https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81395
--- Comment #10 from Paolo Carlini <paolo.carlini at oracle dot com> --- Yes, I agree with your analysis, something seems wrong. I suspsect going to a normal uncommitted mode, thus not setting _M_reading would largely work, but I fear performance implications, etc. I would strongly recommend analyzing next what can wrong if _M_reading remains false after that (a) reading operation...
