+#if defined(PERL_IN_REGCOMP_C) || defined(PERL_IN_UTF8_C)
+#define _invlist_union(a, b, output) _invlist_union_maybe_complement_2nd(a, b, FALSE, output)
+#define _invlist_intersection(a, b, output) _invlist_intersection_maybe_complement_2nd(a, b, FALSE, output)
+
+/* Subtracting b from a leaves in a everything that was there that isn't in b,
+ * that is the intersection of a with b's complement */
+#define _invlist_subtract(a, b, output) _invlist_intersection_maybe_complement_2nd(a, b, TRUE, output)
+#endif
+
+/* record the position of a (?{...}) within a pattern */
+
+struct reg_code_block {
+ STRLEN start;
+ STRLEN end;
+ OP *block;
+ REGEXP *src_regex;
+};
+
+