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object main { // don't do this at home
trait Impl
trait SizeImpl extends Impl { def size = 42 }
trait ColorImpl extends Impl { def color = "red" }
type Both = SizeImpl with ColorImpl
def info(x:Impl) = x match {
case x:Both => "size "+x.size+" color "+x.color // you wish
case x:SizeImpl => "size "+x.size
case x:ColorImpl => "color "+x.color
case _ => "n.a."
}
def info2(x:Impl) = x match {
case x:SizeImpl with ColorImpl => "size "+x.size+" color "+x.color // you wish
case x:SizeImpl => "size "+x.size
case x:ColorImpl => "color "+x.color
case _ => "n.a."
}
def main(args:Array[String]): Unit = {
// make up some class that has a size
class MyNode extends SizeImpl
Console.println("hello " + info(new MyNode))
Console.println("hello " + info2(new MyNode))
}
}
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