optional_depends perl \ "--with-perl" \ "--without-perl" \ "enable perl bindings" && optional_depends python \ "--with-python" \ "--without-python" \ "enable python bindings" && optional_depends swig \ "--with-swig" \ "--without-swig" \ "enable swig" && optional_depends lua51 \ "--with-lua" \ "--without-lua" \ "enable lua51 bindings" && optional_depends gnutls \ "" "" \ "enable gnu tls" && optional_depends libgcrypt \ "" "" \ "enable libgcrypt" && optional_depends gtk-doc \ "--enable-gtk-doc" \ "--disable-gtk-doc" \ "use gtk-doc to build documentation"