which c++ compiler for HP-UX OIC?

IDS 7.31.UC2 HP K260 4 way HP-UX 10.20 I am about to purchase an HP-UX C++ compiler so that I can use the OIC Object Interface for C++ product. (Of course I would rather use g++, but g++ libraries are apparently a lost cause w/ Informix). My question: In order to use OIC, do I need the HP C++ compiler that is based on the AT&T Cfront compiler, or do I need the newer HP aC++ compiler? Both are available. The two compilers are apparently not binary compatible. Which one does Informix want? Any help appreciated. Allen PS - for HP shops, there is good info on the 2 compilers at http://www.hp.com/esy/lang/cpp/tguide/transcontent.html#RN.CVT.1.1