I'm using Rust as a C replacement (I need speed and ability to produce libraries with a C ABI). To me Rust is "C with templates". Rust isn't an OO language in the same style as C++ (instead of inheritance it has trait polymorphism, which is nice, but doesn't always map to C++ design patterns).

I don't use C++, because for every thing that can be written in C++ there's always a more complex/clever version that should have been written instead.