object Test { def main(args:Array[String]): Unit = { val ns = Array(3L, 3L, 3L) val a1: A = new A(ns(0)) val a2: A = new A(ns(0)) println(a1 + a2) } } class A(val u: Long) extends AnyVal { def +(other: A) = new A(other.u + u) }