#include <iostream>
#include <boost/ptr_container/ptr_map.hpp>
 
struct Shape
{
  virtual ~Shape() = 0;
};
 
Shape::~Shape() {}
 
struct Triangle : Shape
{
};
 
struct Circle : Shape
{
};
 
int main()
{
  boost::ptr_map<int, Shape> map;
 
  int index = 0; // needed as insert takes key by non-const ref
  map.insert(index, new Triangle);
  index = 1;
  map.insert(index, new Circle);
 
  if (map.find(0) != map.end())
  {
    std::cout << "found";
  }
}

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