comparison DEPENDENCIES/generic/include/boost/graph/subgraph.hpp @ 16:2665513ce2d3

Add boost headers

+//=======================================================================
+// Copyright 2001 University of Notre Dame.
+// Authors: Jeremy G. Siek and Lie-Quan Lee
+//
+// 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)
+//=======================================================================
+
+#ifndef BOOST_SUBGRAPH_HPP
+#define BOOST_SUBGRAPH_HPP
+
+// UNDER CONSTRUCTION
+
+#include <boost/config.hpp>
+#include <list>
+#include <vector>
+#include <map>
+#include <boost/assert.hpp>
+#include <boost/graph/graph_traits.hpp>
+#include <boost/graph/graph_mutability_traits.hpp>
+#include <boost/graph/properties.hpp>
+#include <boost/iterator/indirect_iterator.hpp>
+
+#include <boost/static_assert.hpp>
+#include <boost/assert.hpp>
+#include <boost/type_traits.hpp>
+#include <boost/mpl/if.hpp>
+#include <boost/mpl/or.hpp>
+
+namespace boost {
+
+struct subgraph_tag { };
+
+/** @name Property Lookup
+ * The local_property and global_property functions are used to create
+ * structures that determine the lookup strategy for properties in subgraphs.
+ * Note that the nested kind member is used to help interoperate with actual
+ * Property types.
+ */
+//@{
+template <typename T>
+struct local_property
+{
+    typedef T kind;
+    local_property(T x) : value(x) { }
+    T value;
+};
+
+template <typename T>
+inline local_property<T> local(T x)
+{ return local_property<T>(x); }
+
+template <typename T>
+struct global_property
+{
+    typedef T kind;
+    global_property(T x) : value(x) { }
+    T value;
+};
+
+template <typename T>
+inline global_property<T> global(T x)
+{ return global_property<T>(x); }
+//@}
+
+// Invariants of an induced subgraph:
+//   - If vertex u is in subgraph g, then u must be in g.parent().
+//   - If edge e is in subgraph g, then e must be in g.parent().
+//   - If edge e=(u,v) is in the root graph, then edge e
+//     is also in any subgraph that contains both vertex u and v.
+
+// The Graph template parameter must have a vertex_index and edge_index
+// internal property. It is assumed that the vertex indices are assigned
+// automatically by the graph during a call to add_vertex(). It is not
+// assumed that the edge vertices are assigned automatically, they are
+// explicitly assigned here.
+
+template <typename Graph>
+class subgraph {
+    typedef graph_traits<Graph> Traits;
+    typedef std::list<subgraph<Graph>*> ChildrenList;
+public:
+    // Graph requirements
+    typedef typename Traits::vertex_descriptor         vertex_descriptor;
+    typedef typename Traits::edge_descriptor           edge_descriptor;
+    typedef typename Traits::directed_category         directed_category;
+    typedef typename Traits::edge_parallel_category    edge_parallel_category;
+    typedef typename Traits::traversal_category        traversal_category;
+
+    // IncidenceGraph requirements
+    typedef typename Traits::out_edge_iterator         out_edge_iterator;
+    typedef typename Traits::degree_size_type          degree_size_type;
+
+    // AdjacencyGraph requirements
+    typedef typename Traits::adjacency_iterator        adjacency_iterator;
+
+    // VertexListGraph requirements
+    typedef typename Traits::vertex_iterator           vertex_iterator;
+    typedef typename Traits::vertices_size_type        vertices_size_type;
+
+    // EdgeListGraph requirements
+    typedef typename Traits::edge_iterator             edge_iterator;
+    typedef typename Traits::edges_size_type           edges_size_type;
+
+    typedef typename Traits::in_edge_iterator          in_edge_iterator;
+
+    typedef typename edge_property_type<Graph>::type   edge_property_type;
+    typedef typename vertex_property_type<Graph>::type vertex_property_type;
+    typedef subgraph_tag                               graph_tag;
+    typedef Graph                                      graph_type;
+    typedef typename graph_property_type<Graph>::type  graph_property_type;
+
+    // Create the main graph, the root of the subgraph tree
+    subgraph()
+        : m_parent(0), m_edge_counter(0)
+    { }
+
+    subgraph(const graph_property_type& p)
+        : m_graph(p), m_parent(0), m_edge_counter(0)
+    { }
+
+    subgraph(vertices_size_type n, const graph_property_type& p = graph_property_type())
+        : m_graph(n, p), m_parent(0), m_edge_counter(0), m_global_vertex(n)
+    {
+        typename Graph::vertex_iterator v, v_end;
+        vertices_size_type i = 0;
+        for(boost::tie(v, v_end) = vertices(m_graph); v != v_end; ++v)
+            m_global_vertex[i++] = *v;
+    }
+
+    // copy constructor
+    subgraph(const subgraph& x)
+        : m_parent(x.m_parent), m_edge_counter(x.m_edge_counter)
+        , m_global_vertex(x.m_global_vertex), m_global_edge(x.m_global_edge)
+    {
+        if(x.is_root())
+        {
+         m_graph = x.m_graph;
+        }
+        // Do a deep copy (recursive).
