A modern programming language that makes developers happier.

kotlinlang

We have no "species scopes" in Kotlin yet (scopes that capture type parameters, but not instances).
Full support for nested TAs requires "species scopes". That's a rather strong change for which we have no resources in 1.1 time frame.
If we introduce nested TAs now with some limited support, fully supporting them later will be a breaking change.
So we decided to postpone them until after 1.1 is stabilized.
Yes, that's a disappointment. Sorry about that :disappointed: