Swift Enumeration order and comparison

Question

I\'ve had trouble finding/understanding documentation on how to compare enums in Swift by their order of definition. Specifically when I create an enumeration such as

Answer 1

This is to some extent the same answer as the OP proposed himself. It does involve a bit of boilerplate code for every enum that you want to be comparable, but I prefer this than having some external magic function that provides comparable to all enums. That can cause problems if you do a quick copy-and-paste from one program to another, and then the enum doesn't work and you can't remember why.

public enum LogLevel: Int, Comparable {
    case verbose
    case debug
    case info
    case warning
    case error
    case severe

    // Implement Comparable
    public static func < (a: LogLevel, b: LogLevel) -> Bool {
        return a.rawValue < b.rawValue
    }
}

EDIT:

This is in response to a comment by @JasonMoore.

Comparable does not require ==. That is required by Equatable, and the Swift standard library automatically provides Equatable for most kinds of enums.

http://www.jessesquires.com/blog/swift-enumerations-and-equatable/

As for >, <= and >=, the Apple documentation says that they are required by Comparable, but that a default implementation is provided (based on use of == and <, I assume).

https://developer.apple.com/documentation/swift/comparable

Here's a bit of code that I ran in the IBM Swift Sandbox - it compiles and runs fine with the above definition.

let a : LogLevel = LogLevel.verbose
let b : LogLevel = LogLevel.verbose
let c : LogLevel = LogLevel.warning

print(a == b)  // prints true
print(a > c)  // prints false
print(a <= c)  // prints true