In between the large static sections of "feature-test macros defined to a static value in C++X -or-later" we have sections of "feature test macros defined to Y in c++MEOW or Z in C++WOOF". For example:

These conditional sections have grown somewhat organically and have therefore become quite messy. I suggested in #2005 (comment) that we should reorder all such sections lexicographically by feature-test macro name. @AdamBucior suggests we should instead disable C4005 in the portion of <yvals_core.h> that defines feature-test macros to allow redefinitions so we can define everything consistently in the static sections.

The latter suggestion seems cleaner to me despite the need to suppress a warning, and should work fine with modules IIUC since the all definitions (both original and redefinitions) of each feature-test macro would appear in the same file.