+        // Only the root graph is copied, the subgraphs contain
+        // only references to the global vertices they own.
+        typename subgraph<Graph>::children_iterator i,i_end;
+        boost::tie(i,i_end) = x.children();
+        for(; i != i_end; ++i)
+        {         
+         subgraph<Graph> child = this->create_subgraph();
+         child = *i;
+         vertex_iterator vi,vi_end;   
+         boost::tie(vi,vi_end) = vertices(*i);
+         for (;vi!=vi_end;++vi)  
+         {
+          add_vertex(*vi,child);
+         }
+       }
+    }
+
+
+    ~subgraph() {
+      for(typename ChildrenList::iterator i = m_children.begin();
+          i != m_children.end(); ++i)
+        {
+            delete *i;
+        }
+    }
+
+    // Return a null vertex descriptor for the graph.
+    static vertex_descriptor null_vertex()
+    { return Traits::null_vertex(); }
+
+
+    // Create a subgraph
+    subgraph<Graph>& create_subgraph() {
+        m_children.push_back(new subgraph<Graph>());
+        m_children.back()->m_parent = this;
+        return *m_children.back();
+    }
+
+    // Create a subgraph with the specified vertex set.
+    template <typename VertexIterator>
+    subgraph<Graph>& create_subgraph(VertexIterator first, VertexIterator last) {
+        m_children.push_back(new subgraph<Graph>());
+        m_children.back()->m_parent = this;
+        for(; first != last; ++first) {
+            add_vertex(*first, *m_children.back());
+        }
+        return *m_children.back();
+    }
+
+    // local <-> global descriptor conversion functions
+    vertex_descriptor local_to_global(vertex_descriptor u_local) const
+    { return is_root() ? u_local : m_global_vertex[u_local]; }
+
+    vertex_descriptor global_to_local(vertex_descriptor u_global) const {
+        vertex_descriptor u_local; bool in_subgraph;
+        if (is_root()) return u_global;
+        boost::tie(u_local, in_subgraph) = this->find_vertex(u_global);
+        BOOST_ASSERT(in_subgraph == true);
+        return u_local;
+    }
+
+    edge_descriptor local_to_global(edge_descriptor e_local) const
+    { return is_root() ? e_local : m_global_edge[get(get(edge_index, m_graph), e_local)]; }
+
+    edge_descriptor global_to_local(edge_descriptor e_global) const
+    { return is_root() ? e_global : (*m_local_edge.find(get(get(edge_index, root().m_graph), e_global))).second; }
+
+    // Is vertex u (of the root graph) contained in this subgraph?
+    // If so, return the matching local vertex.
+    std::pair<vertex_descriptor, bool>
+    find_vertex(vertex_descriptor u_global) const {
+        if (is_root()) return std::make_pair(u_global, true);
+        typename LocalVertexMap::const_iterator i = m_local_vertex.find(u_global);
+        bool valid = i != m_local_vertex.end();
+        return std::make_pair((valid ? (*i).second : null_vertex()), valid);
+    }
+
+    // Is edge e (of the root graph) contained in this subgraph?
+    // If so, return the matching local edge.
+    std::pair<edge_descriptor, bool>
+    find_edge(edge_descriptor e_global) const {
+        if (is_root()) return std::make_pair(e_global, true);
+        typename LocalEdgeMap::const_iterator i =
+          m_local_edge.find(get(get(edge_index, root().m_graph), e_global));
+        bool valid = i != m_local_edge.end();
+        return std::make_pair((valid ? (*i).second : edge_descriptor()), valid);
+    }
+
+    // Return the parent graph.
+    subgraph& parent() { return *m_parent; }
+    const subgraph& parent() const { return *m_parent; }
+
+    // Return true if this is the root subgraph
+    bool is_root() const { return m_parent == 0; }
+
+    // Return the root graph of the subgraph tree.
+    subgraph& root()
+    { return is_root() ? *this : m_parent->root(); }
+
+    const subgraph& root() const
+    { return is_root() ? *this : m_parent->root(); }
+
+    // Return the children subgraphs of this graph/subgraph.
+    // Use a list of pointers because the VC++ std::list doesn't like
+    // storing incomplete type.
+    typedef indirect_iterator<
+        typename ChildrenList::const_iterator
+      , subgraph<Graph>
+      , std::bidirectional_iterator_tag
+    >
+    children_iterator;
+
+    typedef indirect_iterator<
+        typename ChildrenList::const_iterator
+      , subgraph<Graph> const
+      , std::bidirectional_iterator_tag
+    >
+    const_children_iterator;
+
+    std::pair<const_children_iterator, const_children_iterator> children() const {
+      return std::make_pair(const_children_iterator(m_children.begin()),
+                            const_children_iterator(m_children.end()));
+    }
+
+    std::pair<children_iterator, children_iterator> children() {
+      return std::make_pair(children_iterator(m_children.begin()),
+                            children_iterator(m_children.end()));
+    }
+
+    std::size_t num_children() const { return m_children.size(); }
+
+#ifndef BOOST_GRAPH_NO_BUNDLED_PROPERTIES
+    // Defualt property access delegates the lookup to global properties.
