If let tuples in action

gistfile1.txt

    var interpolatedPathPoints : [CGPoint] {
        let numberOfBezierSamples = 6
        var results = [CGPoint]()
        var current : BezierElement? = nil
        for element in elements {
            switch element.elementType.value {
            case kCGPathElementMoveToPoint.value:
                if let point = element.point {results += [point]; current = element}
                break;
            case kCGPathElementAddLineToPoint.value:
                if let point = element.point {results += [point]; current = element}
                break;
            case kCGPathElementCloseSubpath.value:
                current = nil
                break;
            case kCGPathElementAddQuadCurveToPoint.value:
                if let (currentPoint, point, controlPoint1) = tupled(current?.point, element.point, element.controlPoint1) {
                    for index in 1..<numberOfBezierSamples {
                        let percent = CGFloat(index) / CGFloat(numberOfBezierSamples)
                        let point = QuadBezierPoint(percent, currentPoint, controlPoint1, point)
                        results += [point]
                    }
                    results += [element.point!]
                    current = element
                }
                break;
            case kCGPathElementAddCurveToPoint.value:
                if let (currentPoint, point, controlPoint1, controlPoint2) = tupled(current?.point, element.point, element.controlPoint1, element.controlPoint2) {
                    for index in 1..<numberOfBezierSamples {
                        let percent = CGFloat(index) / CGFloat(numberOfBezierSamples)
                        let point = CubicBezierPoint(percent, currentPoint, controlPoint1, controlPoint2, point)
                        results += [point]
                    }
                    results += [element.point!]
                    current = element
                }
                break;
            default:
                break;
            }
        }
        return results
    }