Even the code in the article makes heavy use of C++ features (templates, resource management) and that's not even talking about the Boost intrusive library that

Even the code in the article makes heavy use of C++ features (templates, resource management) and that's not even talking about the Boost intrusive library that gets mentioned, which is knee-deep in template effluvial... Never mind that I've seen plenty of C code with wrapping structs for data structures, too. Intrusive vs. non-intrusive is a design choice in both languages.