--- /dev/null
+/* invlist.h
+ *
+ * Copyright (C) 2012 by Larry Wall and others
+ *
+ * You may distribute under the terms of either the GNU General Public
+ * License or the Artistic License, as specified in the README file.
+ *
+ * This file is a home for static inline functions that cannot go in other
+ * headers files, because they depend on proto.h (included after most other
+ * headers) or struct definitions.
+ *
+ */
+
+#if defined(PERL_IN_UTF8_C) || defined(PERL_IN_REGCOMP_C) || defined(PERL_IN_REGEXEC_C)
+
+#define INVLIST_LEN_OFFSET 0 /* Number of elements in the inversion list */
+#define INVLIST_ITER_OFFSET 1 /* Current iteration position */
+#define INVLIST_PREVIOUS_INDEX_OFFSET 2 /* Place to cache index of previous
+ result */
+
+/* This is a combination of a version and data structure type, so that one
+ * being passed in can be validated to be an inversion list of the correct
+ * vintage. When the structure of the header is changed, a new random number
+ * in the range 2**31-1 should be generated and the new() method changed to
+ * insert that at this location. Then, if an auxiliary program doesn't change
+ * correspondingly, it will be discovered immediately */
+#define INVLIST_VERSION_ID_OFFSET 3
+#define INVLIST_VERSION_ID 290655244
+
+/* For safety, when adding new elements, remember to #undef them at the end of
+ * the inversion list code section */
+
+#define INVLIST_ZERO_OFFSET 4 /* 0 or 1; must be last element in header */
+/* The UV at position ZERO contains either 0 or 1. If 0, the inversion list
+ * contains the code point U+00000, and begins here. If 1, the inversion list
+ * doesn't contain U+0000, and it begins at the next UV in the array.
+ * Inverting an inversion list consists of adding or removing the 0 at the
+ * beginning of it. By reserving a space for that 0, inversion can be made
+ * very fast */
+
+#define HEADER_LENGTH (INVLIST_ZERO_OFFSET + 1)
+
+/* An element is in an inversion list iff its index is even numbered: 0, 2, 4,
+ * etc */
+#define ELEMENT_RANGE_MATCHES_INVLIST(i) (! ((i) & 1))
+#define PREV_RANGE_MATCHES_INVLIST(i) (! ELEMENT_RANGE_MATCHES_INVLIST(i))
+
+PERL_STATIC_INLINE UV*
+S__get_invlist_len_addr(pTHX_ SV* invlist)
+{
+ /* Return the address of the UV that contains the current number
+ * of used elements in the inversion list */
+
+ PERL_ARGS_ASSERT__GET_INVLIST_LEN_ADDR;
+
+ return (UV *) (SvPVX(invlist) + (INVLIST_LEN_OFFSET * sizeof (UV)));
+}
+
+PERL_STATIC_INLINE UV
+S__invlist_len(pTHX_ SV* const invlist)
+{
+ /* Returns the current number of elements stored in the inversion list's
+ * array */
+
+ PERL_ARGS_ASSERT__INVLIST_LEN;
+
+ return *_get_invlist_len_addr(invlist);
+}
+
+PERL_STATIC_INLINE bool
+S__invlist_contains_cp(pTHX_ SV* const invlist, const UV cp)
+{
+ /* Does <invlist> contain code point <cp> as part of the set? */
+
+ IV index = _invlist_search(invlist, cp);
+
+ PERL_ARGS_ASSERT__INVLIST_CONTAINS_CP;
+
+ return index >= 0 && ELEMENT_RANGE_MATCHES_INVLIST(index);
+}
+
+#endif