Boost C++ Libraries: Ticket #5706: Gcc 4.6 warnings for Boost Graph

status changed; resolution set

Jeremiah Willcock — Sun, 17 Jul 2011 11:32:32 GMT

status new → closed
resolution → wontfix

It looks like you are hitting http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47679; it is not a problem with Boost at all, although there is a workaround to silence the warnings at that link.

Tue, 17 Dec 2013 16:24:36 GMT

The warnings are still displayed using gcc 4.7.2 -O3 on Fedora.

In boost/graph/detail/adj_list_edge_iterator.hpp boost::detail::adj_list_edge_iterator::operator!= is implemented as

      inline bool operator!=(const self& x) const {
        return vCurr != x.vCurr
          || (vCurr != vEnd
              && edges BOOST_GRAPH_MEMBER first != x.edges BOOST_GRAPH_MEMBER first);

The unconditional access of this->edges.first and x.edges.first is incorrect in my opinion, as the edges data member in either instance may be uninitialized.

Patching the operator to first check if the edges data members are initialized eliminates the warning and the evaluation should short circuit in the case that they aren't, eliminating the access of edges.first if edges isn't initialized.

      inline bool operator!=(const self& x) const {
        return vCurr != x.vCurr
          || (vCurr != vEnd
              && edges && x.edges && edges BOOST_GRAPH_MEMBER first != x.edges BOOST_GRAPH_MEMBER first);

status, milestone changed; resolution deleted

Tue, 17 Dec 2013 16:26:00 GMT

status closed → reopened
resolution wontfix
milestone Boost 1.48.0 → Boost 1.56.0

Tue, 09 Aug 2016 09:24:10 GMT

Is this still a problem?

timmie@… — Tue, 24 Jan 2017 20:26:11 GMT

It looks like this is still a problem, yes. The file has not been modified since Boost 1.56.