And I would use variadic macros for the PDF_DEBUG_* macros, so that
extra arguments can be passed to be printed, and not only a string.It is a useful feature. Oh, I just noticed I wrote only the first sentence of the paragraph I had in mind XD There is the complete version: It is a useful feature. But variadic arguments for CPP macros is part of the C99 standard. That may introduce portability issues.
