boost/graph/visitors.hpp
//======================================================================= // Copyright 1997, 1998, 1999, 2000 University of Notre Dame. // Authors: Andrew Lumsdaine, Lie-Quan Lee, Jeremy G. Siek // // Distributed under the Boost Software License, Version 1.0. (See // accompanying file LICENSE_1_0.txt or copy at // http://www.boost.org/LICENSE_1_0.txt) //======================================================================= // // Revision History: // 01 April 2001: Modified to use new <boost/limits.hpp> header. (JMaddock) // #ifndef BOOST_GRAPH_GRAPH_SEARCH_VISITORS_HPP #define BOOST_GRAPH_GRAPH_SEARCH_VISITORS_HPP #include <iosfwd> #include <boost/config.hpp> #include <boost/property_map.hpp> #include <boost/graph/graph_traits.hpp> #include <boost/limits.hpp> #include <boost/graph/detail/is_same.hpp> namespace boost { // This is a bit more convenient than std::numeric_limits because // you don't have to explicitly provide type T. template <class T> inline T numeric_limits_max(T) { return (std::numeric_limits<T>::max)(); } //======================================================================== // Event Tags namespace detail { // For partial specialization workaround enum event_visitor_enum { on_no_event_num, on_initialize_vertex_num, on_start_vertex_num, on_discover_vertex_num, on_finish_vertex_num, on_examine_vertex_num, on_examine_edge_num, on_tree_edge_num, on_non_tree_edge_num, on_gray_target_num, on_black_target_num, on_forward_or_cross_edge_num, on_back_edge_num, on_edge_relaxed_num, on_edge_not_relaxed_num, on_edge_minimized_num, on_edge_not_minimized_num }; template<typename Event, typename Visitor> struct functor_to_visitor : Visitor { typedef Event event_filter; functor_to_visitor(const Visitor& visitor) : Visitor(visitor) {} }; } // namespace detail struct on_no_event { enum { num = detail::on_no_event_num }; }; struct on_initialize_vertex { enum { num = detail::on_initialize_vertex_num }; }; struct on_start_vertex { enum { num = detail::on_start_vertex_num }; }; struct on_discover_vertex { enum { num = detail::on_discover_vertex_num }; }; struct on_examine_vertex { enum { num = detail::on_examine_vertex_num }; }; struct on_finish_vertex { enum { num = detail::on_finish_vertex_num }; }; struct on_examine_edge { enum { num = detail::on_examine_edge_num }; }; struct on_tree_edge { enum { num = detail::on_tree_edge_num }; }; struct on_non_tree_edge { enum { num = detail::on_non_tree_edge_num }; }; struct on_gray_target { enum { num = detail::on_gray_target_num }; }; struct on_black_target { enum { num = detail::on_black_target_num }; }; struct on_forward_or_cross_edge { enum { num = detail::on_forward_or_cross_edge_num }; }; struct on_back_edge { enum { num = detail::on_back_edge_num }; }; struct on_edge_relaxed { enum { num = detail::on_edge_relaxed_num }; }; struct on_edge_not_relaxed { enum { num = detail::on_edge_not_relaxed_num }; }; struct on_edge_minimized { enum { num = detail::on_edge_minimized_num }; }; struct on_edge_not_minimized { enum { num = detail::on_edge_not_minimized_num }; }; struct true_tag { enum { num = true }; }; struct false_tag { enum { num = false }; }; //======================================================================== // base_visitor and null_visitor // needed for MSVC workaround template <class Visitor> struct base_visitor { typedef on_no_event event_filter; template <class T, class Graph> void operator()(T, Graph&) { } }; struct null_visitor : public base_visitor<null_visitor> { typedef on_no_event event_filter; template <class T, class Graph> void operator()(T, Graph&) { } }; //======================================================================== // The invoke_visitors() function namespace detail { template <class Visitor, class T, class Graph> inline void invoke_dispatch(Visitor& v, T x, Graph& g, true_tag) { v(x, g); } template <class Visitor, class T, class Graph> inline void invoke_dispatch(Visitor&, T, Graph&, false_tag) { } } // namespace detail template <class Visitor, class Rest, class T, class Graph, class Tag> inline void invoke_visitors(std::pair<Visitor, Rest>& vlist, T x, Graph& g, Tag tag) { typedef typename Visitor::event_filter Category; typedef typename graph_detail::is_same<Category, Tag>::is_same_tag IsSameTag; detail::invoke_dispatch(vlist.first, x, g, IsSameTag()); invoke_visitors(vlist.second, x, g, tag); } #if defined(BOOST_MSVC) && BOOST_MSVC <= 1300 template <class Visitor, class T, class