Using initialize to keep track of instances created by the class object

UsingInitialize.m

#import <Foundation/Foundation.h>

@interface MyClass : NSObject

@end

@implementation MyClass

static NSMutableArray *instances;

+ (void) initialize {
	if (self == [MyClass class]) {
		instances = [[NSMutableArray alloc] init];
	}
}

+ (id) alloc {
	id objCreated =  [super alloc];
	[instances addObject:objCreated];
	
	NSLog(@"Creating");
	
	return objCreated;
}

+ (void) printInstances {
	for (id obj in instances) {
		NSLog(@"%@", obj);
	}
}

- (void) dealloc {
	[instances release];
	
	[super dealloc];
}

@end

int main(int argc, char *argv[]) {
	@autoreleasepool {
		MyClass *obj1 = [[MyClass alloc] init];
		MyClass *obj2 = [[MyClass alloc] init];
		
		[MyClass printInstances];
	}
}