text: // Copyright David Abrahams and Gottfried Ganssauge 2003. Permission
  // to copy, use, modify, sell and distribute this software is granted
  // provided this copyright notice appears in all copies. This software
  // is provided "as is" without express or implied warranty, and with
  // no claim as to its suitability for any purpose.
  # include <boost/python/return_opaque_pointer.hpp>
  # include <boost/python/def.hpp>
  # include <boost/python/module.hpp>
  # include <boost/python/return_value_policy.hpp>
  
  typedef struct opaque_ *opaque;
  typedef struct opaque2_ *opaque2;
  
  opaque the_op   = ((opaque) 0x47110815);
  opaque2 the_op2 = ((opaque2) 0x08154711);
  
  opaque get() { return the_op; }
  
  void use(opaque op)
  {
      if (op != the_op)
          throw std::runtime_error (std::string ("failed"));
  }
  
  int useany(opaque op)
  {
      return op ? 1 : 0;
  }
  
  opaque getnull()
  {
      return 0;
  }
  
  void failuse (opaque op)
  {
      if (op == the_op)
          throw std::runtime_error (std::string ("success"));
  }
  
  opaque2 get2 () { return the_op2; }
  
  void use2 (opaque2 op)
  {
      if (op != the_op2)
          throw std::runtime_error (std::string ("failed"));
  }
  
  void failuse2 (opaque2 op)
  {
      if (op == the_op2)
          throw std::runtime_error (std::string ("success"));
  }
  
  BOOST_PYTHON_OPAQUE_SPECIALIZED_TYPE_ID(opaque_)
  BOOST_PYTHON_OPAQUE_SPECIALIZED_TYPE_ID(opaque2_)
  
  namespace bpl = boost::python;
  
  BOOST_PYTHON_MODULE(opaque_ext)
  {
      bpl::def (
          "get", &::get, bpl::return_value_policy<bpl::return_opaque_pointer>());
      bpl::def ("use", &::use);
      bpl::def ("useany", &::useany);
      bpl::def ("getnull", &::getnull, bpl::return_value_policy<bpl::return_opaque_pointer>());
      bpl::def ("failuse", &::failuse);
  
      bpl::def (
          "get2",
          &::get2,
          bpl::return_value_policy<bpl::return_opaque_pointer>());
      bpl::def ("use2", &::use2);
      bpl::def ("failuse2", &::failuse2);
  }
  