/usr/include/boost/algorithm/string/ is in libboost1.55-dev 1.55.0+dfsg-3.
This file is owned by root:root, with mode 0o755.
..
/usr/include/boost/algorithm/string/case_conv.hpp
/usr/include/boost/algorithm/string/classification.hpp
/usr/include/boost/algorithm/string/compare.hpp
/usr/include/boost/algorithm/string/concept.hpp
/usr/include/boost/algorithm/string/config.hpp
/usr/include/boost/algorithm/string/constants.hpp
/usr/include/boost/algorithm/string/detail/
/usr/include/boost/algorithm/string/detail/case_conv.hpp
/usr/include/boost/algorithm/string/detail/classification.hpp
/usr/include/boost/algorithm/string/detail/find_format.hpp
/usr/include/boost/algorithm/string/detail/find_format_all.hpp
/usr/include/boost/algorithm/string/detail/find_format_store.hpp
/usr/include/boost/algorithm/string/detail/find_iterator.hpp
/usr/include/boost/algorithm/string/detail/finder.hpp
/usr/include/boost/algorithm/string/detail/finder_regex.hpp
/usr/include/boost/algorithm/string/detail/formatter.hpp
/usr/include/boost/algorithm/string/detail/formatter_regex.hpp
/usr/include/boost/algorithm/string/detail/predicate.hpp
/usr/include/boost/algorithm/string/detail/replace_storage.hpp
/usr/include/boost/algorithm/string/detail/sequence.hpp
/usr/include/boost/algorithm/string/detail/trim.hpp
/usr/include/boost/algorithm/string/detail/util.hpp
/usr/include/boost/algorithm/string/erase.hpp
/usr/include/boost/algorithm/string/find.hpp
/usr/include/boost/algorithm/string/find_format.hpp
/usr/include/boost/algorithm/string/find_iterator.hpp
/usr/include/boost/algorithm/string/finder.hpp
/usr/include/boost/algorithm/string/formatter.hpp
/usr/include/boost/algorithm/string/iter_find.hpp
/usr/include/boost/algorithm/string/join.hpp
/usr/include/boost/algorithm/string/predicate.hpp
/usr/include/boost/algorithm/string/predicate_facade.hpp
/usr/include/boost/algorithm/string/regex.hpp
/usr/include/boost/algorithm/string/regex_find_format.hpp
/usr/include/boost/algorithm/string/replace.hpp
/usr/include/boost/algorithm/string/sequence_traits.hpp
/usr/include/boost/algorithm/string/split.hpp
/usr/include/boost/algorithm/string/std/
/usr/include/boost/algorithm/string/std/list_traits.hpp
/usr/include/boost/algorithm/string/std/rope_traits.hpp
/usr/include/boost/algorithm/string/std/slist_traits.hpp
/usr/include/boost/algorithm/string/std/string_traits.hpp
/usr/include/boost/algorithm/string/std_containers_traits.hpp
/usr/include/boost/algorithm/string/trim.hpp
/usr/include/boost/algorithm/string/trim_all.hpp
/usr/include/boost/algorithm/string/yes_no_type.hpp