---
title: CFBagCopyDescriptionCallBack
framework: corefoundation
role: symbol
role_heading: Type Alias
path: corefoundation/cfbagcopydescriptioncallback
---

# CFBagCopyDescriptionCallBack

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

## Declaration

```swift
typealias CFBagCopyDescriptionCallBack = (UnsafeRawPointer?) -> Unmanaged<CFString>?
```

## Parameters

- `value`: The value to be described.

## Return Value

Return Value A textual description of value. Ownership follows the The Create Rule.

## Discussion

Discussion This callback is passed to CFBagCreate(_:_:_:_:) in a CFBagCallBacks structure. This callback is used by the CFCopyDescription(_:) function.

## See Also

### Callbacks

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