Is it possible to get enum description from variable when enum conforms protocol CustomStringConvertible?

Question

Is it possible to get enum description from variable when enum conforms protocol CustomStringConvertible? Simplified definition is:

enum myEnum: CustomStringConvertible {

  case one(p1: Int)
  case two(p: CGPoint)
  case aaa1
  case aaa2

  var description: String {
    return "useless text"
  }
}

Without protocol it's easy:

let testCases = [en.one(p1: 10), en.two(p: CGPoint(x: 2, y: 3)), en.aaa1, en.aaa2]
testCases.forEach{ 
  print( String(reflecting: $0 ), terminator: "\t\t" ) 
} 
=> "en.one(10)      en.two((2.0, 3.0))      en.aaa1     en.aaa2"

But with protocol I'm able only to get first two cases

testCases.forEach{ 
   Mirror(reflecting: $0).children.forEach{ label, value in
      print( label == nil ? value : (label!, value))
   } 
} 
=> ("one", 10), ("two", (2.0, 3.0))

Thus, cases .aaa1, .aaa2 don't have children so I can't separate those cases from each other (except switch-case of course). Within current situation I can extend functionality of that enum but can't edit what was done before.

Is there a way to get general string description for such case?

Answer 1

Yes, you can use Swift's Mirror reflection API. The enum case of an instance is listed as the mirror's child and you can print its label and value like this:

extension myEnum {
    var description: String {
        let mirror = Mirror(reflecting: self)
        var result = ""
        for child in mirror.children {
            if let label = child.label {
                result += "\(label): \(child.value)"
            } else {
                result += "\(child.value)"
            }
        }
        return result
    }
}