$ gcc -c rpmevr.h
$ g++ -c rpmevr.h
rpmevr.h:21: error: use of enum 'evrFlags_e' without previous 
declaration
rpmevr.h:21: error: invalid type in declaration before ';' token
rpmevr.h:22: error: use of enum 'evrFlags_e' without previous 
declaration
rpmevr.h:22: error: invalid type in declaration before ';' token

I know that RPM is a C library, but in this case it's easier to move it 
?
(something like http://www.algonet.se/~afb/rpm/rpm-4.4.9-evrflags.patch)

--anders

PS. It broke APT-RPM, that's why. (only RPM thing I know that uses C++)
     Most likely we need a check-header-use-from-C++-program unit test ?