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authorAnas Nashif <anas.nashif@intel.com>2012-10-30 12:57:26 -0700
committerAnas Nashif <anas.nashif@intel.com>2012-10-30 12:57:26 -0700
commit1a78a62555be32868418fe52f8e330c9d0f95d5a (patch)
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Imported Upstream version 1.49.0upstream/1.49.0
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+// -----------------------------------------------------------
+// lowest_bit.hpp
+//
+// Position of the lowest bit 'on'
+//
+// Copyright (c) 2003-2004, 2008 Gennaro Prota
+//
+// Distributed under the Boost Software License, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at
+// http://www.boost.org/LICENSE_1_0.txt)
+//
+// -----------------------------------------------------------
+
+#ifndef BOOST_LOWEST_BIT_HPP_GP_20030301
+#define BOOST_LOWEST_BIT_HPP_GP_20030301
+
+#include <assert.h>
+#include "boost/pending/integer_log2.hpp"
+
+
+namespace boost {
+
+ template <typename T>
+ int lowest_bit(T x) {
+
+ assert(x >= 1); // PRE
+
+ // clear all bits on except the rightmost one,
+ // then calculate the logarithm base 2
+ //
+ return boost::integer_log2<T>( x - ( x & (x-1) ) );
+
+ }
+
+
+}
+
+
+#endif // include guard