[Bug c/82272] RFE: request a warning for (<nonbool> == <bool>) etc.

[joseph at codesourcery dot com]

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.