contract;
 
// Enums
// - Basics
// - Enums of structs
// - Enum of enums
 
enum Color {
    Red: (),
    Blue: (),
    Green: (),
}
 
// Enums of structs
struct Point {
    x: u64,
    y: u64,
}
 
enum Shape {
    Circle: (Point, u64),
    Triangle: [Point; 3],
}
 
// Enum of enums
enum Error {
    Auth: AuthError,
    Transfer: TransferError,
}
 
enum AuthError {
    NotOwner: (),
    NotApproved: (),
}
 
enum TransferError {
    TransferToZeroAddress: (),
    InsufficientBalance: (),
}
 
abi MyContract {
    fn test_func() -> Error;
}
 
impl MyContract for Contract {
    fn test_func() -> Error {
        let color = Color::Blue;
 
        let circle = Shape::Circle((Point { x: 0, y: 0 }, 1));
        let triangle = Shape::Triangle([
            Point { x: 0, y: 0 },
            Point { x: 1, y: 1 },
            Point { x: 2, y: 0 },
        ]);
 
        let error = Error::Auth(AuthError::NotOwner);
 
        error
    }
}