C++ Forward_list Library - push_front() Function

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Description

The C++ function std::forward_list::push_front() inserts new element at the beginning of the forward_list and increases size of forward_list by one.

Declaration

Following is the declaration for std::forward_list::push_front() function form std::forward_list header.

C++11

void push_front (value_type&& val);

Parameters

val − Value of element to be inserted into forward_list.

Return value

None

Exceptions

This member function never throws exception.

Time complexity

Linear i.e. O(n)

Example

The following example shows the usage of std::forward_list::push_front() function.

#include <iostream>
#include <forward_list>

using namespace std;

int main(void) {

   forward_list<int> fl1 = {1, 2, 3, 4, 5};
   forward_list<int> fl2;

   for (auto it = fl1.begin(); it != fl1.end(); ++it)
      fl2.push_front(move(*it));

   cout << "List fl2 contains following elements" << endl;

   for (auto it = fl2.begin(); it != fl2.end(); ++it)
      cout << *it << endl;

   return 0;
}

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

List fl2 contains following elements
5
4
3
2
1