Python is memory safe? Can’t you access/address memory with C bindings?

  • Traister101
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    8 months ago

    Yes Rust is harder to write than C, that’s basically by design as it’s due to the statically guaranteed memory safety. That’s pretty magical. C doesn’t have that and neither does C++ even with smart pointers and such. Rusts unsafe keyword is poorly named, what it actually does is tell the compiler that you the programmer guarantee Rusts rules are upheld within the unsafe block.

    For example

    Access or modify a mutable static variable

    That is a global, that’s incredibly hard to impossible to statically prove it’s safely done, so you have to do it in an unsafe block. So you violating Rusts rules within an unsafe block is actually using the unsafe block wrong. That’s not what it’s for

    • @Solemarc@lemmy.world
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      8 months ago

      I remember watching a video of someone writing C code and making the same thing in unsafe rust. While the C code worked just fine the rust code had UB in it and was compiled to a different set of instructions.

      Unsafe rust expects you to uphold the same guarantees that normal rust does and so the compiler will make all the same optimisations it would if the code wasn’t unsafe and this caused UB in the example rust code when optimised for performance. It worked just fine on the debug build, but that’s UB for you.

    • @Fal
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      08 months ago

      Yes Rust is harder to write than C

      I would totally argue with this. Rust is way easier to write than C

      • Traister101
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        28 months ago

        I’d probably say it depends but I’m no Rust expert and I have no direct experience with C (though quite familiar with C++).

        Basically I’d expect writing C to be easy, but not safe. IE you can quickly and easily write C that compiles but has runtime issues. Rust for the most part will catch everything but logic issues during/before compilation meaning once the program runs you’ll have very high confidence in it’s runtime behavior leading to time spent “fighting the compiler” instead of figuring out wtf is going wrong at runtime.

        • Traister101
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          28 months ago

          I think primarily I don’t really care to argue about if it’s harder to write or not since it doesn’t really matter. I think the pros Rust provides are worth all it’s cons

        • @Fal
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          -28 months ago

          IE you can quickly and easily write C that compiles but has runtime issues.

          So what’s “easy” about it then? Just getting something to compile? That’s not a very good measure of “easyness”.

      • @vext01@lemmy.sdf.org
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        28 months ago

        I agree for the most part, but writing data structures with shared mutable state can be a total pain in Rust.

        • @Fal
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          -18 months ago

          How so? That’s like, the thing that makes rust awesome to write.

          • @vext01@lemmy.sdf.org
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            18 months ago

            It’s hard to get those kinds of data structures through the borrow checker.

            Try writing a doubly linked list.

            • @Fal
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              -38 months ago

              It’s because it’s hard to make them correct. It’s not any harder to write it in rust than in C. Just C lets you do it wrong

              • @vext01@lemmy.sdf.org
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                18 months ago

                That’s not right.

                Try and write a mutable doubly linked list in Rust and you will find that it’s problematic for the borrow checker.

                Search online and you will find solutions that work around this using ‘RefCell’ (to delegate mutable borrows to runtime), or raw pointers with ‘unsafe’.

                • @calcopiritus@lemmy.world
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                  08 months ago

                  Both RefCell and unsafe are features of the language. That’s like saying python’s OOP sucks if you don’t use the class keyword.

                  • @vext01@lemmy.sdf.org
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                    18 months ago

                    I’m not saying it sucks. I’m saying it can be less straight-forward than conventional languages, even for experienced programmers.

                    The borrow checker is fantastic, but there’s no doubt that it requires a new way of thinking if you’ve never seen Rust before.