ext-boost/boost/mpl/lower_bound.hpp
2014-12-07 23:50:51 +01:00

144 lines
3.5 KiB
C++

#ifndef BOOST_MPL_LOWER_BOUND_HPP_INCLUDED
#define BOOST_MPL_LOWER_BOUND_HPP_INCLUDED
// Copyright Aleksey Gurtovoy 2001-2004
//
// 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)
//
// See http://www.boost.org/libs/mpl for documentation.
// $Id$
// $Date$
// $Revision$
#include <boost/mpl/less.hpp>
#include <boost/mpl/lambda.hpp>
#include <boost/mpl/aux_/na_spec.hpp>
#include <boost/mpl/aux_/config/workaround.hpp>
#if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x610))
# define BOOST_MPL_CFG_STRIPPED_DOWN_LOWER_BOUND_IMPL
#endif
#if !defined(BOOST_MPL_CFG_STRIPPED_DOWN_LOWER_BOUND_IMPL)
# include <boost/mpl/minus.hpp>
# include <boost/mpl/divides.hpp>
# include <boost/mpl/size.hpp>
# include <boost/mpl/advance.hpp>
# include <boost/mpl/begin_end.hpp>
# include <boost/mpl/long.hpp>
# include <boost/mpl/eval_if.hpp>
# include <boost/mpl/prior.hpp>
# include <boost/mpl/deref.hpp>
# include <boost/mpl/apply.hpp>
# include <boost/mpl/aux_/value_wknd.hpp>
#else
# include <boost/mpl/not.hpp>
# include <boost/mpl/find.hpp>
# include <boost/mpl/bind.hpp>
#endif
#include <boost/config.hpp>
namespace boost { namespace mpl {
#if defined(BOOST_MPL_CFG_STRIPPED_DOWN_LOWER_BOUND_IMPL)
// agurt 23/oct/02: has a wrong complexity etc., but at least it works
// feel free to contribute a better implementation!
template<
typename BOOST_MPL_AUX_NA_PARAM(Sequence)
, typename BOOST_MPL_AUX_NA_PARAM(T)
, typename Predicate = less<>
, typename pred_ = typename lambda<Predicate>::type
>
struct lower_bound
: find_if< Sequence, bind1< not_<>, bind2<pred_,_,T> > >
{
};
#else
namespace aux {
template<
typename Distance
, typename Predicate
, typename T
, typename DeferredIterator
>
struct lower_bound_step_impl;
template<
typename Distance
, typename Predicate
, typename T
, typename DeferredIterator
>
struct lower_bound_step
{
typedef typename eval_if<
Distance
, lower_bound_step_impl<Distance,Predicate,T,DeferredIterator>
, DeferredIterator
>::type type;
};
template<
typename Distance
, typename Predicate
, typename T
, typename DeferredIterator
>
struct lower_bound_step_impl
{
typedef typename divides< Distance, long_<2> >::type offset_;
typedef typename DeferredIterator::type iter_;
typedef typename advance< iter_,offset_ >::type middle_;
typedef typename apply2<
Predicate
, typename deref<middle_>::type
, T
>::type cond_;
typedef typename prior< minus< Distance, offset_> >::type step_;
typedef lower_bound_step< offset_,Predicate,T,DeferredIterator > step_forward_;
typedef lower_bound_step< step_,Predicate,T,next<middle_> > step_backward_;
typedef typename eval_if<
cond_
, step_backward_
, step_forward_
>::type type;
};
} // namespace aux
template<
typename BOOST_MPL_AUX_NA_PARAM(Sequence)
, typename BOOST_MPL_AUX_NA_PARAM(T)
, typename Predicate = less<>
>
struct lower_bound
{
private:
typedef typename lambda<Predicate>::type pred_;
typedef typename size<Sequence>::type size_;
public:
typedef typename aux::lower_bound_step<
size_,pred_,T,begin<Sequence>
>::type type;
};
#endif // BOOST_MPL_CFG_STRIPPED_DOWN_LOWER_BOUND_IMPL
BOOST_MPL_AUX_NA_SPEC(2, lower_bound)
}}
#endif // BOOST_MPL_LOWER_BOUND_HPP_INCLUDED