Some Rustaceans go to great lengths to avoid copying data — even once. This is typically noticeable among those with a background in systems programming, who are deeply conscious of performance and memory usage, sometimes to the detriment of code readability. They make heavy use of mut to mutate data in place and frequently try to sidestep .clone() calls at every turn in an attempt to (prematurely) optimize their code. I believe this approach is misguided. Immutability — which means once ...
