It indicates that what the author may want is a more expressive type system, one that can do some static verification(e.g. Scala's Option, Haskell's Maybe). An

It indicates that what the author may want is a more expressive type system, one that can do some static verification(e.g. Scala's Option, Haskell's Maybe). Another way to get the behavior of the described Maybe method is to enforce a coding style where functions require a default return value to be passed in - this lets it be handled in a precise manner and surfaces most problems quickly, without butchering fundamental assumptions of the language. The real difficulty comes in when you want to enforce a branch for functions that are "rarely null" instead of having them blow up much later when you inevitably forget to handle the null case. A lot of the time the only immediate way to avoid this class of error is to use algorithms that will never stumble over a null(which tends to make them a lot slower) - if you have macros or richer type systems, other things are possible of course.