> You build safe abstractions around the ugly low-level pointer handling, you just don't have a keyword for a clear delineation.
The main difference is they are not really safe. It is trivial to accidentally invoke UB with incorrect use of "safe" abstractions in C++ like built-in containers or smart pointers. Keep a reference to a vector element, add a new item to the vector and it will sometimes blow up ;)
I disagree that it is "trivial," at least in the example you stated. This take-reference-then-mutate is exactly the kind of usage that the borrow checker prevents. You have to avoid it systematically in both languages.
The built-in containers are also not the best examples of "safe" abstractions. You can build safer abstractions, and you can employ safer usage patterns of built-in vectors, at non-zero but marginal costs.
The honest view on C++ is that there is no such thing as "safe" in absolute terms, but you have a lot of tools to mitigate the unsafe nature of the core language.
The honest view on Rust is that the idea of categorically excluding memory safety errors didn't quite pan out, but we're nonetheless left with an improvement over C++.
It’s subtle, but you don't avoid “take reference then mutate” in Rust, you are told exactly how to do it without aliasing the memory.
I’m not going to say Rust is perfect, that’s obviously not the case. But I really think your argument, like others are saying, underplays the actual value of Rust.
I’ve written entire projects in both C++ and Rust. I’ve never wasted days debugging memory corruption in Rust. Just sayin’.
The main difference is they are not really safe. It is trivial to accidentally invoke UB with incorrect use of "safe" abstractions in C++ like built-in containers or smart pointers. Keep a reference to a vector element, add a new item to the vector and it will sometimes blow up ;)