>>>#DEFINE MACHINE_NAME SYS(0)
>>>#DEFINE CURRENT_DEFAULT_DRIVE SYS(5)
>>>
>>>Uhh, George, think about these for a minute...
>>
>>What?? Didn't we have a discussion sometime back that defined function calls like these are actually evaluated at run-time not compile time?
>
>If that's true, then I apologize, but it certainly goes against everything I thought I knew about compile time constants.
>
>I just tested it, and by golly, you're right. So what's the trick? Is _any_ function call in a constant evaled at runtime?
>
>(wanders off scratching head)...

Believe me, it left me scratching mine when I first saw it, and yes, it goes against everything I thought I knew about compile time constants. If I were to hazard a SWAG, it looks like if a function call is used, we've got our old macro business going on. If literals are used, then I'd suspect they're treated like any other (normal) compile time constant.