[kaba0]

Rust has sum types named wrongly as enums, which java also has as sealed interfaces. The option type is just one example for a sum type, which is as easy to express in Java as

  sealed interface Option<T> permits Some<T>, None<T> {
    record Some<T>(T value) {}
    record None<T>() {}
  }

Sure, you have written 3 words more than Rust, and?