c++ STL back_inserter() demo

#include <iostream>
#include <vector>

using namespace std;

int main()
{
int arr[] = { 1, 2, 3, 4 };
size_t array_size = sizeof(arr) / sizeof(*arr);
vector<int> ivec(arr, arr + array_size);

vector<int> ivec2;
copy(ivec.begin(), ivec.end(), back_inserter(ivec2));

for (vector<int>::iterator it = ivec2.begin(); it != ivec2.end(); ++it)
{
cout << *it << " ";
}
cout << endl;

return 0;
}