I learnt it at university back then, but I had already toyed with C++11 so I always made puns and called what they were teaching C--. Essentially they were teaching a very old version and the evaluation machines ignored all the "modern" bits back then.
My idea is to either C++20 (not sure if there is a resource to learn directly from C++20 or if there are compilers supporting it) or Rust, personally I would go for C++ seeing as there's a wider ecosystem and tools out there, lots of libraries (which are a bit of a pain to use sometimes) and it is almost anywhere.
But to be fair, I am out of the loop of C++/Rust and what I see in my internet circles is Rust > C++ mostly because of the memory safety; which makes me wonder if it is worth or not; also lots of C++ hate which reminds me of PHP.
By the end of the day your employer will decide which language/version is to be used on a project, so you should check with your employer. That said, even C++98/03 is well an alive; as a consultant I still see a lot of industry projects using C++98/03, some with a few elements of C++11; I rarely see C++17 and never see Rust projects.
My idea is to either C++20 (not sure if there is a resource to learn directly from C++20 or if there are compilers supporting it) or Rust, personally I would go for C++ seeing as there's a wider ecosystem and tools out there, lots of libraries (which are a bit of a pain to use sometimes) and it is almost anywhere.
But to be fair, I am out of the loop of C++/Rust and what I see in my internet circles is Rust > C++ mostly because of the memory safety; which makes me wonder if it is worth or not; also lots of C++ hate which reminds me of PHP.
I just have a hard time making decisions.