#include <iostream>

using namespace std;

class Document
{
public:
  Document ( void ) : docid ( 0 )
  {
  }
  int get_docid ( void );
private:
  int docid;
};
int Document::get_docid ( void )
{
  return docid;
}

int main ( void )
{
  try
  {
    Document mydoc1;
    throw mydoc1;                     //遵循1
  }
  catch ( Document &d )               //遵循2
  {
    cout << d.get_docid ( ) << endl;
  }

  return ( 0 );
}