[stlsoft][fixed_array_1d<>] size overhead

Hi Matthew, I'm using the above class, but I was puzzled by the size occupied by the type (it was 12 bytes on my 32bit system). I would like to get that down to 8 or 4 bytes. It turned out that the allocator (which the classes inherits from) takes up 4 bytes, even though it is in fact an empty class in many cases. I think it should be possible to use something along boost's compressed_pair: http://www.boost.org/libs/utility/compressed_pair.htm to hold the allocator and the size. -Thorsten

Thorsten Ottosen skrev: > Thorsten Ottosen skrev: >> Hi Matthew, >> > > Also, why does the classes not have a swap() member function? Furthermore, I find that it would be useful if one could construct fixed_array_1d<T, A, P, false> from fixed_array_1d<T, A, P, true> (and similar for 2d, 3d, etc) The reason is that it makes it possible to return the view type fixed_array_1d<T, A, P, false> in a class hierarchy where some concrete classes uses, say, fixed_array_1d and some classes use fixed_array_2d. best regards -Thorsten

Thorsten Ottosen skrev: > Thorsten Ottosen skrev: >> Thorsten Ottosen skrev: >>> Hi Matthew, >>> >> >> Also, why does the classes not have a swap() member function? > > Furthermore, I find that it would be useful if one could construct > > fixed_array_1d<T, A, P, false> > > from > > fixed_array_1d<T, A, P, true> [Sorry for the spamming ... I don't know exactly what went wrong] There is another space optimization which is worth persuing: for fixed_array_1d<T, A, P, false> there is never a need to store an allocator (by deriving from it). I can submit a patch for all of these issues, if you agree on them. best regards -Thorsten

Thor just want to let you know that I'm not ignoring. Will back to you in next few days. cheers Matt "Thorsten Ottosen" <nesotto@cs.aau.dk> wrote in message news:fiomkl$2koh$1@digitalmars.com... > Hi Matthew, > > I'm using the above class, but I was puzzled by the size occupied by the type (it was 12 bytes on my 32bit system). > > I would like to get that down to 8 or 4 bytes. It turned out that the allocator (which the classes inherits from) takes up 4 bytes, even though it is in fact an empty class in many cases. > > I think it should be possible to use something along boost's compressed_pair: > > http://www.boost.org/libs/utility/compressed_pair.htm > > to hold the allocator and the size. > > -Thorsten

December 08, 2007

Re: [stlsoft][fixed_array_1d<>] size overhead

Posted by Matthew Wilson
in reply to Thorsten Ottosen

Permalink

Matthew Wilson

Posted in reply to Thorsten Ottosen

Permalink

Please submit patch, and I'll integrate everything I don't disagree with. :-)

btw, just for my information: what are you using them for? Something to do with you PhD?

"Thorsten Ottosen" <nesotto@cs.aau.dk> wrote in message news:4755D786.3000702@cs.aau.dk...
> Thorsten Ottosen skrev:
> > Thorsten Ottosen skrev:
> >> Thorsten Ottosen skrev:
> >>> Hi Matthew,
> >>>
> >>
> >> Also, why does the classes not have a swap() member function?
> >
> > Furthermore, I find that it would be useful if one could construct
> >
> >   fixed_array_1d<T, A, P, false>
> >
> > from
> >
> >   fixed_array_1d<T, A, P, true>
>
> [Sorry for the spamming ... I don't know exactly what went wrong]
>
> There is another space optimization which is worth persuing: for
>
>    fixed_array_1d<T, A, P, false>
>
> there is never a need to store an allocator (by deriving from it).
>
> I can submit a patch for all of these issues, if you agree on them.
>
> best regards
>
> -Thorsten

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