C++

Reference

<queue>

queue

public member function
<queue>

std::queue::pop

void pop();
Remove next element
Removes the next element in the queue, effectively reducing its size by one.

The element removed is the "oldest" element in the queue whose value can be retrieved by calling member queue::front.

This calls the removed element's destructor.

This member function effectively calls the member function pop_front of the underlying container object.

Parameters

none

Return value

none

Example

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// queue::push/pop
#include <iostream>       // std::cin, std::cout
#include <queue>          // std::queue

int main ()
{
  std::queue<int> myqueue;
  int myint;

  std::cout << "Please enter some integers (enter 0 to end):\n";

  do {
    std::cin >> myint;
    myqueue.push (myint);
  } while (myint);

  std::cout << "myqueue contains: ";
  while (!myqueue.empty())
  {
    std::cout << ' ' << myqueue.front();
    myqueue.pop();
  }
  std::cout << '\n';

  return 0;
}
The example uses push to add a new elements to the queue, which are then popped out in the same order.

Complexity

Constant (calling pop_front on the underlying container).

Data races

The container and up to all its contained elements are modified.

Exception safety

Provides the same level of guarantees as the operation performed on the underlying container object.

See also

queue::push
Insert element (public member function)
queue::empty
Test whether container is empty (public member function)