#include <boost/range/adaptor/indirected.hpp>
#include <list>

class Derived;

template<class T>
class Base
{
public:
  T&
  get()
  {
	return x_;
  }

protected:
  typedef std::list<Derived*> DerivedList;
  typedef boost::indirected_range<DerivedList> DerivedRange;

  DerivedRange
  range()
  {
	return DerivedRange(l_);
  }

  DerivedList l_;
  T x_;
};