https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100475
--- Comment #4 from 康桓瑋 <hewillk at gmail dot com> --- (In reply to 康桓瑋 from comment #3) > Also, the operator->() simply uses operator& instead of std::__addressof. > > https://godbolt.org/z/zfGnEoePG Another issue is that the has_value() of this specialization will always return true, which will make the precondition __glibcxx_assert(_M_pred.has_value()) for filter_view's begin() almost useless. Although it is not clear why semiregular-box is partial specialization in gcc-11, it is obvious that this needs to be treated with care.
