Re: [boost] [multi-index] key_value

From: Tal Agmon (tal.boost_at_[hidden])
Date: 2006-08-21 05:50:12

Hi Joaquin,

Sorry for the lack of info in my previous quote.
I appreicate your affort to promptly help me.

What I have is a non_unique which I carry to get all the keys.( I
don't care about the elements)

My guess is that key_extractor()  returns a key_form_element, is quite
redundant in my case.

Regards
Tal

On 8/21/06, JOAQUIN LOPEZ MU?Z <joaquin_at_[hidden]> wrote:
> Hello Tal,
>
> ----- Mensaje original -----
> De: Tal Agmon <tal.boost_at_[hidden]>
> Fecha: Domingo, Agosto 20, 2006 6:20 pm
> Asunto: [boost] [multi-index] key_value
>
> > Hi,
> >
> > I am happy to work with multi_index library up till
> > now I am able to operate successfully a 5 indices
> > with my cranky msvc 6.5 comiler at work.
>
> Remarkable, given the unstability of that old compiler.
>
> > I do have a naive question
> >
> > Is it possible to retreive all key values from an N
> > index_type container? and how can I do it?
>
> I don't understand the question. What do you mean by
> "key value" and by "an N index_type container"? In case
> the following is somewhat related to your problem,
> here's how one can produce the key part of each element
> of a given key-based index (uncompiled, expect typos.)
>
> // multi_index_t is some multi-index container.
> multi_index_t m;
> ...
>
> // index N-th is key-based (for instance, ordered.)
> typedef nth_index<multi_index_t,N>::type index_t;
> const index_t& i=get<N>(m);
> for(index_t::const_iterator it=i.begin();it!=i.end();++it){
>  std::cout<<i.key_extractor()(*it)<<std::endl;
> }
>
> This code uses the member function key_extractor(), which
> returns a copy of the internal key extractor, to extract
> the key part of a given element.
>
> In case your question is not addressed by the snippet
> above, I'd appreciate if you could explain it a little more
> clearly, possibly stating what your final goal is.
>
> Thank you for using Boost.MultiIndex,
>
> Joaquín M López Muñoz
> Telefónica, Investigación y Desarrollo
> _______________________________________________
> Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost
>