import scala.language.experimental.macros import scala.reflect.macros.blackbox.Context trait LegacyLiftable[T] { def apply(universe: scala.reflect.api.Universe, value: T): universe.Tree } object LegacyLiftable { implicit def liftCaseClass[T <: Product]: LegacyLiftable[T] = macro liftCaseClassImpl[T] def liftCaseClassImpl[T: c.WeakTypeTag](c: Context): c.Expr[LegacyLiftable[T]] = { import c.universe._ val tpe = weakTypeOf[T] if (!tpe.typeSymbol.asClass.isCaseClass) c.abort(c.enclosingPosition, "denied") val p = List(q"Literal(Constant(1))") c.Expr[LegacyLiftable[T]] { q""" new LegacyLiftable[$tpe] { def apply(universe: scala.reflect.api.Universe, value: $tpe): universe.Tree = { import universe._ Apply(Select(Ident(TermName("C")), TermName("apply")), List(..$p)) } } """ } } }