Re: [Boost-users] BGL: add_vertex deletes properties

From: Dmitry Bufistov (dmitry_at_[hidden])
Date: 2006-04-20 15:56:59

Fred Labrosse wrote:
> All,
> 
> I have:
> 
>    typedef boost::adjacency_list<boost::listS, boost::listS,
>       boost::undirectedS, place, link> mapType;
> 
>    place* newPlace = new place("here-and-there");
>    mapType::vertex_descriptor newPlaceDesc = add_vertex(*newPlace, theMap);
> 
> where the destructor of place is:
> 
>    place::~place()
>    {
>       // Just to make sure...
>       std::cout << "Deleting place " << name << std::endl;
>       // ...
>    }
> 
> When I run that, I do get:
> 
> Deleting place here-and-there
> 
> just after adding the vertex.  In other words, a property is being deleted, 
> probably a copy of the one I gave. I even tried (to make it explicitly like 
> the documentation says):
> 
>    mapType::vertex_descriptor newPlaceDesc =
>       add_vertex(static_cast<const place&>(*newPlace), theMap);
> 
> and the same happens.
> 
> Is that suppose to happen?
> 
> Cheers,
> 
> Fred
Hola Fred,
I'm pretty sure that add_vertex() takes a copy of property class and 
believe that it is by design. There is the assumption that your property 
class is "easy" for copy.
Pleas correct me if I'm wrong.
--dima