https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91480
--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> --- (In reply to frankhb1989 from comment #0) > Also, in <bits/allocator.h>, `__cpp_lib_allocator_traits_is_always_equal` is > wrongly spelled as `__cpp_lib_allocator_is_always_equal`. This is incorrect. We *also* define __cpp_lib_allocator_traits_is_always_equal, in the appropriate places. So we have an extra, non-standard macro. We don't spell the standard one wrong. The allocator_is_always_equal spelling was present in http://open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4440.html#recs.cpp17 and in http://open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0096r0.html#detail.cpp17 but gone in http://open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0096r1.html#recs.cpp17
