std::advance 给迭代器增加指定偏移量

template < class InputIterator, class Distance >
void advance (InputIterator& it, Distance n);
迭代器辅助函数。
使迭代器it偏移n，其中n为整数。

#include <iostream>     // std::cout#include <iterator>     // std::advance#include <list>         // std::listint main () {  std::list<int> mylist;  for (int i=0; i<10; i++) mylist.push_back (i*10);  std::list<int>::iterator it = mylist.begin();  std::advance (it,5);  std::cout << "The sixth element in mylist is: " << *it << '\n';   std::advance (it,-1);  std::cout << "The fifth element in mylist is: " << *it << '\n';   return 0;}

The sixth element in mylist is: 50
The fifth element in mylist is: 40