[eesmith]

From the C99 draft at https://www.open-std.org/jtc1/sc22/wg14/www/docs/n1256.pdf :

"A string is a contiguous sequence of characters terminated by and including the first null character. .. The length of a string is the number of bytes preceding the null character"

This means, for example, strlen() must always check for the location of the first null character - there's no advantage to checking the length.

How would this work?

  void *x = malloc(8);

   ...
  uint64_t i = 5216694956355289088; // Python: int.from_bytes(b'Hello!\0\0')
  memcpy(x, &i, 8);
  char *s = x;
  puts(s);

Assuming I did it correctly, this should print "Hello!".

When the length get added to the start of the string?