From 2643cb0e3c9b241f4e73c9cf40bd766fda0c01f1 Mon Sep 17 00:00:00 2001
From: Yuichi Nishiwaki <yuichi.nishiwaki@gmail.com>
Date: Tue, 1 Apr 2014 11:39:35 +0900
Subject: [PATCH] add SWAP macro

---
 include/picrin/util.h | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/include/picrin/util.h b/include/picrin/util.h
index 3475caae..1ad80950 100644
--- a/include/picrin/util.h
+++ b/include/picrin/util.h
@@ -35,6 +35,15 @@ extern "C" {
 # define UNREACHABLE() (assert(false))
 #endif
 
+#define SWAP(type,a,b)                          \
+  SWAP_HELPER__(type,GENSYM(tmp),a,b)
+#define SWAP_HELPER__(type,tmp,a,b)             \
+  do {                                          \
+    type tmp = (a);                             \
+    (a) = (b);                                  \
+    (b) = tmp;                                  \
+  } while (0)
+
 #if defined(__cplusplus)
 }
 #endif