How to using UIAlertController with RxSwift

UIAlertController+Ben.swift

import RxSwift
import UIKit

extension UIAlertController {

    struct AlertAction {
        var title: String?
        var style: UIAlertAction.Style

        static func action(title: String?, style: UIAlertAction.Style = .default) -> AlertAction {
            return AlertAction(title: title, style: style)
        }
    }

    static func present(
        in viewController: UIViewController?,
        title: String?,
        message: String? = nil,
        style: UIAlertController.Style = .alert,
        actions: [AlertAction])
        -> Observable<Int> {
        return Observable.create { observer in
            let alertController = UIAlertController(title: title, message: message, preferredStyle: style)

            actions.enumerated().forEach { index, action in
                let action = UIAlertAction(title: action.title, style: action.style) { _ in
                    observer.onNext(index)
                    observer.onCompleted()
                }
                alertController.addAction(action)
            }

            viewController?.present(alertController, animated: true, completion: nil)
            return Disposables.create { alertController.dismiss(animated: true, completion: nil) }
        }
    }
}

/////////
//Usage//
/////////
action.deleteClip
    .flatMapLatest { clip -> Observable<(Clip, Int)> in
        let actions = [UIAlertController.AlertAction(title: "아니요", style: .cancel), UIAlertController.AlertAction(title: "예", style: .default)]
        return UIAlertController.present(in: Navigator.topMostViewController, title: "aaaa", actions: actions)
            .map { (clip, $0) }
    }
    .filter { $0.1 == 1 }
    .map { $0.0 }
    .do(onNext: { [weak self] _ in self?.state.loadingStatus.value = .loading })
    .flatMapLatest(provider.clipService.remove)
    .do(onNext: { [weak self] _ in self?.state.loadingStatus.value = .ready })
    .map { [weak self] clip -> [Clip] in
        let clips = self?.state.sections.value.first?.items ?? []
        return clips.removed(at: clip)
    }
    .map { [Section<Clip>(items: $0)] }
    .bind(to: state.sections)
    .disposed(by: disposeBag)