A trait is a collection of variants that may or may not have unknown members. An enum is a collection of variants that may not have unknown implementations. So

A trait is a collection of variants that may or may not have unknown members. An enum is a collection of variants that may not have unknown implementations. So enums are in some sense a subset of traits. Hence every property of traits is also a property of enums. Does that make sense? Those suggestion of your look interesting, but I haven't thought them through enough to have an opinion.