fusion/support/pair.hpp

0001 /*=============================================================================
0002     Copyright (c) 2001-2011 Joel de Guzman
0003     Copyright (c) 2006 Tobias Schwinger
0004
0005     Distributed under the Boost Software License, Version 1.0. (See accompanying
0006     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0007 ==============================================================================*/
0008 #if !defined(FUSION_PAIR_07222005_1203)
0009 #define FUSION_PAIR_07222005_1203
0010
0011 #include <boost/fusion/support/config.hpp>
0012 #include <iosfwd>
0013
0014 #include <boost/fusion/support/detail/access.hpp>
0015 #include <boost/fusion/support/detail/as_fusion_element.hpp>
0016 #include <boost/config.hpp>
0017 #include <boost/utility/enable_if.hpp>
0018 #include <boost/type_traits/is_convertible.hpp>
0019 #include <boost/type_traits/is_lvalue_reference.hpp>
0020
0021 #if defined (BOOST_MSVC)
0022 #  pragma warning(push)
0023 #  pragma warning (disable: 4512) // assignment operator could not be generated.
0024 #endif
0025
0026 namespace boost { namespace fusion
0027 {
0028     // A half runtime pair where the first type does not have data
0029     template <typename First, typename Second>
0030     struct pair
0031     {
0032         BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
0033         pair()
0034             : second() {}
0035
0036         BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
0037         pair(pair const& rhs)
0038             : second(rhs.second) {}
0039
0040 #if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
0041         BOOST_CXX14_CONSTEXPR BOOST_FUSION_GPU_ENABLED
0042         pair(pair&& rhs)
0043             : second(BOOST_FUSION_FWD_ELEM(Second, rhs.second)) {}
0044 #endif
0045
0046         BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
0047         pair(typename detail::call_param<Second>::type val)
0048             : second(val) {}
0049
0050 #if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
0051         template <typename Second2>
0052         BOOST_FUSION_GPU_ENABLED
0053         pair(Second2&& val
0054           , typename boost::disable_if<is_lvalue_reference<Second2> >::type* /* dummy */ = 0
0055           , typename boost::enable_if<is_convertible<Second2, Second> >::type* /*dummy*/ = 0
0056         ) : second(BOOST_FUSION_FWD_ELEM(Second, val)) {}
0057 #endif
0058
0059         template <typename Second2>
0060         BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
0061         pair(pair<First, Second2> const& rhs)
0062             : second(rhs.second) {}
0063
0064         template <typename Second2>
0065         BOOST_CXX14_CONSTEXPR BOOST_FUSION_GPU_ENABLED
0066         pair& operator=(pair<First, Second2> const& rhs)
0067         {
0068             second = rhs.second;
0069             return *this;
0070         }
0071
0072         BOOST_CXX14_CONSTEXPR BOOST_FUSION_GPU_ENABLED
0073         pair& operator=(pair const& rhs)
0074         {
0075             second = rhs.second;
0076             return *this;
0077         }
0078
0079 #if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
0080         BOOST_CXX14_CONSTEXPR BOOST_FUSION_GPU_ENABLED
0081         pair& operator=(pair&& rhs)
0082         {
0083             second = BOOST_FUSION_FWD_ELEM(Second, rhs.second);
0084             return *this;
0085         }
0086 #endif
0087
0088         typedef First first_type;
0089         typedef Second second_type;
0090         Second second;
0091     };
0092
0093     namespace result_of
0094     {
0095         template<typename First, typename Second>
0096         struct make_pair
0097         {
0098             typedef fusion::pair<First,
0099                         typename detail::as_fusion_element<Second>::type> type;
0100         };
0101
0102         template<class Pair>
0103         struct first
0104         {
0105             typedef typename Pair::first_type type;
0106         };
0107
0108         template<class Pair>
0109         struct second
0110         {
0111             typedef typename Pair::second_type type;
0112         };
0113     }
0114
0115     template <typename First, typename Second>
0116     BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
0117     inline typename result_of::make_pair<First,Second>::type
0118     make_pair(Second const& val)
0119     {
0120         return pair<First, typename detail::as_fusion_element<Second>::type>(val);
0121     }
0122
0123 #if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
0124     template <typename First, typename Second>
0125     BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
0126     inline typename result_of::make_pair<First,Second>::type
0127     make_pair(Second&& val)
0128     {
0129         return pair<First, typename detail::as_fusion_element<Second>::type>(
0130             BOOST_FUSION_FWD_ELEM(Second, val));
0131     }
0132 #endif
0133
0134     template <typename First, typename Second>
0135     inline std::ostream&
0136     operator<<(std::ostream& os, pair<First, Second> const& p)
0137     {
0138         os << p.second;
0139         return os;
0140     }
0141
0142     template <typename First, typename Second>
0143     inline std::istream&
0144     operator>>(std::istream& is, pair<First, Second>& p)
0145     {
0146         is >> p.second;
0147         return is;
0148     }
0149
0150     template <typename First, typename SecondL, typename SecondR>
0151     BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
0152     inline bool
0153     operator==(pair<First, SecondL> const& l, pair<First, SecondR> const& r)
0154     {
0155         return l.second == r.second;
0156     }
0157
0158     template <typename First, typename SecondL, typename SecondR>
0159     BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
0160     inline bool
0161     operator!=(pair<First, SecondL> const& l, pair<First, SecondR> const& r)
0162     {
0163         return l.second != r.second;
0164     }
0165
0166     template <typename First, typename SecondL, typename SecondR>
0167     BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
0168     inline bool
0169     operator<(pair<First, SecondL> const& l, pair<First, SecondR> const& r)
0170     {
0171         return l.second < r.second;
0172     }
0173 }}
0174
0175 #if defined (BOOST_MSVC)
0176 #  pragma warning(pop)
0177 #endif
0178
0179 #endif