Just as comparing apples and oranges is seen as a classic folly, comparing values from different enumerations against each other or converting them
into one another is nonsensical. True, at root enums are simply named numbers, and it’s certainly valid to compare numbers. But an added
layer of meaning is created by an enum, one that goes beyond simple numerical values.
Ignoring that extra layer of meaning is at best a trap for maintainers, who are likely to be hopelessly confused by the code. At worst, it is a
bug, which will lead to unexpected results.
Noncompliant code example
enum apple {BRAEBURN, FUJI, GRANNY_SMITH, RED_DELICIOUS};
enum orange {BLOOD, NAVEL, BITTER, BERGAMOT, MANDARIN};
void makeCider(apple v);
bool fun(apple v1, orange v2) {
makeCider((apple)v2); // Noncompliant
return v1 != v2; // Noncompliant
}
