[boost] [graph] boost::plugin and boost::id_tag ?

Hi, I try to run an example here: http://www.boost.org/doc/libs/1_37_0/libs/property_map/iterator_property_map... typedef boost::adjacency_list<boost::vecS, boost::vecS, boost::bidirectionalS, boost::no_plugin, boost::plugin<boost::id_tag, std::size_t> > Graph; I cannot find boost::plugin and boost::id_tag. Any idea, please ? Thanks