Strongly typed identifiers

stronglyTyped.swift

// Option 1
protocol Identity {
  associatedtype Identifier
  var id: Identifier {get set}
}

struct Person: Identity {
  typealias Identifier = String

  var id: Identifier
  var name: String
  var age: Int?
}

func scrollToPerson(withId id: Person.Identifier) {
}

struct Building: Identity {
  typealias Identifier = Int

  var id: Identifier
  var name: String
  var age: Int?
}

func goToBuilding(id: Building.Identifier) {
}

// Option 2
class Identifier: RawRepresentable, Hashable, Equatable {
    let rawValue: String
    init(rawValue: String) { self.rawValue = rawValue }
 }

class PersonID: Identifier {}
struct Person {
  let id: PersonID
  var name: String
  var age: Int?
}

class BuildingID: Identifier {}
struct Building {
  let id: BuildingID
  var title: String
  var owner: Person
}