Semantics: Try to insert the edge (u,v) into the graph,
returning the inserted edge or a parallel edge and a flag that
specifies whether an edge was inserted. This operation must not
invalidate vertex descriptors or vertex iterators of the graph, though
it may invalidate edge descriptors or edge iterators. Preconditions:u and v are vertices in the
graph. Postconditions:(u,v) is in the edge set of
the graph. The returned edge descriptor will have u in the
source position and v in the target position. If the graph
allows parallel edges, then the returned flag is always
true. If the graph does not allow parallel edges, if
(u,v) was already in the graph then the returned flag is
false. If (u,v) was not in the graph then the returned
flag is true.
Semantics: Remove the edge (u,v) from the graph. If the
graph allows parallel edges this removes all occurrences of (u,v). Precondition:(u,v) is in the edge set of the graph. Postcondition:(u,v) is no longer in the edge set of the graph.
Semantics: Remove all edges to and from vertex u from the graph. Precondition:u is a valid vertex descriptor of
g. Postconditions:u does not appear as a
source or target of any edge in g.
