Racket: Would be beautiful to have `combine-output-ports` procedure.

[EligiusSantori]

With specs:

(combine-output-ports what . with) → output-port?
    what : output-port?
    with : list of output-port?

As example it very useful in this case:

(with-logging-to-port ((combine-output-ports
                        (current-error-port)
                        (open-output-file "my.log"))
    MY-SYNTAX
)

Procedure make-output-port is too unfriendly for this purposes.
I wonder why such procedure isn't already exists in racket/port package.

[lexi-lambda]

I agree that such a function would be useful to have in racket/port, but in the meantime, it might help you to look at make-pipe and copy-port, which together make an implementation of this function pretty easy since copy-port accepts multiple output ports.

[hgluka]

Unless @EligiusSantori wants to, I could implement this as my first contribution to racket :)
Seems straightforward.

[sorawee]

Closed by #2726