| // Copyright (C) 2007 Douglas Gregor |
| |
| // Use, modification and distribution is subject to 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) |
| |
| // Provides support for named vertices in graphs, allowing one to more |
| // easily associate unique external names (URLs, city names, employee |
| // ID numbers, etc.) with the vertices of a graph. |
| #ifndef BOOST_GRAPH_NAMED_GRAPH_HPP |
| #define BOOST_GRAPH_NAMED_GRAPH_HPP |
| |
| #include <boost/config.hpp> |
| #include <boost/type_traits/remove_cv.hpp> |
| #include <boost/type_traits/remove_reference.hpp> |
| #include <boost/multi_index_container.hpp> |
| #include <boost/multi_index/hashed_index.hpp> |
| #include <boost/multi_index/member.hpp> |
| #include <boost/optional.hpp> |
| #include <boost/throw_exception.hpp> |
| #include <stdexcept> // for std::runtime_error |
| |
| namespace boost { namespace graph { |
| |
| /******************************************************************* |
| * User-customized traits * |
| *******************************************************************/ |
| |
| /** |
| * @brief Trait used to extract the internal vertex name from a vertex |
| * property. |
| * |
| * To enable the use of internal vertex names in a graph type, |
| * specialize the @c internal_vertex_name trait for your graph |
| * property (e.g., @c a City class, which stores information about the |
| * vertices in a road map). |
| */ |
| template<typename VertexProperty> |
| struct internal_vertex_name |
| { |
| /** |
| * The @c type field provides a function object that extracts a key |
| * from the @c VertexProperty. The function object type must have a |
| * nested @c result_type that provides the type of the key. For |
| * more information, see the @c KeyExtractor concept in the |
| * Boost.MultiIndex documentation: @c type must either be @c void |
| * (if @c VertexProperty does not have an internal vertex name) or |
| * a model of @c KeyExtractor. |
| */ |
| typedef void type; |
| }; |
| |
| #ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION |
| /** |
| * Extract the internal vertex name from a @c property structure by |
| * looking at its base. |
| */ |
| template<typename Tag, typename T, typename Base> |
| struct internal_vertex_name<property<Tag, T, Base> > |
| : internal_vertex_name<Base> { }; |
| #endif |
| |
| /** |
| * Construct an instance of @c VertexProperty directly from its |
| * name. This function object should be used within the @c |
| * internal_vertex_constructor trait. |
| */ |
| template<typename VertexProperty> |
| struct vertex_from_name |
| { |
| private: |
| typedef typename internal_vertex_name<VertexProperty>::type extract_name_type; |
| |
| typedef typename remove_cv< |
| typename remove_reference< |
| typename extract_name_type::result_type>::type>::type |
| vertex_name_type; |
| |
| public: |
| typedef vertex_name_type argument_type; |
| typedef VertexProperty result_type; |
| |
| VertexProperty operator()(const vertex_name_type& name) |
| { |
| return VertexProperty(name); |
| } |
| }; |
| |
| /** |
| * Throw an exception whenever one tries to construct a @c |
| * VertexProperty instance from its name. |
| */ |
| template<typename VertexProperty> |
| struct cannot_add_vertex |
| { |
| private: |
| typedef typename internal_vertex_name<VertexProperty>::type extract_name_type; |
| |
| typedef typename remove_cv< |
| typename remove_reference< |
| typename extract_name_type::result_type>::type>::type |
| vertex_name_type; |
| |
| public: |
| typedef vertex_name_type argument_type; |
| typedef VertexProperty result_type; |
| |
| VertexProperty operator()(const vertex_name_type& name) |
| { |
| boost::throw_exception(std::runtime_error("add_vertex: " |
| "unable to create a vertex from its name")); |
| } |
