https://twitter.com/CodaFi_/status/937414749083578368

EnumEqualitySwitch.swift

// These three types are simplified versions of the ones in my real project.
public struct Domain {
  public let string: String
}
public enum Taglike {
  case someCase
}
final class Contact {
  let email = ""
}

private enum Cell {
  case contact(Contact)
  case contactsSeparator
  case tag(Taglike)
  case showCreatedByMe
  case showWorkAppDomain(Domain)
  case showWorkAppDomainAndTrashed
  case addContact
  case addTag((String) -> ())
  case enableContacts
}

private func ==(lhs: Cell, rhs: Cell) -> Bool {
  switch (lhs, rhs) {
  case let (.contact(a), .contact(b)):
    return a.email == b.email
  case let (.tag(a), .tag(b)):
    return a == b
  case (.showCreatedByMe, .showCreatedByMe),
       (.showWorkAppDomain, .showWorkAppDomain),
       (.showWorkAppDomainAndTrashed, .showWorkAppDomainAndTrashed),
       (.addContact, .addContact),
       (.addTag, .addTag),
       (.enableContacts, .enableContacts),
       (.contactsSeparator, .contactsSeparator):
    return true
  case (.contact, _),
       (.tag, _),
       (.showCreatedByMe, _),
       (.showWorkAppDomain, _),
       (.showWorkAppDomainAndTrashed, _),
       (.addContact, _),
       (.addTag, _),
       (.enableContacts, _),
       (.contactsSeparator, _):
    return false
  }
}