https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118408
--- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> --- (In reply to Jonathan Wakely from comment #4) > (In reply to TC from comment #0) > - some programs consistently using the new ABI would get two identical > definitions of _Scanner member functions, but that just results in slightly > larger executables, the behaviour would be correct. > - programs consistently using the old ABI would be unaffected. > - programs using std::regex with both ABIs would no longer crash Some of them, no? Only if one rebuilds all the new ABI std::regex using objects with newer gcc. Anyway, I think changing it now could be fine. On the other side, was std::regex a thing in libstdc++ when we used to have just the old ABI (i.e. an era where building with the old ABI was the norm, rather than trying to do something really weird)?
