https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80635
--- Comment #17 from Martin Sebor <msebor at gcc dot gnu.org> --- The only way to avoid the warning in C (or std::optional) that I can think of is to somehow obscure the access to the boolean flag. Using volatile works but looks like it has a cost that users wouldn't be happy about. Using a relaxed __atomic_store/_load also works and the optimized code doesn't look as bad, at least not for the test case. Obviously, neither is pretty but might be worth looking into some more as a workaround.
