Convert RawRepresentable / enum to an Array

EnumToArray

import Foundation

protocol RawEnumerable: RawRepresentable {
    static var first: Self? { get }
}

extension RawEnumerable where RawValue == Int {

    static var first: Self? {
        guard let first = Self(rawValue: 0) else {
            fatalError("RawEnumerable must have a valid `first` case")
        }
        return first
    }

    static func cases(from startCase: Self? = Self.first, to endCase: Self? = nil) -> [Self] {
        var result: [Self] = []
        var rawValue = startCase?.rawValue ?? 0
        let endValue = endCase?.rawValue ?? .max
        while let caseValue = Self(rawValue: rawValue), rawValue <= endValue {
            result.append(caseValue)
            rawValue += 1
        }
        return result
    }

}

enum MyEnum: Int, RawEnumerable {
    case one, two, three, four, five, six
}

print(MyEnum.cases())
print(MyEnum.cases(from: .two))
print(MyEnum.cases(to: .three))
print(MyEnum.cases(from: .four, to: .five))