+    template <typename Descriptor>
+    typename graph::detail::bundled_result<Graph, Descriptor>::type&
+    operator[](Descriptor x)
+    { return is_root() ? m_graph[x] : root().m_graph[local_to_global(x)]; }
+
+    template <typename Descriptor>
+    typename graph::detail::bundled_result<Graph, Descriptor>::type const&
+    operator[](Descriptor x) const
+    { return is_root() ? m_graph[x] : root().m_graph[local_to_global(x)]; }
+
+    // Local property access returns the local property of the given descripor.
+    template <typename Descriptor>
+    typename graph::detail::bundled_result<Graph, Descriptor>::type&
+    operator[](local_property<Descriptor> x)
+    { return m_graph[x.value]; }
+
+    template <typename Descriptor>
+    typename graph::detail::bundled_result<Graph, Descriptor>::type const&
+    operator[](local_property<Descriptor> x) const
+    { return m_graph[x.value]; }
+
+    // Global property access returns the global property associated with the
+    // given descriptor. This is an alias for the default bundled property
+    // access operations.
+    template <typename Descriptor>
+    typename graph::detail::bundled_result<Graph, Descriptor>::type&
+    operator[](global_property<Descriptor> x)
+    { return (*this)[x.value]; }
+
+    template <typename Descriptor>
+    typename graph::detail::bundled_result<Graph, Descriptor>::type const&
+    operator[](global_property<Descriptor> x) const
+    { return (*this)[x.value]; }
+
+#endif // BOOST_GRAPH_NO_BUNDLED_PROPERTIES
+
+    //  private:
+    typedef typename property_map<Graph, edge_index_t>::type EdgeIndexMap;
+    typedef typename property_traits<EdgeIndexMap>::value_type edge_index_type;
+    BOOST_STATIC_ASSERT((!is_same<edge_index_type,
+                        boost::detail::error_property_not_found>::value));
+
+private:
+    typedef std::vector<vertex_descriptor> GlobalVertexList;
+    typedef std::vector<edge_descriptor> GlobalEdgeList;
+    typedef std::map<vertex_descriptor, vertex_descriptor> LocalVertexMap;
+    typedef std::map<edge_index_type, edge_descriptor> LocalEdgeMap;
+    // TODO: Should the LocalVertexMap be: map<index_type, descriptor>?
+    // TODO: Can we relax the indexing requirement if both descriptors are
+    // LessThanComparable?
+    // TODO: Should we really be using unorderd_map for improved lookup times?
+
+public: // Probably shouldn't be public....
+    Graph m_graph;
+    subgraph<Graph>* m_parent;
+    edge_index_type m_edge_counter; // for generating unique edge indices
+    ChildrenList m_children;
+    GlobalVertexList m_global_vertex; // local -> global
+    LocalVertexMap m_local_vertex;  // global -> local
+    GlobalEdgeList m_global_edge;              // local -> global
+    LocalEdgeMap m_local_edge; // global -> local
+
+    edge_descriptor local_add_edge(vertex_descriptor u_local,
+                                   vertex_descriptor v_local,
+                                   edge_descriptor e_global)
+    {
+        edge_descriptor e_local;
+        bool inserted;
+        boost::tie(e_local, inserted) = add_edge(u_local, v_local, m_graph);
+        put(edge_index, m_graph, e_local, m_edge_counter++);
+        m_global_edge.push_back(e_global);
+        m_local_edge[get(get(edge_index, this->root()), e_global)] = e_local;
+        return e_local;
+    }
+};
+
+template <typename Graph>
+struct vertex_bundle_type<subgraph<Graph> >
+    : vertex_bundle_type<Graph>
+{ };
+
+template<typename Graph>
+struct edge_bundle_type<subgraph<Graph> >
+    : edge_bundle_type<Graph>
+{ };
+
+template<typename Graph>
+struct graph_bundle_type<subgraph<Graph> >
+    : graph_bundle_type<Graph>
+{ };
+
+//===========================================================================
+// Functions special to the Subgraph Class
+
+template <typename G>
+typename subgraph<G>::vertex_descriptor
+add_vertex(typename subgraph<G>::vertex_descriptor u_global,
+           subgraph<G>& g)
+{
+    BOOST_ASSERT(!g.is_root());
+    typename subgraph<G>::vertex_descriptor u_local, v_global;
+    typename subgraph<G>::edge_descriptor e_global;
+
+    u_local = add_vertex(g.m_graph);
+    g.m_global_vertex.push_back(u_global);
+    g.m_local_vertex[u_global] = u_local;
+
+    subgraph<G>& r = g.root();
+
+    // remember edge global and local maps
+    {
+        typename subgraph<G>::out_edge_iterator ei, ei_end;
+        for (boost::tie(ei, ei_end) = out_edges(u_global, r);
+            ei != ei_end; ++ei) {
+            e_global = *ei;
+            v_global = target(e_global, r);
+            if (g.find_vertex(v_global).second == true)
+            g.local_add_edge(u_local, g.global_to_local(v_global), e_global);
+        }
+    }
+    if (is_directed(g)) { // not necessary for undirected graph
+        typename subgraph<G>::vertex_iterator vi, vi_end;
+        typename subgraph<G>::out_edge_iterator ei, ei_end;
+        for(boost::tie(vi, vi_end) = vertices(r); vi != vi_end; ++vi) {
+            v_global = *vi;
+            if (v_global == u_global)
+                continue; // don't insert self loops twice!
