On Tuesday, 2 July 2019 at 14:36:04 UTC, Jesse Phillips wrote: > > > With D support for both covariance and contravariance, you > should be covered. You desired model behavior should just fall > into place. > > Could you throw up a working example as a gist? Might take a > hack at it. Here is a related article https://he-the-great.livejournal.com/54436.html