Re: [boost] Submission: Fixed-Capacity STL Containers Library (Re:STLcontainer of fixed capacity but

From: Andrei Alexandrescu (andrewalex_at_[hidden])
Date: 2002-02-08 10:08:45

> I have rewritten my fixed_capacity_vector class to solve the second
> problem (construction of non-POD objects).
>
>
http://groups.yahoo.com/group/boost/files/fixed_capacity/fixed_capacity_2002
0208.zip
>
> I believe that non-POD objects are now constructed and destructed in a
> proper way.  As for the alignment problem, however, I'm not sure if
> the current implementation is portable or not.

The implementation is not portable, and potentially wasteful (jeopardizing
the very intent of fixed_vector). I privately emailed you (and Ralf) some
stuff that might be of interest. As you follow Variant.zip, also look up
explanations in
http://oonumerics.org/tmpw01/alexandrescu.pdf.

>  I will greatly
> appreciate comments and suggestions from all of you on this point.

1. Casting pointers to integers doesn't help much in portable code.

2. Duplicating code to treat PODs and non-PODs is NOT the way to go. Use one
implementation for both. You may want to segregate implementations in a
limited way just for optimization's sake.

I wonder why wouldn't you give it a shot at writing a full-blown vector in
which your storage method is a policy. You're not that far from such an
approach (your fixed_vector_base basically defines your storage policy).

Andrei the manipulative one

---------------------------------
Check out THE C++ Seminar:  3 Days with 5 Experts
http://www.gotw.ca/cpp_seminar/