extern bool extl_table_gets_o(ExtlTab ref, const char *entry, Obj **ret);
extern bool extl_table_gets_i(ExtlTab ref, const char *entry, int *ret);
extern bool extl_table_gets_d(ExtlTab ref, const char *entry, double *ret);
extern bool extl_table_gets_o(ExtlTab ref, const char *entry, Obj **ret);
extern bool extl_table_gets_i(ExtlTab ref, const char *entry, int *ret);
extern bool extl_table_gets_d(ExtlTab ref, const char *entry, double *ret);