The way the equivalencies system is desined, I don't really see how a class would be helpful here - in the end it still has to look like a function.

What *does* make sense from the user perspective is to have this be a default equivalency for a `Flux` class.  This was actually the primary use case that was in mind when the equivalencies system was designed.  #1577 (or perhaps a follow-on PR built off that) should definitely implement that.