The Graph concept contains a few requirements that are common to all the graph concepts. These include some associated types for vertex_descriptor, edge_descriptor, etc.
Note: A model of Graph is not required to be a model of Assignable, algorithms should pass graph objects by reference.
| G | A type that is a model of Graph. |
| g | An object of type G. |
boost::graph_traits<G>::vertex_descriptor A vertex descriptor corresponds to a unique vertex in an abstract graph instance. A vertex descriptor must be Default Constructible, Assignable, and Equality Comparable. |
boost::graph_traits<G>::edge_descriptor An edge descriptor corresponds to a unique edge (u,v) in a graph. An edge descriptor must be Default Constructible, Assignable, and Equality Comparable. |
boost::graph_traits<G>::directed_category This type shall be convertible to directed_tag or undirected_tag. |
boost::graph_traits<G>::edge_parallel_category This describes whether the graph class allows the insertion of parallel edges (edges with the same source and target). The two tags are allow_parallel_edge_tag and disallow_parallel_edge_tag. |
boost::graph_traits<G>::traversal_category This describes the ways in which the vertices and edges of the graph can be visited. The choices are incidence_graph_tag, adjacency_graph_tag, bidirectional_graph_tag, vertex_list_graph_tag, edge_list_graph_tag, and adjacency_matrix_tag. |
boost::graph_traits<G>::null_vertex() |
Returns a special boost::graph_traits<G>::vertex_descriptor object which does not refer to any vertex of graph object which type is G. |
template <class G>
struct GraphConcept
{
typedef typename boost::graph_traits<G>::vertex_descriptor vertex_descriptor;
typedef typename boost::graph_traits<G>::edge_descriptor edge_descriptor;
typedef typename boost::graph_traits<G>::directed_category directed_category;
typedef typename boost::graph_traits<G>::edge_parallel_category edge_parallel_category;
typedef typename boost::graph_traits<G>::traversal_category traversal_category;
void constraints() {
function_requires< DefaultConstructibleConcept<vertex_descriptor> >();
function_requires< EqualityComparableConcept<vertex_descriptor> >();
function_requires< AssignableConcept<vertex_descriptor> >();
function_requires< DefaultConstructibleConcept<edge_descriptor> >();
function_requires< EqualityComparableConcept<edge_descriptor> >();
function_requires< AssignableConcept<edge_descriptor> >();
}
G g;
};
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Copyright © 2000-2001 Jeremy Siek, Indiana University ([email protected]) |
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