using System;

public class Program

{

    public static void Main()

    {

        // wrapper class

        Base64String s1 = "";

        GenericClass<Base64String> test0 = new GenericClass<Base64String> {     

            Foo = ""

        };

        // named tuple (2nd param is required but can be ignored :-/)

        //(string Base64, string _) t2 = ("", "");

        //var y = t2.Base64;

        GenericClass<(string Base64, string _)> test2 = new GenericClass<(string Base64, string _)> {       

            Foo = new ("", "nop")

        };

        // 1-value tuple (but not named)

        //ValueTuple<string> t1 = new ("");

        //var x = t1.Item1;

        GenericClass<ValueTuple<string>> test1 = new GenericClass<ValueTuple<string>> {     

            Foo = new ("")

        };

    }

    public class GenericClass<T> {

        public T Foo {get;set;}

    }

    public class Base64String {

        //TODO equality

        public Base64String(string variant)

        {

            Value = variant;

        }

        public string Value { private set; get; }

        public static implicit operator Base64String (string m)

        {

            return new Base64String(m);

        }

​

        public static implicit operator string (Base64String m)

        {

            return m.Value;

        }

    }

}