"Jens Muller" wrote in message news:...

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Jens, I think that you are missing something. As for me, the property_traits class is just a way of uniform data manipulation.

If every pm needed to be a class, there would be no need for the *_traits template classes.

http://www.boost.org/libs/graph/doc/leda_conversion.html

The Adaptor pattern [12] typically requires that the adaptee object be contained inside a new class that provides the desired interface. This containment is not required when wrapping a graph for BGL because the BGL graph interface consists solely of free (global) functions. Instead of creating a new graph class, you need to overload all the free functions required by the interface. We call this free function wrapper approach external adaptation

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All types associated with a BGL graph class are accessed though the graph_traits class. We can partially specialize this traits class for the LEDA GRAPH class in the following way.

The same is done here for vectors and the like.

Unfortunately I can't follow this :-(

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Your class has to be a model of this abstract concept. (To be a Read Property Map it is enough to have 3 typedefs and get() function, see Concept Checking Class in the documentation that you referred).

Yes, it says the get() free function and 3 typedefs in property_traits need to be defined.

Anyway, it works now, see attachments.

The changes in "bfs_map_test.cpp" are exactly I was thinking of)

One question remains, though:

template ColorValue MapAsColorMap::get(key_type key) { return (boost::get(pm_, key)==white_) ? boost::color_traits<ColorValue>::white() : boost::color_traits<ColorValue>::black(); }

works, while get(pm_, key) without boost:: doesn't.

Shouldn't the right get function be found by Koenig lookup?

Probably yes, but AFAIK not all compilers have it implemented.

http://www.boost.org/libs/property_map/ReadablePropertyMap.html says, too, that get is required, not boost::get ...

I think this is because ReadablePropertyMapConcept class already defined in boost:: namespace. Regards, --Dmitry.