[MINOR] tools: add two macros MID_RANGE and MAX_RANGE

Those will be used later, they return the largest and middle integer
possible for a given variable or type.

diff --git a/include/common/tools.h b/include/common/tools.h
index 526ea7fbfaf420433fa23283d06cc06a115541d9..398383ad38419358fd5db37315c473b7daaf6654 100644 (file)
--- a/include/common/tools.h
+++ b/include/common/tools.h
@@ -1,22 +1,22 @@
 /*
-  include/common/tools.h
-  Trivial macros needed everywhere.
-
-  Copyright (C) 2000-2006 Willy Tarreau - w@1wt.eu
-  
-  This library is free software; you can redistribute it and/or
-  modify it under the terms of the GNU Lesser General Public
-  License as published by the Free Software Foundation, version 2.1
-  exclusively.
-
-  This library is distributed in the hope that it will be useful,
-  but WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-  Lesser General Public License for more details.
-
-  You should have received a copy of the GNU Lesser General Public
-  License along with this library; if not, write to the Free Software
-  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ * include/common/tools.h
+ * Trivial macros needed everywhere.
+ *
+ * Copyright (C) 2000-2011 Willy Tarreau - w@1wt.eu
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation, version 2.1
+ * exclusively.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */
 
 #ifndef _COMMON_TOOLS_H
@@ -33,6 +33,14 @@
 #define MAX(a, b) (((a) > (b)) ? (a) : (b))
 #endif
 
+/* return an integer of type <ret> with only the highest bit set. <ret> may be
+ * both a variable or a type.
+ */
+#define MID_RANGE(ret) ((typeof(ret))1 << (8*sizeof(ret) - 1))
+
+/* return the largest possible integer of type <ret>, with all bits set */
+#define MAX_RANGE(ret) (~(typeof(ret))0)
+
 #endif /* _COMMON_TOOLS_H */
 
 /*