How to define “type disjunction” (union types)?

Question

One way that has been suggested to deal with double definitions of overloaded methods is to replace overloading with pattern matching:

object Bar {
   def fo         


        

Answer 1

Dotty, a new experimental Scala compiler, supports union types (written A | B), so you can do exactly what you wanted:

def foo(xs: (String | Int)*) = xs foreach {
   case _: String => println("str")
   case _: Int => println("int")
}