| }; |
| |
| /** |
| * @brief Trait used to construct an instance of a @c VertexProperty, |
| * which is a class type that stores the properties associated with a |
| * vertex in a graph, from just the name of that vertex property. This |
| * operation is used when an operation is required to map from a |
| * vertex name to a vertex descriptor (e.g., to add an edge outgoing |
| * from that vertex), but no vertex by the name exists. The function |
| * object provided by this trait will be used to add new vertices |
| * based only on their names. Since this cannot be done for arbitrary |
| * types, the default behavior is to throw an exception when this |
| * routine is called, which requires that all named vertices be added |
| * before adding any edges by name. |
| */ |
| template<typename VertexProperty> |
| struct internal_vertex_constructor |
| { |
| /** |
| * The @c type field provides a function object that constructs a |
| * new instance of @c VertexProperty from the name of the vertex (as |
| * determined by @c internal_vertex_name). The function object shall |
| * accept a vertex name and return a @c VertexProperty. Predefined |
| * options include: |
| * |
| * @c vertex_from_name<VertexProperty>: construct an instance of |
| * @c VertexProperty directly from the name. |
| * |
| * @c cannot_add_vertex<VertexProperty>: the default value, which |
| * throws an @c std::runtime_error if one attempts to add a vertex |
| * given just the name. |
| */ |
| typedef cannot_add_vertex<VertexProperty> type; |
| }; |
| |
| #ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION |
| /** |
| * Extract the internal vertex constructor from a @c property structure by |
| * looking at its base. |
| */ |
| template<typename Tag, typename T, typename Base> |
| struct internal_vertex_constructor<property<Tag, T, Base> > |
| : internal_vertex_constructor<Base> { }; |
| #endif |
| |
| /******************************************************************* |
| * Named graph-specific metafunctions * |
| *******************************************************************/ |
| namespace detail { |
| /** @internal |
| * Extracts the type of a bundled vertex property from a vertex |
| * property. The primary template matches when we have hit the end |
| * of the @c property<> list. |
| */ |
| template<typename VertexProperty> |
| struct extract_bundled_vertex |
| { |
| typedef VertexProperty type; |
| }; |
| |
| /** @internal |
| * Recursively extract the bundled vertex property from a vertex |
| * property. |
| */ |
| template<typename Tag, typename T, typename Base> |
| struct extract_bundled_vertex<property<Tag, T, Base> > |
| : extract_bundled_vertex<Base> |
| { }; |
| |
| /** |
| * We have found the bundled vertex property type, marked with |
| * vertex_bundle_t. |
| */ |
| template<typename T, typename Base> |
| struct extract_bundled_vertex<property<vertex_bundle_t, T, Base> > |
| { |
| typedef T type; |
| }; |
| |
| /** |
| * Translate @c no_property into @c error_property_not_found when we |
| * have failed to extract a bundled vertex property type. |
| */ |
| template<> |
| struct extract_bundled_vertex<no_property> |
| { |
| typedef boost::detail::error_property_not_found type; |
| }; |
| } |
| |
| /******************************************************************* |
| * Named graph mixin * |
| *******************************************************************/ |
| |
| /** |
| * named_graph is a mixin that provides names for the vertices of a |
| * graph, including a mapping from names to vertices. Graph types that |
| * may or may not be have vertex names (depending on the properties |
| * supplied by the user) should use maybe_named_graph. |
| * |
| * Template parameters: |
| * |
| * Graph: the graph type that derives from named_graph |
