.front() c++
// queue::front
#include <iostream>       // std::cout
#include <queue>          // std::queue
int main ()
{
  std::queue<int> myqueue;
  myqueue.push(77);
  myqueue.push(16);
	cout << myqueue.front();
  myqueue.front() -= myqueue.back();    // 77-16=61
  std::cout << "myqueue.front() is now " << myqueue.front() << '\n';
  return 0;
}
