Thread: Pointers and Efficiency

Originally Posted by CornedBee

Nothing, really. You just have to remember that, once you have a reference member, several things happen. First, you don't get a generated copy assignment operator. Second, the class is no longer a POD, even if it would have been otherwise. Third, if the reference can refer to different objects in different instances, you cannot implement a reliable assignment operator or a reliable swap, because the functions would have to fail for objects coming - in your example - from different worlds. Built-in xenophobia

So when I said that references make poor class members, I was referring to the fact that having a reference member affects the design of the class.

Ah, understood. So what do you prefer for saving an argument taken by const reference as class member, if you want to get a (relyable) copy/assignment operator?

Code:

class Entity
{
   Entity(const World& _world)
   :m_world(_world)
   // or
   :msp_world(&_world)
   {}

   World m_world; // initiate (probably complex)   copying

   // or

   const shared_ptr<World> msp_world;
};

Originally Posted by CornedBee

Unless I don't need them to be assignable, in which case I use a reference. I can't think of anything more semantic.

Yes, but you pointed out that then there is no copy assignment operator generated and a hand made one can't e relieable, if there are more than one possible object to reference. So what to use if I'd absolutely need copying and assignment?

Ok, that java comparison confused me, because I'm not into java very much. Thank you