Thanks a lot, even though I read half of the BGL book I didnt get this difference. I cant say Im good with techniques like that. Best, Tasos
----------------------------------------------------------------------
Message: 1 Date: Thu, 31 Jan 2013 11:12:29 -0500 (EST) From: Jeremiah Willcock <jewillco@osl.iu.edu> To: boost-users@lists.boost.org Subject: Re: [Boost-users] [Graph] visitor dijkstra_shortest_paths Message-ID: <alpine.LRH.2.03.1301311111140.64740@cs.indiana.edu> Content-Type: text/plain; charset="iso-8859-1"; Format="flowed"
On Thu, 31 Jan 2013, The Maschine wrote:
Hi all,
Can someone explain me why I get an error with the first one and not the
second?
1)
(error)?boost::dijkstra_shortest_paths(m_ugraph,*vertex_iterator_begin,? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
?boost::distance_map(boost::make_iterator_property_map(dist_map.begin(), boost::get(boost::vertex_index, m_ugraph))),
boost::visitor(dijkstra_vis( *vertex_iterator_begin, superStorage ) ));
The syntax for named parameters in Boost.Graph requires periods, so all named arguments show up as a single argument to C++.
2) (good)?boost::dijkstra_shortest_paths(m_ugraph,*vertex_iterator_begin,? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?boost::distance_map(boost::make_iterator_property_map(dist_map.begin(), boost::get(boost::vertex_index, m_ugraph))).visitor(dijkstra_vis( *vertex_iterator_begin, superStorage ))?);
Why I need to "." the visitor on the distance_map?
That's how it was implemented (before Boost.Parameter or variadic templates existed).
BFS is ok with it:
(good) boost::breadth_first_search(m_ugraph, *vertex_iterator_begin ,
boost::visitor(bfs_vis(
*vertex_iterator_begin, superStorage ) ));
You only have one named argument there; if you had more, you would need to use a period between those as well.
-- Jeremiah Willcock