C++ List pop_back()

void  pop_back();

#include <iostream>
#include<list>
using namespace std;
int main()
{
   list<int> li={6,7,8,9};
   list<int>::iterator itr;
   li.pop_back();
   li.pop_back();
  for(itr=li.begin();itr!=li.end();++itr)
  cout<<*itr<<",";
  return 0;
}

6,7