The Scope of Enumerators

The Scope of Enumerators

The members of an enumerated type are called enumerators. For example:

   enum Direction  {    Up, // an enumerator    Down // another enumerator  };  int main()  {}

An enumerator’s scope is the one enclosing the enumeration, not the enumeration itself. In other words, the identifiers Up and Down are defined in the global scope because the enumeration Direction is global. For this reason, you can’t use the these identifiers in other enumerations, as this will cause a name conflict:

   enum Mood  {    Up, // clashes with Direction's 'Up'    Down // clashes with Direction's 'Down'  };

To avoid such conflicts, you can declare an enum type in a more restricted scope rather than the global scope. For example, you can declare it in a class or in a namespace:

   namespace GUI  {    enum Direction    {       Up,       Down    };  }  GUI::Direction dir;  dir=GUI::Up; // unambiguous  


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