container/map/convert.hpp

0001 /*=============================================================================
0002     Copyright (c) 2001-2011 Joel de Guzman
0003
0004     Distributed under the Boost Software License, Version 1.0. (See accompanying
0005     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0006 ==============================================================================*/
0007 #if !defined(FUSION_CONVERT_MAIN_09232005_1340)
0008 #define FUSION_CONVERT_MAIN_09232005_1340
0009
0010 #include <boost/fusion/support/config.hpp>
0011 #include <boost/fusion/container/map/map.hpp>
0012
0013 namespace boost { namespace fusion { namespace detail
0014 {
0015     template <typename It, bool is_assoc>
0016     struct pair_from
0017     {
0018         typedef typename result_of::value_of<It>::type type;
0019
0020         BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
0021         static inline type call(It const& it)
0022         {
0023             return *it;
0024         }
0025     };
0026
0027     template <typename It>
0028     struct pair_from<It, true>
0029     {
0030         typedef typename result_of::key_of<It>::type key_type;
0031         typedef typename result_of::value_of_data<It>::type data_type;
0032         typedef typename fusion::pair<key_type, data_type> type;
0033
0034         BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
0035         static inline type call(It const& it)
0036         {
0037             return type(deref_data(it));
0038         }
0039     };
0040 }}}
0041
0042 ///////////////////////////////////////////////////////////////////////////////
0043 // Without variadics, we will use the PP version
0044 ///////////////////////////////////////////////////////////////////////////////
0045 #if !defined(BOOST_FUSION_HAS_VARIADIC_MAP)
0046 # include <boost/fusion/container/map/detail/cpp03/convert.hpp>
0047
0048 #else
0049 ///////////////////////////////////////////////////////////////////////////////
0050 // C++11 variadic implementation
0051 ///////////////////////////////////////////////////////////////////////////////
0052 #include <boost/fusion/container/map/detail/build_map.hpp>
0053
0054 namespace boost { namespace fusion
0055 {
0056     namespace result_of
0057     {
0058         template <typename Sequence>
0059         struct as_map :
0060             detail::build_map<
0061                 typename result_of::begin<Sequence>::type
0062               , typename result_of::end<Sequence>::type
0063               , is_base_of<
0064                     associative_tag
0065                   , typename traits::category_of<Sequence>::type>::value
0066             >
0067         {
0068         };
0069     }
0070
0071     template <typename Sequence>
0072     BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
0073     inline typename result_of::as_map<Sequence>::type
0074     as_map(Sequence& seq)
0075     {
0076         typedef result_of::as_map<Sequence> gen;
0077         return gen::call(fusion::begin(seq), fusion::end(seq));
0078     }
0079
0080     template <typename Sequence>
0081     BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
0082     inline typename result_of::as_map<Sequence const>::type
0083     as_map(Sequence const& seq)
0084     {
0085         typedef result_of::as_map<Sequence const> gen;
0086         return gen::call(fusion::begin(seq), fusion::end(seq));
0087     }
0088
0089     namespace extension
0090     {
0091         template <typename T>
0092         struct convert_impl;
0093
0094         template <>
0095         struct convert_impl<map_tag>
0096         {
0097             template <typename Sequence>
0098             struct apply
0099             {
0100                 typedef typename
0101                     result_of::as_map<Sequence>::type
0102                 type;
0103
0104                 BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
0105                 static type call(Sequence& seq)
0106                 {
0107                     typedef result_of::as_map<Sequence> gen;
0108                     return gen::call(fusion::begin(seq), fusion::end(seq));
0109                 }
0110             };
0111         };
0112     }
0113 }}
0114
0115 #endif
0116 #endif
0117