タプルのネストも可能

   class Program
    {
        static void Main(string[] args)
        {
 
            var users = new List<
                (int No,
                (string firstName,string secondName) Name
                ,int age
                ,string gender)>();
 
            users.Add((1,
                ("Tanaka", "Hisashi"),
                19,
                "Male"));
 
            foreach (var user in users)
            {
                Console.WriteLine(user.Name.firstName + user.Name.secondName);
            }
 
            Console.ReadLine();
        }
    }