X-Git-Url: http://git.ozlabs.org/?p=ccan;a=blobdiff_plain;f=ccan%2Fhtable%2Fhtable.h;h=9845388e1b9f47b7938e765a4682c7b4aee689fe;hp=e150c2ef0958065d3e289482d78dfe8267017a9b;hb=5ff76d983c62c8fc489672a1f89927ee3ba58e5d;hpb=7b56762984ce66f38728b542ca347bcb6fe3e981

diff --git a/ccan/htable/htable.h b/ccan/htable/htable.h
index e150c2ef..9845388e 100644
--- a/ccan/htable/htable.h
+++ b/ccan/htable/htable.h
@@ -35,6 +35,7 @@ struct htable {
  *	// For simplicity's sake, say hash value is contents of elem.
  *	static size_t rehash(const void *elem, void *unused)
  *	{
+ *		(void)unused;
  *		return *(size_t *)elem;
  *	}
  *	static struct htable ht = HTABLE_INITIALIZER(ht, rehash, NULL);
@@ -74,6 +75,25 @@ bool htable_init_sized(struct htable *ht,
  */
 void htable_clear(struct htable *ht);
 
+/**
+ * htable_copy - duplicate a hash table.
+ * @dst: the hash table to overwrite
+ * @src: the hash table to copy
+ *
+ * Only fails on out-of-memory.
+ *
+ * Equivalent to (but faster than):
+ *    if (!htable_init_sized(dst, src->rehash, src->priv, 1U << src->bits))
+ *	   return false;
+ *    v = htable_first(src, &i);
+ *    while (v) {
+ *		htable_add(dst, v);
+ *		v = htable_next(src, i);
+ *    }
+ *    return true;
+ */
+bool htable_copy(struct htable *dst, const struct htable *src);
+
 /**
  * htable_rehash - use a hashtree's rehash function
  * @elem: the argument to rehash()