Re: [Boost-users] Property map deletion

From: Jeremy Siek (jsiek_at_[hidden])
Date: 2003-11-14 14:44:52

Hi David,

You can not empty (reclaim the space) for internal properties (without
removing the edges or vertices).

Instead I would recommend using external properties... this is in fact the
primary reason that the BGL supports external properties. See the example

exterior_properties.cpp

Cheers,
Jeremy

On Fri, 14 Nov 2003, David Ohlemacher wrote:

ohlema> Hi all.
ohlema>
ohlema> Partway through my app's execution, I find that I no longer need the
ohlema> values in a custom internal property map (edge).  The map potentially
ohlema> may be quite large.
ohlema>
ohlema> What is the best way to empty it?
ohlema>
ohlema> Thanks,
ohlema> -d
ohlema>
ohlema> > Here is my implementation. It is right out of your (very helpful) book.
ohlema> >
ohlema> > -d
ohlema> >
ohlema> > namespace boost
ohlema> > {
ohlema> >    // ECInGraph custom properties.
ohlema> >    enum vertex_com_t           {vertex_com      = 1223497};
ohlema> >    enum edge_nEmailsIn_t       {edge_nEmailsIn  = 1223498};
ohlema> >    enum edge_nEmailsOut_t      {edge_nEmailsOut = 1223499};
ohlema> >    enum edge_sourceVD_t        {edge_sourceVD   = 1223500};
ohlema> >    BOOST_INSTALL_PROPERTY (vertex, com);
ohlema> >    BOOST_INSTALL_PROPERTY (edge, nEmailsIn);
ohlema> >    BOOST_INSTALL_PROPERTY (edge, nEmailsOut);
ohlema> >    BOOST_INSTALL_PROPERTY (edge, sourceVD);
ohlema> > }
ohlema> >
ohlema> >
ohlema> > typedef boost::property <boost::edge_nEmailsOut_t, int,
ohlema> >    boost::property <boost::edge_nEmailsIn_t, int,
ohlema> >    boost::property <boost::edge_sourceVD_t, unsigned int> > >
ohlema> > InGraphEdgeProps;
ohlema> > typedef boost::property <boost::vertex_name_t, std::string,
ohlema> >    boost::property <boost::vertex_com_t, int> >
ohlema> > InGraphVertexProps;
ohlema> >
ohlema> > typedef boost::adjacency_list <
ohlema> >        boost::vecS,            // Edge list is a std::vector
ohlema> >        boost::vecS,            // Vertex list is a std::vector
ohlema> >        boost::undirectedS,     // undirected graph
ohlema> >        InGraphVertexProps,     // Vertex properties
ohlema> >        InGraphEdgeProps,       // Edge properties
ohlema> >        boost::no_property      // Graph properties
ohlema> >    > ECInGraph;
ohlema> >
ohlema> >
ohlema> > void EC::InitGraphPropertyMaps()
ohlema> > {
ohlema> >    // m_inGraph property maps.
ohlema> >    m_g2VName       = boost::get(boost::vertex_name, m_inGraph);
ohlema> >    m_g2Com         = boost::get(boost::vertex_com, m_inGraph);
ohlema> >    m_g2EmailsIn    = boost::get(boost::edge_nEmailsIn, m_inGraph);
ohlema> >    m_g2EmailsOut   = boost::get(boost::edge_nEmailsOut, m_inGraph);
ohlema> >    m_g2SourceVD    = boost::get(boost::edge_sourceVD, m_inGraph);
ohlema> > }
ohlema> >
ohlema>
ohlema>
ohlema> _______________________________________________
ohlema> Boost-users mailing list
ohlema> Boost-users_at_[hidden]
ohlema> http://lists.boost.org/mailman/listinfo.cgi/boost-users
ohlema>

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 Jeremy Siek                          http://php.indiana.edu/~jsiek/
 Ph.D. Student, Indiana Univ. B'ton   email: jsiek_at_[hidden]
 C++ Booster (http://www.boost.org)   office phone: [phone]
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