Get the latest tech news
Open and closed universes (2021)
How to write types that represent choices.
A future version may depend on some other library, for example toml, and you’d have to add a new option to the Error type: A downside is that traits make each choice in an open universe a type, not a value, so operations like equality become harder to define. It isn’t impossible, though: the trait could require a key method which returns a many-strings type.
Or read this on Hacker News