C++ Tutorial/STL Algorithms Modifying sequence operations/partition

#include <algorithm>
#include <vector>
#include <iostream>
using namespace std;
bool IsEven (const int& nNumber)
{
    return ((nNumber % 2) == 0);
}
int main ()
{
    vector <int> v;
    for (int nNum = 0; nNum < 10; ++ nNum)
        v.push_back (nNum);
    // a copy of the sample vector
    vector <int> vecCopy (v);
    // use stable_partition on the vecCopy - maintains relative order
    stable_partition (vecCopy.begin (), vecCopy.end (), IsEven);
    for (size_t nItem = 0; nItem < vecCopy.size (); ++ nItem)
        cout << vecCopy [nItem] << " ";
    return 0;
}