Description : insert() is a function in C++ STL which inserts new elements before the element at the specified position, effectively increasing the container size by the number of elements inserted.
Example:
// initialising the vector
std::vector<int> vec = { 10, 20, 30, 40 };
// inserts 5 at front
auto it = vec.insert(vec.begin(), 5);
std::cout << "The vector elements are: ";
for (auto it = vec.begin(); it != vec.end(); ++it)
std::cout << *it << " ";
std::cout << std::endl;