005高阶功能

import UIKit // (Strinfg) -> Void func logToConsole(_ msg: String) { print(msg + " From Console") } func logToFile(_ msg: String) { print(msg + " From File") } func logToWindow(_ msg: String) { print(msg + " From Windows") } enum Logger { case Console, File, Windows var print: (String) -> () { switch self { case .Console: return logToConsole