loadUnaligned(fromByteOffset:as:)

Declaration

func loadUnaligned<T>(fromByteOffset offset: Int = 0, as type: T.Type) -> T where T : BitwiseCopyable

Parameters

• offset:

  The offset into the slice’s memory, in bytes, at which to begin reading data for the new instance. The default is zero.

• type:

  The type to use for the newly constructed instance. The memory must be initialized to a value of a type that is layout compatible with type.

Return Value

A new instance of type T, copied from the buffer pointer’s memory.

Discussion

This function only supports loading trivial types. A trivial type does not contain any reference-counted property within its in-memory stored representation. The memory at offset bytes into the buffer slice must be laid out identically to the in-memory representation of T.

You can use this method to create new values from the buffer pointer’s underlying bytes. The following example creates two new Int32 instances from the memory referenced by the buffer pointer someBytes. The bytes for a are copied from the first four bytes of someBytes, and the bytes for b are copied from the fourth through seventh bytes.

let a = someBytes[..<4].loadUnaligned(as: Int32.self)
let b = someBytes[3...].loadUnaligned(as: Int32.self)

The memory to read for the new instance must not extend beyond the memory region represented by the buffer pointer slice—that is, offset + MemoryLayout<T>.size must be less than or equal to the slice’s count.