C++26 will not be perfect. You might want to watch Herb Sutter‘s recently uploaded talk https://youtu.be/kKbT0Vg3ISw to get some ideas how to implement your ideas with reflection. It will not be perfect. However, your proposal would target C++29 and we‘ll have much better reflection support in C++29. I believe a good library-based solution using C++29 reflection should be possible by then.