https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91356
--- Comment #7 from Marc Glisse <glisse at gcc dot gnu.org> --- (In reply to Jonathan Wakely from comment #6) > libstdc++ would not take > advantage of it because it would break the library's stable ABI. There is always this mode (is it _GLIBCXX_INLINE_VERSION? I thought I remembered a different name) that nobody uses, that doesn't care about binary compatibility, but can be used to experiment...