AssertFuncExample2.swift

struct User {
  struct Prefs {
    let email: Bool, sms: Bool
  }
  let name: String, prefs: Prefs
}
let user = User(name: "Test", prefs: Prefs(email: true, sms: false))

// Previously:
assert(user.name.isEmpty) == true

// Now, thanks to @dynamicMemberLookup:
assert(user).name.isEmpty == true

// When combined with closures, the real power starts to reveal itself:
assert(user) {
  $0.name == "Test"
  $0.prefs.email == true
  $0.prefs.sms == false
}

// Deep Nesting
assert(user) {
  $0.name == "Test"
  assert($0.prefs) {
    $0.email == true
    $0.sms == false
  }
}