Re: [Boost-users] [bimap] Creating a bimap fom a std::map

Lex Wassenberg wrote:

I am not sure wether I understand this whole discussion, but I think that I do so I would like Edward to consider this:

Suppose you have a std::map m with the elements (1,10), (2,20), (3,20), (4,20), (5,30), and you code: Boost::bimap bm(m);

Now what??

Bimap automatically adds the map data to the left side of the bimap. If any data can not be added, such as the (3,20), (4,20), it acts in exactly the same fashion as it normally would when one tries to insert a data pair which is not distinct both ways. My point is that I wanted a constructor as above: Boost::bimap bm(m); to do essentially: bm.left.insert(m.begin(),m.end()); Evidently the implementor of bimap does not agree so I have chosen not to pursue this suggestion any further. But I doubt I will be the last person suggesting this.

Regards

Lex

...

-----Oorspronkelijk bericht----- Van: boost-users-bounces@lists.boost.org [mailto:boost-users- bounces@lists.boost.org] Namens Matias Capeletto Verzonden: Wednesday, 25 November 2009 23:50 Aan: boost-users@lists.boost.org Onderwerp: Re: [Boost-users] [bimap] Creating a bimap fom a std::map

...

Whether I go:

bm.left.insert( m.begin(), m.end() );

or

bm.right.insert( m.begin(), m.end() );

,when both types are the same, is totally irrelevant to further use of

On Wed, Nov 25, 2009 at 5:35 PM, Edward Diener wrote: the

...

bimap. Is this not correct ? No, it is not correct. A bimap is a mapping between two sets of elements (named the left set, and the right set) that can be viewed as a std map or as a std map. In this particular example both sets hold elements of the same type but which one is the left and which one is the right matters. Imagine that you need a mapping between names and surnames (bimap,tagged >), and you want to insert from a std::map that maps from surnames to names. I hope it is more clear now. Regards Matias

---

Boost-users mailing list Boost-users@lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users