RAII example 3

raii_example3.cpp

int demo3(){
  A *a = new A;
  int ra = a -> func();
  if(ra == 2) {
    try {
      B *b = new B;
    }
    catch (...)
    {
      delete a;
      throw;
    }
    int rb = b->func();
    delete a;
    delete b;
    return rb;
    
  } else if(ra  == 1) {
    try {
      C *c = new C;
    }
    catch (...)
    {
      delete a;
      throw;
    }
    int rc = c->func();
    delete a;
    delete c;
    return rc;
    
  }
  delete a;
  return ra; 
}