+            if (!g.find_vertex(v_global).second)
+                continue; // not a subgraph vertex => try next one
+            for(boost::tie(ei, ei_end) = out_edges(*vi, r); ei != ei_end; ++ei) {
+                e_global = *ei;
+                if(target(e_global, r) == u_global) {
+                    g.local_add_edge(g.global_to_local(v_global), u_local, e_global);
+                }
+            }
+        }
+    }
+
+    return u_local;
+}
+
+// NOTE: Descriptors are local unless otherwise noted.
+
+//===========================================================================
+// Functions required by the IncidenceGraph concept
+
+template <typename G>
+std::pair<typename graph_traits<G>::out_edge_iterator,
+          typename graph_traits<G>::out_edge_iterator>
+out_edges(typename graph_traits<G>::vertex_descriptor v, const subgraph<G>& g)
+{ return out_edges(v, g.m_graph); }
+
+template <typename G>
+typename graph_traits<G>::degree_size_type
+out_degree(typename graph_traits<G>::vertex_descriptor v, const subgraph<G>& g)
+{ return out_degree(v, g.m_graph); }
+
+template <typename G>
+typename graph_traits<G>::vertex_descriptor
+source(typename graph_traits<G>::edge_descriptor e, const subgraph<G>& g)
+{ return source(e, g.m_graph); }
+
+template <typename G>
+typename graph_traits<G>::vertex_descriptor
+target(typename graph_traits<G>::edge_descriptor e, const subgraph<G>& g)
+{ return target(e, g.m_graph); }
+
+//===========================================================================
+// Functions required by the BidirectionalGraph concept
+
+template <typename G>
+std::pair<typename graph_traits<G>::in_edge_iterator,
+          typename graph_traits<G>::in_edge_iterator>
+in_edges(typename graph_traits<G>::vertex_descriptor v, const subgraph<G>& g)
+{ return in_edges(v, g.m_graph); }
+
+template <typename G>
+typename graph_traits<G>::degree_size_type
+in_degree(typename graph_traits<G>::vertex_descriptor v, const subgraph<G>& g)
+{ return in_degree(v, g.m_graph); }
+
+template <typename G>
+typename graph_traits<G>::degree_size_type
+degree(typename graph_traits<G>::vertex_descriptor v, const subgraph<G>& g)
+{ return degree(v, g.m_graph); }
+
+//===========================================================================
+// Functions required by the AdjacencyGraph concept
+
+template <typename G>
+std::pair<typename subgraph<G>::adjacency_iterator,
+          typename subgraph<G>::adjacency_iterator>
+adjacent_vertices(typename subgraph<G>::vertex_descriptor v, const subgraph<G>& g)
+{ return adjacent_vertices(v, g.m_graph); }
+
+//===========================================================================
+// Functions required by the VertexListGraph concept
+
+template <typename G>
+std::pair<typename subgraph<G>::vertex_iterator,
+          typename subgraph<G>::vertex_iterator>
+vertices(const subgraph<G>& g)
+{ return vertices(g.m_graph); }
+
+template <typename G>
+typename subgraph<G>::vertices_size_type
+num_vertices(const subgraph<G>& g)
+{ return num_vertices(g.m_graph); }
+
+//===========================================================================
+// Functions required by the EdgeListGraph concept
+
+template <typename G>
+std::pair<typename subgraph<G>::edge_iterator,
+          typename subgraph<G>::edge_iterator>
+edges(const subgraph<G>& g)
+{ return edges(g.m_graph); }
+
+template <typename G>
+typename subgraph<G>::edges_size_type
+num_edges(const subgraph<G>& g)
+{ return num_edges(g.m_graph); }
+
+//===========================================================================
+// Functions required by the AdjacencyMatrix concept
+
+template <typename G>
+std::pair<typename subgraph<G>::edge_descriptor, bool>
+edge(typename subgraph<G>::vertex_descriptor u,
+     typename subgraph<G>::vertex_descriptor v,
+     const subgraph<G>& g)
+{ return edge(u, v, g.m_graph); }
+
+//===========================================================================
+// Functions required by the MutableGraph concept
+
+namespace detail {
+
+    template <typename Vertex, typename Edge, typename Graph>
+    void add_edge_recur_down(Vertex u_global, Vertex v_global, Edge e_global,
+                             subgraph<Graph>& g);
+
+    template <typename Vertex, typename Edge, typename Children, typename G>
+    void children_add_edge(Vertex u_global, Vertex v_global, Edge e_global,
+                           Children& c, subgraph<G>* orig)
+    {
+        for(typename Children::iterator i = c.begin(); i != c.end(); ++i) {
+            if ((*i)->find_vertex(u_global).second &&
+                (*i)->find_vertex(v_global).second)
+            {
+                add_edge_recur_down(u_global, v_global, e_global, **i, orig);
+            }
+        }
+    }
+
+    template <typename Vertex, typename Edge, typename Graph>
+    void add_edge_recur_down(Vertex u_global, Vertex v_global, Edge e_global,
