Type Alias

CFDictionaryRetainCallBack

Prototype of a callback function used to retain a value or key being added to a dictionary.

Declaration

typedef const void *(*CFDictionaryRetainCallBack)(CFAllocatorRef allocator, const void *value);

Parameters

allocator

The dictionary’s allocator.

value

The value being added to the dictionary.

Return Value

The value or key to store in the dictionary, which is usually the value parameter passed to this callback, but may be a different value if a different value should be stored in the collection.

Discussion

This callback is passed to CFDictionaryCreate in a CFDictionaryKeyCallBacks and CFDictionaryValueCallBacks structure.

See Also

Callbacks

CFDictionaryApplierFunction

Prototype of a callback function that may be applied to every key-value pair in a dictionary.

CFDictionaryCopyDescriptionCallBack

Prototype of a callback function used to get a description of a value or key in a dictionary.

CFDictionaryEqualCallBack

Prototype of a callback function used to determine if two values or keys in a dictionary are equal.

CFDictionaryHashCallBack

Prototype of a callback function invoked to compute a hash code for a key. Hash codes are used when key-value pairs are accessed, added, or removed from a collection.

CFDictionaryReleaseCallBack

Prototype of a callback function used to release a key-value pair before it’s removed from a dictionary.