/usr/include/mdds/ is in libmdds-dev 0.5.4-1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/mdds/flat_segment_tree.hpp
/usr/include/mdds/flat_segment_tree_def.inl
/usr/include/mdds/flat_segment_tree_itr.hpp
/usr/include/mdds/global.hpp
/usr/include/mdds/hash_container/
/usr/include/mdds/hash_container/map.hpp
/usr/include/mdds/mixed_type_matrix.hpp
/usr/include/mdds/mixed_type_matrix_def.inl
/usr/include/mdds/mixed_type_matrix_element.hpp
/usr/include/mdds/mixed_type_matrix_flag_storage.hpp
/usr/include/mdds/mixed_type_matrix_storage.hpp
/usr/include/mdds/mixed_type_matrix_storage_filled_linear.inl
/usr/include/mdds/mixed_type_matrix_storage_filled_nested_array.inl
/usr/include/mdds/mixed_type_matrix_storage_sparse.inl
/usr/include/mdds/node.hpp
/usr/include/mdds/point_quad_tree.hpp
/usr/include/mdds/quad_node.hpp
/usr/include/mdds/rectangle_set.hpp
/usr/include/mdds/rectangle_set_def.inl
/usr/include/mdds/segment_tree.hpp