> They might argue that the snippets don't show there is any real ergonomic problem, because the solutions to make the snippets compile are completely trivial.

> They might argue that the snippets don't show there is any real ergonomic problem, because the solutions to make the snippets compile are completely trivial. In the last example, I could just derive Clone + Copy for Id. I’ll bite a little bit. If I write: struct Thing(u32); Then I need to make a choice: is Thing a plain value that its holders can freely clone or is Thing an affine object that is gone when consumed? I think it’s great that Rust makes this explicit, even if it’s a tiny bit odd that one option is a default and the other option is rather verbose. If I could have a unicorn, too, I’d also like to be able to request “linear” behavior, i.e. disallow code that fails to consume the object. Sure, I suppose someone could invent a language where an LLM reads the type definitions and fills in the blanks as to what uses are valid, but this seems like a terrible idea. Or one could use a language without affine types (most languages, and even C++’s move feature entirely fails to enforce any sort of good behavior).