Strong disagree. Unless you're using it as "C with classes", C++ is a nightmare hell language that you should only use if you're forced to by your environment. Stay far away.
C is a fine language, but it is from the 60s and 70s and feels like it. Rust is very nice, although poor for half-assed prototyping (which is actually maybe a good thing). Both are fine choices for systems-level programming.
Yes, I'd say at worst its 20% slower. The implementation is naive and readable (and therefor hackable). I did not have the time to implement all the heuristics that make STL as fast as it. The goal is hackability and ease of use (think text book function examples), while giving embedded engineers (or even desktop engineers with an aversion to C++) a chance to focus on getting their work done.
That, and lighting fast compile times, where programming feels like (oh, the heresy) a _drastically reduced C++_.
C is a fine language, but it is from the 60s and 70s and feels like it. Rust is very nice, although poor for half-assed prototyping (which is actually maybe a good thing). Both are fine choices for systems-level programming.