Question

I have a several classes DemandBuilding, Factory, Farm and some others. I want to store instances of these in a single 2d array, I did this by making a base class, Building, which does nothing but allows me to do this: (Note that the second vector is because it is a 2d vector for storing these buildings on a map)

vector<vector<Building*> > map;

Instead of this:

vector<vector<DemandBuilding*> > demand_buildings;
vector<vector<Factory*> > factories;
vector<vector<Farm*> > farms;
//etc...

(I’m away from my computer so I’m not sure that this is legal C++, although I think it is)
To me this looks like an incorrect use of inheritance, is it?

EDIT: Thanks for helping that there is nothing conceptually wrong with this but I have since realized that doing this wont help my situation, thanks anyway.

Answer 1

Conceptually there’s nothing wrong with this – it all depends on how you use it. If you find yourself having to cast a lot, you may need to rethink the design.

Also, you very likely should have a virtual destructor, if you delete a Building * and the destructor isn’t virtual, the subclass destructor is not executed.