Re: [Boost-users] Info about a graph with structure instead node

Thanks for your help. But if I have a list of structures like this how can I implement a graph? typedef struct Conceptual { char* Name; char* Type; Conceptual* Next; Conceptual() {Next=NULL; Name=NULL; Type=NULL; } }; typedef Conceptual* ListPtr; I have think to create a univocal variable for every word and to create a dynamic matrix of connections or a pointer inside the list of structure, I haven't also decide. Thanks Daniele Doug Gregor wrote:

On Jul 12, 2004, at 3:36 AM, Daniele Carlucci wrote:

...

Hi all, I'm a newby in this library. I'm interested to make a graph of network. It's possible or is very hard to make? I want to have inside every node a struct.

Anything is possible with the BGL :) This particular thing is too hard to do at the moment, but will become much easier as soon as we release 1.32.0 (in about 2 weeks):

First step is to create a property tag for your struct:

enum vertex_mystruct_t { vertex_mystruct };

Now make that tag a full-fledged graph property tag:

namespace boost { BOOST_INSTALL_PROPERTY(vertex, mystruct); }

Now when you create your graph type, you can store a value of any type X along with each vertex like this (the first three parameters can be anything, of course):

struct X { int foo; };

typedef adjacency_list > Graph; Graph g; // creating a graph instance

To actually get at the X values for each vertex, we need to grab the property map:

property_map::type X_map(get(vertex_mystruct, g));

Now, finally, we can get to the X structure for any vertex_descriptor v:

X_map[v].foo = 17;

In 1.32.0, the BGL will support "bundled properties", which means that this whole e-mail would boil down to:

typedef adjacency_list Graph; Graph g; graph_traits<Graph>::vertex_descriptor v = ...; g[v].foo = 17;

Doug

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