CODEWITHSUNDEEP
swiftenumeration
Janyee
Janyee

Reputation: 124

Type 'FileManager.SearchPathDirectory' does not conform to protocol 'CaseIterable' in Swift

I want to use CaseIterable on FileManager.SearchPathDirectory:

extension FileManager.SearchPathDirectory: CaseIterable {}

but I get the error: "Type 'FileManager.SearchPathDirectory' does not conform to protocol 'CaseIterable'".

I suspect that RawValue is causing the problem. Next step I tried to write an enum with RawValue:

struct My {
    enum Number: UInt {
        case One = 1
        case Two = 2
    }
}
extension My.Number: CaseIterable {}

for item in My.Number.allCases {
    print(item)
}

Seems to be no problem. In the second attempt, I added the protocol stubs:

extension FileManager.SearchPathDirectory: CaseIterable {
    public typealias AllCases = UInt
    public static var allCases: [Self] = [.adminApplicationDirectory, .allApplicationsDirectory, .desktopDirectory]
}

The problem remains. Does anyone know the solution?

Upvotes: 1

Views: 299

Answers (1)

Leo Dabus
Leo Dabus

Reputation: 236538

CaseIterable protocol only requires you to implement a static var allCases with a collection of all values of this type and an a associatedtype AllCases which is a type that can represent a collection of all values of this type.

The issue in your implementation is that your AllCases typealias should be a collection of FileManager.SearchPathDirectory which can be also written as [Self] instead of UInt:

extension FileManager.SearchPathDirectory: CaseIterable {
    public typealias AllCases = [Self]
    public static var allCases: AllCases = [.adminApplicationDirectory, .allApplicationsDirectory, .desktopDirectory]
}

for directory in FileManager.SearchPathDirectory.allCases {
    print(directory.rawValue)
}

This will print:

4
100
12

Upvotes: 1

Related Questions