Type Alias

CFBagRetainCallBack

Prototype of a callback function used to retain a value being added to a bag.

Declaration

typealias CFBagRetainCallBack = (CFAllocator?, UnsafeRawPointer?) -> UnsafeRawPointer?

Parameters

allocator

The bag’s allocator.

value

The value being added to the bag.

Return Value

The value to store in the bag, 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 CFBagCreate(_:_:_:_:) in a CFBagCallBacks structure.

See Also

Callbacks

typealias CFBagApplierFunction

Prototype of a callback function that may be applied to every value in a bag.

typealias CFBagCopyDescriptionCallBack

Prototype of a callback function used to get a description of a value in a bag.

typealias CFBagEqualCallBack

Prototype of a callback function used to determine if two values in a bag are equal.

typealias CFBagHashCallBack

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

typealias CFBagReleaseCallBack

Prototype of a callback function used to release a value before it’s removed from a bag.