/usr/include/websocketpp/transport/ is in libwebsocketpp-dev 0.7.0-11.
This file is owned by root:root, with mode 0o755.
..
/usr/include/websocketpp/transport/asio/
/usr/include/websocketpp/transport/asio/base.hpp
/usr/include/websocketpp/transport/asio/connection.hpp
/usr/include/websocketpp/transport/asio/endpoint.hpp
/usr/include/websocketpp/transport/asio/security/
/usr/include/websocketpp/transport/asio/security/base.hpp
/usr/include/websocketpp/transport/asio/security/none.hpp
/usr/include/websocketpp/transport/asio/security/tls.hpp
/usr/include/websocketpp/transport/base/
/usr/include/websocketpp/transport/base/connection.hpp
/usr/include/websocketpp/transport/base/endpoint.hpp
/usr/include/websocketpp/transport/debug/
/usr/include/websocketpp/transport/debug/base.hpp
/usr/include/websocketpp/transport/debug/connection.hpp
/usr/include/websocketpp/transport/debug/endpoint.hpp
/usr/include/websocketpp/transport/iostream/
/usr/include/websocketpp/transport/iostream/base.hpp
/usr/include/websocketpp/transport/iostream/connection.hpp
/usr/include/websocketpp/transport/iostream/endpoint.hpp
/usr/include/websocketpp/transport/stub/
/usr/include/websocketpp/transport/stub/base.hpp
/usr/include/websocketpp/transport/stub/connection.hpp
/usr/include/websocketpp/transport/stub/endpoint.hpp