https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94924
--- Comment #2 from rhalbersma <rhalbersma at gmail dot com> --- OK, Alisdair Meredith points out on Twitter that in [class.compare.default]/6 there is a special sentence on array class data members In that list, any subobject of array type is recursively expanded to the sequence of its elements, in the order of increasing subscript. So only direct array comparisons are deprecated.