In my project I include stddef.h but find error on __CX2__
it's a bug or not
I try to modify it to #if defined (__CX2__) and passed.
what mains about __CX2__ ?
They are also at the very end of the list of diagnostics - which suggests they are (relatively) new and, perhaps, relatively untested...
Maybe this was actually a test-case for warning 322 that slipped into the release...
;-)