https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91636
--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> --- There is no standard output because there's no standard build of GCC. The output depends how it's configured and built. On RHEL/CentOS 6 and 7 the devtoolset compiler only supports the old std::string implementation. If you want the new std::string you need to compile GCC yourself (and live with the fact all the system libraries use the old string) or use RHEL/CentOS 8.
