Using enum to subscript an array in swift 4.0

Question

iOS 11.x Swift 4.0

This doesn't compile cause you cannot subscript an array with an emum it seems? Is there a type I can use that will work?

enum axis:Int {
  case x = 0
  case y = 1
}

var cords = [[10,21],[23,11],[42,12],[31,76]]
var smallestCord:Int = Int.max
var smallestSet:[Int] = []
for cord in cords {
  if cord[axis.x] < smallestCord {
    smallestCord = cord[axis.x]
    smallestSet = cord
  }
}
print("\(smallestCord) \(smallestSet)")

Got it work with a static var like this? but can I make an enum work?

private struct axis {
  static let x = 0
  static let y = 1
}

Answer 1

You can by adding an extension to Array, but this is a case of "what you could do" rather than "what you should do"

extension Array {
    subscript(index: axis) -> Element {
        return self[index.rawValue]
    }
}

---

What you should do instead is to define proper data structures to encapsulate your data:

struct Point {
    var x: Int
    var y: Int

    // For when you need to convert it to array to pass into other functions
    func toArray() -> [Int] {
        return [x, y]
    }
}

let cords = [
    Point(x: 10, y: 21),
    Point(x: 23, y: 11),
    Point(x: 42, y: 12),
    Point(x: 31, y: 76)
]
let smallestSet = cords.min(by: { $0.x < $1.x })!
let smallestCord = smallestSet.x
print("\(smallestCord) \(smallestSet.toArray())")

Answer 2

You should use rawValue instead of an enum instance itself, e.g cord[axis.x.rawValue] instead of cord[axis.x]. Read more about it here.