---
title: release
framework: Core Foundation
role: symbol
role_heading: Instance Property
path: corefoundation/cftreecontext/release
---

# release

The callback used to release a previously retained info field. If this parameter is not a pointer to a function of the correct prototype, the behavior is undefined. This value may be NULL.

## Declaration

```swift
var release: CFTreeReleaseCallBack!
```