+                             subgraph<Graph>& g, subgraph<Graph>* orig)
+    {
+        if(&g != orig ) {
+            // add local edge only if u_global and v_global are in subgraph g
+            Vertex u_local, v_local;
+            bool u_in_subgraph, v_in_subgraph;
+            boost::tie(u_local, u_in_subgraph) = g.find_vertex(u_global);
+            boost::tie(v_local, v_in_subgraph) = g.find_vertex(v_global);
+            if(u_in_subgraph && v_in_subgraph) {
+                g.local_add_edge(u_local, v_local, e_global);
+            }
+        }
+        children_add_edge(u_global, v_global, e_global, g.m_children, orig);
+    }
+
+    template <typename Vertex, typename Graph>
+    std::pair<typename subgraph<Graph>::edge_descriptor, bool>
+    add_edge_recur_up(Vertex u_global, Vertex v_global,
+                      const typename Graph::edge_property_type& ep,
+                      subgraph<Graph>& g, subgraph<Graph>* orig)
+    {
+        if(g.is_root()) {
+            typename subgraph<Graph>::edge_descriptor e_global;
+            bool inserted;
+            boost::tie(e_global, inserted) = add_edge(u_global, v_global, ep, g.m_graph);
+            put(edge_index, g.m_graph, e_global, g.m_edge_counter++);
+            g.m_global_edge.push_back(e_global);
+            children_add_edge(u_global, v_global, e_global, g.m_children, orig);
+            return std::make_pair(e_global, inserted);
+        } else {
+            return add_edge_recur_up(u_global, v_global, ep, *g.m_parent, orig);
+        }
+    }
+
+} // namespace detail
+
+// Add an edge to the subgraph g, specified by the local vertex descriptors u
+// and v. In addition, the edge will be added to any (all) other subgraphs that
+// contain vertex descriptors u and v.
+
+template <typename G>
+std::pair<typename subgraph<G>::edge_descriptor, bool>
+add_edge(typename subgraph<G>::vertex_descriptor u,
+         typename subgraph<G>::vertex_descriptor v,
+         const typename G::edge_property_type& ep,
+         subgraph<G>& g)
+{
+    if (g.is_root()) {
+        // u and v are really global
+        return detail::add_edge_recur_up(u, v, ep, g, &g);
+    } else {
+        typename subgraph<G>::edge_descriptor e_local, e_global;
+        bool inserted;
+        boost::tie(e_global, inserted) =
+            detail::add_edge_recur_up(g.local_to_global(u),
+                                      g.local_to_global(v),
+                                      ep, g, &g);
+        e_local = g.local_add_edge(u, v, e_global);
+        return std::make_pair(e_local, inserted);
+    }
+}
+
+template <typename G>
+std::pair<typename subgraph<G>::edge_descriptor, bool>
+add_edge(typename subgraph<G>::vertex_descriptor u,
+         typename subgraph<G>::vertex_descriptor v,
+         subgraph<G>& g)
+{ return add_edge(u, v, typename G::edge_property_type(), g); }
+
+namespace detail {
+    //-------------------------------------------------------------------------
+    // implementation of remove_edge(u,v,g)
+    template <typename Vertex, typename Graph>
+    void remove_edge_recur_down(Vertex u_global, Vertex v_global,
+                                subgraph<Graph>& g);
+
+    template <typename Vertex, typename Children>
+    void children_remove_edge(Vertex u_global, Vertex v_global,
+                              Children& c)
+    {
+        for(typename Children::iterator i = c.begin(); i != c.end(); ++i) {
+            if((*i)->find_vertex(u_global).second &&
+               (*i)->find_vertex(v_global).second)
+            {
+                remove_edge_recur_down(u_global, v_global, **i);
+            }
+        }
+    }
+
+    template <typename Vertex, typename Graph>
+    void remove_edge_recur_down(Vertex u_global, Vertex v_global,
+                                subgraph<Graph>& g)
+    {
+        Vertex u_local, v_local;
+        u_local = g.m_local_vertex[u_global];
+        v_local = g.m_local_vertex[v_global];
+        remove_edge(u_local, v_local, g.m_graph);
+        children_remove_edge(u_global, v_global, g.m_children);
+    }
+
+    template <typename Vertex, typename Graph>
+    void remove_edge_recur_up(Vertex u_global, Vertex v_global,
+                              subgraph<Graph>& g)
+    {
+        if(g.is_root()) {
+            remove_edge(u_global, v_global, g.m_graph);
+            children_remove_edge(u_global, v_global, g.m_children);
+        } else {
+            remove_edge_recur_up(u_global, v_global, *g.m_parent);
+        }
+    }
+
+    //-------------------------------------------------------------------------
+    // implementation of remove_edge(e,g)
+
+    template <typename G, typename Edge, typename Children>
+    void children_remove_edge(Edge e_global, Children& c)
+    {
+        for(typename Children::iterator i = c.begin(); i != c.end(); ++i) {
+            std::pair<typename subgraph<G>::edge_descriptor, bool> found =
