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accessing array index through pointer

Started by mjs1 Nov 7, 2005 at 11:41 PM 3 replies 300+ views

Original Post

Nov 7, 2005 at 11:41 PM

My function has as a parameter a pointer to an array. I'm not sure what the proper syntax is to access an element of the array the pointer is referencing: int Region :: boundingBoxTest(S_Shape* iShape, vector<S_Face>* iFaces) { for (int i = 0; i < iFaces->size(); i++) { if (isBBoxDisjoint(iFaces) == false) // this is a syntax error { } } } Thanks for any help!

Conner McCloud

159

Conner McCloud

Nov 7, 2005 at 11:47 PM

iFaces is a vector*. So, iFaces[n] refers to the n-th vector in the 'array' iFaces. In order to turn iFaces into a vector, it must be dereferenced:

(*iFaces).size();(*iFaces)[5];//etc

In addition to this, consider passing iFaces as a references, rather than a pointer. The chances of the calling function screwing up and sending boundingBoxTest bad data is considerably smaller that way. Plus, you avoid all the explicit dereferences.

CM

Last Attacker

Nov 7, 2005 at 11:48 PM

Could you give us a prototype of isBBoxDisjoint?
Just to see what parameters that accepts. Maybe its that because as far as I can remember (a few years back when I still used vectors before writing my own) a pointer to a vector, you can still access its array elements by using it asif it wasn't a pointer like you did with iFaces.
I'm speaking under correction.

Dave Hunt

146

Dave Hunt

Nov 7, 2005 at 11:48 PM

You can also use

iFaces->at(i);

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