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In Defense of C++

(dayvster.com)
185 points todsacerdoti | 2 comments | 16 Sep 25 19:40 UTC | HN request time: 0.031s | source
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BeetleB ◴[16 Sep 25 21:57 UTC] No.45268708[source]▶
> Here’s a rule of thumb I like to follow for C++: make it look as much like C as you possibly can, and avoid using too many advanced features of the language unless you really need to.

Also, avoid using C++ classes while you're at it.

I recently had to go back to writing C++ professionally after a many-year hiatus. We code in C++23, and I got a book to refresh me on the basics as well as all the new features.

And man, doing OO in C++ just plain sucks. Needing to know things like copy and swap, and the Rule of Three/Five/Zero. Unless you're doing trivial things with classes, you'll need to know these things. If you don't need to know those things, you might as well stick to structs.

Now I'll grant C++23 is much nicer than C++03 (just import std!) I was so happy to hear about optional, only to find out how fairly useless it is compared to pretty much every language that has implemented a "Maybe" type. Why add the feature if the compiler is not going to protect you from dereferencing without checking?

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fluoridation ◴[17 Sep 25 04:42 UTC] No.45271753[source]▶
std::optional does have dereference checking, but it's a run-time check: std::optional<T>::value(). Of course, you'll get an exception if the optional is empty, because there's nothing else for the callee to do.
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1. BeetleB ◴[17 Sep 25 15:27 UTC] No.45277012[source]▶
> but it's a run-time check

And that's the problem. In other languages that have a Maybe type, it's a compile time check. If your code is not handling the "empty" case, it will simply fail to compile.

I honestly don't see any value in std::optional compared to the behavior pre-std::optional. What does it bring to the table for pointers, for example?

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2. fluoridation ◴[17 Sep 25 19:42 UTC] No.45280510[source]▶
Nothing, but I don't think anyone uses std::optional<T *>. However, if you need to specify an optional integer, std::optional is much clearer than encoding the null value as a negative or other such hacks. Another use of std::optional is to delay construction of an object without an extra dynamic allocation. That's way more convenient than using placement new.