Why does the Scala compiler disallow overloaded methods with default arguments?

Question

While there might be valid cases where such method overloadings could become ambiguous, why does the compiler disallow code which is neither ambiguous at compile time nor at

Answer 1

I can't answer your question, but here is a workaround:

implicit def left2Either[A,B](a:A):Either[A,B] = Left(a)
implicit def right2Either[A,B](b:B):Either[A,B] = Right(b)

def foo(a: Either[Int, String], b: Int = 42) = a match {
  case Left(i) => i + b
  case Right(s) => s + b
}

If you have two very long arg lists which differ in only one arg, it might be worth the trouble...