Re: speed versus OO

For instance take: heavely used classes, lets say Vector(not the
dynamic datatype but a mathematical vector) and Point. They have both
3 class variables x, y and z and some functions they both use.

Now the question is, would subclassing these 2 classes have any
negative effect on the speed of a program that uses these classes very
frequently, i.e. the raytracer I'm building. So completely different
types of classes versus inheritance, which would be faster? Or doesn't
it matter.
My thought would be that its slower and the only gain is that its
easier in a conceptual way to use inheritance, but I don't need a good
design in the first place, I need speed!

I'm most likely not going to use inheritance for that reason but also
because those classes "have" to be differentiated from eachother. By
that I mean they can't just take over eachothers identity. Normal n =
v with v a Vector may not be possible, even used explicit to make
sure, and this kind of concretisation is what one loses by the
abstraction of the superclass no? Or is it my responsability not to
lose the identity of a class into the abstraction of the superclass.

I think I'm starting to get crazy about all the newly gained c++
information that I don't know where to put it all at once =). I'll get
myself some sleep first and maybe tomorow I'll be back on track.