I thought that was one of the most fascinating parts - Rust&#x27;s borrow-checker enforces the Law of Demeter and Principle of Least Privilege as a side-effect.<p>Code that takes a full structure when it only needs to operate on a part of the structure <i>is</i> badly designed.  It&#x27;s not conveying the full information about the data that it actually needs, which means that unexpected dependencies can crop up, implicit in the body of the function, as the code is modified later on.  This is behind a lot of long-term maintenance messes; I remember a few multi-year projects at Google to break up &quot;data whales&quot; where a single class had become a dumping ground for all the information needed within a request.<p>Thing is, we all do it, because taking a reference to a general object and then pulling out the specific parts you need means that you don&#x27;t have to change the function signature if the specific parts you need change.  This saves <i>a lot</i> of work when you&#x27;re iterating quickly and discovering new requirements.  You&#x27;re trading ease of modification now for difficulty of comprehension later, which is usually the economically wise choice for you but means that the people who come after you will have a mess to untangle.<p>This makes me think that Rust will be a very poor language for exploratory programming, but a very good one for programming-in-the-large, where you&#x27;re building a massive system for requirements that are largely known.