C++ List Library - pop_front() Function


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Description

The C++ function std::list::pop_front() removes first element from list and reduces size of list by one.

Declaration

Following is the declaration for std::list::pop_front() function form std::list header.

C++98

void pop_front();

Parameters

None

Return value

None

Exceptions

This member function never throws exception. Calling this function on empty list causes undefined behavior.

Time complexity

Constant i.e. O(1)

Example

The following example shows the usage of std::list::pop_front() function.

#include <iostream>
#include <list>

using namespace std;

int main(void) {
   list<int> l = {1, 2, 3, 4, 5};

   cout << "List contains following elements before pop_back operation" << endl;

   for (auto it = l.begin(); it != l.end(); ++it)
      cout << *it << endl;

   l.pop_front();

   cout << "List contains following elements after pop_back operation" << endl;

   for (auto it = l.begin(); it != l.end(); ++it)
      cout << *it << endl;

   return 0;
}

Let us compile and run the above program, this will produce the following result −

List contains following elements before pop_back operation
1
2
3
4
5
List contains following elements after pop_back operation
2
3
4
5
list.htm
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