Question

The following code fails when the constructor parameter is declared with val

Works:

class Poso(array : Array[_ <: Any])
object Test {
  new Poso(classOf[Retention].getEnumConstants())
}

Doesn’t work:

class Poso(val array : Array[_ <: Any])
object Test {
  new Poso(classOf[Retention].getEnumConstants())
}

The compiler gives the error:

Error in Scala compiler: type mismatch; found :java.lang.Object required: array[java.lang.Object]

Without being able to give a line number.

Answer 1

Looks like a bug in Scala compiler (it dies on an exception). You should probably report it to Scala developers.

Using AnyRef instead of Any fixed it for me:

class Poso(val array : Array[_ <: AnyRef])
object Test {
  new Poso(classOf[java.lang.annotation.Retention].getEnumConstants())
}