https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117785
--- Comment #28 from Hana Dusíková <hanicka at hanicka dot net> --- (In reply to Jakub Jelinek from comment #27) > (In reply to Hana Dusíková from comment #26) > > (In reply to Jakub Jelinek from comment #25) > > > In the end this is done only for classes derived from std::exception, to > > > match e.g. the verbose terminate handler at runtime. > > > > I wonder why? > > Jason Merrill asked for that during patch review: > https://gcc.gnu.org/pipermail/gcc-patches/2025-July/688997.html > "This will work for any class type with a what() method, which is > different from vterminate.cc that only calls what() for a type derived > from std::exception. I think it makes sense to be consistent with that; > a what() from an unrelated class might mean something different." Okay, what I tried (and failed to my limited knowledge of doing it lowlevel without AST present) is to allow any `constexpr const` overload of `what` without arguments which returns pointer to any char type or anything which has `.size()` and `.data()` returning pointer to any char type. Because then I can do the formatting only when `what()` is evaluated. But this interpretation of wording is also correct.
