[Insight-developers] SmartPointer comparison operators

[Aljaz Noe]

> The only methods that need to return SmartPointers are those  constructing
> objects and not holding pointer to the newly constructed object.

In this case, FEM code doesn't need smart pointers at all. We always make
sure that pointers are kept where required.

> We could check this now and leave only the minimum number of required
> SmartPointers. That will make unnecessary the CMake flag :
>
>           FEM_USE_SMART_POINTERS

If this definition is in conflict with something else, you can remove it
right now, with no side effects on the code. The FEM code internally doesn't
depend on the SP functionality. I'll later remove the #ifdef's from files.

> The FEM code seems to be evolving quite fast, we could coordinate a day
> or two for doing these changes on FEM and avoid disturbing the code that
> you are modifying right now.

Yes. I currently have a lot of things to worry about. Maybe it would be best
to wait. Just give me a couple of days to finish the new Element base class.

Aljaz