---
title: release
framework: foundation
role: symbol
role_heading: Instance Property
path: foundation/nsmaptablevaluecallbacks/release
---

# release

Points to the function that decrements a reference count for the given element, and if the reference count becomes zero, frees the given element. If NULL, then nothing is done for reference counting or releasing.

## Declaration

```swift
var release: ((NSMapTable<AnyObject, AnyObject>, UnsafeMutableRawPointer) -> Void)?
```