comparison DEPENDENCIES/generic/include/boost/pending/lowest_bit.hpp @ 16:2665513ce2d3

Add boost headers
author Chris Cannam
date Tue, 05 Aug 2014 11:11:38 +0100
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15:663ca0da4350 16:2665513ce2d3
1 // -----------------------------------------------------------
2 // lowest_bit.hpp
3 //
4 // Position of the lowest bit 'on'
5 //
6 // Copyright (c) 2003-2004, 2008 Gennaro Prota
7 //
8 // Distributed under the Boost Software License, Version 1.0.
9 // (See accompanying file LICENSE_1_0.txt or copy at
10 // http://www.boost.org/LICENSE_1_0.txt)
11 //
12 // -----------------------------------------------------------
13
14 #ifndef BOOST_LOWEST_BIT_HPP_GP_20030301
15 #define BOOST_LOWEST_BIT_HPP_GP_20030301
16
17 #include <assert.h>
18 #include "boost/pending/integer_log2.hpp"
19
20
21 namespace boost {
22
23 template <typename T>
24 int lowest_bit(T x) {
25
26 assert(x >= 1); // PRE
27
28 // clear all bits on except the rightmost one,
29 // then calculate the logarithm base 2
30 //
31 return boost::integer_log2<T>( x - ( x & (x-1) ) );
32
33 }
34
35
36 }
37
38
39 #endif // include guard