let regex = try Regex(#"Hi, WWDC\d{2}!"#)

    let regex = /Hi, WWDC\d{2}!/

    @available(macOS 13.0, iOS 16.0, watchOS 9.0, tvOS 16.0, *)
    extension Regex {
        public init<Content>(@RegexComponentBuilder _ content: () -> Content) where Output == Content.RegexOutput, Content : RegexComponent
    }

    import RegexBuilder

    let regex = Regex {
        "Hi, WWDC"
        Repeat(.digit, count: 2)
        "!"
    }

    import RegexBuilder

    let regex = Regex {
        "Hi, WWDC"
        Repeat(.digit, count: 2)
        "!"
    }

    let input = "Hi, WWDC21! Hi, WWDC22! Hi Hello"

    let match1 = try regex.firstMatch(in: input)?.output // Hi, WWDC21!
    let match2 = input.firstMatch(of: regex)?.output // Hi, WWDC21!

    import RegexBuilder

    let regex = Regex {
        "Hi, WWDC"
        Repeat(.digit, count: 2)
        "!"
    }

    let input = "Hi, WWDC21! Hi, WWDC22! Hi Hello"

    let firstMatch: Regex.Match? = input.firstMatch(of: regex)
    print("First Matched: \(firstMatch?.output)")
    // First Matched: Optional("Hi, WWDC21!")
    
    let wholeMatch: Regex.Match? = input.wholeMatch(of: regex)
    print("Whole Matched: \(wholeMatch?.output)")
    // Whole Matched: nil
    
    let matches: [Regex.Match] = input.matches(of: regex)
    print("Matched: \(matches.map { $0.output })")
    // Matched: ["Hi, WWDC21!", "Hi, WWDC22!"]

    import RegexBuilder

    let regex = Regex {
        "Hi, WWDC"
        Capture {
            Repeat(.digit, count: 2)
        }
        "!"
    }

    let input = "Hi, WWDC21! Hi, WWDC22! Hi Hello"

    if let firstMatch = input.firstMatch(of: regex) {
        let (firstMatched, digits) = firstMatch.output
        print(firstMatched) // Hi, WWDC21!
        print(digits) // 21
    }