Borrowing isn't implicit, as you have an &. But even beyond that, clone is not implicit because it may be an expensive operation, and so Rust wants to expose th

Borrowing isn't implicit, as you have an &. But even beyond that, clone is not implicit because it may be an expensive operation, and so Rust wants to expose that to you. It avoids issues like this: https://news.ycombinator.com/item?id=8704318 https://news.ycombinator.com/item?id=8704318