[qtplatypus]

Sum types and Generics solve different but related problems. So they are not really comparable. I would like to see both get implemented.

[ccktlmazeltov]

I'd say it's really hard to abuse sum types, I wouldn't say the same of generics.

[qtplatypus]

That is true. However sum types don't allow us to abstract over common code. For example a sum type wouldn't allow us to create a type safe channel "fan in" function that works for all channel types.