* and a table of all the options with their descriptions. If an option has
* description opt_hidden, it is not shown here.
*
+ * The table of options is formatted such that descriptions are
+ * wrapped on space boundaries. If a description has a "\n" that is
+ * left intact, and the following characters indented appropriately.
+ * If the description begins with one or more space/tab (or has a
+ * space or tab following a "\n") that line is output without wrapping.
+ *
* If "extra" is NULL, then the extra information is taken from any
* registered option which calls opt_usage_and_exit(). This avoids duplicating
* that string in the common case.
*
* The result should be passed to free().
+ *
+ * See Also:
+ * opt_usage_and_exit()
+ *
+ * Example:
+ * opt_register_arg("--explode|--boom", explode, NULL, NULL,
+ * "This line will be wrapped by opt_usage\n"
+ * " But this won't because it's indented.");
*/
char *opt_usage(const char *argv0, const char *extra);