If I remember correctly, they’re written by the original zeromq author. He has a blog post about how he realized that C++ was not ideal for the architecture he was using, and decided to make a clean break.
Edit: Found it. https://250bpm.com/blog:4/
Edit: Found it. https://250bpm.com/blog:4/
My takeaway is that even though these newer libs seem to be simpler and avoid some issues, they've just never caught on.
I've seen this sentiment before from C enthusiasts. Maybe it makes sense on the Linux kernel, where you don't want to keep telling contributors not to use the most common C++ features.
But I don't think it makes sense on very small projects, and maybe I just draw the dividing line for where it stops working at a different size of project than he did.
[1] Exceptions suck and constructors suck and C++ would be better if it was just Rust with no borrow-checker.