FunctionSwift

withUnsafeBytes(of:_:)

Invokes the given closure with a buffer pointer covering the raw bytes of the given argument.

func withUnsafeBytes<T, Result>(of value: T, _ body: (UnsafeRawBufferPointer) throws -> Result) rethrows -> Result

Parameters

value

An instance to temporarily access through a raw buffer pointer.

body

A closure that takes a raw buffer pointer to the bytes of value as its sole argument. If the closure has a return value, that value is also used as the return value of the withUnsafeBytes(of:_:) function. The buffer pointer argument is valid only for the duration of the closure’s execution. It is undefined behavior to attempt to mutate through the pointer by conversion to UnsafeMutableRawBufferPointer or any other mutable pointer type. If you want to mutate a value by writing through a pointer, use withUnsafeMutableBytes(of:_:) instead.

Returns

The return value, if any, of the body closure.

Overview

The buffer pointer argument to the body closure provides a collection interface to the raw bytes of value. The buffer is the size of the instance passed as value and does not include any remote storage.