Another style question

[Eric Lemings]

I've noticed a lot of #ifdef and #ifndef directives in the code.
Personally, I prefer to always use plain old #if directives since
a compound `#if defined foo || defined bar` is more readable and
consistent with simple #if directives IMHO than
`#ifdef foo || defined bar`.
 
Just wondering if there is a preference here.  Would a simple
`#if defined foo` be permissible?
 
Brad.