+ /* One and only one of opt_* must be set. */
+ const struct notmuch_opt_desc *opt_inherit;
+ bool *opt_bool;
+ int *opt_int;
+ int *opt_keyword;
+ int *opt_flags;
+ const char **opt_string;
+ const char **opt_position;
+
+ /* for opt_keyword only: if no matching arguments were found, and
+ * keyword_no_arg_value is set, then use keyword_no_arg_value instead. */
+ const char *keyword_no_arg_value;
+
+ /* Must be set except for opt_inherit and opt_position. */