list 迭代器随机范围内移动

Increments an iterator by a specified number of positions.

template<class InputIterator, class Distance>
   void advance(
      InputIterator& _InIt, 
      Distance _Off
   );

std::list<int> m_list; 
for( int i=0; i<10; i++ ) 
  m_list.push_back( i ); 
list<int>::iterator it = m_list.begin();
advance(it,9);
cout << *it << endl;