char *pkg_state_want_to_str(pkg_state_want_t sw);
pkg_state_want_t pkg_state_want_from_str(char *str);
char *pkg_state_flag_to_str(pkg_state_flag_t sf);
-pkg_state_flag_t pkg_state_flag_from_str(char *str);
+pkg_state_flag_t pkg_state_flag_from_str(const char *str);
char *pkg_state_status_to_str(pkg_state_status_t ss);
-pkg_state_status_t pkg_state_status_from_str(char *str);
+pkg_state_status_t pkg_state_status_from_str(const char *str);
int pkg_version_satisfied(pkg_t *it, pkg_t *ref, const char *op);