Re: auto_ptr who is right?

Barry <dhb52@126.com> wrote in message...


It does NOT work. Did you read what Peter said?

You can't return an object A pointer where it is expected to return an
std::auto_ptr object. If it does compile and run, it's UB.
What you were trying to do is akin to:
   std::string Line("Hello World!");
   int Number = Line;


You'll have to ask that where you got STLPort.

Does this compile for you?

// includes here
struct Pizza{
     Pizza( std::string const& name) : name_(name) {}
     void Show( std::ostream &out ) const {
          out<<name_<<" Pizza"<<std::endl;
          }
    private:
     std::string name_;
     };

class AbstractFactory{ public:
     virtual std::auto_ptr<Pizza> CreatePizza() = 0;
     virtual Pizza* CreatePizza2() = 0;
     virtual ~AbstractFactory() {}
     };

class NestFactory : public AbstractFactory{
     virtual std::auto_ptr<Pizza> CreatePizza(){
          return std::auto_ptr<Pizza>( new Pizza( "Nest" ) );
          }
     virtual Pizza* CreatePizza2(){
          return new Pizza( "Nest2" );
          }
     };

int main(){
     std::auto_ptr<AbstractFactory> pFactory( new NestFactory );
     std::auto_ptr<Pizza> pPizza = pFactory->CreatePizza();
     pPizza->Show( std::cout );
     std::auto_ptr<Pizza> pPizza2( pFactory->CreatePizza2() );
     pPizza2->Show( std::cout );
     return 0;
     } // main()