Boost::Polygon - Polygon 90 Set Concept de allocate memory

Question

I am using Boost::Polygon - Polygon 90 Set Concept to store a huge amount of rectangels. Unfortunately I cannot de allocate the memory after I am done.

Here is a minimal example. I'd like to de allocate the memory of the polygon set at a certain point. The clear() command does not de allocate (as mentioned in the docu).

Anyone an idea how to de allocate without running out of scope?

#include <iostream>
#include <boost/polygon/polygon.hpp>

// Namespaces
using namespace std;
namespace bp = boost::polygon;

// Typedefs
typedef bp::rectangle_data<int> bpRect;
typedef bp::polygon_90_set_data<int> bpPolygonSet;

int main()
{

  bpPolygonSet ps;

  cout << "Filling" << endl;     
  for (int i=0; i<10000000; i++){
    bpRect rect(i, i, i+1, i+1);
    ps.insert(rect);
  }

  // clear() does not de allocate
  ps.clear();      
  cout << "Cleared" << endl;     

  std::cin.get();   

  return 0;
}