==67758== Invalid read of size 8

==67758==    at 0x1009CE2A1: void boost::detail::r_c_shortest_paths_dispatch<...>(...) (r_c_shortest_paths.hpp:425)
==67758==    by 0x1009CCE2D: void boost::r_c_shortest_paths<...>(...) (r_c_shortest_paths.hpp:506)
==67758==    by 0x1009D4D9A: HeuristicsSolver::solve_on_reduced_graph(float) const (heuristics_solver.cpp:178)
==67758==    by 0x1009DB102: SPSolver::solve(std::vector<Column, std::allocator<Column> >&) (sp_solver.cpp:75)
==67758==    by 0x1009DEA65: main (main.cpp:35)

==67758==  Address 0x104903a40 is 0 bytes inside a block of size 88 free'd

==67758==    at 0x5632: free (in /usr/local/Cellar/valgrind/3.8.1/lib/valgrind/vgpreload_memcheck-amd64-darwin.so)
==67758==    by 0x1009CF3A3: __gnu_cxx::new_allocator<boost::r_c_shortest_paths_label<...>*, unsigned long) (ext/new_allocator.h:110)
==67758==    by 0x1009CDA18: void boost::detail::r_c_shortest_paths_dispatch<...>(...) (r_c_shortest_paths.hpp:314)
==67758==    by 0x1009CCE2D: void boost::r_c_shortest_paths<...>(...) (r_c_shortest_paths.hpp:506)
==67758==    by 0x1009D4D9A: HeuristicsSolver::solve_on_reduced_graph(float) const (heuristics_solver.cpp:178)
==67758==    by 0x1009DB102: SPSolver::solve(std::vector<Column, std::allocator<Column> >&) (sp_solver.cpp:75)
==67758==    by 0x1009DEA65: main (main.cpp:35)