public static (bool success, bool res) Parse(string str)
        {                
            if (string.Compare("true", str, true) == 0)
                return (true, true);
            return (false, false);
        }

      public class BaseRes { }
        public class None : BaseRes { }
        public class Some<T> : BaseRes
        {
            public T Value { get; private set; }
            public Some(T t)
            {
                Value = t;
            }
        }

        public static BaseRes ParseBool(string str)
        {
            if (string.Compare("true", str, true) == 0)
                return new Some<bool>(true);
            return new None();
        }