my first post here, so I hope not to miss some mailing list rule.

I'm experiencing some problems in using graph internal properties.

I have to generate a graph from a database and I need to differentiate nodes in my graph,

namely I will have 2 different node categories, say cat1_node and cat2_node.

Each category should have its own property attached.

Ex: say N1 is a cat1_node and N2 is a cat2_node. I want N1 to have a "name" (string)

property while N2 a "length" (int) property and both have a "label" (string) property.

To achieve this I though I could use inheritance in the following manner:

class generic_vertex_property{

public:

generic_vertex_property(){type = 0;}

int type;

std::string label;

};

class cat1_property: public generic_vertex_property{

public:

std::string name;

};

class cat2_property: public generic_vertex_property{

public:

int length;

};

In this way, I though, I can define my graph something like:

typedef adjacency_list< vecS, vecS, directedS, property<vertex_p_t, generic_vertex_property*> > Graph;

cat1_property *v1 = new cat1_property();

cat2_property *v2 = new cat2_property();

v1->label = "v1_label";

v1->name = "v1_name";

v2->label = "v2_label";

v2->length = 10;

add_vertex(VertexProperty(v1),G);

add_vertex(VertexProperty(v2),G);

This actually compiles and runs without errors.

The problem comes when I try to access the verteces through a property_map, like:

vertex_p_map_t vertex_p_map = get(vertex_p, G); //where vertex_p_map_t and vertex_p have been define before

Indeed from such get function I have objects of type generic_vertex_property,

thus, when trying to access a property of the sone classes I got this compile error:

error: ‘class generic_vertex_property’ has no member named ‘name’

I hope I was clear enough, if necessary I can also send the full code.

Is there a way to get a property map with the "original" object types (as inserted)?

Do you have some good websites with practical examples, code snippets and so on about BGL?

Last question comes as, in my opinion, the reference manual is quite complete, but

1) lot of examples are not compiling ( look like they have not been updated to the last boost version)

2) examples are usually very basic and it is very hard to get the general rules behind it.