A dictionary that preserves the uniqueness of both its keys and its values.

Use BijectiveDictionary when you want to:

• enforce that both keys and values are unique.
• find a value by key in O(1) time.
• find a key by value in O(1) time.
• retrieve the inverse in O(1) time.

BijectiveDictionary implements six classes to provide ordering, mutability and thread-safety.

• OPCBijectiveDictionary
• OPCMutableBijectiveDictionary
• OPCOrderedBijectiveDictionary
• OPCMutableOrderedBijectiveDictionary
• OPCThreadSafeMutableBijectiveDictionary
• OPCThreadSafeMutableOrderedBijectiveDictionary

Sample Usage

OPCMutableBijectiveDictionary *dict = [OPCMutableBijectiveDictionary dictionary];

// Add a new key-value pair.
dict[@"key"] = @"value";

// Retrieve the value for @"key".
NSString *value = dict[@"key"];

// Retrieve the key for @"value".
NSString *key = dict.inverse[@"value"];

Requirements

Minimum iOS Target: 5.0

Installation

BijectiveDictionary is available through CocoaPods. To install, add the following line to your Podfile and then run pod install.

pod 'BijectiveDictionary'

Authors

• Peter Meyers [email protected]
• Zach Langley [email protected]

License

BijectiveDictionary is available under the MIT license. See the LICENSE file for more info.