问题
I would like to ask what's the reason behind using FOUNDATION_EXPORT instead of extern in Objective C projects.
I've checked this question and using FOUNDATION_EXPORT has earned whopping 340 points (1st place) whereas using extern only 74 points (2nd place).
Could anybody explain why? Is there any practical reason for using FOUNDATION_EXPORT instead of extern?
Thanks!
回答1:
If you look in NSObjCRuntime.h (in Foundation) you will see that FOUNDATION_EXPORT compiles to extern in C, extern "C" in C++, and other things in Win32. So, it's a bit more compatible. For most projects, this won't make any difference.
来源：https://stackoverflow.com/questions/10953221/foundation-export-vs-extern