宏定义生成单例

宏定义–生成单例

#define SHARE_INSTANCE(class) \+(instancetype)shareInstance \{ \static dispatch_once_t class##_predicate; \static class *class##_instance = nil; \dispatch_once(&class##_predicate, \^() { \class##_instance = [[class alloc] init]; \}); \return class##_instance; \}