---
title: "__unaligned"
ms.date: "12/17/2018" 
f1_keywords: ["__unaligned_cpp", "__unaligned", "_unaligned"]
helpviewer_keywords: ["__unaligned keyword [C++]"]
ms.assetid: 0cd83aad-1840-47e3-ad33-59bfcbe6375b
---
# __unaligned

**Microsoft-specific**. When you declare a pointer with the **`__unaligned`** modifier, the compiler assumes that the pointer addresses data that is not aligned. Consequently, platform-appropriate code is generated to handle unaligned reads and writes through the pointer.

## Remarks

This modifier describes the alignment of the data addressed by the pointer; the pointer itself is assumed to be aligned.

The necessity for the **`__unaligned`** keyword varies by platform and environment. Failure to mark data appropriately can result in issues ranging from performance penalties to hardware faults. The **`__unaligned`** modifier is not valid for the x86 platform.

For compatibility with previous versions, **`_unaligned`** is a synonym for **`__unaligned`** unless compiler option [`/Za` \(Disable language extensions)](../build/reference/za-ze-disable-language-extensions.md) is specified.

For more information about alignment, see:

- [`align`](../cpp/align-cpp.md)

- [`alignof` Operator](../cpp/alignof-operator.md)

- [`pack`](../preprocessor/pack.md)

- [`/Zp` (Struct Member Alignment)](../build/reference/zp-struct-member-alignment.md)

- [Examples of Structure Alignment](../build/x64-software-conventions.md#examples-of-structure-alignment)

## See also

[Keywords](../cpp/keywords-cpp.md)