Property Wrapper 入門 - Qiita

struct Person { private let _age: BehaviorSubject<Int> var age: Observable<Int> { _age.asObservable() } init(initialAge: Int) { _age = BehaviorSubject(initialAge) } } @propertyWrapper struct PropertyPublished<Value> { private(set) var wrappedValue: Value { didSet { subject.onNext(wrappedValue) } } var projectedValue: Observable<Value> { subject.asObservable() } private let subject: BehaviorSubject