## AdjacencyMatrix

The AdjacencyMatrix concept refines Graph concept and adds the requirement for efficient access to any edge in the graph given the source and target vertices. No Boost Graph Library algorithms currently use this concept. However there are algorithms not yet implemented such as Floyd-Warshall that would require this concept.

### Refinement of

Graph

### Associated Types

`boost::graph_traits<G>::traversal_category` This tag type must be convertible to `adjacency_matrix_tag`.

### Valid Expressions

Name | Expression | Return Type | Description
--- | --- | --- | ---
Direct Edge Access | `edge(u,v,g)` | `std::pair<edge_descriptor, bool>` | Returns a pair consisting of a flag saying whether there exists an edge between `u` and `v` in graph `g`, and consisting of the edge descriptor if the edge was found.

### Complexity guarantees

The `edge()` function must return in constant time.

### Models

`adjacency_matrix`

### Concept Checking Class

      template <class G>
      struct AdjacencyMatrix
      {
        typedef typename boost::graph_traits<G>::edge_descriptor edge_descriptor;
        void constraints() {
          p = edge(u, v, g);
        }
        typename boost::graph_traits<G>::vertex_descriptor u, v;
        std::pair<bool, edge_descriptor> p;
        G g;
      };

Copyright © 2000-2001 | Jeremy Siek, Indiana University (jsiek@osl.iu.edu)