https://gcc.gnu.org/bugzilla/show_bug.cgi?id=127005
--- Comment #3 from Jan Engelhardt <jengelh at inai dot de> --- I think that, asking container<T> from within ~T about the properties of the container is undefined, and that only decltype(container)::reset() causes .has_value() to have a properly-observable state within ~T, namely false.
