That IS better than Rust since it migrates the type from n container members to just the 1 container. It doesn't seem possible to replicate that in Rust[0].
My Rust evangelism IS hurt by this. But its HP bar is big[1].
0: https://news.ycombinator.com/item?id=10891892
1: https://www.reddit.com/r/rust/comments/bya8k6/programming_wi...