queue::front


public member function
      value_type& front ( );
const value_type& front ( ) const;

Access next element

Returns a reference to the next element in the queue. This is the "oldest" element in the queue and the same element that is popped out from the queue if member queue::pop is called.

This member function effectively calls the member with the same name in the underlying container object.

Parameters

none

Return value

A reference to the next element in the queue.

Member type value_type is defined to the type of value contained by the underlying container, which shall be the same as the first template parameter (T).

Example

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// queue::front
#include <iostream>
#include <queue>
using namespace std;

int main ()
{
  queue<int> myqueue;

  myqueue.push(77);
  myqueue.push(16);

  myqueue.front() -= myqueue.back();    // 77-16=61

  cout << "myqueue.front() is now " << myqueue.front() << endl;

  return 0;
}


Output:
myqueue.front() is now 61


Complexity

Constant.

See also

queue::pop Delete next element (public member function)
queue::back Access last element (public member function)