I've been wondering about debug-ability of code using reflection. X-Macros are quite annoying to step through in most debuggers, though possible. While the code in the first example is evaluated fully at compile-time, how would you approach debugging it?

Nothing that makes it straightforward. Testing via `static_assert` is a good strategy, but it's not debugging. I believe there are some ways of printing custom diagnostics during compilation, but I am not aware of any step-by-step debugging tool that runs at compile-time.

In practice, I haven't really needed to ever debug `consteval` functions -- it's quite easy to get the right behavior down thanks to `static_assert`-based testing and thanks to the fact that they do not depend on external state (simpler).

I mean it's still C++ that's compiled and executed, surely the compiler would be able to provide a way to hook into that?