/usr/include/boost/proto/detail/ is in libboost1.62-dev 1.62.0+dfsg-5.
This file is owned by root:root, with mode 0o755.
..
/usr/include/boost/proto/detail/and_n.hpp
/usr/include/boost/proto/detail/any.hpp
/usr/include/boost/proto/detail/args.hpp
/usr/include/boost/proto/detail/as_expr.hpp
/usr/include/boost/proto/detail/as_lvalue.hpp
/usr/include/boost/proto/detail/basic_expr.hpp
/usr/include/boost/proto/detail/class_member_traits.hpp
/usr/include/boost/proto/detail/decltype.hpp
/usr/include/boost/proto/detail/deduce_domain.hpp
/usr/include/boost/proto/detail/deduce_domain_n.hpp
/usr/include/boost/proto/detail/deep_copy.hpp
/usr/include/boost/proto/detail/deprecated.hpp
/usr/include/boost/proto/detail/dont_care.hpp
/usr/include/boost/proto/detail/expr.hpp
/usr/include/boost/proto/detail/expr_funop.hpp
/usr/include/boost/proto/detail/extends_funop.hpp
/usr/include/boost/proto/detail/extends_funop_const.hpp
/usr/include/boost/proto/detail/funop.hpp
/usr/include/boost/proto/detail/generate_by_value.hpp
/usr/include/boost/proto/detail/ignore_unused.hpp
/usr/include/boost/proto/detail/is_noncopyable.hpp
/usr/include/boost/proto/detail/lambda_matches.hpp
/usr/include/boost/proto/detail/local.hpp
/usr/include/boost/proto/detail/make_expr.hpp
/usr/include/boost/proto/detail/make_expr_.hpp
/usr/include/boost/proto/detail/make_expr_funop.hpp
/usr/include/boost/proto/detail/matches_.hpp
/usr/include/boost/proto/detail/memfun_funop.hpp
/usr/include/boost/proto/detail/or_n.hpp
/usr/include/boost/proto/detail/poly_function.hpp
/usr/include/boost/proto/detail/poly_function_funop.hpp
/usr/include/boost/proto/detail/poly_function_traits.hpp
/usr/include/boost/proto/detail/preprocessed/
/usr/include/boost/proto/detail/preprocessed/and_n.hpp
/usr/include/boost/proto/detail/preprocessed/args.hpp
/usr/include/boost/proto/detail/preprocessed/basic_expr.hpp
/usr/include/boost/proto/detail/preprocessed/class_member_traits.hpp
/usr/include/boost/proto/detail/preprocessed/deduce_domain_n.hpp
/usr/include/boost/proto/detail/preprocessed/deep_copy.hpp
/usr/include/boost/proto/detail/preprocessed/expr.hpp
/usr/include/boost/proto/detail/preprocessed/expr_variadic.hpp
/usr/include/boost/proto/detail/preprocessed/extends_funop.hpp
/usr/include/boost/proto/detail/preprocessed/extends_funop_const.hpp
/usr/include/boost/proto/detail/preprocessed/funop.hpp
/usr/include/boost/proto/detail/preprocessed/generate_by_value.hpp
/usr/include/boost/proto/detail/preprocessed/lambda_matches.hpp
/usr/include/boost/proto/detail/preprocessed/make_expr.hpp
/usr/include/boost/proto/detail/preprocessed/make_expr_.hpp
/usr/include/boost/proto/detail/preprocessed/make_expr_funop.hpp
/usr/include/boost/proto/detail/preprocessed/matches_.hpp
/usr/include/boost/proto/detail/preprocessed/memfun_funop.hpp
/usr/include/boost/proto/detail/preprocessed/or_n.hpp
/usr/include/boost/proto/detail/preprocessed/poly_function_funop.hpp
/usr/include/boost/proto/detail/preprocessed/poly_function_traits.hpp
/usr/include/boost/proto/detail/preprocessed/template_arity_helper.hpp
/usr/include/boost/proto/detail/preprocessed/traits.hpp
/usr/include/boost/proto/detail/preprocessed/unpack_expr_.hpp
/usr/include/boost/proto/detail/preprocessed/vararg_matches_impl.hpp
/usr/include/boost/proto/detail/remove_typename.hpp
/usr/include/boost/proto/detail/static_const.hpp
/usr/include/boost/proto/detail/template_arity.hpp
/usr/include/boost/proto/detail/template_arity_helper.hpp
/usr/include/boost/proto/detail/traits.hpp
/usr/include/boost/proto/detail/unpack_expr_.hpp
/usr/include/boost/proto/detail/vararg_matches_impl.hpp