I do not know how to solve the problem you described, but another way of speeding up a switch statement might be using the GCC extension "Labels as Values". http://gcc.gnu.org/onlinedocs/gcc/Labels-as-Values.html You can retain compatibility to standard C by writing two versions of the code, one which uses GCC extension and which does not. Your reaction_t would be an enum for standard C and a void * for gcc. I am using this trick for my python-like Generator class with iterator interface (http://vc.falma.de/cfc/tree/cfc/generator.hh) Would this help? Christoph