| * |
| * Vertex: the type of a vertex descriptor in Graph. Note: we cannot |
| * use graph_traits here, because the Graph is not yet defined. |
| * |
| * VertexProperty: the type stored with each vertex in the Graph. |
| */ |
| template<typename Graph, typename Vertex, typename VertexProperty> |
| class named_graph |
| { |
| public: |
| /// The type of the function object that extracts names from vertex |
| /// properties. |
| typedef typename internal_vertex_name<VertexProperty>::type extract_name_type; |
| /// The type of the "bundled" property, from which the name can be |
| /// extracted. |
| typedef typename detail::extract_bundled_vertex<VertexProperty>::type |
| bundled_vertex_property_type; |
| |
| /// The type of the function object that generates vertex properties |
| /// from names, for the implicit addition of vertices. |
| typedef typename internal_vertex_constructor<VertexProperty>::type |
| vertex_constructor_type; |
| |
| /// The type used to name vertices in the graph |
| typedef typename remove_cv< |
| typename remove_reference< |
| typename extract_name_type::result_type>::type>::type |
| vertex_name_type; |
| |
| /// The type of vertex descriptors in the graph |
| typedef Vertex vertex_descriptor; |
| |
| private: |
| /// Key extractor for use with the multi_index_container |
| struct extract_name_from_vertex |
| { |
| typedef vertex_name_type result_type; |
| |
| extract_name_from_vertex(Graph& graph, const extract_name_type& extract) |
| : graph(graph), extract(extract) { } |
| |
| const result_type& operator()(Vertex vertex) const |
| { |
| return extract(graph[vertex]); |
| } |
| |
| Graph& graph; |
| extract_name_type extract; |
| }; |
| |
| public: |
| /// The type that maps names to vertices |
| typedef multi_index::multi_index_container< |
| Vertex, |
| multi_index::indexed_by< |
| multi_index::hashed_unique<multi_index::tag<vertex_name_t>, |
| extract_name_from_vertex> > |
| > named_vertices_type; |
| |
| /// The set of vertices, indexed by name |
| typedef typename named_vertices_type::template index<vertex_name_t>::type |
| vertices_by_name_type; |
| |
| /// Construct an instance of the named graph mixin, using the given |
| /// function object to extract a name from the bundled property |
| /// associated with a vertex. |
| named_graph(const extract_name_type& extract = extract_name_type(), |
| const vertex_constructor_type& vertex_constructor |
| = vertex_constructor_type()); |
| |
| /// Notify the named_graph that we have added the given vertex. The |
| /// name of the vertex will be added to the mapping. |
| void added_vertex(Vertex vertex); |
| |
| /// Notify the named_graph that we are removing the given |
| /// vertex. The name of the vertex will be removed from the mapping. |
| void removing_vertex(Vertex vertex); |
| |
| /// Notify the named_graph that we are clearing the graph. |
| /// This will clear out all of the name->vertex mappings |
| void clearing_graph(); |
| |
| /// Retrieve the derived instance |
| Graph& derived() { return static_cast<Graph&>(*this); } |
| const Graph& derived() const { return static_cast<const Graph&>(*this); } |
| |
| /// Extract the name from a vertex property instance |
| typename extract_name_type::result_type |
| extract_name(const bundled_vertex_property_type& property); |
| |
| /// Search for a vertex that has the given property (based on its |
| /// name) |
| optional<vertex_descriptor> |
| vertex_by_property(const bundled_vertex_property_type& property); |
| |
| /// Mapping from names to vertices |
| named_vertices_type named_vertices; |
| |
| /// Constructs a vertex from the name of that vertex |
| vertex_constructor_type vertex_constructor; |
| }; |
| |
| /// Helper macro containing the template parameters of named_graph |
