Besides what I've already said about Rust in the past¹, the only thing that I understand Rust has over C++ is additional cross-checks, performed at every compilation. In C++ these kind of additional expensive operations are covered by optional 3rd party tools, in this particular case by static code analyzers. There is a good (i.e. useful) reason to engineer the compilation in such separate steps. Of course, the option of having the entire batch of operations tightly integrated has benefits (as well as drawbacks), but that's just about it.