I wrote C code with dispatch tables to implement "virtual functions" for structs with method calls .. those were local to a dot-c file, with corresponding exte

I wrote C code with dispatch tables to implement "virtual functions" for structs with method calls .. those were local to a dot-c file, with corresponding external dot-h interfaces defined.. all of that by my own design, for a framework for graphics programming .. in the early 90s. The techniques were known, just not common. Borland had great products, and was killed by "bloody means", by MSFT, in public view.