| #define BGL_NAMED_GRAPH_PARAMS \ |
| typename Graph, typename Vertex, typename VertexProperty |
| /// Helper macro containing the named_graph<...> instantiation |
| #define BGL_NAMED_GRAPH \ |
| named_graph<Graph, Vertex, VertexProperty> |
| |
| template<BGL_NAMED_GRAPH_PARAMS> |
| BGL_NAMED_GRAPH::named_graph(const extract_name_type& extract, |
| const vertex_constructor_type& vertex_constructor) |
| : named_vertices( |
| typename named_vertices_type::ctor_args_list( |
| boost::make_tuple( |
| boost::make_tuple( |
| 0, // initial number of buckets |
| extract_name_from_vertex(derived(), extract), |
| boost::hash<vertex_name_type>(), |
| std::equal_to<vertex_name_type>())))), |
| vertex_constructor(vertex_constructor) |
| { |
| } |
| |
| template<BGL_NAMED_GRAPH_PARAMS> |
| inline void BGL_NAMED_GRAPH::added_vertex(Vertex vertex) |
| { |
| named_vertices.insert(vertex); |
| } |
| |
| template<BGL_NAMED_GRAPH_PARAMS> |
| inline void BGL_NAMED_GRAPH::removing_vertex(Vertex vertex) |
| { |
| named_vertices.erase(vertex); |
| } |
| |
| template<BGL_NAMED_GRAPH_PARAMS> |
| inline void BGL_NAMED_GRAPH::clearing_graph() |
| { |
| named_vertices.clear(); |
| } |
| |
| template<BGL_NAMED_GRAPH_PARAMS> |
| typename BGL_NAMED_GRAPH::extract_name_type::result_type |
| BGL_NAMED_GRAPH::extract_name(const bundled_vertex_property_type& property) |
| { |
| return named_vertices.key_extractor().extract(property); |
| } |
| |
| template<BGL_NAMED_GRAPH_PARAMS> |
| optional<typename BGL_NAMED_GRAPH::vertex_descriptor> |
| BGL_NAMED_GRAPH:: |
| vertex_by_property(const bundled_vertex_property_type& property) |
| { |
| return find_vertex(extract_name(property), *this); |
| } |
| |
| /// Retrieve the vertex associated with the given name |
| template<BGL_NAMED_GRAPH_PARAMS> |
| optional<Vertex> |
| find_vertex(typename BGL_NAMED_GRAPH::vertex_name_type const& name, |
| const BGL_NAMED_GRAPH& g) |
| { |
| typedef typename BGL_NAMED_GRAPH::vertices_by_name_type |
| vertices_by_name_type; |
| |
| // Retrieve the set of vertices indexed by name |
| vertices_by_name_type const& vertices_by_name |
| = g.named_vertices.template get<vertex_name_t>(); |
| |
| /// Look for a vertex with the given name |
| typename vertices_by_name_type::const_iterator iter |
| = vertices_by_name.find(name); |
| |
| if (iter == vertices_by_name.end()) |
| return optional<Vertex>(); // vertex not found |
| else |
| return *iter; |
| } |
| |
| /// Retrieve the vertex associated with the given name, or add a new |
| /// vertex with that name if no such vertex is available. |
| template<BGL_NAMED_GRAPH_PARAMS> |
| Vertex |
| add_vertex(typename BGL_NAMED_GRAPH::vertex_name_type const& name, |
| BGL_NAMED_GRAPH& g) |
| { |
| if (optional<Vertex> vertex = find_vertex(name, g)) |
| /// We found the vertex, so return it |
| return *vertex; |
| else |
| /// There is no vertex with the given name, so create one |
| return add_vertex(g.vertex_constructor(name), g.derived()); |
| } |
| |
| /// Add an edge using vertex names to refer to the vertices |
| template<BGL_NAMED_GRAPH_PARAMS> |
| std::pair<typename graph_traits<Graph>::edge_descriptor, bool> |
| add_edge(typename BGL_NAMED_GRAPH::vertex_name_type const& u_name, |
| typename BGL_NAMED_GRAPH::vertex_name_type const& v_name, |
| BGL_NAMED_GRAPH& g) |
| { |
| return add_edge(add_vertex(u_name, g.derived()), |
| add_vertex(v_name, g.derived()), |
| g.derived()); |
| } |
| |
| /// Add an edge using vertex descriptors or names to refer to the vertices |
| template<BGL_NAMED_GRAPH_PARAMS> |
| std::pair<typename graph_traits<Graph>::edge_descriptor, bool> |
| add_edge(typename BGL_NAMED_GRAPH::vertex_descriptor const& u, |
| typename BGL_NAMED_GRAPH::vertex_name_type const& v_name, |
| BGL_NAMED_GRAPH& g) |
