Learning any of C, C++, Rust or other systems languages takes way, way more than a week or a month. For C, the simplest of the three, it is usually rated at 3 m

Learning any of C, C++, Rust or other systems languages takes way, way more than a week or a month. For C, the simplest of the three, it is usually rated at 3 months. What happens is that if you are already proficient in one of them, one of the others takes way less time (specially in the case of C++, given it forces you to learn almost all paradigms). In addition, writing a small program does not mean you have learnt C, C++ or Rust.