On Fri, 18 Jan 2019 10:07:41 -0500, Steven Schveighoffer wrote: > But what is the common interface between those 2 types? Even in > Dcollections, where RedBlackTree came from, there was no interfaces that > didn't specify the type they were dealing with. In other words, there is > no common interface for sets of 2 different types.
.empty(), .clear(), .length(), and .toString(sink, formatspec). Which is kind of anemic. Might as well use Object.