trait DB
object DB {
  val live: Layer[Any, DB] = Layer.resource {
    makeRes("db").as(new DB {})
  }
}

trait HttpCli
object HttpCli {
  val live: Layer[Any, HttpCli] = Layer.resource {
    makeRes("httpClient").as(new HttpCli {})
  }
}

trait AClient
object AClient {
  val live: Layer[HttpCli, AClient] = Layer.function { (a: HttpCli) =>
    makeRes("AClient").as(new AClient {})
  }
}

trait Service1
object Service1 {
  val live: Layer[DB & HttpCli, Service1] = Layer.function {
    (db: DB, http: HttpCli) =>
    IO(new Service1 {}).toResource
  }
}
trait Service2
object Service2 {
  val live: Layer[DB & AClient, Service2] = Layer.function {
    (db: DB, aclient: AClient) =>
    IO(new Service2 {}).toResource
  }
}

trait App
object App {
  val live: Layer[Service1 & Service2, App] = Layer.function {
    (s1: Service1, s2: Service2) =>
    makeRes("app").as(new App {})
  }
}

val appLayer: Layer[Any, App] =
    (DB.live ++ (HttpCli.live >+> AClient.live)) >>> (Service1.live ++ Service2.live) >>> App.live // Munally construction

val appLayer = Layer.make[App]( // Auto construction
    DB.live,
    HttpCli.live,
    AClient.live,
    Service1.live,
    Service2.live,
    App.live
  )

appLayer.build(ZEnv(())).use { env =>
  IO.println(env.get[App])
}