id	summary	reporter	owner	description	type	status	milestone	component	version	severity	resolution	keywords	cc
12038	Max-flow algorithms not working with named parameters.	Maël Valais <mael.valais@…>	Jeremiah Willcock	"The named parameter called ""edge capacity"" is not working. As explained at the end of #8791, this is due to a slight inversion:

The line in `boost/graph/named_function_params.hpp:326`
{{{#!cpp
typedef typename detail::choose_iml_result<boost::mph::true_, Graph, typename get_param_type<Params, edge_capacity_t>::type, edge_capacity_t>::type CapacityEdgeMap;
}}}
should rather be
{{{#!cpp
typedef typename detail::choose_iml_result<boost::mph::true_, Graph, typename get_param_type<edge_capacity_t, Params>::type, edge_capacity_t>::type CapacityEdgeMap;
}}}

Here are the max-flow algorithms that are currently not working with the named parameter ""Edge Capacity"":
- edmonds_karp_max_flow,
- push_relabel_max_flow,
- boykov_kolmogorov_max_flow.


---------
Minimal not-working example:
{{{#!cpp
#include <boost/config.hpp>
#include <iostream>
#include <string>
#include <boost/graph/edmonds_karp_max_flow.hpp>
#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/read_dimacs.hpp>
#include <boost/graph/graph_utility.hpp>
#include <boost/graph/find_flow_cost.hpp>

using namespace boost;
typedef adjacency_list_traits<vecS,vecS,directedS> traits;
struct edge_t {
	double capacity;
	float cost;
	float residual_capacity;
	traits::edge_descriptor reversed_edge;
};
struct node_t {
	std::string name;
	boost::default_color_type color;
	traits::edge_descriptor predecessor;
};
typedef adjacency_list < listS, vecS, directedS, node_t, edge_t > Graph;

int main()
{
	Graph g;
	property_map < Graph, double edge_t::* >::type capacity = get(&edge_t::capacity, g);
	property_map < Graph, float edge_t::* >::type cost = get(&edge_t::cost, g);
	property_map < Graph, float edge_t::* >::type residual_capacity = get(&edge_t::residual_capacity, g);
	property_map < Graph, traits::edge_descriptor edge_t::* >::type rev = get(&edge_t::reversed_edge, g);
	property_map < Graph, std::string node_t::* >::type name = get(&node_t::name, g);
	property_map < Graph, boost::default_color_type node_t::* >::type col = get(&node_t::color, g);
	property_map < Graph, traits::edge_descriptor node_t::* >::type pred = get(&node_t::predecessor, g);
	traits::vertex_descriptor s, t;
	read_dimacs_max_flow(g, capacity, rev, s, t);

	// XXX The ""named parameter version"" (producing errors)
	// XXX I chose to show the error with edmonds_karp_max_flow().
	flow = edmonds_karp_max_flow(g, s, t,
			capacity_map(capacity)
			.residual_capacity_map(residual_capacity)
			.reverse_edge_map(rev)
			.color_map(col)
			.predecessor_map(pred));

	return EXIT_SUCCESS;
}
}}}"	Bugs	new	To Be Determined	graph	Boost 1.57.0	Problem