#import "Thing.h" | |
@interface Thing () | |
@end | |
@implementation Thing | |
+ (instancetype)thing { | |
static Thing* thing = nil; | |
static dispatch_once_t onceToken; | |
dispatch_once(&onceToken, ^{ | |
thing = [[[self class] alloc] init]; | |
}); | |
return thing; | |
} | |
- (void)sayHello { | |
NSLog(@"Hello World"); | |
} | |
@end |