/usr/include/boost/lexical_cast/ is in libboost1.62-dev 1.62.0+dfsg-5.
This file is owned by root:root, with mode 0o755.
..
/usr/include/boost/lexical_cast/bad_lexical_cast.hpp
/usr/include/boost/lexical_cast/detail/
/usr/include/boost/lexical_cast/detail/converter_lexical.hpp
/usr/include/boost/lexical_cast/detail/converter_lexical_streams.hpp
/usr/include/boost/lexical_cast/detail/converter_numeric.hpp
/usr/include/boost/lexical_cast/detail/inf_nan.hpp
/usr/include/boost/lexical_cast/detail/is_character.hpp
/usr/include/boost/lexical_cast/detail/lcast_char_constants.hpp
/usr/include/boost/lexical_cast/detail/lcast_unsigned_converters.hpp
/usr/include/boost/lexical_cast/detail/widest_char.hpp
/usr/include/boost/lexical_cast/lexical_cast_old.hpp
/usr/include/boost/lexical_cast/try_lexical_convert.hpp