c.swift

import UIKit

extension UIBezierPath {
    
    func traverseElements() -> NSArray {
        
        var array: [AnyObject] = []
        withUnsafeMutablePointer(&array) {
            arrayPtr -> Void in

            CGPathApply(CGPath, UnsafeMutablePointer(arrayPtr), {
                (arrayPointer: UnsafeMutablePointer<Void>,
                elementPointer: UnsafePointer<CGPathElement>) -> Void in
                
                var array = UnsafeMutablePointer<[AnyObject]>(arrayPointer).memory
                let element = unsafeBitCast(elementPointer.memory, CGPathElement.self)
                
                // Populate the array with something, print out stuff during traversal
                switch element.type {
                case .AddCurveToPoint:
                    print("Add Curve to Point", element.points[0], element.points[1], element.points[2])
                    array.append("Curve")
                case .AddLineToPoint:
                    print("Add Line to Point", element.points[0])
                    array.append("line")
                case .AddQuadCurveToPoint:
                    print("Add Quad to Point", element.points[0], element.points[1])
                    array.append("quad")
                case .CloseSubpath:
                    print("Close subpath")
                    array.append("close")
                case .MoveToPoint:
                    print("move to point", element.points[0])
                    array.append("move")
                }
            })
        }
        
        return array
    }
}

let path = UIBezierPath(roundedRect: CGRectMake(0, 0, 50, 20), cornerRadius: 4)
let array = path.traverseElements()
print(array)