[Bug libstdc++/71771] DR 685 applied incorrectly

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71771

--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> ---
But we do have greedy_ops::operator- defined in
testsuite/util/testsuite_greedy_ops.h  ... drat.