对象添加到集合引用计数不+1的几种方式：
1.weakObject
TestModel *model = [[TestModel alloc] init];
NSLog(@"添加集合前:%ld", (long)CFGetRetainCount((__bridge CFTypeRef)model)); // RetainCount:1
// @property (nonatomic, weak) id value;
WeakObject *wo = [[WeakObject alloc] init];
wo.value = model;
NSMutableArray *array = [[NSMutableArray alloc] init];
[array addObject:wo];
NSLog(@"添加集合后:%ld", (long)CFGetRetainCount((__bridge CFTypeRef)model)); // RetainCount:1
2.NSHashTable
TestModel *model = [[TestModel alloc] init];
NSLog(@"添加集合前:%ld", (long)CFGetRetainCount((__bridge CFTypeRef)model)); // RetainCount:1
NSHashTable *hashTable = [NSHashTable hashTableWithOptions:NSPointerFunctionsWeakMemory];
[hashTable addObject:model];
NSLog(@"添加集合后:%ld", (long)CFGetRetainCount((__bridge CFTypeRef)model)); // RetainCount:1
3.NSMapTable
TestModel *model = [[TestModel alloc] init];
NSLog(@"添加集合前:%ld", (long)CFGetRetainCount((__bridge CFTypeRef)model)); // RetainCount:1
NSMapTable *mapTable = [NSMapTable weakToWeakObjectsMapTable];
[mapTable setObject:model forKey:@"test"];
NSLog(@"添加集合后:%ld", (long)CFGetRetainCount((__bridge CFTypeRef)model)); // RetainCount:1
4.NSPointerArray
TestModel *model = [[TestModel alloc] init];
NSLog(@"添加集合前:%ld", (long)CFGetRetainCount((__bridge CFTypeRef)model)); // RetainCount:1
NSPointerArray *pointerArray = [NSPointerArray weakObjectsPointerArray];
[pointerArray addPointer:(__bridge void * _Nullable)(model)];
NSLog(@"添加集合后:%ld", (long)CFGetRetainCount((__bridge CFTypeRef)model)); // RetainCount:1
