id,summary,reporter,owner,description,type,status,milestone,component,version,severity,resolution,keywords,cc
3506,Graph's Tour / Dijkstra's parent nodes,JDKunkMailing@…,Andrew Sutton,"In the tour (http://www.boost.org/doc/libs/1_40_0/libs/graph/doc/quick_tour.html), the last step has me going through and finding all the parents of nodes in Dijkstra algorithm. However, the way the default constructor of Vertex() was set up, it could not find vertex 0 when the parent is 0. Specifically, p[*vi] == Vertex() returned true, when the parent was zero and when there is no parent.

There are two ways to look at this problem. 

First, it is not a bug. Whoever uses the library should get used to working around this.

Second, the default Vertex() should be denoted with an invalid id such that no valid vertex can be Vertex(). 


I would prefer the latter, or another way to work around this issue. 

Vertex is 
typedef boost::graph_traits<Graph>::vertex_descriptor Vertex;

I used 
MSVC 9.0, Win32(Windows7), Intel x2 processors, ... what else?

- Jeff Kunkel",Bugs,closed,Boost 1.41.0,graph,Boost 1.40.0,Not Applicable,fixed,,