You're absolutely correct, boost::preprocessor has an obligation towards backwards compatibility that independent efforts do not. This obligation is a double-ed

You're absolutely correct, boost::preprocessor has an obligation towards backwards compatibility that independent efforts do not. This obligation is a double-edged sword: when I pick a library, I want it to be modern; 5 years later, I shouldn't be forced to refactor my code to match a library update. There's a good parallel here with boost::python vs. pybind11; there's always room for more and newer entrants, but most of them will not overcome the first-mover advantage. On the boost front, I should have noted the difference between VMD [1] and boost::preprocessor [2]. I think VMD [1] trades some backwards compatibility for coherence and consistency and is a better starting point for new code. [1]: https://www.boost.org/doc/libs/1_70_0/libs/vmd/doc/html/index.html https://www.boost.org/doc/libs/1_70_0/libs/vmd/doc/html/inde... [2]: https://www.boost.org/doc/libs/1_76_0/libs/preprocessor/doc/index.html https://www.boost.org/doc/libs/1_76_0/libs/preprocessor/doc/...