subscript property using enum String failing with 'Cannot assign value of type <enumType> to type AnyObject'

Question

I've got a class with a subscript property (it inherits from another class that takes type 'AnyObject' in a subscript).

public var payFrequency: PayFrequency {
    get { return self["payFrequency"] as? PayFrequency ?? .Weekly }
    set(value) { self["payFrequency"] = value }
}

The compiler complains that I:

Cannot assign value of type 'PayFrequency' to type AnyObject

When I try to cast value to AnyObject:

set(value) { self["payFrequency"] = value as? AnyObject }

...it compiles, but fails to set the value to anything (when I get the variable, it always returns the default .Weekly).

Here's the enum:

public enum PayFrequency: String {
    case Weekly = "weekly"
    case SemiMonthly = "semi-monthly"
    case BiWeekly = "bi-weekly"
    case Monthly = "monthly"
}

How can I get this enum to work with AnyObject, OR how can I update the getter/setter of the subscript to properly store the enum value?

Answer 1

AnyObject is not compatible with enums, as enums are value types, while AnyObject corresponds to a reference.

You can try using NSString for the enum declaration, and use it's raw value within the property.

public enum PayFrequency: NSString {

public var payFrequency: PayFrequency {
    get { return PayFrequency(rawValue: self["payFrequency"] as? String ?? "") ?? .Weekly }
    set(value) { self["payFrequency"] = value.rawValue }
}

or keep the enum declaration the same, Swift should be able to bridge between String and NSString.