This sort of thing worked in Boost 1.55.0: #include <boost/filesystem.hpp> #include <boost/range.hpp> #include <boost/range/adaptor/filtered.hpp> struct pred { bool operator()(const boost::filesystem::directory_entry & dirent) const { return true; } }; int main() { const auto dirent_range = boost::make_iterator_range(boost::filesystem::directory_iterator("/"), boost::filesystem::directory_iterator()); const auto filtered_dirent_range = boost::adaptors::filter(dirent_range, pred()); } Not so in 1.56.0 [output from Apple's clang 3.4]: boost/concept_check.hpp:210:9: error: no viable conversion from 'boost::single_pass_traversal_tag' to 'boost::forward_traversal_tag' Y y = x; ^ ~ The full error output is much more verbose and I can provide it if desired; but the above is the gist of the situation, as I understand it: directory_iterators are SinglePass iterators; filter operates on ForwardTraversal iterators; and the SinglePass iterator cannot be converted to the ForwardTraversal one. Is this situation deliberate or an unintended side effect? Is there some similarly succinct means of filtering a file/directory listing? -- Braden McDaniel <braden@endoframe.com>