---
title: CFBagReleaseCallBack
framework: corefoundation
role: symbol
role_heading: Type Alias
path: corefoundation/cfbagreleasecallback
---

# CFBagReleaseCallBack

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

## Declaration

```swift
typealias CFBagReleaseCallBack = (CFAllocator?, UnsafeRawPointer?) -> Void
```

## Parameters

- `allocator`: The bag’s allocator.
- `value`: The value being removed from the bag.

## Discussion

Discussion This callback is passed to CFBagCreate(_:_:_:_:) in a CFBagCallBacks structure.

## See Also

### Callbacks

- [CFBagApplierFunction](corefoundation/cfbagapplierfunction.md)
- [CFBagCopyDescriptionCallBack](corefoundation/cfbagcopydescriptioncallback.md)
- [CFBagEqualCallBack](corefoundation/cfbagequalcallback.md)
- [CFBagHashCallBack](corefoundation/cfbaghashcallback.md)
- [CFBagRetainCallBack](corefoundation/cfbagretaincallback.md)