https://github.com/arximboldi/immer
https://github.com/arximboldi/lager
https://github.com/arximboldi/zug
Also, I very agree with what @jasode has said. C++ will be interesting for you if you can do interesting things in C++. That is the main reason I use it: there are certain domains where I work: professional music software, graphics, film, robotics, etc. where there are no solid alternatives (maybe Rust/Nim/Zig if you are very adventurous). This kind of software is actually really cool, it's creative and enhances artists's lives and does not live in magical "clouds" but runs on your machine. The language is imperfect and complicated but working in these domains is really cool and it makes the experience of taming the beast of C++ enjoyable :)