POC of custom conditional warnings exploiting C++26's expansion statements and deprecated attribute for compile-time debugging

I came up with this hacky trick for custom compiler warnings (not errors) that are conditional on a compile-time known bool. I know it is not the prettiest error message but it at least has all the relevant information to be useful for compile-time (print) debugging. Thought it would be cool to share here and please let me know if there is a better way to achieve this or if it can be achieved in C++23 or prior. Check it out here: https://godbolt.org/z/br6vGdvex

https://redd.it/1pr7dpm
@r_cpp