detail/utility/any.hpp

0001 ///////////////////////////////////////////////////////////////////////////////
0002 // any.hpp
0003 //
0004 //  Copyright 2008 Eric Niebler. Distributed under the Boost
0005 //  Software License, Version 1.0. (See accompanying file
0006 //  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0007
0008 #ifndef BOOST_XPRESSIVE_DETAIL_UTILITY_ANY_HPP_EAN_11_19_2005
0009 #define BOOST_XPRESSIVE_DETAIL_UTILITY_ANY_HPP_EAN_11_19_2005
0010
0011 #include <boost/version.hpp>
0012
0013 #if BOOST_VERSION >= 103300
0014
0015 // In Boost 1.33+, we have a cons list in Fusion, so just include it.
0016
0017 # if BOOST_VERSION >= 103500
0018 #  include <boost/fusion/include/any.hpp> // Boost 1.35+ has Fusion2
0019 # else
0020 #  include <boost/spirit/fusion/algorithm/any.hpp> // Fusion1
0021 # endif
0022
0023 #else
0024
0025 # include <boost/spirit/fusion/sequence/begin.hpp>
0026 # include <boost/spirit/fusion/sequence/end.hpp>
0027 # include <boost/spirit/fusion/iterator/equal_to.hpp>
0028 # include <boost/mpl/bool.hpp>
0029 # include <boost/spirit/fusion/iterator/equal_to.hpp>
0030 # include <boost/spirit/fusion/iterator/next.hpp>
0031 # include <boost/spirit/fusion/iterator/deref.hpp>
0032
0033 namespace boost { namespace fusion
0034 {
0035
0036     namespace detail
0037     {
0038         template <typename First, typename Last, typename F>
0039         inline bool
0040         any(First const&, Last const&, F const&, mpl::true_)
0041         {
0042             return false;
0043         }
0044
0045         template <typename First, typename Last, typename F>
0046         inline bool
0047         any(First const& first, Last const& last, F const& f, mpl::false_)
0048         {
0049             if(f(*first))
0050                 return true;
0051             return detail::any(fusion::next(first), last, f
0052               , meta::equal_to<BOOST_DEDUCED_TYPENAME meta::next<First>::type, Last>());
0053         }
0054     }
0055
0056     namespace meta
0057     {
0058         template <typename Sequence, typename F>
0059         struct any
0060         {
0061             typedef bool type;
0062         };
0063     }
0064
0065     namespace function
0066     {
0067         struct any
0068         {
0069             template <typename Sequence, typename F>
0070             struct apply
0071             {
0072                 typedef bool type;
0073             };
0074
0075             template <typename Sequence, typename F>
0076             inline bool
0077             operator()(Sequence const& seq, F const& f) const
0078             {
0079                 return detail::any(
0080                         fusion::begin(seq)
0081                       , fusion::end(seq)
0082                       , f
0083                       , meta::equal_to<
0084                             BOOST_DEDUCED_TYPENAME meta::begin<Sequence>::type
0085                           , BOOST_DEDUCED_TYPENAME meta::end<Sequence>::type>());
0086             }
0087
0088             template <typename Sequence, typename F>
0089             inline bool
0090             operator()(Sequence& seq, F const& f) const
0091             {
0092                 return detail::any(
0093                         fusion::begin(seq)
0094                       , fusion::end(seq)
0095                       , f
0096                       , meta::equal_to<
0097                             BOOST_DEDUCED_TYPENAME meta::begin<Sequence>::type
0098                           , BOOST_DEDUCED_TYPENAME meta::end<Sequence>::type>());
0099             }
0100         };
0101     }
0102
0103     function::any const any = function::any();
0104 }}
0105
0106 #endif
0107
0108 #endif