Well, opaque types are pretty useful. However with my initial dev with dotty, this particular feature that I am getting at has failed.
Well, I might be wrong by the way (still not exp with dotty). So take it with a grain of salt
Please find my example
I wouldn't prefer anything more (as code) to make the above snippet work because that defeats the purpose.
The good thing, it fails with ambiguity rather than picking the wrong implementation