Nothing, if new standards are opted in via a #pragma.
I'm not sure that's this easy, because of the copy-and-paste nature of C's "libraries" via pre-processor #include directives.
Not really. We already have `#pragma once` which is per-file, not per-translation-unit.
Why do you think that would be necessary?
It's the only way to really solve the problem. Simply creating a safer alternative won't help, they already exist. The real problem is the vast ocean of already existing critical unsafe code
The whole reason C code is used is that it can be used for free. In other words, infinitely more than they're spending now. More than even the CCP is willing to spend to protect state secrets.