trait WhoAreYou {
  def whatClassAmI: Class[_] = this.getClass
  println("I've been mixed into " + whatClassAmI)

  if (whatClassAmI == classOf[Bar]) {
    println("Holy cow batman, I'm part of a Bar")
  }
}

class Foo extends WhoAreYou
class Bar extends WhoAreYou

object MyApp {
  val f = new Foo
  val b = new Bar

  def main(args: Array[String]) {
    println("foo " + f.whatClassAmI)
    println("bar " + b.whatClassAmI)
  }
}