libc++ support this with _LIBCPP_DEBUG=1 (http://releases.llvm.org/8.0.0/projects/libcxx/docs/DesignDocs/DebugMode.html#using-debug-mode). _LIBCPP_DEBUG=1. Using that found multiple real bugs: https://gerrit.gromacs.org/c/9357/ . MSVC's std-lib also supports this: https://docs.microsoft.com/en-us/cpp/standard-library/debug-iterator-support?view=vs-2017 using either debug build or _ITERATOR_DEBUG_LEVEL. But we don't have any configuration in Jenkins which enables this mode for either libc++ (_LIBCPP_DEBUG) or MSVC (_ITERATOR_DEBUG_LEVEL or Debug build). Ideally we should have one configuration for each (or test whether they both find the same set of bugs) but we should at least have one configuration.