A while ago I made XXType (MatType, VecType etc) const char* I now think that was a mistake. I'd like to change them to just char* XXType and change the prototypes XXXSetType(XXXXX x,XXXType t) ------> XXXSetType(XXXXXX x,const XXXType t) XXXGetType(XXXXX x,XXXType *t) -----> XXXGetType(XXXXXX x,const XXTYPE* t) Can anyone suggest a technical reason why this is a bad idea before I push the code? I will warn before I push so that if you are in the middle of some delicate coding and are afraid this will break things you can avoid pulling for a while. Thanks Barry Note this means if you have code like VecType t = VECMPI; you would need to change it to const VecType t = VECMPI;