How to define "type disjunction" (union types)?

One way that has been suggested to deal with double definitions of overloaded methods is to replace overloading with pattern matching: object Bar { def foo(xs: Any*) = xs foreach { case _:String => println("str") case _:Int => println("int") case _ => throw new UglyRuntimeException() } } This approach requires that we surrender static type checking on the arguments to foo. It would be much nicer t

[matsu_chara]

"Dotty, a new experimental Scala compiler, supports union types (written A | B)"