struct outp_driver *outp_drivers (struct outp_driver *);
bool outp_parse_options (struct substring options,
bool (*) (struct outp_driver *, const char *key,
const struct string *value),
struct outp_driver *);
struct outp_driver *outp_drivers (struct outp_driver *);
bool outp_parse_options (struct substring options,
bool (*) (struct outp_driver *, const char *key,
const struct string *value),
struct outp_driver *);