[Bug preprocessor/48865] It would be useful to have a way to check the value of a #define at preprocessing time

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48865

--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> 2011-05-04 
12:11:04 UTC ---
Teach them to how to pipe the output of gcc -E -dD to grep, it'll do them good
in the long run.