Yes, which is why I would always use the second example for the print function. Edit: In fact it is possible to handle the cases explicitly while enforcing typ

Yes, which is why I would always use the second example for the print function. Edit: In fact it is possible to handle the cases explicitly while enforcing types by having the X-macros call functions in the switch/case and declaring prototypes via the macros: #define X(type, ...) void printSettings_ ## name(type); SETTINGS #undef X void printSettings(const Setting& s) { switch(s.tag) { #define X(type, name) \ case t_ ## type: printSettings_ ## name(s.name); break; SETTINGS #undef X } } Then you define printSettings_... and have them do stuff with the data.