ceph/src/boost/libs/iostreams/include/boost/iostreams/detail/codecvt_helper.hpp

   1 // (C) Copyright 2008 CodeRage, LLC (turkanis at coderage dot com)
   2 // (C) Copyright 2003-2007 Jonathan Turkanis
   3 // Distributed under the Boost Software License, Version 1.0. (See accompanying
   4 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt.)
   5
   6 // See http://www.boost.org/libs/iostreams for documentation.
   7
   8 // Contains the definition of the template codecvt_helper, useful for
   9 // defining specializations of std::codecvt where state_type != mbstate_t.
  10 // Compensates for the fact that some standard library implementations
  11 // do not derive the primiary codecvt template from locale::facet or
  12 // provide the correct member types and functions.
  13
  14 // Usage:
  15 //
  16 // // In global namespace:
  17 // BOOST_IOSTREAMS_CODECVT_SPEC(mystate)
  18 //
  19 // // In user namespace:
  20 // template<typename Intern, typename Extern>
  21 // struct mycodecvt : codecvt_helper<Intern, Extern, State> { ... };
  22 //
  23 // // Or:
  24 // struct mycodecvt : codecvt_helper<wchar_t, char, State> { ... };
  25 //
  26 // Etc.
  27
  28 #ifndef BOOST_IOSTREAMS_DETAIL_CODECVT_HELPER_HPP_INCLUDED
  29 #define BOOST_IOSTREAMS_DETAIL_CODECVT_HELPER_HPP_INCLUDED
  30
  31 #if defined(_MSC_VER)
  32 # pragma once
  33 #endif
  34
  35 #include <boost/config.hpp>  // Put size_t in std, BOOST_MSVC, Dinkum.
  36 #include <boost/detail/workaround.hpp>
  37 #include <algorithm>         // min.
  38 #include <cstddef>           // size_t.
  39 #include <locale>            // locale, codecvt_base, codecvt.
  40 #include <boost/iostreams/detail/config/codecvt.hpp>
  41
  42 //------------------Definition of traits--------------------------------------//
  43
  44 namespace boost { namespace iostreams { namespace detail {
  45
  46 #if !BOOST_WORKAROUND(BOOST_DINKUMWARE_STDLIB, == 1) //-----------------------//
  47
  48 template<typename T>
  49 struct codecvt_intern { typedef typename T::intern_type type; };
  50
  51 template<typename T>
  52 struct codecvt_extern { typedef typename T::extern_type type; };
  53
  54 #else // #if !BOOST_WORKAROUND(BOOST_DINKUMWARE_STDLIB, == 1) //--------------//
  55
  56 template<typename T>
  57 struct codecvt_intern { typedef typename T::from_type type; };
  58
  59 template<typename T>
  60 struct codecvt_extern { typedef typename T::to_type type; };
  61
  62 #endif // #if !BOOST_WORKAROUND(BOOST_DINKUMWARE_STDLIB, == 1) //-------------//
  63
  64 template<typename T>
  65 struct codecvt_state { typedef typename T::state_type type; };
  66
  67 } } } // End namespaces detail, iostreams, boost.
  68
  69 //------------------Definition of codecvt_impl--------------------------------//
  70
  71 #if defined(BOOST_IOSTREAMS_NO_PRIMARY_CODECVT_DEFINITION) || \
  72     defined(BOOST_IOSTREAMS_EMPTY_PRIMARY_CODECVT_DEFINITION) || \
  73     defined(BOOST_IOSTREAMS_NO_LOCALE) \
  74     /**/
  75
  76 namespace boost { namespace iostreams { namespace detail {
  77
  78 template<typename Intern, typename Extern, typename State>
  79 struct codecvt_impl : std::locale::facet, std::codecvt_base {
  80 public:
  81     typedef Intern  intern_type;
  82     typedef Extern  extern_type;
  83     typedef State   state_type;
  84
  85     codecvt_impl(std::size_t refs = 0) : std::locale::facet(refs) { }
  86
  87     std::codecvt_base::result
  88     in( State& state, const Extern* first1, const Extern* last1,
  89         const Extern*& next1, Intern* first2, Intern* last2,
  90         Intern*& next2 ) const
  91     {
  92         return do_in(state, first1, last1, next1, first2, last2, next2);
  93     }
  94
  95     std::codecvt_base::result
  96     out( State& state, const Intern* first1, const Intern* last1,
  97          const Intern*& next1, Extern* first2, Extern* last2,
  98          Extern*& next2 ) const
  99     {
 100         return do_out(state, first1, last1, next1, first2, last2, next2);
 101     }
 102
 103     std::codecvt_base::result
 104     unshift(State& state, Extern* first2, Extern* last2, Extern*& next2) const
 105     {
