boost/fusion/algorithm/query/detail/any.hpp
/*=============================================================================
Copyright (c) 2001-2011 Joel de Guzman
Copyright (c) 2005 Eric Niebler
Copyright (c) 2007 Dan Marsden
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)
==============================================================================*/
#if !defined(FUSION_ANY_05052005_1229)
#define FUSION_ANY_05052005_1229
#include <boost/mpl/bool.hpp>
#include <boost/fusion/sequence/intrinsic/begin.hpp>
#include <boost/fusion/sequence/intrinsic/end.hpp>
#include <boost/fusion/iterator/advance.hpp>
#include <boost/fusion/iterator/equal_to.hpp>
#include <boost/fusion/iterator/next.hpp>
#include <boost/fusion/iterator/deref.hpp>
#include <boost/fusion/iterator/distance.hpp>
namespace boost { namespace fusion {
struct random_access_traversal_tag;
namespace detail
{
template <typename First, typename Last, typename F>
inline bool
linear_any(First const&, Last const&, F const&, mpl::true_)
{
return false;
}
template <typename First, typename Last, typename F>
inline bool
linear_any(First const& first, Last const& last, F& f, mpl::false_)
{
typename result_of::deref<First>::type x = *first;
return f(x) ||
detail::linear_any(
fusion::next(first)
, last
, f
, result_of::equal_to<typename result_of::next<First>::type, Last>());
}
template <typename Sequence, typename F, typename Tag>
inline bool
any(Sequence const& seq, F f, Tag)
{
return detail::linear_any(
fusion::begin(seq)
, fusion::end(seq)
, f
, result_of::equal_to<
typename result_of::begin<Sequence>::type
, typename result_of::end<Sequence>::type>());
}
template<int N>
struct unrolled_any
{
template <typename It, typename F>
static bool call(It const& it, F f)
{
return
f(*it) ||
f(*fusion::advance_c<1>(it))||
f(*fusion::advance_c<2>(it)) ||
f(*fusion::advance_c<3>(it)) ||
detail::unrolled_any<N-4>::call(fusion::advance_c<4>(it), f);
}
};
template<>
struct unrolled_any<3>
{
template <typename It, typename F>
static bool call(It const& it, F f)
{
return
f(*it) ||
f(*fusion::advance_c<1>(it)) ||
f(*fusion::advance_c<2>(it));
}
};
template<>
struct unrolled_any<2>
{
template <typename It, typename F>
static bool call(It const& it, F f)
{
return
f(*it) ||
f(*fusion::advance_c<1>(it));
}
};
template<>
struct unrolled_any<1>
{
template <typename It, typename F>
static bool call(It const& it, F f)
{
return f(*it);
}
};
template<>
struct unrolled_any<0>
{
template <typename It, typename F>
static bool call(It const& it, F f)
{
return false;
}
};
template <typename Sequence, typename F>
inline bool
any(Sequence const& seq, F f, random_access_traversal_tag)
{
typedef typename result_of::begin<Sequence>::type begin;
typedef typename result_of::end<Sequence>::type end;
return detail::unrolled_any<result_of::distance<begin, end>::type::value>::call(
fusion::begin(seq), f);
}
}}}
#endif
