Re: [Boost-users] [MultiIndex] Key extraction from a base member
Hello Bruno, thanks for using Boost.MultiIndex! ----- Mensaje original ----- De: Bruno Martínez <br1@internet.com.uy> Fecha: Miércoles, Octubre 19, 2005 10:46 pm Asunto: [Boost-users] [MultiIndex] Key extraction from a base member
Hi.
I have the following problem with MultiIndex. For
struct Base { int id; };
struct Der : Base { };
I can't make a key extractor.
[explanation on why it doesnt work snipped]
Maybe the solution is to put some enable_ifs in member.
Basically, something like that should be done, right. Actually enable_if only works for highly compliant compilers, so I'll have to resort to some uglier mechanism, but it can be done. This is planned to be solved (or added as a new feature, if you wish) in Boost 1.34. The problem was first brought to my attention in http://tinyurl.com/dnfzs. In the meantime I'm afraid you are forced to write your own key extractor (which is trivial, in any case.) Best regards, Joaquín M López Muñoz Telefónica, Investigación y Desarrollo
On Wed, 19 Oct 2005 20:12:08 -0200, JOAQUIN LOPEZ MU?Z <joaquin@tid.es> wrote:
Hello Bruno, thanks for using Boost.MultiIndex!
Thank you, Joaquín! It's a great piece of work.
Basically, something like that should be done, right. Actually enable_if only works for highly compliant compilers, so I'll have to resort to some uglier mechanism, but it can be done. This is planned to be solved (or added as a new feature, if you wish) in Boost 1.34. The problem was first brought to my attention in http://tinyurl.com/dnfzs. In the meantime I'm afraid you are forced to write your own key extractor (which is trivial, in any case.)
Sorry, I should have searched a little bit better. In any case, I'm confused as to why can't I cast a Base::member to Derived::member at compile time. Any idea? I searched comp.lang.c++[.moderated] without success. Bruno
participants (2)
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Bruno Martínez -
JOAQUIN LOPEZ MU?Z