In Dart 3 you have patterns and sealed class families to achieve that. See my comment above[1]. The syntax is unfortunately more verbose, but if all goes well

In Dart 3 you have patterns and sealed class families to achieve that. See my comment above[1]. The syntax is unfortunately more verbose, but if all goes well we will address that issue this year. [1]: https://news.ycombinator.com/item?id=39613415 https://news.ycombinator.com/item?id=39613415