/usr/include/boost/detail/ is in libboost1.58-dev 1.58.0+dfsg-5ubuntu3.
This file is owned by root:root, with mode 0o755.
..
/usr/include/boost/detail/algorithm.hpp
/usr/include/boost/detail/allocator_utilities.hpp
/usr/include/boost/detail/atomic_count.hpp
/usr/include/boost/detail/atomic_redef_macros.hpp
/usr/include/boost/detail/atomic_undef_macros.hpp
/usr/include/boost/detail/basic_pointerbuf.hpp
/usr/include/boost/detail/binary_search.hpp
/usr/include/boost/detail/bitmask.hpp
/usr/include/boost/detail/call_traits.hpp
/usr/include/boost/detail/catch_exceptions.hpp
/usr/include/boost/detail/compressed_pair.hpp
/usr/include/boost/detail/container_fwd.hpp
/usr/include/boost/detail/dynamic_bitset.hpp
/usr/include/boost/detail/endian.hpp
/usr/include/boost/detail/fenv.hpp
/usr/include/boost/detail/has_default_constructor.hpp
/usr/include/boost/detail/identifier.hpp
/usr/include/boost/detail/indirect_traits.hpp
/usr/include/boost/detail/interlocked.hpp
/usr/include/boost/detail/is_incrementable.hpp
/usr/include/boost/detail/is_sorted.hpp
/usr/include/boost/detail/is_xxx.hpp
/usr/include/boost/detail/iterator.hpp
/usr/include/boost/detail/lcast_precision.hpp
/usr/include/boost/detail/lightweight_main.hpp
/usr/include/boost/detail/lightweight_mutex.hpp
/usr/include/boost/detail/lightweight_test.hpp
/usr/include/boost/detail/lightweight_test_report.hpp
/usr/include/boost/detail/lightweight_thread.hpp
/usr/include/boost/detail/named_template_params.hpp
/usr/include/boost/detail/no_exceptions_support.hpp
/usr/include/boost/detail/numeric_traits.hpp
/usr/include/boost/detail/ob_compressed_pair.hpp
/usr/include/boost/detail/quick_allocator.hpp
/usr/include/boost/detail/reference_content.hpp
/usr/include/boost/detail/scoped_enum_emulation.hpp
/usr/include/boost/detail/select_type.hpp
/usr/include/boost/detail/sp_typeinfo.hpp
/usr/include/boost/detail/templated_streams.hpp
/usr/include/boost/detail/utf8_codecvt_facet.hpp
/usr/include/boost/detail/utf8_codecvt_facet.ipp
/usr/include/boost/detail/winapi/
/usr/include/boost/detail/winapi/GetCurrentProcess.hpp
/usr/include/boost/detail/winapi/GetCurrentThread.hpp
/usr/include/boost/detail/winapi/GetLastError.hpp
/usr/include/boost/detail/winapi/GetProcessTimes.hpp
/usr/include/boost/detail/winapi/GetThreadTimes.hpp
/usr/include/boost/detail/winapi/LocalFree.hpp
/usr/include/boost/detail/winapi/basic_types.hpp
/usr/include/boost/detail/winapi/config.hpp
/usr/include/boost/detail/winapi/crypt.hpp
/usr/include/boost/detail/winapi/directory_management.hpp
/usr/include/boost/detail/winapi/dll.hpp
/usr/include/boost/detail/winapi/error_handling.hpp
/usr/include/boost/detail/winapi/file_management.hpp
/usr/include/boost/detail/winapi/handles.hpp
/usr/include/boost/detail/winapi/memory.hpp
/usr/include/boost/detail/winapi/process.hpp
/usr/include/boost/detail/winapi/security.hpp
/usr/include/boost/detail/winapi/synchronization.hpp
/usr/include/boost/detail/winapi/system.hpp
/usr/include/boost/detail/winapi/thread.hpp
/usr/include/boost/detail/winapi/thread_pool.hpp
/usr/include/boost/detail/winapi/time.hpp
/usr/include/boost/detail/winapi/timers.hpp
/usr/include/boost/detail/winapi/tls.hpp
/usr/include/boost/detail/winapi/waitable_timer.hpp
/usr/include/boost/detail/workaround.hpp