Yep, plenty of C modules do hacks to block access except through the defined API. Most are content simply to use void pointers in public header files, but some

Yep, plenty of C modules do hacks to block access except through the defined API. Most are content simply to use void pointers in public header files, but some do nasty things like generating a random integer at library initialisation time and xor'ing all returned pointers by that number before returning it. (Eww.)