Swift 3 Range Idea: One range type to rule them all 👑

RangeTesting.swift

/*Assert methods*/
class RangeAsserter{
    static func equals(_ a: IRange, _ b:IRange) -> Bool {
        return a.start == b.start && a.end == b.end
    }
}
/*Parser methods*/
class RangeParser{
    static func length(_ range:IRange) -> Int {
        return (range.end) - (range.start)
    }
}
/**
 * Serves as a common denominator for Range and CountableRange
 * Apples motivation for seperating these types was:
 * 1. Make a light-weight range type that only holds 2 Ints (start and end)
 * 2. Make a heavy-weight range type that holds a copy of the original Collection type (aka Array)
 * With IRange we create an universal API to access both types
 */
protocol IRange{
    var end:Int {get }
    var start:Int {get }
}
extension IRange{
    var length:Int {return RangeParser.length(self)}
    func equals(_ range:IRange)->Bool{return RangeAsserter.equals(self,range)}
}
/**
 * We inject IRange functionality onto both Range types: Range and CountableRange
 * So that Range and CountableRange can be treated the same way with out too much verbosity and complex syntactical sugar
 */
extension Range:IRange{
    var start:Int {return self.lowerBound as! Int}
    var end:Int {return self.upperBound as! Int}
}
extension CountableRange:IRange{
    var start:Int {return self.lowerBound as! Int}
    var end:Int {return self.upperBound as! Int}
}
/*testing*/
let countableRange:CountableRange<Int> = (0..<4)
countableRange.length//4
let range:Range = 2..<5
range.length//3
countableRange.equals(range)//false
(0..<4).equals(0..<4)//true

Nice idea but ultimately wasn't pursued.