Idk. Did you see the "Buffer reuse" section of this blog post? [1]

Kudos to that guy for solving the puzzle, but I really don't want to use a special trick to get the compiler to let me reuse a buffer in a for loop.

[1]: https://davidlattimore.github.io/posts/2025/09/02/rustforge-...

I've never seen `split_off_mut` but I do use `split_at_mut` quite often to solve similar issues. Using a slice instead of using a Vec directly also tends to greatly simplify things.

I also don't fully understand the buffer reuse example. Why would you want to store references to a string after the string ceases to exist?