tree.h is production-proven and available under a very liberal license (ISC). tree.h is also fairly extensively documented (e.g. https://man.openbsd.org/tree.3)

tree.h is production-proven and available under a very liberal license (ISC). tree.h is also fairly extensively documented (e.g. https://man.openbsd.org/tree.3); https://man.openbsd.org/tree.3); the only real footgun the API allows is documented under "NOTES". You are, of course, right that pointer-heavy data structures do not perform optimally on modern hardware. But I've still reached for tree.h quite a few times, because it gives you a very flexible data structure that Just Works with little fuss and minimal dependencies.