/usr/include/boost/variant/ is in libboost1.49-dev 1.49.0-3.2.
This file is owned by root:root, with mode 0o755.
..
/usr/include/boost/variant/apply_visitor.hpp
/usr/include/boost/variant/bad_visit.hpp
/usr/include/boost/variant/detail/
/usr/include/boost/variant/detail/apply_visitor_binary.hpp
/usr/include/boost/variant/detail/apply_visitor_delayed.hpp
/usr/include/boost/variant/detail/apply_visitor_unary.hpp
/usr/include/boost/variant/detail/backup_holder.hpp
/usr/include/boost/variant/detail/bool_trait_def.hpp
/usr/include/boost/variant/detail/bool_trait_undef.hpp
/usr/include/boost/variant/detail/cast_storage.hpp
/usr/include/boost/variant/detail/config.hpp
/usr/include/boost/variant/detail/enable_recursive.hpp
/usr/include/boost/variant/detail/enable_recursive_fwd.hpp
/usr/include/boost/variant/detail/forced_return.hpp
/usr/include/boost/variant/detail/generic_result_type.hpp
/usr/include/boost/variant/detail/has_nothrow_move.hpp
/usr/include/boost/variant/detail/has_trivial_move.hpp
/usr/include/boost/variant/detail/initializer.hpp
/usr/include/boost/variant/detail/make_variant_list.hpp
/usr/include/boost/variant/detail/move.hpp
/usr/include/boost/variant/detail/over_sequence.hpp
/usr/include/boost/variant/detail/substitute.hpp
/usr/include/boost/variant/detail/substitute_fwd.hpp
/usr/include/boost/variant/detail/variant_io.hpp
/usr/include/boost/variant/detail/visitation_impl.hpp
/usr/include/boost/variant/get.hpp
/usr/include/boost/variant/recursive_variant.hpp
/usr/include/boost/variant/recursive_wrapper.hpp
/usr/include/boost/variant/recursive_wrapper_fwd.hpp
/usr/include/boost/variant/static_visitor.hpp
/usr/include/boost/variant/variant.hpp
/usr/include/boost/variant/variant_fwd.hpp
/usr/include/boost/variant/visitor_ptr.hpp