I think the biggest reasons to go with c++ over rust would be mature compilers and the relative abundance of mature libraries, and possibly your existing knowledge of the language.
It seems like the bigger question is what are the goals of your project(s)? Like if gaining more experience with rust is a primary goal, then the aforementioned advantages are pretty much moot. OTOH if a project could benefit a lot from leveraging mature compilers and libraries, or if you can't afford the additional time investment associated with becoming proficient with a new language, then c++ may well make more sense.
It seems like the bigger question is what are the goals of your project(s)? Like if gaining more experience with rust is a primary goal, then the aforementioned advantages are pretty much moot. OTOH if a project could benefit a lot from leveraging mature compilers and libraries, or if you can't afford the additional time investment associated with becoming proficient with a new language, then c++ may well make more sense.