1
2#ifndef BOOST_MPL_LOWER_BOUND_HPP_INCLUDED
3#define BOOST_MPL_LOWER_BOUND_HPP_INCLUDED
4
5// Copyright Aleksey Gurtovoy 2001-2004
6//
7// Distributed under the Boost Software License, Version 1.0.
8// (See accompanying file LICENSE_1_0.txt or copy at
9// http://www.boost.org/LICENSE_1_0.txt)
10//
11// See http://www.boost.org/libs/mpl for documentation.
12
13// $Id$
14// $Date$
15// $Revision$
16
17#include <boost/mpl/less.hpp>
18#include <boost/mpl/lambda.hpp>
19#include <boost/mpl/aux_/na_spec.hpp>
20#include <boost/mpl/aux_/config/workaround.hpp>
21
22#if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x610))
23# define BOOST_MPL_CFG_STRIPPED_DOWN_LOWER_BOUND_IMPL
24#endif
25
26#if !defined(BOOST_MPL_CFG_STRIPPED_DOWN_LOWER_BOUND_IMPL)
27# include <boost/mpl/minus.hpp>
28# include <boost/mpl/divides.hpp>
29# include <boost/mpl/size.hpp>
30# include <boost/mpl/advance.hpp>
31# include <boost/mpl/begin_end.hpp>
32# include <boost/mpl/long.hpp>
33# include <boost/mpl/eval_if.hpp>
34# include <boost/mpl/prior.hpp>
35# include <boost/mpl/deref.hpp>
36# include <boost/mpl/apply.hpp>
37# include <boost/mpl/aux_/value_wknd.hpp>
38#else
39# include <boost/mpl/not.hpp>
40# include <boost/mpl/find.hpp>
41# include <boost/mpl/bind.hpp>
42#endif
43
44#include <boost/config.hpp>
45
46namespace boost { namespace mpl {
47
48#if defined(BOOST_MPL_CFG_STRIPPED_DOWN_LOWER_BOUND_IMPL)
49
50// agurt 23/oct/02: has a wrong complexity etc., but at least it works
51// feel free to contribute a better implementation!
52template<
53 typename BOOST_MPL_AUX_NA_PARAM(Sequence)
54 , typename BOOST_MPL_AUX_NA_PARAM(T)
55 , typename Predicate = less<>
56 , typename pred_ = typename lambda<Predicate>::type
57 >
58struct lower_bound
59 : find_if< Sequence, bind1< not_<>, bind2<pred_,_,T> > >
60{
61};
62
63#else
64
65namespace aux {
66
67template<
68 typename Distance
69 , typename Predicate
70 , typename T
71 , typename DeferredIterator
72 >
73struct lower_bound_step_impl;
74
75template<
76 typename Distance
77 , typename Predicate
78 , typename T
79 , typename DeferredIterator
80 >
81struct lower_bound_step
82{
83 typedef typename eval_if<
84 Distance
85 , lower_bound_step_impl<Distance,Predicate,T,DeferredIterator>
86 , DeferredIterator
87 >::type type;
88};
89
90template<
91 typename Distance
92 , typename Predicate
93 , typename T
94 , typename DeferredIterator
95 >
96struct lower_bound_step_impl
97{
98 typedef typename divides< Distance, long_<2> >::type offset_;
99 typedef typename DeferredIterator::type iter_;
100 typedef typename advance< iter_,offset_ >::type middle_;
101 typedef typename apply2<
102 Predicate
103 , typename deref<middle_>::type
104 , T
105 >::type cond_;
106
107 typedef typename prior< minus< Distance, offset_> >::type step_;
108 typedef lower_bound_step< offset_,Predicate,T,DeferredIterator > step_forward_;
109 typedef lower_bound_step< step_,Predicate,T,next<middle_> > step_backward_;
110 typedef typename eval_if<
111 cond_
112 , step_backward_
113 , step_forward_
114 >::type type;
115};
116
117
118} // namespace aux
119
120template<
121 typename BOOST_MPL_AUX_NA_PARAM(Sequence)
122 , typename BOOST_MPL_AUX_NA_PARAM(T)
123 , typename Predicate = less<>
124 >
125struct lower_bound
126{
127 private:
128 typedef typename lambda<Predicate>::type pred_;
129 typedef typename size<Sequence>::type size_;
130
131 public:
132 typedef typename aux::lower_bound_step<
133 size_,pred_,T,begin<Sequence>
134 >::type type;
135};
136
137#endif // BOOST_MPL_CFG_STRIPPED_DOWN_LOWER_BOUND_IMPL
138
139BOOST_MPL_AUX_NA_SPEC(2, lower_bound)
140
141}}
142
143#endif // BOOST_MPL_LOWER_BOUND_HPP_INCLUDED
144

source code of boost/boost/mpl/lower_bound.hpp