viewmode.swift

// 以下サイトの4.1.2RELEASEで動きます。
// http://online.swiftplayground.run/
import Foundation 

enum ViewMode: Equatable {
    case normal
    case createPosition(CGPoint)
    case editMode

    var isCreatePosition: Bool {
        switch self {
        case .createPosition:
            return true
        default:
            return false
        }
    }
}

let current: ViewMode = .normal
let next: ViewMode = .createPosition(.zero)

// 普通にswitchではだめ?
switch next {
case .createPosition:
    print("is create Position")
default:
    print("is not createPosition")    
}

// それかcomputed property化？
if !next.isCreatePosition {
    print("is not createPosition")
}

これも良さそう

if case .createPosition(let _) = current {} else {  
  print("is not createPosition") 
}