https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89452
--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> --- (In reply to Baykov Nikita from comment #0) > 4. pptr() is a null pointer. Paragraphs [stringbuf.cons]/3, > [streambuf.cons]/1, [stringbuf. members]/3 guarantee it. That's no longer true, see PR 80676. It's still true in the libstdc++ implementation today though.
