A clean representation of a semantic version number in swift so you can compare version numbers as if they were numbers

VersionNumber.swift

/**
 Represents a semantic version number in the form X.Y.Z
 
 Its most useful feature is that it implements `Comparable`
 making for easy comparison checks.
 */
struct VersionNumber {
    let version: String
    
    init(version: String) {
        self.version = version.ensureSemanticallyCorrect()
    }
    
    func compare(version: VersionNumber) -> NSComparisonResult {
        return self.version.compare(version.version)
    }
}

func <(lhs: VersionNumber, rhs: VersionNumber) -> Bool {
    return lhs.version.compare(rhs.version) == .OrderedAscending
}

func ==(lhs: VersionNumber, rhs: VersionNumber) -> Bool {
    return lhs.version.compare(rhs.version) == .OrderedSame
}

extension VersionNumber: Comparable {
}

extension String {
    /// make sure that we always have a semantic version in the form X.Y.Z
    func ensureSemanticallyCorrect() -> String {
        var comps = self
        for _ in componentsSeparatedByString(".").count..<3 {
            comps += ".0"
        }
        return comps
    }
}

extension VersionNumber: CustomStringConvertible {
    var description: String {
        return self.version
    }
}

usage

let upgradingToVersion = VersionNumber(version: "1.2.0")
let upgradingFromVersion = VersionNumber(version: "1.1.0")
if upgradingFromVersion < upgradingToVersion {
    //1.1.0 is less than 1.2.0 so our code will enter here
}