 106         return do_unshift(state, first2, last2, next2);
 107     }
 108
 109     bool always_noconv() const throw() { return do_always_noconv(); }
 110
 111     int max_length() const throw() { return do_max_length(); }
 112
 113     int encoding() const throw() { return do_encoding(); }
 114
 115     int length( BOOST_IOSTREAMS_CODECVT_CV_QUALIFIER State& state,
 116                 const Extern* first1, const Extern* last1,
 117                 std::size_t len2 ) const throw()
 118     {
 119         return do_length(state, first1, last1, len2);
 120     }
 121 protected:
 122     std::codecvt_base::result
 123     virtual do_in( State&, const Extern*, const Extern*, const Extern*&,
 124                    Intern*, Intern*, Intern*& ) const
 125     {
 126         return std::codecvt_base::noconv;
 127     }
 128
 129     std::codecvt_base::result
 130     virtual do_out( State&, const Intern*, const Intern*, const Intern*&,
 131                     Extern*, Extern*, Extern*& ) const
 132     {
 133         return std::codecvt_base::noconv;
 134     }
 135
 136     std::codecvt_base::result
 137     virtual do_unshift(State&, Extern*, Extern*, Extern*&) const
 138     {
 139         return std::codecvt_base::ok;
 140     }
 141
 142     virtual bool do_always_noconv() const throw() { return true; }
 143
 144     virtual int do_max_length() const throw() { return 1; }
 145
 146     virtual int do_encoding() const throw() { return 1; }
 147
 148     virtual int do_length( BOOST_IOSTREAMS_CODECVT_CV_QUALIFIER State&,
 149                            const Extern* first1, const Extern* last1,
 150                            std::size_t len2 ) const throw()
 151     {
 152         return (std::min)(static_cast<std::size_t>(last1 - first1), len2);
 153     }
 154 };
 155
 156 } } } // End namespaces detail, iostreams, boost.
 157
 158 #endif // no primary codecvt definition, empty definition.
 159
 160 //------------------Definition of BOOST_IOSTREAMS_CODECVT_SPEC----------------//
 161
 162 #if defined(BOOST_IOSTREAMS_NO_PRIMARY_CODECVT_DEFINITION) || \
 163     defined(BOOST_IOSTREAMS_EMPTY_PRIMARY_CODECVT_DEFINITION) \
 164     /**/
 165 #  define BOOST_IOSTREAMS_CODECVT_SPEC(state) \
 166     namespace std { \
 167         template<typename Intern, typename Extern> \
 168         class codecvt<Intern, Extern, state> \
 169             : public ::boost::iostreams::detail::codecvt_impl< \
 170                          Intern, Extern, state \
 171                      > \
 172         { \
 173         public: \
 174             codecvt(std::size_t refs = 0) \
 175                 : ::boost::iostreams::detail::codecvt_impl< \
 176                       Intern, Extern, state \
 177                   >(refs) \
 178                 { } \
 179             static std::locale::id id; \
 180         }; \
 181         template<typename Intern, typename Extern> \
 182         std::locale::id codecvt<Intern, Extern, state>::id; \
 183     } \
 184     /**/
 185 #else
 186 # define BOOST_IOSTREAMS_CODECVT_SPEC(state)
 187 #endif // no primary codecvt definition, or empty definition.
 188
 189 namespace boost { namespace iostreams { namespace detail {
 190
 191 //------------------Definition of codecvt_helper------------------------------//
 192
 193 template<typename Intern, typename Extern, typename State>
 194 struct codecvt_helper : std::codecvt<Intern, Extern, State> {
 195     typedef Intern  intern_type;
 196     typedef Extern  extern_type;
 197     typedef State   state_type;
 198     codecvt_helper(std::size_t refs = 0)
 199     #if !defined(BOOST_IOSTREAMS_NO_CODECVT_CTOR_FROM_SIZE_T)
 200         : std::codecvt<Intern, Extern, State>(refs)
 201     #else
 202         : std::codecvt<Intern, Extern, State>()
 203     #endif
 204         { }
 205 #ifdef BOOST_IOSTREAMS_NO_CODECVT_MAX_LENGTH
 206     int max_length() const throw() { return do_max_length(); }
 207 protected:
 208     virtual int do_max_length() const throw() { return 1; }
 209 #endif
 210 };
 211
 212 } } } // End namespaces detail, iostreams, boost.
 213
 214 #endif // #ifndef BOOST_IOSTREAMS_DETAIL_CODECVT_HELPER_HPP_INCLUDED