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# CFTreeRetainCallBack

Callback function used to retain a program-defined information pointer.

```
typealias CFTreeRetainCallBack = (UnsafeRawPointer?) -> UnsafeRawPointer?
```

## Parameters

`info`

The program-supplied information pointer provided in a [`CFTreeContext`](/documentation/CoreFoundation/CFTreeContext) structure.

## Return Value

The value to use whenever the information pointer is retained, which is usually the `info` parameter passed to this callback, but may be a different value if a different value should be used.

## Discussion

---

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