property_writer
Writes the property value of a vertex or edge to an output iterator when an event occurs. Useful for debugging or logging during graph traversal.
Defined in: <boost/graph/visitors.hpp>
Models: EventVisitor
Typical event: on_discover_vertex, on_examine_edge
Example
#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/breadth_first_search.hpp>
#include <boost/graph/visitors.hpp>
#include <iostream>
#include <iterator>
int main() {
using namespace boost;
using Graph = adjacency_list<vecS, vecS, undirectedS>;
Graph g(5);
add_edge(0, 1, g);
add_edge(0, 2, g);
add_edge(1, 3, g);
add_edge(2, 4, g);
// Print vertex indices as they are discovered
std::ostream_iterator<int> out(std::cout, " ");
auto vis = make_bfs_visitor(
write_property(get(vertex_index, g), out, on_discover_vertex())
);
std::cout << "BFS discovery order: ";
breadth_first_search(g, vertex(0, g), visitor(vis));
std::cout << "\n";
}BFS discovery order: 0 1 2 3 4Synopsis
template <typename PropertyMap, typename OutputIterator, typename EventTag>
struct property_writer;
template <typename PropertyMap, typename OutputIterator, typename EventTag>
property_writer<PropertyMap, OutputIterator, EventTag>
write_property(PropertyMap pa, OutputIterator out, EventTag);