+/**
+ * An option with user-defined syntax. @xtype is a <<xtypes:struct_xtype,`xtype`>>
+ * describing the syntax, @target is a variable of the corresponding type. If the @OPT_REQUIRED_VALUE
+ * flag is not set, the parser must be able to parse a NULL value.
+ **/
+#define OPT_XTYPE(shortopt, longopt, target, ttype, fl, desc) { .letter = shortopt, .name = longopt, .ptr = &target, .u.xtype = &ttype, .flags = fl, .help = desc, .cls = OPT_CL_STATIC, .type = CT_XTYPE }
+
+/** Multi-valued option of extended type. @target should be a growing array of the right kind of items. **/
+#define OPT_XTYPE_MULTIPLE(shortopt, longopt, target, ttype, fl, desc) { .letter = shortopt, .name = longopt, .ptr = &target, .u.xtype = &ttype, .flags = fl, .help = desc, .cls = OPT_CL_MULTIPLE, .type = CT_XTYPE }
+