I understand that given you are listing Rust alongside Solidity, your interest might be in cryptocurrencies, but I still thought this might be worth to ask.

I'm very experienced in C++98, less so in C++11 and successors as I spent most of my time on other languages this decade (OCaml, Scala and R). C++11 is much more modern and appealing, so I'm wondering whether I should update my C++ skills, learn Julia, learn Rust, or a combination of those.