> On Dec 9, 2015, at 14:57 , Quincey Morris
> <[email protected]> wrote:
>
> On Dec 9, 2015, at 14:35 , Rick Mann <[email protected]> wrote:
>>
>> If I have var foo : [Int], how can I get that type, Int? I need to get the
>> size of each element.
>
> I imagine there’s a direct way, but I can’t find it in a program. You can do
> something like this:
>
> strideofValue (foo [0]) // but this requires foo.count
> != 0, or:
> strideof (foo [0].dynamicType) // which seems to work in a
> playground even for empty arrays
>
> Note that I’m not sure there’s an API guarantee that the Array<> elements are
> stored contiguously in memory. If you want that, you should probably use
> ContiguousArray<> instead. (That also gives you API to directly/unsafely
> access the memory too, IIRTGHF** correctly.)
>
> Do be careful, though. If you’re accessing Ints raw-ly, and (say) saving them
> or transmitting them to another application or platform, you might also have
> to worry about element size and endianness differences, theoretically.
Actually, looking further, what I have is an UnsafePointer<Int32>. This is
actually coming from Objective-C++ code (it's how I bridge my Swift code to our
extensive C++ codebase). The class has a property:
@property (nonatomic, readonly, nullable) const int* faceIndexes;
Which shows up in swift as UnsafePointer<Int32>, and I can treat it as an array:
myObjCObj.faceIndexes[0]
So, really, I need to get at the UnsafePointer's type. Is that:
var up: UnsafePointer<Int32>
sizeof(up.memory.dynamicType)
That seems to work. Wordy, but gets the job done.
>
> ** "If I Read The Generated Header File"
--
Rick Mann
[email protected]
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