Comment by SloopJon

Personally, I don't know what you mean about Rust being too massive. One thing I am wary of is using a truly massive language like C++ on a multi-programmer project without consensus on which features to use and how to use them. Maybe you have in mind something like that?

If you want the simplicity of C with more safety, maybe tooling like Frama-C, a MISRA C conformance checker, or just aggressive use of static and dynamic analysis tools like ASAN and UBSAN. You can also disable certain optimizations (e.g., strict aliasing) to steer away from some of the major pitfalls of UB.