+              (*i)->find_edge(e_global);
+            if (!found.second) {
+              continue;
+            }
+            children_remove_edge<G>(e_global, (*i)->m_children);
+            remove_edge(found.first, (*i)->m_graph);
+        }
+    }
+
+} // namespace detail
+
+template <typename G>
+void
+remove_edge(typename subgraph<G>::vertex_descriptor u,
+            typename subgraph<G>::vertex_descriptor v,
+            subgraph<G>& g)
+{
+    if(g.is_root()) {
+        detail::remove_edge_recur_up(u, v, g);
+    } else {
+        detail::remove_edge_recur_up(g.local_to_global(u),
+                                     g.local_to_global(v), g);
+    }
+}
+
+template <typename G>
+void
+remove_edge(typename subgraph<G>::edge_descriptor e, subgraph<G>& g)
+{
+    typename subgraph<G>::edge_descriptor e_global = g.local_to_global(e);
+#ifndef NDEBUG
+    std::pair<typename subgraph<G>::edge_descriptor, bool> fe = g.find_edge(e_global);
+    BOOST_ASSERT(fe.second && fe.first == e);
+#endif //NDEBUG
+    subgraph<G> &root = g.root(); // chase to root
+    detail::children_remove_edge<G>(e_global, root.m_children);
+    remove_edge(e_global, root.m_graph); // kick edge from root
+}
+
+// This is slow, but there may not be a good way to do it safely otherwise
+template <typename Predicate, typename G>
+void
+remove_edge_if(Predicate p, subgraph<G>& g) {
+  while (true) {
+    bool any_removed = false;
+    typedef typename subgraph<G>::edge_iterator ei_type;
+    for (std::pair<ei_type, ei_type> ep = edges(g);
+         ep.first != ep.second; ++ep.first) {
+      if (p(*ep.first)) {
+        any_removed = true;
+        remove_edge(*ep.first, g);
+        break; /* Since iterators may be invalidated */
+      }
+    }
+    if (!any_removed) break;
+  }
+}
+
+template <typename G>
+void
+clear_vertex(typename subgraph<G>::vertex_descriptor v, subgraph<G>& g) {
+  while (true) {
+    typedef typename subgraph<G>::out_edge_iterator oei_type;
+    std::pair<oei_type, oei_type> p = out_edges(v, g);
+    if (p.first == p.second) break;
+    remove_edge(*p.first, g);
+  }
+}
+
+namespace detail {
+    template <typename G>
+    typename subgraph<G>::vertex_descriptor
+    add_vertex_recur_up(subgraph<G>& g)
+    {
+        typename subgraph<G>::vertex_descriptor u_local, u_global;
+        if (g.is_root()) {
+            u_global = add_vertex(g.m_graph);
+            g.m_global_vertex.push_back(u_global);
+        } else {
+            u_global = add_vertex_recur_up(*g.m_parent);
+            u_local = add_vertex(g.m_graph);
+            g.m_global_vertex.push_back(u_global);
+            g.m_local_vertex[u_global] = u_local;
+        }
+        return u_global;
+    }
+} // namespace detail
+
+template <typename G>
+typename subgraph<G>::vertex_descriptor
+add_vertex(subgraph<G>& g)
+{
+    typename subgraph<G>::vertex_descriptor  u_local, u_global;
+    if(g.is_root()) {
+        u_global = add_vertex(g.m_graph);
+        g.m_global_vertex.push_back(u_global);
+        u_local = u_global;
+    } else {
+        u_global = detail::add_vertex_recur_up(g.parent());
+        u_local = add_vertex(g.m_graph);
+        g.m_global_vertex.push_back(u_global);
+        g.m_local_vertex[u_global] = u_local;
+    }
+    return u_local;
+}
+
+
+#if 0
+// TODO: Under Construction
+template <typename G>
+void remove_vertex(typename subgraph<G>::vertex_descriptor u, subgraph<G>& g)
+{ BOOST_ASSERT(false); }
+#endif
+
+//===========================================================================
+// Functions required by the PropertyGraph concept
+
+/**
+ * The global property map returns the global properties associated with local
+ * descriptors.
+ */
+template <typename GraphPtr, typename PropertyMap, typename Tag>
+class subgraph_global_property_map
+    : public put_get_helper<
+        typename property_traits<PropertyMap>::reference,
+        subgraph_global_property_map<GraphPtr, PropertyMap, Tag>
+    >
+{
+    typedef property_traits<PropertyMap> Traits;
+public:
+    typedef typename mpl::if_<is_const<typename remove_pointer<GraphPtr>::type>,
+                              readable_property_map_tag,
+                              typename Traits::category>::type
+      category;
+    typedef typename Traits::value_type value_type;
+    typedef typename Traits::key_type key_type;
+    typedef typename Traits::reference reference;
+
+    subgraph_global_property_map()
+    { }
+
+    subgraph_global_property_map(GraphPtr g, Tag tag)
+        : m_g(g), m_tag(tag)
+    { }
+
+    reference operator[](key_type e) const {
+        PropertyMap pmap = get(m_tag, m_g->root().m_graph);
+        return m_g->is_root()
+            ? pmap[e]
+            : pmap[m_g->local_to_global(e)];
+    }
+
+    GraphPtr m_g;
+    Tag m_tag;
+};
+
+/**
+ * The local property map returns the local property associated with the local
+ * descriptors.
