C++ Forward_list Library - insert_after() Function

Description

The C++ function std::forward_list::insert_after() extends iterator by inserting range of elements after position in forward_list. This member function increases size of the forward_list.

Declaration

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

C++11

template <class InputIterator>
iterator insert_after ( const_iterator position, InputIterator first, InputIterator last );

Parameters

• position − Position in the forward_list after which new element to be inserted.

• first − Iterator to the initial position.

• last − Iterator to the final position.

Return value

Returns a random access iterator which points to the newly inserted element.

Exceptions

If reallocation fails bad_alloc exception is thrown.

Time complexity

Linear i.e. O(n)

Example

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

#include <iostream>
#include <forward_list>

using namespace std;

int main(void) {

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

   fl2.insert_after(fl2.begin(), fl1.begin(), fl1.end());

   cout << "List 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 contains following elements
1
2
3
4
5