>>23
1. not a feature of C
2. warning in both C and C++, can be ignored
3. your code doesnt work, supposed to be ++d, day_of_week is a type, strict type checking, not a problem, quit whining
4. strict type checking, not a problem, quit whining
5. cross initialisation, not a problem, quit whining
so your so called useful stuff is a bunch of useless shit, congrats