/*
 *  ex_remove_if.cpp
 *
 * Formatted with tabstops = 4
 *
 */

#include <iostream>
#include <utility>
#include <boost/graph/graph_traits.hpp>
#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/graph_utility.hpp>

template<typename WMap>
class Remover
{
public:
	Remover(const WMap& weights, int threshold)
	: m_weights(weights), m_threshold(threshold) {}
	
	template<typename ED>
	bool operator()(ED w) const { return m_weights[w] < m_threshold; }

private:
	const WMap&	m_weights;
	int			m_threshold;
};

using namespace boost;

int
main()
{
    // create typedefs for the Graph, Edge and weight_map types
    typedef adjacency_list<vecS, vecS, undirectedS,
			no_property, property<edge_weight_t, int> >	Graph;
    typedef std::pair<int, int>							Edge;
	typedef property_map<Graph, edge_weight_t>::type	weight_map_type;
	
    // Make convenient labels for the vertices
    enum { A, B, C, D, E, N };
    const int	num_vertices = N;
    const char*	name = "ABCDE";
	
	int			weights[] = { 1, 2, 1, 2, 7, 3, 1, 3, 1 };
    Edge		edge_array[] = { Edge(A, C), Edge(B, B), Edge(B, D), Edge(B, E),
					Edge(C, B), Edge(C, D), Edge(D, E), Edge(E, A), Edge(E, B) };
    const int	num_edges = sizeof(edge_array)/sizeof(edge_array[0]);
	
    // declare a graph object
	Graph			g(edge_array, edge_array + num_edges, weights, num_vertices);
	
	// print the graph before deleting edges
	std::cout << "Graph Before remove_edge_if:\n";
	print_graph(g, name);
	
	// remove edges of weight < 2
	Remover<weight_map_type>	r(get(edge_weight, g), 2);
	remove_edge_if(r, g);
	
	// print the graph after deleting edges
	std::cout << "\nGraph After remove_edge_if:\n";
	print_graph(g, name);
	
	return 0;
}