> On Nov 3, 2016, at 7:16 AM, Manfred Schubert via swift-users
> <[email protected]> wrote:
>
>
>> Am 02.11.2016 um 18:37 schrieb Rien <[email protected]>:
>>
>>>>
>>>> var rawPtr = UnsafeMutableRawPointer.allocate(bytes: 2, alignedTo: 0)
>>>>
>>>> var widePtr = rawPtr.bindMemory(to: Int16.self, capacity: 1)
>>>>
>>>> widePtr.pointee = 32
>>>>
>>>> var narrowPtr = rawPtr.bindMemory(to: UInt8.self, capacity: 2)
>>>>
>>>> narrowPtr[0] = 16
>>>> narrowPtr[1] = 255
>>>>
>>>> print(widePtr.pointee)
>>>
>>> This compiles and runs as expected, but it should not be allowed if I
>>> understand things correctly. So shouldn’t it be a compile time error or
>>> crash at runtime? If not, what do I get over how it was before where I was
>>> casting to a typed pointer?
>>
>> Why do you think it should not be allowed.
>> AFAICS everything is correct.
>
> If I understand the documentation correctly, this should not be allowed,
> because it’s not allowed to access memory as different types at the same
> time. It needs to be „bound“ to the type first, and can only be bound to one
> type at a time, so all access as another type must be encapsulated within a
> closure.
Yes, this would work
withMemoryRebound(to: UInt16.self, capacity: 1) { print($0.pointee) }
So would this
rawPtr.bindMemory(to: Int16.self, capacity: 1)
print(widePtr.pointee)
Or this
rawPtr.load(as: UInt16.self)
-Andy
>
>
> Manfred
> _______________________________________________
> swift-users mailing list
> [email protected]
> https://lists.swift.org/mailman/listinfo/swift-users
_______________________________________________
swift-users mailing list
[email protected]
https://lists.swift.org/mailman/listinfo/swift-users
