Comment by flohofwoe

It's still not really wrong though. The C standard is just the minimal common feature set guaranteed by different C compilers, and even then there are significant differences between how those compilers implement the standard (e.g. the new C23 auto behaves differently between gcc and clang - and that's fully sanctioned by the C standard).

The actually interesting stuff happens outside the standard in vendor-specific language extensions (like the clang extended vector extension).