https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82272
--- Comment #4 from joseph at codesourcery dot com <joseph at codesourcery dot com> --- I should point out that expanding to the tokens 0 and 1 for C does not in any way prevent warning (it's a perfectly reasonable optional style warning); you could for example have the preprocessor specially mark the macros true and false when defined in stdbool.h in a system include directory, and then specially mark tokens resulting from their expansions so that the compiler can warn for dubious comparisons. So, whether or not the standard should require those exact token expansions, the standard does not prevent such warnings, though it may make them more complicated to implement.
