Different Int Types in iPhone 5 and iPhone 6

Question

I am reading a static Stream of Ints into an Array of Ints:

func create_int_array_from_nsmutable(nsdata:NSMutableData)  -> [Int] {
    let pointer = UnsafePointer<Int>(nsdata.bytes)
    let count = nsdata.length / sizeof(Int);
    // Get buffer pointer and make an array out of it
    let buffer = UnsafeBufferPointer<Int>(start:pointer, count:count)
    let array = [Int](buffer)
    return array;
}

Now I realize, that in the iPhone 5 an Int has a size of 4 and on iPhone 6 or the iPad has a size of 8, which leads to totally different results.

Has someone a hint how to read this stream in both cases and get the same result?

Should I use the Int64 Type? Does Int64 exists exact for that reason, e.g. to solve compatibility problems?

Answer 1

The statement that iPhones and iPads have a different size for the Int value type is wrong, 32-bit and 64-bit processors have this difference.

From the Swift docs:

• On a 32-bit platform, Int is the same size as Int32.
• On a 64-bit platform, Int is the same size as Int64.

Unless you need to work with a specific size of integer, always use Int for integer values in your code. This aids code consistency and interoperability. Even on 32-bit platforms, Int can store any value between -2,147,483,648 and 2,147,483,647, and is large enough for many integer ranges.

If you need to keep your Integer size consistent across multiple architectures, use Int32.