---
title: sizeFunction
framework: foundation
role: symbol
role_heading: Instance Property
path: foundation/nspointerfunctions/sizefunction
---

# sizeFunction

The function used to determine the size of pointers.

## Declaration

```swift
var sizeFunction: ((UnsafeRawPointer) -> Int)? { get set }
```

## Discussion

Discussion This function is used for copy-in operations (unless the collection has an object personality).

## See Also

### Personality Functions

- [hashFunction](foundation/nspointerfunctions/hashfunction.md)
- [isEqualFunction](foundation/nspointerfunctions/isequalfunction.md)
- [descriptionFunction](foundation/nspointerfunctions/descriptionfunction.md)