[a1369209993]

Nope, printf is a regular function - regular functions can use varargs just fine.

And it's C; everything bypasses the type system and says "trust me". Memory allocation bypasses the type system and says "trust me".

  struct foo* foo = malloc(sizeof foo);
  // yep, this is definitely the right number of bytes

If you want strong typing (!= static typing), C is not the language you should be using, printf or no printf.