[Python-Dev] Why aren't we allowing the use of C11?

Hi everyone, PEP 7 says that C code should conform to C89 with a subset of C99 allowed. It's 2021 and all the major compilers support C11 (ignoring the optional parts). C11 has support for thread locals, static asserts, and anonymous structs and unions. All useful features. Is there a good reason not to start using C11 now? Cheers, Mark.