OOP in C
A whole book on this topic was already written in 1993 by Axel-Tobias Schreiner. It seems to be freely available nowadays:<p><a href="https://www.cs.rit.edu/~ats/books/ooc.pdf" rel="nofollow">https://www.cs.rit.edu/~ats/books/ooc.pdf</a><p>(edit: link updated to point to author's website)