import scala.collection.mutable.HashMap object AssertionError extends AnyRef with App { abstract class A {} object A1 extends A {} object A2 extends A {} class Manager { final class B {} val map = new HashMap[A, B] } def test[T](f: => T) { f } test { val manager = new Manager // This line is illegal and causes a compiler crash with Scala 2.3.1 assert(manager.map(A2) == List(manager.map(A2, A1))) } }