leunam217

I don't think that it would bring a lot of value as you can construct variant containers with immutability. 

@thecotne I'm not sure to understand your point. But it was just a comment saying that with the current features we can simulate covariant wrappers types. Sorry if it was...

By the way when this will be possible, There will be one more example for issue #267.  [Try](https://hegel.js.org/try#MYGwhgzhAEDCD2AXAdgU2gbwFDWssAtqgFzQD8EiATgJbIDmWO0EqiAcoagBT5ECUmZrkQALGhAB0fdAF48XZgF8sKrMHjJK0KqjAATTSACeAfQ0pUAJlIASAJIECAV0RgARiFQAeDAqKklLQMADQsbJwB0NyCsgB80M7I+qgAZnSo+tBKCfJ+MqQA5BZohWGsHFykqUnAiDSaMX5iEtJcsgBEzgAOEB1K2Uy6BkZmJdaSFZE8ggD0syyi8M4gWahUVPBUWEA)