下标的使用不明确

该代码块以前可以工作，但现在不行了。我在纬度和经度变量上收到错误“'下标'的使用不明确”。这是怎么回事？这是因为 Swift 更新吗？

func showPrecincts() {

    var urlBoundaries = "http://www.oklahomadata.org/boundary/1.0/boundary/?contains=" + "\(coords!.latitude)" + "," + "\(coords!.longitude)" + "&sets=precincts"

    Alamofire.request(.GET, urlBoundaries, parameters: ["foo": "bar"])
        .responseJSON { response in

            if let data = response.result.value {

                let nestedCoordinates = data.valueForKeyPath("objects.simple_shape.coordinates") as! Array<AnyObject>

                let bug1 = nestedCoordinates.first as! Array<AnyObject>
                let bug2 = bug1.first as! Array<AnyObject>
                let coordinates = bug2.first as! Array<AnyObject>

                var convertedCoords: [CLLocationCoordinate2D] = []

                for individualCoordinates in coordinates  {
                    let lat = (individualCoordinates[1] as! Double)
                    let long = (individualCoordinates[0] as! Double)
                    var newCoords = CLLocationCoordinate2DMake(lat, long)
                    convertedCoords.append(newCoords)
                }
                print(convertedCoords)

}

coordinates被转换为数组AnyObject.
编译器不知道它实际上是一个数组Double在另一个数组中。

沮丧coordinates to Array<[Double]>

let coordinates = bug2.first as! Array<[Double]>

然后你就可以获取元素而无需进一步类型转换

let lat = individualCoordinates[1]
let long = individualCoordinates[0]