Re: [Boost-users] [Boost.Graph] Parameter for the Dijkstra-Algorithm

From: Doug Gregor (dgregor_at_[hidden])
Date: 2007-07-03 11:22:50

On Jul 3, 2007, at 5:07 AM, Ewgenij Sokolovski wrote:

> Hello, I read in the documentation that the parameter weight_map of  
> dijkstra_shortest_paths should be a model of Readable Property Map.
>
> http://www.boost.org/libs/graph/doc/dijkstra_shortest_paths.html
>
> Readable Property Map interface defines a function get(), which has  
> to be contained in each implementation of the interface. OK so far.  
> But when you look at the example provided with the boost library,  
> you see that a simple STL vector is used as weight map.
>
> http://www.boost.org/libs/graph/example/dijkstra-example.cpp
>
> And STL vector doesn't provide a get() function at all. So the  
> whole thing shouldn't work at all. So where is the magic  
> explanation?:)

The magic is on line 139 of boost/property_map.hpp, which turns  
pointers into property maps.

        - Doug