Я пытаюсь описать типы, которые содержит класс case.
import shapeless._
import shapeless.ops.hlist.LiftAll
trait Desc[T] {
def description: String
}
case class Foo(f: Int)
object Foo {
implicit val description: Desc[Foo] = new Desc[Foo] { val description = "foo" }
}
case class SomeCaseClass(f: Foo)
val gen = Generic[SomeCaseClass]
val lifted = implicitly[LiftAll[Desc, gen.Repr]].instances.toList
Дает мне
could not find implicit value for parameter toTraversableAux: shapeless.ops.hlist.ToTraversable.Aux[shapeless.ops.hlist.LiftAll[Playground.this.Desc,Playground.this.gen.Repr]#Out,List,Lub]
not enough arguments for method toList: (implicit toTraversableAux: shapeless.ops.hlist.ToTraversable.Aux[shapeless.ops.hlist.LiftAll[Playground.this.Desc,Playground.this.gen.Repr]#Out,List,Lub])toTraversableAux.Out.
Unspecified value parameter toTraversableAux.
Скастите здесь: https://scastie.scala-lang.org/bXu71pMQQzCqrrsahVBkWA