No, you're exactly right. If you think about it, both of these things are (almost) exactly equivalent. In both cases you are separating out a third control branch. The only difference is the syntax you use to specify what happens on that third branch, and whether or not that branch is taken immediately when the non-true-non-false value is generated. It is exactly the difference between (say)dividing by zero throwing an exception or returning an infinity or a NaN.