I think you meant thanks to a sane(r) macro system? Both Rust and C++ use monomorphisation for generics, I believe shitty compiler errors are due to C++'s templating.
I’m what way can you have ‘generics’ in C++ that are not based on templating? I am almost certain that any implementation of anything ‘generic’ templates are inherently involved. Maybe I’m wrong about what you mean by generics though.