Template method : Generic IEnumerator : Generic C# Examples

    
/*Quote  from:  

Book  Accelerated  C#  2005
        *  By  Trey  Nash
        *  ISBN:  1-59059-717-6
        *  432  pp.
        *  Published:  Aug  2006
        *  Price:  $39.99


*/


using  System;
using  System.Collections.Generic;

public  class  MyContainer<T>  :  IEnumerable<T>
{
        public  void  Add(  T  item  )  {
                impl.Add(  item  );
        }

        //  Converter<TInput,  TOutput>  is  a  new  delegate  type  introduced
        //  in  the  .NET  Framework  that  can  be  wired  up  to  a  method  that
        //  knows  how  to  convert  the  TInput  type  into  a  TOutput  type.
        public  void  Add<R>(  MyContainer<R>  otherContainer,Converter<R,  T>  converter  )  {
                foreach(  R  item  in  otherContainer  )  {
                        impl.Add(  converter(item)  );
                }
        }

        public  IEnumerator<T>  GetEnumerator()  {
                foreach(  T  item  in  impl  )  {
                        yield  return  item;
                }
        }

        System.Collections.IEnumerator  System.Collections.IEnumerable.GetEnumerator()  {
                return  GetEnumerator();
        }

        private  List<T>  impl  =  new  List<T>();
}

public  class  EntryPoint
{
        static  void  Main()  {
                MyContainer<long>  lContainer  =  new  MyContainer<long>();
                MyContainer<int>  iContainer  =  new  MyContainer<int>();

                lContainer.Add(  1  );
                lContainer.Add(  2  );
                iContainer.Add(  3  );
                iContainer.Add(  4  );

                lContainer.Add(  iContainer,
                                                EntryPoint.IntToLongConverter  );

                foreach(  long  l  in  lContainer  )  {
                        Console.WriteLine(  l  );
                }
        }

        static  long  IntToLongConverter(  int  i  )  {
                return  i;
        }
}