[boost] Re: Raw Array Classes

From: Reid Sweatman (reids_at_[hidden])
Date: 1999-08-19 13:46:56

> For every vector implemetation I have seen vector<T>::iterator is the
> moral equivalent of T*.  Or is that not what you meant?

Well, "moral equivalent" and the same thing aren't the same thing, so it's
not what I meant <g>.  What I want is a second access method that is
*exactly* like good old C pointers, and that I can do the standard array
indexing tricks on to treat the data as multidimensional if I want, or hand
the pointer off to an assembler routine and have no problems.

Frankly, I've never been totally clear on whether or not STL vectors are
even required to maintain contiguous memory locations, let alone ones that
have specified address alignments, which can be critical in CPU cache
management.  Maybe I'm wrong, and there *is* a contiguity requirement, and
maybe it would be enough to set the data packing *before* creating the
vector.  But as for being able to pass an iterator off to an assembler
routine as a pointer, I'm not so sure, especially if a resize occurs.  Most
of my applications for such a thing would use pre-specified array sizes, but
not always.

Comments?