What C preprocessor conditional should I use for OS X specific code?

Question

What C preprocessor conditional should I use for OS X specific code? I need to include a specific library if I am compiling for OS X or a different header if I am compiling for

Answer 1

__APPLE__ will tell you you're compiling on an Apple platform. Unless you need to support MacOS versions before OS X, that should be good enough. Alternately, you could use __APPLE__ and __MACH__ to make sure you're compiling on OS X.