David Abrahams wrote:
Vladimir Prus <ghost@cs.msu.su> writes:
I've just made an attempt to use the named parameters library (currently in review queue, and available at http://groups.yahoo.com/group/boost/files/named_params.zip) to simply properties in BGL.
I've tried to implement this idea, but run into the problems. First issue is documentation: it gives
foo_impl(foo_keywords(a0));
as example, while the code uses:
return f_impl(f_keywords()(t, name_));
Which has extra '()' after f_keywords.
Uh, yeah. I think I need to let Daniel answer for that problem.
Yeah I'll take care of it.. Thanks.
The second problem is that I need to create a type for 'keywords' (derived from 'keywords<...>' and use it for passing arguments). The docs suggest to create a number of forwarding functions, but given that a number of vertex properties can be rather large (and is actually unbounded), this does not seem good.
Isn't the number of properties bounded by the graph type? Couldn't you create some metafunction to generate the keywords<> type from the graph and use Boost.PP to generate overloads on this form (please ignore all the BGL related errors here): template<class G, class A0, .., class AN> typename enable_if_graph< G , typename graph_traits<G>::edge_descriptor
::type add_edge( typename graph_traits<G>::vertex_descriptor u , typename graph_traits<G>::vertex_descriptor v , A0 const& a0 , ... , AN const& an , G& g) { typename keywords_for_graph<G>::type kw; return add_edge_impl(u, v, g, kw(a0, ..., an)); }
-- Daniel Wallin