class Compare
{
public:
   Compare (int i) : _i(i){}
   //this does not compile, but what's the proper way to define
   // function object for the sort method in ptr_vector?
   bool operator<(const A& v1, const A& v2)
   {
      return (v1.i > v2.i) &&(_i != 1);
   }
private:
  int _i;
};