using System;

​

public static class Exts {    

        public static string Arr(this string self, params object[] args) 

        {

            return string.Format(self, args);

        }

        public static string Inst(this string self, int arg) 

        {

            return string.Format(self, arg);

        }

        public static string Obj(this string self, Object arg) 

        {

            return string.Format(self, arg);

        }    

}

​

public class App

{

    //[Bridge.Rules(Boxing = Bridge.BoxingRule.Managed)] 

    public static string ExtArrWithBoxingEnabled(DateTime i) 

    {

        return "{0:0000}".Arr(i.Month);

    }

    //[Bridge.Rules(Boxing = Bridge.BoxingRule.Managed)] 

    public static string ExtInstWithBoxingEnabled(DateTime i) 

    {

        return "{0:0000}".Inst(i.Month);

    }

    //[Bridge.Rules(Boxing = Bridge.BoxingRule.Managed)] 

    public static string ExtObjWithBoxingEnabled(DateTime i) 

    {

        return "{0:0000}".Obj(i.Month);

    }

    //[Bridge.Rules(Boxing = Bridge.BoxingRule.Managed)] 

    public static string RegularCallWithBoxingEnabled(DateTime i) 

    {

        return string.Format("{0:0000}",i.Month);

    }

    public static void Main()

    {

        var bug = 0;

        var x = new System.DateTime(2001, 2, 3);

        try {

            if (ExtArrWithBoxingEnabled(x) != "0002") {

                bug++;

                Console.WriteLine("[1] didn't get expected value");

            }

        } catch(Exception) {

            bug++;

            Console.WriteLine("[2] call failed");

        } 

        try {

            if (ExtInstWithBoxingEnabled(x) != "0002") {

                bug++;

                Console.WriteLine("[3] didn't get expected value");

            }

        } catch(Exception) {

            bug++;

            Console.WriteLine("[4] call failed");

        }

        try {

            if (ExtObjWithBoxingEnabled(x) != "0002") {

                bug++;

                Console.WriteLine("[5] didn't get expected value");

            }

        } catch(Exception) {

            bug++;

            Console.WriteLine("[6] call failed");

        }

        try {

            if (RegularCallWithBoxingEnabled(x) != "0002") {

                bug++;

                Console.WriteLine("[7] didn't get expected value");

            }

        } catch(Exception) {

            bug++;

            Console.WriteLine("[8] call failed");

        }

        Console.WriteLine("outcome: "+ (bug == 0 ? "success" : "error(s)"));

    }

}