+/* This bit is used internally like RE_CONTEXT_INDEP_ANCHORS but only
+ for ^, because it is difficult to scan the regex backwards to find
+ whether ^ should be special. */
+#define RE_CARET_ANCHORS_HERE (RE_ICASE << 1)
+
+/* If this bit is set, then \{ cannot be first in an bre or
+ immediately after an alternation or begin-group operator. */
+#define RE_CONTEXT_INVALID_DUP (RE_CARET_ANCHORS_HERE << 1)
+
+/* If this bit is set, then no_sub will be set to 1 during
+ re_compile_pattern. */
+#define RE_NO_SUB (RE_CONTEXT_INVALID_DUP << 1)
+