user: Can you explain some differences between the Rust and C++ programming languages

assistant: While Rust and C++ are similar in many ways, they differ in even more. Here is a list of some of the most important differences:

1) While C++ is considered an object oriented language, Rust is more similar to a procedural language, with functional programming influences. As such, Rust lacks essential object oriented features found in C++, such as inheritance. Rust programs achieve similar benefits using the concept of "traits" and Rust's more powerful macro system to avoid the kind of boilerplate features like inheritance are usually used to eliminate.
2) Rust features a much more powerful macro system than C++. Where C++ macros are a simple text replacement, Rust macros are full Rust programs that run at compile time and directly modify the Abstract Syntax Tree to write code automatically. As Rust macros have the entire turing complete Rust language available to them, it's even possible to re-implement missing features like inheritance as a macro in Rust.
3) While Rust and C++ both have strict type systems, the type system in C++ is more or less a one to one translation of machine types such int, bool, char etc., while Rust's type system is something called an "Algebraic Type System" that can model more complex relationships. The Rust type system is more similar to functional programming languages such as Haskell than it is to C++. Rust's so called "expressive types" can be used to model domain information, and avoid errors by making bad states unrepresentable in the type system, it becomes a compile time error. It should be noted that Rust also includes the basic machine types like C++ does (i32, f64, bool, etc), as well as the algebraic types. Algebraic types are powerful and offer many benefits, but may be considered more complicated or confusing and potentially take longer to write. Some people prefer C++'s much simpler type system for this reason.
4) Rust lacks the concept of an exception or a null type like you might see in C++, instead preferring to model errors as explicit values in the type system. A rather than crash on failure, a Rust function that might fail returns a value of Result<value, error>, which is either a valid value, or an error. Similarly, a function that might or might not return a value returns an Option<Some(value), None>, rather than a value that could be null. This is different from a null in the sense that it forces you to pull the value out of the option type before using it, therefore handling the case that it's None. As a result, in combination with Rust's memory safety features, it's nearly impossible to write a Rust program that crashes unless you either call the panic!() function to manually crash the program, or write so called "unsafe" code, eg, your Rust program can still crash if you were to call a C function that crashes.
5) While C and C++ put a large emphasis on manipulating raw pointers, Rust largely hides the details of pointers away from you for memory safety and features almost no manual pointer manipulation. Rust pointers are called "references", and they're strictly policed by the "borrow checker" at runtime. In general, this means that things like memory leaks, use after free errors, dangling pointers, and segfaults are virtually non-issues in Rust, as if you were using a garbage collected language. It also makes concurrent programming significantly less error prone, preventing race conditions. However, the downside is that many new Rust users find themselves "fighting the borrow checker" as it prevents them from writing code that might fail. It also makes more difficult to write pointer based datastructures such as trees, graphs, and linked lists in Rust. It is also possible to manually turn off the borrow checker and write "unsafe" code in Rust that allows you to do all these things, such as pointer arithmetic, but you lose the memory safety benefits of the borrow checker when you do so.