Contents

storeBytes(of:toByteOffset:as:)

Stores a value’s bytes into the buffer pointer slice’s raw memory at the specified byte offset.

Declaration

func storeBytes<T>(of value: T, toByteOffset offset: Int = 0, as type: T.Type)

Parameters

  • value:

    The value to store as raw bytes.

  • offset:

    The offset in bytes into the buffer pointer slice’s memory to begin writing bytes from the value. 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.

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.

The memory written to 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.

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.

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.