https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106798
--- Comment #1 from 康桓瑋 <hewillk at gmail dot com> --- (In reply to 康桓瑋 from comment #0) > __i[__j] requires random_access_iterator, which is unnecessary. In fact it's just a typo, it should be _M_current[__j] = std::move(__i._M_current[__j]);