//

// ASWeakSet.h

// AsyncDisplayKit

//

// Created by Adlai Holler on 1/7/16.

//

// Copyright (c) 2014-present, Facebook, Inc. All rights reserved.

// This source code is licensed under the BSD-style license found in the

// LICENSE file in the root directory of this source tree. An additional grant

// of patent rights can be found in the PATENTS file in the same directory.

//

#import <Foundation/Foundation.h>

#import <AsyncDisplayKit/ASBaseDefines.h>

NS_ASSUME_NONNULL_BEGIN

/**

* A class similar to NSSet that stores objects weakly.

* Note that this class uses NSPointerFunctionsObjectPointerPersonality –

* that is, it uses shifted pointer for hashing, and identity comparison for equality.

*/

@interface ASWeakSet<__covariant ObjectType> : NSObject<NSFastEnumeration>

/// Returns YES if the receiver is empty, NO otherwise.

@property (nonatomic, readonly, getter=isEmpty) BOOL empty;

/// Returns YES if `object` is in the receiver, NO otherwise.

- (BOOL)containsObject:(ObjectType)object AS_WARN_UNUSED_RESULT;

/// Insets `object` into the set.

- (void)addObject:(ObjectType)object;

/// Removes object from the set.

- (void)removeObject:(ObjectType)object;

/// Removes all objects from the set.

- (void)removeAllObjects;

/// Returns a standard *retained* NSArray of all objects. Not free to generate, but useful for iterating over contents.

- (NSArray *)allObjects AS_WARN_UNUSED_RESULT;

/**

* How many objects are contained in this set.

* NOTE: This computed property is O(N). Consider using the `empty` property.

*/

@property (nonatomic, readonly) NSUInteger count;

@end

NS_ASSUME_NONNULL_END