Unscoped (or Plain or C-Style) Enumerations Plain (or C-style) enums are entered in the same scope as the name of their enum, and implicitly convert to their integer value, e.g.
enum Color { red, green, blue }; int col = green; Color c2 = 1; // error: invalid conversion from 'int' to 'Color' [-fpermissive] enum CardColor { red, black }; // Error: "red" conflicts with a previous declaration...