# storeBytes(of:toByteOffset:as:) Stores the given value’s bytes into raw memory at the specified offset. ``` func storeBytes(of value: T, toByteOffset offset: Int = 0, as type: T.Type) where T : BitwiseCopyable, T : ~Escapable ``` ## Parameters `value` The value to store as raw bytes. `offset` The offset from this pointer, in bytes. `offset` must be nonnegative. The default is zero. `type` The type of `value`. ## Discussion The type `T` to be stored must be a trivial type. The memory must also be uninitialized, initialized to `T`, or initialized to another trivial type that is layout compatible with `T`. After calling `storeBytes(of:toByteOffset:as:)`, the memory is initialized to the raw bytes of `value`. If the memory is bound to a type `U` that is layout compatible with `T`, then it contains a value of type `U`. Calling `storeBytes(of:toByteOffset:as:)` does not change the bound type of the memory. > Note: A trivial type can be copied with just a bit-for-bit copy without > any indirection or reference-counting operations. Generally, native > Swift types that do not contain strong or weak references or other > forms of indirection are trivial, as are imported C structs and enums. If you need to store into memory a copy of a value of a type that isn’t trivial, you cannot use the `storeBytes(of:toByteOffset:as:)` method. Instead, you must know either initialize the memory or, if you know the memory was already bound to `type`, assign to the memory. For example, to replace a value stored in a raw pointer `p`, where `U` is the current type and `T` is the new type, use a typed pointer to access and deinitialize the current value before initializing the memory with a new value: ``` let typedPointer = p.bindMemory(to: U.self, capacity: 1) typedPointer.deinitialize(count: 1) p.initializeMemory(as: T.self, repeating: newValue, count: 1) ``` --- 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)