Comment by _gabe_
1 day ago
> What is mess in C++?
Just a couple examples:
How do you make a shallow copy of an object in C++, how do you do the same thing in C? Knowing I can just memcpy _any_ struct in C and have a valid shallow copy is pretty huge.
How do you create a stable ABI in C++? How do you make one in C? In C, knowing that all my exported functions will mostly just work and be stable as long as I don’t change the interface is also huge and allows you to create cross language bindings pretty trivially.
You can’t necessarily do that in C either, it depends on if your object is in a container that relies on pointer stability. Intrusive linked lists are common in C and they get broken by this, for example.
> How do you make a shallow copy of an object in C++
Shallow copies aren't generally possible for classes storing something indirectly, since it violates ownership semantics. That's not how things are done in C++.. Operator = is usually used for making copies, which is optimized to memcpy for POD structures, but for something more complex may perform extra work for doing an actual deep copy.
> How do you create a stable ABI in C++
It's a complex topic. Basic ABI for calling functions is identical to C. But one need to keep in mind, that type layouts and internal implementations of library types (like containers) may differ from implementation to implementation and from version to version.
> knowing that all my exported functions will mostly just work and be stable as long as I don’t change the interface
Nothing prevents you doing this in C++. You can have C-style external interface and use all goods of C++ internally.
Yeah, and that's the reason why people prefer to write in C.
"That's not how things are done in C++" I like C, because I can just decide for myself how things are done here.
> Nothing prevents you doing this in C++.
You left out the part of my comment where I said “pretty trivially” lol. C++ is mostly a superset of C, which is why I’m not arguing that it’s impossible to do these things in C++. I like C++ too, and think some of the things in there are great. But the simplicity of C is nice. I would often get overwhelmed thinking about all the different constructors in C++ and what I needed to do to ensure that I didn’t accidentally tank performance by copying objects around everywhere (and potentially calling some invisible constructor that did extra work in the copy function). In C, I know when I memcpy it’s just gonna move some bytes around.
Overall, I really don’t care all that much one way or the other. But I can see how people could prefer C to C++. I could also see how people prefer C++. I really really miss function overloading and <string.h> when I use C
QED.
You seem to be asking question "why people use hacks in C instead of coding in other languages which are more C++ like". Then you describe what is to be C++ like. Well, maybe the issue is that certain people precisely want to avoid the features you just described. Have you considered that?
Calling memcpy on any random old struct in C is how you get bugs. If the struct contains other pointers: who is in charge of freeing them? What if the struct has internal pointers (a pointer pointing to a subobject of the struct)? You are playing with fire and you know it.