>you can write anything in C!
stdargs.h and by extension, stdio.h cannot be implemented using any version of the C standard, stdargs.h is a set of macros that that calls several compiler built-in functions, like __builtin_va_arg() in order to implement functions that take an arbitrary number of arguments, such as printf.
>>62372840
and what do you think the compiler and it's builtin functions come from?
furthermore when one says you can write anything in C usually it's just another way of saying it's turing complete
>>62372840
stdarg.h is part of the C language