----- Mensaje original ----- De: Thorsten Ottosen <thorsten.ottosen@dezide.com> Fecha: Sábado, Febrero 24, 2007 7:49 pm Asunto: Re: [boost] [Review][bimap] Para: boost@lists.boost.org [...]
Anyway, I can't help think about it this way:
1. boost::bimap<T,U> is implemented in terms of Boost.MI
2. somewhere in this data-structure lies a bunch of T objects and U object
The internal data structure stores a bunch of objects of type relation<T,U>. Ts and Us are not allocated separately.
3. upon map.insert( bimap::relation( T(), U() ) ), the T and U object is copied to their respective objects inside the datastructure
B.MI accepts an object, say x, of type relation<T,U>, as an atomic entity, and copies it to its final destination. The positioning of this object in both "views" of the bimap is done according to key extractors such that key1(x)==x.left, key2(x)==x.right. So to speak, B.MI does not know about the internal structure of relation<T,U>: the element object is treated as an unanalyzed entity from which keys are extracted using the appropriate key extractors.
If that is true, I have a hard time seing how creating a temporary relation() object can make a difference.
I hope the above clarifies the situation. If this is not the case, please don't hesitate to come back to me. I know my English is a barrier to explaning subtle concepts clearly. Joaquín M López Muñoz Telefónica, Investigación y Desarrollo