template <class T>  class actioncontainer  {  public:      //构造函数      actioncontainer()      {          m_nRedoPos = 0;          m_nUndoPos = 0;      }      //容器的接口函数      void add(T value);      T redo();      T undo();      //容器的属性  private:      int m_nRedoPos;      int m_nUndoPos;      const static int ACTION_SIZE=5;        T m_RedoAction[ACTION_SIZE];      T m_UndoAction[ACTION_SIZE];  };    template<class T>  void actioncontainer<T>::add(T value)  {      if (m_nUndoPos >= ACTION_SIZE)      {          //如果容器已潢，刚调整添加位置          m_nUndoPos = ACTION_SIZE - 1;          for(int i = 0; i < ACTION_SIZE; i++)          {              m_UndoAction[i] = m_UndoAction[i+1];          }      }      m_UndoAction[m_nUndoPos++] = value;  }    template<class T>  T actioncontainer<T>::redo()  {      //将恢复动作复制到撤销数组中      m_UndoAction[m_nUndoPos++] = m_RedoAction[--m_nRedoPos];        //返回恢复的动作      return m_RedoAction[m_nRedoPos];  }    template<class T>  T actioncontainer<T>::undo()  {      m_RedoAction[m_nRedoPos++] = m_UndoAction[--m_nUndoPos];        return m_UndoAction[m_nUndoPos];  }

// test_iostream.cpp : 定义控制台应用程序的入口点。  //  #include "StdAfx.h"  #include "main.h"  using namespace std;    int _tmain(int argc, _TCHAR* argv[])  {      actioncontainer<int> intaction;        //向容器中加动作      intaction.add(1);      intaction.add(2);      intaction.add(3);      intaction.add(4);        //撤销上一步动作      int nUndo = intaction.undo();      nUndo = intaction.undo();        //恢复      int nRedo = intaction.redo();      return 0;  }