Overloads for "..." exist with these types of results: ClosedRange <Bound>, CountableClosedRange <Bound>

Question

Swift 2

let gap = CGFloat(randomInRange(StackGapMinWidth...maxGap)) 

Missing label for argument "range:" in call

Swift 3 - new bug

 let gap = CGFloat(randomInRange(range: StackGapMinWidth...maxGap)) 

No candidates "..." create the expected context result type "Range"

Overloads for '...' exist with these types of results: ClosedRange, CountableClosedRange

Answer 1

With Swift 3, ..< and ... different ranges are produced:

• ..< creates a Range (or CountableRange , depending on the base type), which describes a half-open range that does not include an upper bound.
• ... creates a ClosedRange (or CountableClosedRange ) that describes a closed range that includes an upper bound.

If randomInRange() calculates a random number in a given range, including the upper bound, then it should be defined as

 func randomInRange(range: ClosedRange<Int>) -> Int { // ... } 

and you can call him

 let lo = 1 let hi = 10 let r = randomInRange(range: lo ... hi)