Function type parameters can be instantiated to types which capture the root cap #15058
Description
Compiler version
Head of CC experiment.
Minimized code
Both of the calls to withSession should be rejected (note the first one is also affected by #15057):
scala> class Session // defined class Session scala> def withSession[T](thunk : ({*} Session) => T): T = thunk(new Session) def withSession[T](thunk: ({*} Session) => T): T scala> withSession(t => t) val res1: Session = Session@7866a0b3 scala> withSession[{*} Session](t => t) val res2: {*} Session = Session@14e53307