Returns the set of labels associated with edge "e" (and also the labels
associated with the sibling of "e" if edge_type() is UNDIRECTED).
Labels are sorted and duplicate labels are automatically removed.
This method uses an output parameter rather than returning by value in
order to avoid allocating a new vector on every call to this method.
Returns the set of labels associated with edge "e" (and also the labels associated with the sibling of "e" if edge_type() is UNDIRECTED). Labels are sorted and duplicate labels are automatically removed.
This method uses an output parameter rather than returning by value in order to avoid allocating a new vector on every call to this method.