# MemoryLayout The memory layout of a type, describing its size, stride, and alignment. ``` @frozen enum MemoryLayout where T : ~Copyable, T : ~Escapable ``` ## Overview You can use `MemoryLayout` as a source of information about a type when allocating or binding memory using raw pointers. The following example declares a `Point` type with `x` and `y` coordinates and a Boolean `isFilled` property. ``` struct Point { let x: Double let y: Double let isFilled: Bool } ``` The size, stride, and alignment of the `Point` type are accessible as static properties of `MemoryLayout`. ``` // MemoryLayout.size == 17 // MemoryLayout.stride == 24 // MemoryLayout.alignment == 8 ``` Always use a multiple of a type’s `stride` instead of its `size` when allocating memory or accounting for the distance between instances in memory. This example allocates uninitialized raw memory with space for four instances of `Point`. ``` let count = 4 let pointPointer = UnsafeMutableRawPointer.allocate( byteCount: count * MemoryLayout.stride, alignment: MemoryLayout.alignment) ``` ## Topics ### Accessing the Layout of a Type Use these static properties to access a type’s layout. For example, the size of a `Double` instance is `MemoryLayout.size`. [`size`](/documentation/Swift/MemoryLayout/size) The contiguous memory footprint of `T`, in bytes. [`alignment`](/documentation/Swift/MemoryLayout/alignment) The default memory alignment of `T`, in bytes. [`stride`](/documentation/Swift/MemoryLayout/stride) The number of bytes from the start of one instance of `T` to the start of the next when stored in contiguous memory or in an `Array`. ### Accessing the Layout of a Value Pass an instance to these static methods to acess the layout for that instance’s type. [`stride(ofValue:)`](/documentation/Swift/MemoryLayout/stride(ofValue:)) Returns the number of bytes from the start of one instance of `T` to the start of the next when stored in contiguous memory or in an `Array`. [`size(ofValue:)`](/documentation/Swift/MemoryLayout/size(ofValue:)) Returns the contiguous memory footprint of the given instance. [`alignment(ofValue:)`](/documentation/Swift/MemoryLayout/alignment(ofValue:)) Returns the default memory alignment of `T`. ### Querying Type Properties [`offset(of:)`](/documentation/Swift/MemoryLayout/offset(of:)) Returns the offset of an inline stored property within a type’s in-memory representation. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)