C++ List Library - insert() Function

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Description

The C++ function std::list::insert() extends list by inserting new elements in the container. This member function increases size of the list.

Declaration

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

C++98

template <class InputIterator>
void insert (iterator position, InputIterator first, InputIterator last);

C++11

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

Parameters

• position − Position in the list where new element to be inserted.

• first − Input iterator to the initial position in range.

• last − Input iterator to the final position in range.

Return value

Returns an 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::list::insert() function.

#include <iostream>
#include <list>

using namespace std;

int main(void) {
   list<int> l1 = {3, 4, 5};
   list<int> l2 = {1, 2};

   l1.insert(l1.begin(), l2.begin(), l2.end());

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

   for (auto it = l1.begin(); it != l1.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