meatballtest.swift

        class ParkBenchTimer {
        
        let startTime:CFAbsoluteTime
        var endTime:CFAbsoluteTime?
        
        init() {
            startTime = CFAbsoluteTimeGetCurrent()
        }
        
        func stop() -> CFAbsoluteTime {
            endTime = CFAbsoluteTimeGetCurrent()
            
            return duration!
        }
        
        var duration:CFAbsoluteTime? {
            if let endTime = endTime {
                return endTime - startTime
            } else {
                return nil
            }
        }
    }


    let t1 = ParkBenchTimer()
    var i = 0
    var s: String = ""
    for e in a {
        s = e
        i += 1
    }
    print("Took \(t1.stop())s final \(i)\(s)")
    let t2 = ParkBenchTimer()
    a.forEach {
        s = $0
        i += 1
    }
    print("Took \(t2.stop())s final \(i)\(s)")
    
    let t3 = ParkBenchTimer()
    for e in a {
        s = e
        i += 1
    }
    print("Took \(t3.stop())s final \(i)\(s)")

//Took 0.00463801622390747s final 100000100000
//Took 0.0364949703216553s final 200000100000
//Took 0.0037190318107605s final 300000100000