X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Flibpspp%2Fbt.h;h=0ee29898e8263eeb434d8987192157c771fbb19a;hb=aaf7e27cbda4b400b6a98360fa7bab08e26c8696;hp=7045632ef204e2edd228dc4dd8473174318212be;hpb=d0b91eae59319ab2756d0d43b9cb15eb9cd3c234;p=pspp

diff --git a/src/libpspp/bt.h b/src/libpspp/bt.h
index 7045632ef2..0ee29898e8 100644
--- a/src/libpspp/bt.h
+++ b/src/libpspp/bt.h
@@ -1,5 +1,5 @@
 /* PSPP - a program for statistical analysis.
-   Copyright (C) 2007, 2009 Free Software Foundation, Inc.
+   Copyright (C) 2007, 2009, 2010 Free Software Foundation, Inc.
 
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -23,6 +23,7 @@
    balancing applied to the balanced tree, as its operation is
    fully encapsulated. */
 
+#include <stdbool.h>
 #include <stddef.h>
 #include <libpspp/cast.h>
 
@@ -80,4 +81,11 @@ static inline size_t bt_count (const struct bt *bt)
   return bt->size;
 }
 
+/* Return true if BT contains no nodes,
+   false if BT contains at least one node. */
+static inline bool bt_is_empty (const struct bt *bt)
+{
+  return bt->size == 0;
+}
+
 #endif /* libpspp/bt.h */