Why do I get an error when directly comparing two enums?

Question

I have some code I\'m porting to a new platform, and it started giving me an error about comparing two enumerators from two different enumerator-lists. I\'m confused why it\'s g

Answer 1

This isn't a warning because of a standards compliance issue, it's one of those "this doesn't seem right" kind of warnings. If you think of the typical uses of enums, doing such a comparison doesn't make much sense in many cases. For example:

enum Day {
  Sunday,
  Monday,
  Tuesday,
  Wednesday,
  Thursday,
  Friday,
  Saturday
};

enum Month {
  January,
  February,
  March,
  April,
  May,
  June,
  July,
  August,
  September,
  October,
  November,
  December
};

enum Day day = Wednesday;
enum Month month = April; 

if (day == month) { ... }

This evaluates to true, but in general the comparison wouldn't make much sense. If you know you meant it, the typecast will convince the compiler, as you noted.