/usr/include/boost/units/base_units/imperial/ is in libboost1.55-dev 1.55.0+dfsg-3.
This file is owned by root:root, with mode 0o755.
..
/usr/include/boost/units/base_units/imperial/conversions.hpp
/usr/include/boost/units/base_units/imperial/drachm.hpp
/usr/include/boost/units/base_units/imperial/fluid_ounce.hpp
/usr/include/boost/units/base_units/imperial/foot.hpp
/usr/include/boost/units/base_units/imperial/furlong.hpp
/usr/include/boost/units/base_units/imperial/gallon.hpp
/usr/include/boost/units/base_units/imperial/gill.hpp
/usr/include/boost/units/base_units/imperial/grain.hpp
/usr/include/boost/units/base_units/imperial/hundredweight.hpp
/usr/include/boost/units/base_units/imperial/inch.hpp
/usr/include/boost/units/base_units/imperial/league.hpp
/usr/include/boost/units/base_units/imperial/mile.hpp
/usr/include/boost/units/base_units/imperial/ounce.hpp
/usr/include/boost/units/base_units/imperial/pint.hpp
/usr/include/boost/units/base_units/imperial/pound.hpp
/usr/include/boost/units/base_units/imperial/quart.hpp
/usr/include/boost/units/base_units/imperial/quarter.hpp
/usr/include/boost/units/base_units/imperial/stone.hpp
/usr/include/boost/units/base_units/imperial/thou.hpp
/usr/include/boost/units/base_units/imperial/ton.hpp
/usr/include/boost/units/base_units/imperial/yard.hpp