For a C++ -> Rust comparison, I think the best examples would be changing return types. Imagine in C++ if you wanted to change a `Foo*` to a `unique_ptr<Foo>`.

For a C++ -> Rust comparison, I think the best examples would be changing return types. Imagine in C++ if you wanted to change a `Foo*` to a `unique_ptr<Foo>`. All the rules about when you can safely use/share this thing and who needs to deallocate this thing becomes a pain to figure out throughout the code base. With rust, because ownership is baked into the type system, those classes of problems just don't exist. Change it from a `Foo&` to a `Box<Foo>`, no problem. The compiler will blow up and tell you exactly where (and how) to fix those things. This applies to more than just memory allocations. Imagine calling a method from 2 threads that manipulates shared memory. Rust won't allow you to do that without protecting that memory with something like a `Mutex`.