   public mutating func replaceAllMatching(pattern: String, with template: String) {
     replaceAllMatching(Regex(pattern), with: template)
   }
+
+
+
+  // MARK: Replacing all matches (nonmutating)
 
   /// Returns a new string where each substring matched by `regex` is replaced
   /// with `template`.

extension String {

  // MARK: Replacing the first match

  /// If `regex` matches at least one substring, replace the first match with
  /// `template`.

    return replacingFirstMatching(Regex(pattern), with: template)
  }



  // MARK: Replacing all matches (mutating)

  /// Replace each substring matched by `regex` with `template`.
  ///
