std::list

list容器的倒序访问

// list::rbegin/rend
#include <iostream>
#include <list>

int main ()
{
  std::list<int> mylist;
  for (int i=1; i<=5; ++i) mylist.push_back(i);

  std::cout << "mylist backwards:";
  for (std::list<int>::reverse_iterator rit=mylist.rbegin(); rit!=mylist.rend(); ++rit)
    std::cout << ' ' << *rit;

  std::cout << '\n';

  return 0;
}

输出

mylist backwards:5 4 3 2 1 

list容器为空时的迭代结束条件

容器为空时，begin()==end()，rbegin()==rend()，所以不需要先判断是不是空，直接用rbegin()!=rend()来结束循环是没问题的， 这能够节省一些不必要的检查代码。

// list::rbegin/rend
#include <iostream>
#include <list>

int main ()
{
  std::list<int> mylist;

  std::cout << "mylist backwards:";
  for (std::list<int>::reverse_iterator rit=mylist.rbegin(); rit!=mylist.rend(); ++rit)
    std::cout << ' ' << *rit;

  std::cout << '\n';

  return 0;
}

输出

mylist backwards:

list容器insert示例

// inserting into a list
#include <iostream>
#include <list>
#include <vector>

int main ()
{
  std::list<int> mylist;
  std::list<int>::iterator it;

  // set some initial values:
  for (int i=1; i<=5; ++i) mylist.push_back(i); // 1 2 3 4 5

  it = mylist.begin();
  ++it;       // it points now to number 2           ^

  mylist.insert (it,10);                        // 1 10 2 3 4 5

  // "it" still points to number 2                      ^
  mylist.insert (it,2,20);                      // 1 10 20 20 2 3 4 5

  --it;       // it points now to the second 20            ^

  std::vector<int> myvector (2,30);
  mylist.insert (it,myvector.begin(),myvector.end());
                                                // 1 10 20 30 30 20 2 3 4 5
                                                //               ^
  std::cout << "mylist contains:";
  for (it=mylist.begin(); it!=mylist.end(); ++it)
    std::cout << ' ' << *it;
  std::cout << '\n';

  return 0;
}