• 5C5C5C@programming.dev
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    edit-2
    1 year ago

    You can call it writing buggy code based on misconceptions, but the fact that it's possible (and not even especially difficult) to misuse smart pointers badly enough to produce program crashes and undefined behavior is still a fundamental weakness of C++ as a language.

    As a counterexample, this type of bug is impossible to produce in Rust without explicitly using the unsafe keyword, and that keyword is something that is almost never used by regular developers and is an easy thing to audit for.

    Edit: That being said, if you're stuck using C++ then obviously using smart pointers is the right thing to do whereas using raw pointers and managing the memory yourself is completely asinine, so if the author's point is to not use smart pointers in C++ then I suppose they want you to just... Leak memory? Because if you're able to figure out where it's safe to free a raw pointer, then you're able to figure out how to correctly use a smart pointer in that situation.

    • lysdexic@programming.dev
      hexagon
      M
      ·
      edit-2
      1 year ago

      the fact that it’s possible (and not even especially difficult) to misuse smart pointers

      Any tool can be misused, but there's a saying about those who blame the tools.

      If you use a component designed to take over the ownership of an object but somehow make the mistake of assigning the same object to multiple components, the problem is not the language you're using. The problem is that you aren't paying attention to what you're doing.

      • 5C5C5C@programming.dev
        ·
        1 year ago

        That's awfully reductive.

        Tools can absolutely vary in their qualities and in their risks / benefits. I don't know what kind of engineer wouldn't evaluate their choice of tools before using them. If you have a tool that explodes in your face when it gets jostled, that's a badly designed tool.

        If you have no other choice for the work you need to do, then okay.. get very good at using the dangerous tool. But if an alternative tool exists that is not only safer but also more efficient, easier to use, and more productive in every use case then the biggest problem really is the choice of tool.

        • lysdexic@programming.dev
          hexagon
          M
          ·
          1 year ago

          That’s awfully reductive.

          It really isn't. Otherwise there would be programming languages out there that would make it impossible to write buggy code, and there is nothing of the sort.

          Tools can absolutely vary in their qualities and in their risks / benefits.

          You still get bugs. This isn't up for discussion. In fact, the only difference is that somehow you assert that C++ suffers from this issue but started to backpedal when any language other than C++ is brought into the picture. That hardly sounds like a personal assertion that's grounded and well founded.

          • 5C5C5C@programming.dev
            ·
            1 year ago

            What exactly have I backpedaled on in any of my replies?

            Rust.

            Rust eliminates entire categories of bugs at compile time with performance that is on par with C++ and often better.

            I do get bugs in my Rust code, but do you want to know what they are? Once in a while I forget to type a ! in an if-statement. Or I accidentally type && when I meant to type ||. These mistakes are trivially caught in unit tests or with a single run of the application and easily fixed. It's also very rare for me to actually make these mistakes. Almost every single time I compile my Rust code, everything works on the first try. But I confess, once in a while one of these minor bugs slips in there.

            So yes bugs are possible in every language. But there's a lot to be said about what kinds of bugs are possible, what the risks of those bugs are, and what the process of mitigating them is like. A memory corruption bug is an entirely different beast from a simple Boolean logic bug.

    • QuadriLiteral@programming.dev
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      edit-2
      1 year ago

      I agree with what you're saying even though I do think a lot of C++'s bad rep comes either from C or from pre-C++11 code. I also think that modern code should include clang-tidy in the CI, and if so at least simple mistakes like in OPs code would be flagged with "warning: Use of memory after it is freed [clang-analyzer-cplusplus.NewDelete]"

      https://clang-tidy.godbolt.org/z/8E169bons

      Note that all of the warnings in there are valid and should be fixed, so it's not like wading through a see of false positives. That being said, the post is interesting in its explanation of why the example does what it does. Too bad all of the other stuff in there is bonkers.

      • 5C5C5C@programming.dev
        ·
        1 year ago

        Linters are good and should absolutely be used in any serious C++ project, but they can only catch the most basic sources of UB. I almost never make a mistake that a static analyzer can catch. It's the multithreaded lifetime issues and data races that ambush you the hardest, and I don't see any way a C++ static analyzer could hope to catch those.

        But yes, most of the original post is bonkers and has the totally wrong conclusion.