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#ifndef KML_BASE_REFERENT_H__
#define KML_BASE_REFERENT_H__

// This file contains the implementation of the Referent class which holds
// the reference counter used by boost::intrusive_ptr.  The Referent class
// is a base class of all KML DOM Elements and also the base TempFile
// class.  Neither the Referent class nor the methods here are part of the
// libkml public API.

namespace kmlbase {

// This class implements the reference count used by boost::intrusive_ptr.
class Referent {
 public:
  // The constructor only constructs the Referent object.  The reference
  // count is incremented if and when the Referent-derived object is assigned
  // to a boost::intrusive_ptr.
  Referent() : ref_count_(0) {}
  virtual ~Referent() {}

  // This method is used by intrusive_ptr_add_ref() to increment the reference
  // count of a given Referent-derived object.
  void add_ref() {
    ++ref_count_;
  }

  // This method is used by intrusive_ptr_release() to decrement the reference
  // count of a given Referent-derived object.
  int release() {
    return --ref_count_;
  }

  // This is for debugging purposes only.
  int get_ref_count() const {
    return ref_count_;
  }

 private:
  int ref_count_;
};

// These declarations are for the implementation of the functions used within
// boost::intrusive_ptr to manage Referent-derived objects..  See referent.cc
// and boost/intrusive_ptr.hpp.
void intrusive_ptr_add_ref(kmlbase::Referent* r);
void intrusive_ptr_release(kmlbase::Referent* r);

} // end namespace kmlbase

#endif  // KML_BASE_REFERENT_H__