上で出て来たenumでstateパターン、無理やりRawValueに振る舞いを実装して見た https://gist.github.com/norio-nomura/65db97c4786851bc368a8d68834fb31b (edited)

https://qiita.com/hikaruna/items/7d2e919be0bc93bf3f45 を RawRepresentable で実装

https://qiita.com/hikaruna/items/7d2e919be0bc93bf3f45 を RawRepresentable で実装