+ */
+template <typename GraphPtr, typename PropertyMap, typename Tag>
+class subgraph_local_property_map
+    : public put_get_helper<
+        typename property_traits<PropertyMap>::reference,
+        subgraph_local_property_map<GraphPtr, PropertyMap, Tag>
+    >
+{
+    typedef property_traits<PropertyMap> Traits;
+public:
+    typedef typename mpl::if_<is_const<typename remove_pointer<GraphPtr>::type>,
+                              readable_property_map_tag,
+                              typename Traits::category>::type
+      category;
+    typedef typename Traits::value_type value_type;
+    typedef typename Traits::key_type key_type;
+    typedef typename Traits::reference reference;
+
+    typedef Tag tag;
+    typedef PropertyMap pmap;
+
+    subgraph_local_property_map()
+    { }
+
+    subgraph_local_property_map(GraphPtr g, Tag tag)
+        : m_g(g), m_tag(tag)
+    { }
+
+    reference operator[](key_type e) const {
+        // Get property map on the underlying graph.
+        PropertyMap pmap = get(m_tag, m_g->m_graph);
+        return pmap[e];
+    }
+
+    GraphPtr m_g;
+    Tag m_tag;
+};
+
+namespace detail {
+    // Extract the actual tags from local or global property maps so we don't
+    // try to find non-properties.
+    template <typename P> struct extract_lg_tag { typedef P type; };
+    template <typename P> struct extract_lg_tag< local_property<P> > {
+        typedef P type;
+    };
+    template <typename P> struct extract_lg_tag< global_property<P> > {
+        typedef P type;
+    };
+
+    // NOTE: Mysterious Property template parameter unused in both metafunction
+    // classes.
+    struct subgraph_global_pmap {
+        template <class Tag, class SubGraph, class Property>
+        struct bind_ {
+            typedef typename SubGraph::graph_type Graph;
+            typedef SubGraph* SubGraphPtr;
+            typedef const SubGraph* const_SubGraphPtr;
+            typedef typename extract_lg_tag<Tag>::type TagType;
+            typedef typename property_map<Graph, TagType>::type PMap;
+            typedef typename property_map<Graph, TagType>::const_type const_PMap;
+        public:
+            typedef subgraph_global_property_map<SubGraphPtr, PMap, TagType> type;
+            typedef subgraph_global_property_map<const_SubGraphPtr, const_PMap, TagType>
+            const_type;
+        };
+    };
+
+    struct subgraph_local_pmap {
+        template <class Tag, class SubGraph, class Property>
+        struct bind_ {
+            typedef typename SubGraph::graph_type Graph;
+            typedef SubGraph* SubGraphPtr;
+            typedef const SubGraph* const_SubGraphPtr;
+            typedef typename extract_lg_tag<Tag>::type TagType;
+            typedef typename property_map<Graph, TagType>::type PMap;
+            typedef typename property_map<Graph, TagType>::const_type const_PMap;
+        public:
+            typedef subgraph_local_property_map<SubGraphPtr, PMap, TagType> type;
+            typedef subgraph_local_property_map<const_SubGraphPtr, const_PMap, TagType>
+            const_type;
+        };
+    };
+
+    // These metafunctions select the corresponding metafunctions above, and
+    // are used by the choose_pmap metafunction below to specialize the choice
+    // of local/global property map. By default, we defer to the global
+    // property.
+    template <class Tag>
+    struct subgraph_choose_pmap_helper {
+        typedef subgraph_global_pmap type;
+    };
+    template <class Tag>
+    struct subgraph_choose_pmap_helper< local_property<Tag> > {
+        typedef subgraph_local_pmap type;
+    };
+    template <class Tag>
+    struct subgraph_choose_pmap_helper< global_property<Tag> > {
+        typedef subgraph_global_pmap type;
+    };
+
+    // As above, unless we're requesting vertex_index_t. Then it's always a
+    // local property map. This enables the correct translation of descriptors
+    // between local and global layers.
+    template <>
+    struct subgraph_choose_pmap_helper<vertex_index_t> {
+        typedef subgraph_local_pmap type;
+    };
+    template <>
+    struct subgraph_choose_pmap_helper< local_property<vertex_index_t> > {
+        typedef subgraph_local_pmap type;
+    };
+    template <>
+    struct subgraph_choose_pmap_helper< global_property<vertex_index_t> > {
+        typedef subgraph_local_pmap type;
+    };
+
+    // Determine the kind of property. If SameType<Tag, vertex_index_t>, then
+    // the property lookup is always local. Otherwise, the lookup is global.
