C# generic list copy with constructor

     
using System;
using System.Collections;
using System.Collections.Generic;
namespace Business.Web.Models {
    public class DtoMapper {
      // this is generic method replacing non-generic metod 
      // InvoiceDto_OLD provided in source below   
        public List<T2> Transform<T1,T2>(List<T1> i, Func<T1,T2> del)
        {
            List<T2> ret = new List<T2>();

            foreach (T1 val in i) {
                ret.Add(del(val));
            }
            return ret;
        }

        // generic method can be called as follows:
         public List<InvoiceDto> InvoiceDto(List<Invoice> i) {
            return Transform<Invoice,InvoiceDto> (i.ToList(),l=>new InvoiceDto(l));
         }

        //  this is sample of old non-generic method 
        public List<InvoiceDto> InvoiceDto_OLD(List<Invoice> i) {
            List<InvoiceDto> ret = new List<InvoiceDto>();

            foreach (Invoice invoice in i) {
                ret.Add(new InvoiceDto(invoice) );
            }
            return ret;
        }
    }
}
    

more...