https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81395
--- Comment #6 from Paolo Carlini <paolo.carlini at oracle dot com> --- The relevant xsgetn code essentially is an optimization, right? Shouldn't be too difficult to figure out what would happen in the slow, correct case... What's wrong with a normal uncommitted case, thus _M_reading = false? Performance? Correctness?
