SD 有趣的宏定义

Strong 、 weak

#ifndef weakify
#define weakify(...) \
sd_keywordify \
metamacro_foreach_cxt(sd_weakify_,, __weak, __VA_ARGS__)
#endif

#ifndef strongify
#define strongify(...) \
sd_keywordify \
_Pragma("clang diagnostic push") \
_Pragma("clang diagnostic ignored \"-Wshadow\"") \
metamacro_foreach(sd_strongify_,, __VA_ARGS__) \
_Pragma("clang diagnostic pop")
#endif

#define sd_weakify_(INDEX, CONTEXT, VAR) \
CONTEXT __typeof__(VAR) metamacro_concat(VAR, _weak_) = (VAR);

#define sd_strongify_(INDEX, VAR) \
__strong __typeof__(VAR) VAR = metamacro_concat(VAR, _weak_);

#if DEBUG
#define sd_keywordify autoreleasepool {}
#else
#define sd_keywordify try {} @catch (...) {}
#endif

onExit

#if DEBUG
#define sd_keywordify autoreleasepool {}
#else
#define sd_keywordify try {} @catch (...) {}
#endif

#ifndef onExit
#define onExit \
sd_keywordify \
__strong sd_cleanupBlock_t metamacro_concat(sd_exitBlock_, __LINE__) __attribute__((cleanup(sd_executeCleanupBlock), unused)) = ^
#endif