别人写的一个环缓冲类，比较简洁，也没有平台相关。没有测试有没有BUG，仅供参考

 /*-------------------------
  * Author: XadillaX       |
  * Data: 2010/10/3        |
  * Class: CircleBuffer    |
  *------------------------|---*/
  
 #ifndef CircleBuffer_H
 #define CircleBuffer_H
  
 #ifndef SAFEDEL(p)
   #define SAFEDEL(p) { delete p; p = NULL; }
 #endif
  
 /*
  * 类：环形缓冲区
  */
 template<typename ElemType>
 class CircleBuffer {
 private:
     ElemType *Arr;
     int _l;
     int _c;
     int _size;
     int _cnt;
  
     int conv(int i);
 public:
     CircleBuffer(int MaxSize = 65535);
     ~CircleBuffer();
  
     bool push(ElemType ele);
     void clear();
     bool pop(ElemType &ele);
     bool empty();
     int count();
     int GetSize();
 };
  
 /*
  * 实现环形缓冲区
  */
 template<typename ElemType>
 CircleBuffer<ElemType>::CircleBuffer(int MaxSize) : _size(MaxSize)
 {
     if(_size < 1) _size = 1;
     Arr = new ElemType[MaxSize];
     _l = _c = _size - 1;
     _cnt = 0;
 }
  
 template<typename ElemType>
 CircleBuffer<ElemType>::~CircleBuffer()
 {
     delete []Arr;
     Arr = NULL;
 }
  
 template<typename ElemType>
 int CircleBuffer<ElemType>::conv(int i)
 {
     return (i < _size) ? i : 0;
 }
  
 template<typename ElemType>
 bool CircleBuffer<ElemType>::push(ElemType ele)
 {
     if(_cnt < _size)
     {
         _l = conv(_l + 1);
         Arr[_l] = ele;
         _cnt++;
  
         return true;
     }
     else return false;
 }
  
 template<typename ElemType>
 bool CircleBuffer<ElemType>::pop(ElemType &ele)
 {
     if(_cnt == 0) return false;
     else
     {
         _cnt--;
         _c = conv(_c + 1);
         ele = Arr[_c];
         return true;
     }
 }
  
 template<typename ElemType>
 int CircleBuffer<ElemType>::count()
 {
     return _cnt;
 }
  
 template<typename ElemType>
 bool CircleBuffer<ElemType>::empty()
 {
     if(!_cnt) return true;
     else return false;
 }
 
 template<typename ElemType>
 int CircleBuffer<ElemType>::GetSize()
 {
     return _size;
 }
  
 template<typename ElemType>
 void CircleBuffer<ElemType>::clear()
 {
     _l = _c = _size - 1;
     _cnt = 0;
 }
 #endif