Composition of arbitrary opaque-typed objects

[heaven-born]

We can't compose two arbitrary objects because it requires resolving multiple issues related to duplicated methods and fields, but can scala compiler at least "fake" the composition for arbitrary opaque-typed objects when both of them out of the scope of their visibility? And then restrict this object to pass to a method where both the internals are visible.

opaque type Database = SomeClassA
opaque type Logging = SomeClassB

val d:Database = ???
val l:Logging = ???

val dl: Database & Logging = Opaque.compose(d,l)