https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94268
--- Comment #5 from fdlbxtqi <euloanty at live dot com> --- Here is the proof. https://bitbucket.org/ejsvifq_mabmip/fast_io/src/reserver_test/benchmarks/0000.10m_size_t/unit/streambuf_io_observer___gnu_cxx_stdio_filebuf.cc
