From ce845156b8a69ad6f32bb2db2ae5290374dbb0b5 Mon Sep 17 00:00:00 2001
From: Jeremiah Willcock <jewillco@osl.iu.edu>
Date: Tue, 3 Apr 2012 04:44:40 +0000
Subject: [PATCH] Added null_vertex()

[SVN r77733]
---
 include/boost/graph/vector_as_graph.hpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/boost/graph/vector_as_graph.hpp b/include/boost/graph/vector_as_graph.hpp
index c1799993..7bc8ac38 100644
--- a/include/boost/graph/vector_as_graph.hpp
+++ b/include/boost/graph/vector_as_graph.hpp
@@ -79,6 +79,7 @@ namespace boost {
     typedef typename std::vector<EdgeList>::size_type vertices_size_type;
     typedef void edges_size_type;
     typedef typename EdgeList::size_type degree_size_type;
+    static V null_vertex() {return V(-1);}
   };
   template <class EdgeList>
   struct edge_property_type< std::vector<EdgeList> >