| { |
| return add_edge(u, |
| add_vertex(v_name, g.derived()), |
| g.derived()); |
| } |
| |
| /// Add an edge using vertex descriptors or names to refer to the vertices |
| template<BGL_NAMED_GRAPH_PARAMS> |
| std::pair<typename graph_traits<Graph>::edge_descriptor, bool> |
| add_edge(typename BGL_NAMED_GRAPH::vertex_name_type const& u_name, |
| typename BGL_NAMED_GRAPH::vertex_descriptor const& v, |
| BGL_NAMED_GRAPH& g) |
| { |
| return add_edge(add_vertex(u_name, g.derived()), |
| v, |
| g.derived()); |
| } |
| |
| #undef BGL_NAMED_GRAPH |
| #undef BGL_NAMED_GRAPH_PARAMS |
| |
| /******************************************************************* |
| * Maybe named graph mixin * |
| *******************************************************************/ |
| |
| #ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION |
| /** |
| * A graph mixin that can provide a mapping from names to vertices, |
| * and use that mapping to simplify creation and manipulation of |
| * graphs. |
| */ |
| template<typename Graph, typename Vertex, typename VertexProperty, |
| typename ExtractName |
| = typename internal_vertex_name<VertexProperty>::type> |
| struct maybe_named_graph : public named_graph<Graph, Vertex, VertexProperty> |
| { |
| }; |
| |
| /** |
| * A graph mixin that can provide a mapping from names to vertices, |
| * and use that mapping to simplify creation and manipulation of |
| * graphs. This partial specialization turns off this functionality |
| * when the @c VertexProperty does not have an internal vertex name. |
| */ |
| template<typename Graph, typename Vertex, typename VertexProperty> |
| struct maybe_named_graph<Graph, Vertex, VertexProperty, void> |
| { |
| /// The type of the "bundled" property, from which the name can be |
| /// extracted. |
| typedef typename detail::extract_bundled_vertex<VertexProperty>::type |
| bundled_vertex_property_type; |
| |
| /// Notify the named_graph that we have added the given vertex. This |
| /// is a no-op. |
| void added_vertex(Vertex) { } |
| |
| /// Notify the named_graph that we are removing the given |
| /// vertex. This is a no-op. |
| void removing_vertex(Vertex) { } |
| |
| /// Notify the named_graph that we are clearing the graph. This is a |
| /// no-op. |
| void clearing_graph() { } |
| |
| /// Search for a vertex that has the given property (based on its |
| /// name). This always returns an empty optional<> |
| optional<Vertex> |
| vertex_by_property(const bundled_vertex_property_type&) |
| { |
| return optional<Vertex>(); |
| } |
| }; |
| #else |
| template<typename Graph, typename Vertex, typename VertexProperty, |
| typename ExtractName |
| = typename internal_vertex_name<VertexProperty>::type> |
| struct maybe_named_graph |
| { |
| /// The type of the "bundled" property, from which the name can be |
| /// extracted. |
| typedef typename detail::extract_bundled_vertex<VertexProperty>::type |
| bundled_vertex_property_type; |
| |
| /// Notify the named_graph that we have added the given vertex. This |
| /// is a no-op. |
| void added_vertex(Vertex) { } |
| |
| /// Notify the named_graph that we are removing the given |
| /// vertex. This is a no-op. |
| void removing_vertex(Vertex) { } |
| |
| /// Notify the named_graph that we are clearing the graph. This is a |
| /// no-op. |
| void clearing_graph() { } |
| |
| /// Search for a vertex that has the given property (based on its |
| /// name). This always returns an empty optional<> |
| template<typename Property> |
| optional<Vertex> |
| vertex_by_property(const bundled_vertex_property_type&) |
| { |
| return optional<Vertex>(); |
| } |
| }; |
| #endif // BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION |
| |
| } } // end namespace boost::graph |
| |
| #endif // BOOST_GRAPH_NAMED_GRAPH_HPP |