+    // NOTE: Property parameter is basically unused.
+    template <class Tag, class Graph, class Property>
+    struct subgraph_choose_pmap {
+        typedef typename subgraph_choose_pmap_helper<Tag>::type Helper;
+        typedef typename Helper::template bind_<Tag, Graph, Property> Bind;
+        typedef typename Bind::type type;
+        typedef typename Bind::const_type const_type;
+    };
+
+    // Used by the vertex/edge property selectors to determine the kind(s) of
+    // property maps used by the property_map type generator.
+    struct subgraph_property_generator {
+        template <class SubGraph, class Property, class Tag>
+        struct bind_ {
+            typedef subgraph_choose_pmap<Tag, SubGraph, Property> Choice;
+            typedef typename Choice::type type;
+            typedef typename Choice::const_type const_type;
+        };
+    };
+
+  } // namespace detail
+
+template <>
+struct vertex_property_selector<subgraph_tag> {
+    typedef detail::subgraph_property_generator type;
+};
+
+template <>
+struct edge_property_selector<subgraph_tag> {
+    typedef detail::subgraph_property_generator type;
+};
+
+// ==================================================
+// get(p, g), get(p, g, k), and put(p, g, k, v)
+// ==================================================
+template <typename G, typename Property>
+typename property_map<subgraph<G>, Property>::type
+get(Property p, subgraph<G>& g) {
+    typedef typename property_map< subgraph<G>, Property>::type PMap;
+    return PMap(&g, p);
+}
+
+template <typename G, typename Property>
+typename property_map<subgraph<G>, Property>::const_type
+get(Property p, const subgraph<G>& g) {
+    typedef typename property_map< subgraph<G>, Property>::const_type PMap;
+    return PMap(&g, p);
+}
+
+template <typename G, typename Property, typename Key>
+typename property_traits<
+    typename property_map<subgraph<G>, Property>::const_type
+>::value_type
+get(Property p, const subgraph<G>& g, const Key& k) {
+    typedef typename property_map< subgraph<G>, Property>::const_type PMap;
+    PMap pmap(&g, p);
+    return pmap[k];
+}
+
+template <typename G, typename Property, typename Key, typename Value>
+void put(Property p, subgraph<G>& g, const Key& k, const Value& val) {
+    typedef typename property_map< subgraph<G>, Property>::type PMap;
+    PMap pmap(&g, p);
+    pmap[k] = val;
+}
+
+// ==================================================
+// get(global(p), g)
+// NOTE: get(global(p), g, k) and put(global(p), g, k, v) not supported
+// ==================================================
+template <typename G, typename Property>
+typename property_map<subgraph<G>, global_property<Property> >::type
+get(global_property<Property> p, subgraph<G>& g) {
+    typedef typename property_map<
+        subgraph<G>, global_property<Property>
+    >::type Map;
+    return Map(&g, p.value);
+}
+
+template <typename G, typename Property>
+typename property_map<subgraph<G>, global_property<Property> >::const_type
+get(global_property<Property> p, const subgraph<G>& g) {
+    typedef typename property_map<
+        subgraph<G>, global_property<Property>
+    >::const_type Map;
+    return Map(&g, p.value);
+}
+
+// ==================================================
+// get(local(p), g)
+// NOTE: get(local(p), g, k) and put(local(p), g, k, v) not supported
+// ==================================================
+template <typename G, typename Property>
+typename property_map<subgraph<G>, local_property<Property> >::type
+get(local_property<Property> p, subgraph<G>& g) {
+    typedef typename property_map<
+        subgraph<G>, local_property<Property>
+    >::type Map;
+    return Map(&g, p.value);
+}
+
+template <typename G, typename Property>
+typename property_map<subgraph<G>, local_property<Property> >::const_type
+get(local_property<Property> p, const subgraph<G>& g) {
+    typedef typename property_map<
+        subgraph<G>, local_property<Property>
+    >::const_type Map;
+    return Map(&g, p.value);
+}
+
+template <typename G, typename Tag>
+inline typename graph_property<G, Tag>::type&
+get_property(subgraph<G>& g, Tag tag) {
+    return get_property(g.m_graph, tag);
+}
+
+template <typename G, typename Tag>
+inline const typename graph_property<G, Tag>::type&
+get_property(const subgraph<G>& g, Tag tag) {
+    return get_property(g.m_graph, tag);
+}
+
+//===========================================================================
+// Miscellaneous Functions
+
+template <typename G>
+typename subgraph<G>::vertex_descriptor
+vertex(typename subgraph<G>::vertices_size_type n, const subgraph<G>& g)
+{ return vertex(n, g.m_graph); }
+
+//===========================================================================
+// Mutability Traits
+// Just pull the mutability traits form the underlying graph. Note that this
+// will probably fail (badly) for labeled graphs.
+template <typename G>
+struct graph_mutability_traits< subgraph<G> > {
+    typedef typename graph_mutability_traits<G>::category category;
+};
+
+} // namespace boost
+
+#endif // BOOST_SUBGRAPH_HPP