Adding zero in c preprocessor statement
addition, c, c-preprocessor, zero
Solution
That avoids a preprocessor syntax error if `__STDC_VERSION__` is defined as an empty token (e.g. with `#define __STDC_VERSION__`).
(Thanks to Jens Gustedt for pointing out that the first version of my answer was wrong.)
Problem
While looking through some c header files (specifically `stdarg.h`), I noticed a very peculiar line: ``` #if !defined(__STRICT_ANSI__) || __STDC_VERSION__ + 0 >= 199900L ``` The strange part is the `+ 0`. Zero is the additive identity; it's one of the various math has of writing `noop`. What purpose does adding zero have in the above preprocessor statement? I know that there's all sorts of weird preprocessor magic out there, but this just seems ridiculous.