immutable objects, alike in every way,
> which need to be distinguished?
Two read-only windows in a GUI with the same contents (and
the application doesn't know about internal WM information such as position
or other attributes which may distinguish them).
Two outgoing socket connections to the same destination (and the
application again doesn't know about internal states of the sockets).
In general, this situation is quite common in modelling input/output,
since in this case applications tend to have an incomplete or `loose'
view on the outside world.