Graph
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., and the
num_vertices() and num_edges() functions. One should
note that a model of Graph is not required to be a model of Assignable,
so algorithms should pass graph objects by reference.
Notation
| G |
A type that is a model of Graph. |
| g |
An object of type G. |
Associated Types
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
The choices are directed_tag and 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.
|
Valid Expressions
None required.
Concept Checking Class
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;
};
See Also
Graph concepts