Emitting messages at compile time with std::format
R0[[P2758R5] (Emitting messages at compile time)](https://wg21.link/p2758r5) is still working its way through the committee, but in the meantime [[P3391R2] (constexpr std::format)](https://wg21.link/p3391r2) has been adopted for C++26. Which means that the former paper can continue to just provide the lower level interface that accepts `std::string_view` while this paper can provide the more complex formatting API that is built on top of `std::format`.