Error when adding an edge in an adjacency list

[ernest.galbrun@…]

I encountered a regression using the boost graph library, but I am not exactly sure what caused the regression since the file concerned has not changed for a couple of months.

Here is a little code snippet showing the bug. I am using Visual Studio 2013, 64 bits. The bug occurs both in debug and release mode :

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

void main() {

typedef boost::adjacency_list<boost::vecS, boost::vecS, boost::directedS, int, int> Graph; Graph g(2); auto result = add_edge(0, 1, g); boost::graph_traits<Graph>::edge_iterator ei, ei_end; boost::tie(ei, ei_end) = boost::edges(g); std::cout << "edge target is: " << (*ei).m_target << std::endl;

}

The result is an uninitialized value of the target vertex: 14829735431805717965.

After investigation of the issue, it seems that the problem lies in adjacency_list.hpp, pushing the newly created edge into the container, it makes a copy from a rvalue reference. This copy does move the property unique_ptr but does not copy the target value of the edge.

I used the qttqched patch to fix this, it simply consists in copying the m_target propoerty of the edge along the m_property.

[ernest.galbrun@…]

p

[ernest.galbrun@…]

patch proposing fix

[Eric Niebler]

The following pull request (currently merged to the develop branch, but not master) has fixed this issue for me. Can you please update and confirm that your issue is fixed?

[Andrey Semashev]

The pull request is actually this one: ​https://github.com/boostorg/graph/pull/14

[ernest.galbrun@…]

Yes it works, thanks for the fix. I think it deserves to be pushed quickly in the release branch since right now the graph library does not work at all with visual studio.

[Eric Niebler]

Fixed for 1.56.