What complexity specifically does Rust add to that model?
- Rust doesn’t let you pretend that memory is a flat array of bytes - Single ownership of data can be annoying in some cases - The borrow checker pointing out that you’re trying to do something stupid with pointers (again) can be annoying
Of course, I’m of the opinion that the hassles are worth it, especially the borrow checker. Almost every time I have to fight the borrow checker, it’s because I haven’t thought properly about the pointers involved and tried to do something stupid.
Further, the borrow checker does not care about pointers, only references. With pointers, you are on your own. It is true that using pointers in Rust is more cumbersome than it could be. But it is much easier to compartmentalise the pointer parts into separate functions and expose references instead.
I agree that some paradigms and patterns are genuinely difficult to use, e.g. any intrusive data structure, but I do not see the contentious link between simple memory models and the borrow checker and the like.
And I guess I'm imprecise saying pointers where I mean borrowed values, but my point is that a borrow is just a pointer with additional type checking. More formally: C pointers are a complete but unsound formal system, whereas Rust borrows are sound but incomplete. And every time I get in a fight with the borrow checker, it's because I'm doing something unsound, not because the system is incomplete.