public Calendar UpdateCalendar(CalendarDay cDay)
{
Calendar tmpCal = (Calendar)this.Clone();
tmpCal.calendarDays[cDay.day - 1] = cDay;
return(tmpCal);
}
static void Main(string[] args)
{
CalendarDay[] cd = new CalendarDay[7];
cd[0] = new CalendarDay(1, 1, "meeting");
cd[1] = new CalendarDay(2, 1, "tests");
cd[2] = new CalendarDay(3, 1, "review");
Calendar baseCal = new Calendar(cd);
System.Console.WriteLine("Original");
baseCal.Print();
Calendar personalCal = baseCal.UpdateCalendar(new CalendarDay(1, 1, "urgent flight"));
System.Console.WriteLine("Updated = new (Immutable)");
personalCal.Print();
System.Console.WriteLine("Original is still alive");
baseCal.Print();
System.Console.Read();
}