c# Stack 栈的实现

c# 中 Stack 栈的实现
from MSDN C# Language Specification
using System;
public class Stack
{
   private Node first = null;
   public bool Empty {
      get {
         return (first == null);
      }
   }
   public object Pop() {
      if (first == null)
         throw new Exception("Can't Pop from an empty Stack.");
      else {
         object temp = first.Value;
         first = first.Next;
         return temp;
      }
   }
   public void Push(object o) {
      first = new Node(o, first);
   }
   private class Node
   {
      public Node Next;
      public object Value;
      public Node(object value): this(value, null) {}
      public Node(object value, Node next) {
         Next = next;
         Value = value;
      }
   }
}

from:

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/csspec/html/vclrfcsharpspec_1_4.asp