In Scala, is there a way to express the type that is the intersection of all applications of [a higher-kinded type that has an invariant type parameter]?
type Bound
trait A[T <: Bound]
// How to express I in real Scala?
type I = & { A[T] : T <: Bound }
def subtypingRelation[T <: Bound]: I <:< A[T] =
summon[I <:< A[T]]
Really, any type that satisfies I <: A[T] for all T <: Bound would do for my use case, as long as it is treated normally by the compiler.
Unfortunately, Nothing is treated abnormally by the compiler, at least when it comes to type inference, so it is not an option for my use case.
For those curious about the use case, it is to model the syntax of [a language that has pattern matching as well as subtypes].