Amzd

extension String? {
    /// This property is true on encountering one of "Y", "y", "T", "t", or a digit 1-9—the method ignores any trailing characters.
    /// This property is false if the receiver doesn’t begin with a valid decimal text representation of a number.
    ///
    /// The property assumes a decimal representation and skips whitespace at the beginning of the string. 
    /// It also skips initial whitespace characters, or optional -/+ sign followed by zeroes.
    var yN: Bool { if let self { NSString(string: self).boolValue } else { false } }
    /// This property is true when it is empty (or nil) or when yN is true
    var Yn: Bool { (self?.isEmpty ?? true) || yN }
}

Amzd

/// https://gist.github.com/Amzd/93f2e7b4712242ec4e17476146f528a2
public struct Version: Codable {
    public var major: UInt
    public var minor: UInt
    public var patch: UInt
    public var identifier: String?

    public var stringValue: String {
        "\(major).\(minor).\(patch)" + (identifier.flatMap { "-\($0)" } ?? "")
    }