Question

Getting hung up on an apparently simple problem, for which there is plenty of information (too much to sift through to know what on earth the current status is).

At any rate, here goes.

trait _Foo
class Foo Extends _Foo with WhoAmI
trait WhoAmI {
  def who = {
    getClass match {
      case x: _Foo => "should be Foo instance, which extends _Foo"
      case _ => "why?"
    }
  }
}
val foo = new Foo
foo.who

have tried a guard with classOf and isAssignableFrom, as well as looping through x.getInterfaces (I do at least see _Foo there), but no luck in terms of a direct “lean” match.

Is this erasure “at work” or am I missing an obvious 1-liner?

If this is a duplicate of many other threads, we can close, but please point me in the right direction! 😉

Thanks

Answer 1

You should use this instead of getClass:

this match {

Currently you are calling getClass (which returns object of Class[T] type) – for sure the java.lang.Class class does not extend your _Foo trait – that’s “why?“