Graph, class Tag> inline void invoke_visitors(base_visitor<Visitor>& vis, T x, Graph& g, Tag) { typedef typename Visitor::event_filter Category; typedef typename graph_detail::is_same<Category, Tag>::is_same_tag IsSameTag; Visitor& v = static_cast<Visitor&>(vis); detail::invoke_dispatch(v, x, g, IsSameTag()); } #else template <class Visitor, class T, class Graph, class Tag> inline void invoke_visitors(Visitor& v, T x, Graph& g, Tag) { typedef typename Visitor::event_filter Category; typedef typename graph_detail::is_same<Category, Tag>::is_same_tag IsSameTag; detail::invoke_dispatch(v, x, g, IsSameTag()); } #endif //======================================================================== // predecessor_recorder template <class PredecessorMap, class Tag> struct predecessor_recorder : public base_visitor<predecessor_recorder<PredecessorMap, Tag> > { typedef Tag event_filter; predecessor_recorder(PredecessorMap pa) : m_predecessor(pa) { } template <class Edge, class Graph> void operator()(Edge e, const Graph& g) { put(m_predecessor, target(e, g), source(e, g)); } PredecessorMap m_predecessor; }; template <class PredecessorMap, class Tag> predecessor_recorder<PredecessorMap, Tag> record_predecessors(PredecessorMap pa, Tag) { return predecessor_recorder<PredecessorMap, Tag> (pa); } //======================================================================== // edge_predecessor_recorder template <class PredEdgeMap, class Tag> struct edge_predecessor_recorder : public base_visitor<edge_predecessor_recorder<PredEdgeMap, Tag> > { typedef Tag event_filter; edge_predecessor_recorder(PredEdgeMap pa) : m_predecessor(pa) { } template <class Edge, class Graph> void operator()(Edge e, const Graph& g) { put(m_predecessor, target(e, g), e); } PredEdgeMap m_predecessor; }; template <class PredEdgeMap, class Tag> edge_predecessor_recorder<PredEdgeMap, Tag> record_edge_predecessors(PredEdgeMap pa, Tag) { return edge_predecessor_recorder<PredEdgeMap, Tag> (pa); } //======================================================================== // distance_recorder template <class DistanceMap, class Tag> struct distance_recorder : public base_visitor<distance_recorder<DistanceMap, Tag> > { typedef Tag event_filter; distance_recorder(DistanceMap pa) : m_distance(pa) { } template <class Edge, class Graph> void operator()(Edge e, const Graph& g) { typename graph_traits<Graph>::vertex_descriptor u = source(e, g), v = target(e, g); put(m_distance, v, get(m_distance, u) + 1); } DistanceMap m_distance; }; template <class DistanceMap, class Tag> distance_recorder<DistanceMap, Tag> record_distances(DistanceMap pa, Tag) { return distance_recorder<DistanceMap, Tag> (pa); } //======================================================================== // time_stamper template <class TimeMap, class TimeT, class Tag> struct time_stamper : public base_visitor<time_stamper<TimeMap, TimeT, Tag> > { typedef Tag event_filter; time_stamper(TimeMap pa, TimeT& t) : m_time_pa(pa), m_time(t) { } template <class Vertex, class Graph> void operator()(Vertex u, const Graph&) { put(m_time_pa, u, ++m_time); } TimeMap m_time_pa; TimeT& m_time; }; template <class TimeMap, class TimeT, class Tag> time_stamper<TimeMap, TimeT, Tag> stamp_times(TimeMap pa, TimeT& time_counter, Tag) { return time_stamper<TimeMap, TimeT, Tag>(pa, time_counter); } //======================================================================== // property_writer template <class PA, class OutputIterator, class Tag> struct property_writer : public base_visitor<property_writer<PA, OutputIterator, Tag> > { typedef Tag event_filter; property_writer(PA pa, OutputIterator out) : m_pa(pa), m_out(out) { } template <class T, class Graph> void operator()(T x, Graph&) { *m_out++ = get(m_pa, x); } PA m_pa; OutputIterator m_out; }; template <class PA, class OutputIterator, class Tag> property_writer<PA, OutputIterator, Tag> write_property(PA pa, OutputIterator out, Tag) { return property_writer<PA, OutputIterator, Tag>(pa, out); } #define BOOST_GRAPH_EVENT_STUB(Event,Kind) \ typedef ::boost::Event Event##_type; \ template<typename Visitor> \ Kind##_visitor<std::pair<detail::functor_to_visitor<Event##_type, \ Visitor>, Visitors> > \ do_##Event(Visitor visitor) \ { \ typedef std::pair<detail::functor_to_visitor<Event##_type, Visitor>, \ Visitors> visitor_list; \ typedef Kind##_visitor<visitor_list> result_type; \ return result_type(visitor_list(visitor, m_vis)); \ } } /* namespace boost */ #endif