https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90239
--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> --- It appears that I am mistaken, the paper mentions the recursive handling of std::pair in the abstract. That change in semantics wasn't obvious from the proposed wording. So I just need to use the new functions in <scoped_allocator>, and correct the status docs for GCC 9.1
