Existential Any

existential.swift

import Foundation

protocol User: Identifiable {
  var firstName: String { get set }
  var lastName: String { get set }
}

func printUserName(_ user: any User) {
  print("\(user.firstName) \(user.lastName)")
}

enum AdminRole {
  case manager
  case finances
  case support
}

struct Admin: User {
  // Identifiable
  var id: Int

  // User
  var firstName: String
  var lastName: String

  var roles: [AdminRole]
}

let admin = Admin(id: 1, firstName: "John", lastName: "Doe", roles: [.manager, .finances])
printUserName(admin)