1 files changed, 17 insertions, 0 deletions
diff --git a/mergesort.h b/mergesort.h
new file mode 100644
index 0000000000..644cff1f96
--- /dev/null
+++ b/mergesort.h
@@ -0,0 +1,17 @@
+#ifndef MERGESORT_H
+#define MERGESORT_H
+
+/*
+ * Sort linked list in place.
+ * - get_next_fn() returns the next element given an element of a linked list.
+ * - set_next_fn() takes two elements A and B, and makes B the "next" element
+ *   of A on the list.
+ * - compare_fn() takes two elements A and B, and returns negative, 0, positive
+ *   as the same sign as "subtracting" B from A.
+ */
+void *llist_mergesort(void *list,
+		      void *(*get_next_fn)(const void *),
+		      void (*set_next_fn)(void *, void *),
+		      int (*compare_fn)(const void *, const void *));
+
+#endif