// segment of code that instantiates the features
// no error checking provided--for illustration
// purposes only

// each feature object needs to know the model number
// and feature ID it corresponds to in order to retrieve
// information when requested. Note how this information
// is passed into each object's constructor

   // open model
   modelNum= V1OpenModel( modelName);

   nElements= V1GetNumberofElements(modelNum);

   Feature *features[MAXFEATURES];

   // do for each feature in the model
   for (i= 0; i < nElements; i++) {
      // determine feature present and create
      // appropriate feature object
      switch( V1GetType( modelNum, i)) {
         case SLOT:
            features[i]=
               new V1Slot( modelNum,
                           V1GetID( modelNum, i));
            break;

         case HOLE:

            features[i]=
               new V1Hole( modelNum,
                           V1GetID( modelNum, i));
            break;
         ...
      }
   }

// modelNum and myID are private members containing
// information about the model and feature (in V1) this
// feature corresponds to

double V1Slot::getX () {
   // call appropriate method for V1 to get needed
   // information. Note: this method may actually
   // call several methods in V1
   // to get the information.
   return V1GetXforSlot( modelNum, myID);
}

double V1Hole::getX () {
   // call appropriate method for V1 to get needed
   // information. Note: this method may actually
   // call several methods in V1
   // to get the information.
   return V1GetXforHole( modelNum, myID);
}

// segment of code that instantiates the features
// no error checking provided--for illustration
// purposes only

// each feature object needs to know the feature in the
// V2 system it corresponds to in order to retrieve
// information when requested. Note how this information
// is passed into each object's constructor

   // open model
   myModel= V2OpenModel( modelName);

   nElements= myModel->getNumElements();
   Feature *features[MAXFEATURES];

   OOGFeature *oogF;
   // do for each feature in the model
   for (i= 0; i < nElements; i++) {
      // determine feature present and create
      // appropriate feature object
      oogF= myModel->getElement(i);

      switch( oogF->myType()) {
         case SLOT:
            features[i]= new V2Slot( oogF);
            break;

         case HOLE:

            features[i]= new V2Hole( oogF);
            break;
         ...

      }
   }
}

// oogF is a reference to the feature object in V2 that
// the object containing it corresponds to

double V2Slot::getX () {
  // call appropriate method on oogF to get needed
  // information.
  return oogF->getX();
}

double V2Hole::getX () {
  // call appropriate method on oogF to get needed
  // information.
  return oogF->getX();
}