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enum
Syntax:
  enum name {name-list} var-list;

The enum keyword is used to create an enumerated type named name that consists of the elements in name-list. The var-list argument is optional.

For example:

   enum color {red, orange, yellow, green, blue, indigo, violet};
   color c1 = indigo;
   if( c1 == indigo ) {
     cout << "c1 is indigo" << endl;
   }