This will get you a compiler crash in every version of Scala 2.x. I'm surprised I never noticed this before. Is there a ticket for this already? trait X { type Z } trait Y { type Z } type A = X { type Z = Int } type B = Y { type Z = Char } implicitly[A with B =:= B with A]
Presumptuous me, only testing 2.13.0-M3... I only tested Dotty 0.8.0-RC1. I'm not so proactive staying up to date with these prerelease versions.