---
title: CTRunDelegateGetAscentCallback
framework: coretext
role: symbol
role_heading: Type Alias
path: coretext/ctrundelegategetascentcallback
---

# CTRunDelegateGetAscentCallback

Defines a pointer to a function that determines typographic ascent of glyphs in the run.

## Declaration

```swift
typealias CTRunDelegateGetAscentCallback = (UnsafeMutableRawPointer) -> CGFloat
```

## Parameters

- `refCon`: The reference-constant value supplied to the doc://com.apple.coretext/documentation/CoreText/CTRunDelegateCreate(_:_:) function when the run delegate was created.

## Return Value

Return Value The typographic ascent of glyphs in the run associated with the run delegate.

## Discussion

Discussion You would declare the get-ascent function like this if you were to name it MyGetAscentCallback:

## See Also

### Callbacks

- [CTRunDelegateGetDescentCallback](coretext/ctrundelegategetdescentcallback.md)
- [CTRunDelegateGetWidthCallback](coretext/ctrundelegategetwidthcallback.md)
- [CTRunDelegateDeallocateCallback](coretext/ctrundelegatedeallocatecallback.md)