I’ve asked José in person 2 years ago on ElixirConfEU, if we could simply ditch opaque from MapSet declaration, and he answered “with new gradual types the issue’s gone.” It’s not.
I have a handful of MapSet helpers I use in each and every project, like mapset_size/1 guard and smart pattern-matching, and I always hesitate to add it because it enforces me to ignore dialyzer warnings which I dislike.
What’s indeed the issue with making a mapset implementation not opaque (besides it’s academically wrong :))?
