---
title: "CFBagReplaceValue(_:_:)"
framework: corefoundation
role: symbol
role_heading: Function
path: "corefoundation/cfbagreplacevalue(_:_:)"
---

# CFBagReplaceValue(_:_:)

Replaces a value in a mutable bag.

## Declaration

```swift
func CFBagReplaceValue(_ theBag: CFMutableBag!, _ value: UnsafeRawPointer!)
```

## Parameters

- `theBag`: The bag from which value is to be replaced.
- `value`: The value to be replaced in the collection. If this value does not already exist in the collection, the function does nothing. You may pass the value itself instead of a pointer if it is pointer-size or less. The equal callback provided when theBag was created is used to compare. If the equal callback was NULL, pointer equality (in C, ==) is used. If value, or any other value in theBag, is not understood by the equal callback, the behavior is undefined.

## Discussion

Discussion Depending on the implementation of the equal callback specified when creating theBag, the object that is replaced by value may not have the same pointer equality.

## See Also

### Modifying a Mutable Bag

- [CFBagAddValue(_:_:)](corefoundation/cfbagaddvalue(_:_:).md)
- [CFBagRemoveAllValues(_:)](corefoundation/cfbagremoveallvalues(_:).md)
- [CFBagRemoveValue(_:_:)](corefoundation/cfbagremovevalue(_:_:).md)
- [CFBagSetValue(_:_:)](corefoundation/cfbagsetvalue(_:_:).md)