Unsigned Long Long from Double in Swift

Question

I used to use the following in Objective-C:

double currentTime = CFAbsoluteTimeGetCurrent();

// self.startTime is called before, like     
// self.startTime = CFAbsoluteTimeGetCurrent();

double elapsedTime = currentTime - self.startTime;

// Convert the double to milliseconds
unsigned long long milliSecs = (unsigned long long)(elapsedTime * 1000);

In my swift code I have at the moment:

let currentTime: Double = CFAbsoluteTimeGetCurrent()
let elapsedTime: Double = currentTime - startTime

let milliSecs: CUnsignedLongLong = elapsedTime * 1000

However I get the error that a double cannot be converted to a CUnsignedLongLong which makes sense. Is there a way to cast it like in Objective-C though? Is there a way around this?

score 25 · Accepted Answer · answered Jul 27 '15 at 17:33

25

Is there a way to cast it like in Objective C though? Is there a way around this?

let milliSecs = CUnsignedLongLong(elapsedTime * 1000)

Or

let milliSecs = UInt64(elapsedTime * 1000)

answered Jul 27 '15 at 17:33

simons

2,220
2
16
20

score 5 · Answer 2 · answered Jul 27 '15 at 17:36

CUnsignedLongLong is defined in the standard library by:

typealias CUnsignedLongLong = UInt64

So to convert a Double to CUnsignedLongLong, you need to create a new instance of CUnsignedLongLong using

CUnsignedLongLong(elapsedTime * 1000)

or

UInt64(elapsedTime * 1000)

score 2 · Answer 3 · answered Jul 27 '15 at 17:41

2

Swift doesn't allow for implicit type conversion. Create the value using the constructor for its type.

let milliSecs = CFUnsignedLongLong(elapsedTime * 1000)

answered Jul 27 '15 at 17:41

orahman

76
3

Unsigned Long Long from Double in Swift

3 Answers3