Dear Icl users, due to a subtle effect of the changed hint semantics for associative containers, the icl library is broken in versions <= 1.55.0 when used with new STL-libraries that implement the new c++11 standard. This bug is fixed in the upcoming Boost 1.56.0. (see regression tests at http://www.boost.org/development/tests/master/developer/icl.html). Since the release of boost 1.56.0 seems to take longer than planned due to restructuring efforts for modular-boost, users of Boost.Icl affected by the problem may choose to pull the fixed Boost.Icl directly from the git repository and replace your_boost_1_55_0/boost/icl with the new code. The libs/icl part does not need an update. Another possibility is to apply the patch-file diff_icl_1_55_0_and_master.patch that is attached to this post to your local boost library 1.55.0: 1. cd to your_boost_1_55_0 root directory. your_boost_1_55_0> 2. From the command line type your_boost_1_55_0> patch -p2 < diff_icl_1_55_0_and_master.patch You may check the patched library by moving to your_boost_1_55_0/libs/icl/test and run your_boost_1_55_0/libs/icl/test> bjam Sorry for the inconvenience. Best regards, Joachim P.S.: For those interested in details of the issue here is a report: The semantics of insertion with hint in associative containers changed in c++11 form insert-after-hint (c++98/03) to insert-before-hint (c++11) see e.g. proposal N1780: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2005/n1780.html so for an associative container c of type C, a value x and an iterator hint c.insert(hint, x); //tries to insert x right after hint in c++98 c.insert(hint, x); //tries to insert x before hint in c++11 In accordance with this behavior, if using the insert function std::pair<bool, iterator> C::insert(value_type const& x); (success, hint) = c.insert(x); the iterator hint of unsuccessful insertion is the matching hint, pointing to [c++98] the last element y in c that is not greater x, so x can be inserted *after* that hint. [c++11] the first element z in c that is greater than x, so x can be inserted *before* that hint. In Boost.Icl I used the returned hint-iterator of the insert function, that always returned the last overlapping interval y for an inserted interval x given the interval's exclusive-less ordering under c++98. With the changed hint semantics, this returned hint-iterator did not point to the last interval y overlapping x anymore but to the first interval z not overlapping x. Therefore the code was broken and returned false results. -- Interval Container Library [Boost.Icl] http://www.joachim-faulhaber.de