Section-count.swift

// If rawValue is `Int`...
enum FizzBuzz: Int {
    case fizz
    case buzz

    static let count: Int = {
        var count = 0
        while let _ = FizzBuzz(rawValue: max) { count += 1 }
        return count
    }()
}

// Extension
protocol EnumCountable {
    static var count: Int { get }
}

extension EnumCountable where Self: RawRepresentable, Self.RawValue == Int {
    static var count: Int {
        var count = 0
        while let _ = Self(rawValue: count) { count += 1 }
        return count
    }
}

// If rawValue is not `Int`...
enum FizzBuzz: String {
    case fizz
    case buzz
    case count
}

FizzBuzz.count.hashValue