Should `output` and `outputable/c` also accept a generic interface?

[dented42]

in scribble/text the output function can deal with most/many common datatypes, and I believe that it would be useful if there was a gen:outputable interface that custom structs could conform to so that the user (or rather, me) doesn't have as much boilerplate to write when I want to output my own structure types over and over again.