Question

Just out of curiosity, asking this

Like the expression one below

a = (condition) ? x : y; // two outputs

why can’t we have an operator for enums?
say,

myValue = f ??? fnApple() : fnMango() : fnOrange(); // no. of outputs specified in the enum definition

instead of switch statements (even though refactoring is possible)

---

enum Fruit
{
    apple,
    mango,
    orange      
};

Fruit f = Fruit.apple;

---

Or is it some kind of useless operator?

Answer 1

I can’t say I’ve ever wanted such an operator – which would be incredibly brittle by relying on the ordering of the enum values. You can easily use a switch:

switch (f)
{
    case Fruit.Apple: myValue = fnApple(); break;
    case Fruit.Mango: myValue = fnMango(); break;
    case Fruit.Orange: myValue = fnOrange(); break;
    default: throw new ArgumentOutOfRangeException("f");
}

Alternatively, create a map:

static readonly Dictionary<Fruit, Func<Foo>> FruitFunctions = 
    new Dictionary<Fruit, Func<Foo>> {
    { Fruit.Apple, fnApple },
    { Fruit.Mango, fnMango },
    { Fruit.Orange, fnOrange }
};
...

myValue = FruitFunctions[f]();

I’ve used both techniques in various situations, and far prefer them to the suggested operator, I’m afraid.