Im trying to write an extension for an enum that is CaseIterable so that i can get an array of the raw values instead of the cases, Im not entirely sure how to do that though
extension CaseIterable {
static var allValues: [String] {
get {
return allCases.map({ option -> String in
return option.rawValue
})
}
}
}
i need to add a where clause somehow, if i dont have a where clause i get an error saying 'map' produces '[T]', not the expected contextual result type '[String]'
Anyone know if there is a good way of going about this?
my enums i want this function to work on look a bit like this
enum TypeOptions: String, CaseIterable {
case All = "all"
case Article = "article"
case Show = "show"
}
Not all enumeration types have an associated RawValue, and if they have then it is not necessarily a String.
Therefore you need to restrict the extension to enumeration types which are RawRepresentable, and define the return value as an array of RawValue:
extension CaseIterable where Self: RawRepresentable {
static var allValues: [RawValue] {
return allCases.map { $0.rawValue }
}
}
Examples:
enum TypeOptions: String, CaseIterable {
case all
case article
case show
case unknown = "?"
}
print(TypeOptions.allValues) // ["all", "article", "show", "?" ]
enum IntOptions: Int, CaseIterable {
case a = 1
case b = 4
}
print(IntOptions.allValues) // [1, 4]
enum Foo: CaseIterable {
case a
case b
}
// This does not compile:
print(Foo.allValues) // error: Type 'Foo' does not conform to protocol 'RawRepresentable'