Or.scala

implicit def l[A,B]: Either[A =:= A, A =:= B] = Left(=:=.tpEquals[A])
implicit def r[A,B]: Either[B =:= A, B =:= B] = Right(=:=.tpEquals[B])

def valueIsIntOrString[T](value: T)(implicit param: Either[T =:= String, T =:= Int]) = param match {
  case Left(t2String) =>
    println("value is String")
    println(t2String(value))
  case Right(t2Int) =>
    println("value is Int")
    println(t2Int(value))
}

valueIsIntOrString(100)
valueIsIntOrString("Foo")
// valueIsIntOrString(1.0) // Compilation Error