---
title: "alignedDown(toMultipleOf:)"
framework: swift
role: symbol
role_heading: Instance Method
path: "swift/unsafemutablerawpointer/aligneddown(tomultipleof:)"
---

# alignedDown(toMultipleOf:)

Obtain the preceding pointer whose bit pattern is a multiple of alignment.

## Declaration

```swift
func alignedDown(toMultipleOf alignment: Int) -> UnsafeMutableRawPointer
```

## Parameters

- `alignment`: The alignment of the returned pointer, in bytes. alignment must be a whole power of 2.

## Return Value

Return Value A pointer aligned to alignment.

## Discussion

Discussion If the bit pattern of self is a multiple of alignment, this function returns self.