boost/iostreams/detail/resolve.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 #ifndef BOOST_IOSTREAMS_DETAIL_RESOLVE_HPP_INCLUDED
   9 #define BOOST_IOSTREAMS_DETAIL_RESOLVE_HPP_INCLUDED
  10
  11 #if defined(_MSC_VER) && (_MSC_VER >= 1020)
  12 # pragma once
  13 #endif
  14
  15 #include <boost/config.hpp> // partial spec, put size_t in std.
  16 #include <cstddef>          // std::size_t.
  17 #include <boost/detail/is_incrementable.hpp>
  18 #include <boost/detail/workaround.hpp>
  19 #include <boost/iostreams/detail/adapter/mode_adapter.hpp>
  20 #include <boost/iostreams/detail/adapter/output_iterator_adapter.hpp>
  21 #include <boost/iostreams/detail/adapter/range_adapter.hpp>
  22 #include <boost/iostreams/detail/config/gcc.hpp>
  23 #include <boost/iostreams/detail/config/overload_resolution.hpp>
  24 #include <boost/iostreams/detail/config/wide_streams.hpp>
  25 #include <boost/iostreams/detail/enable_if_stream.hpp>
  26 #include <boost/iostreams/detail/is_dereferenceable.hpp>
  27 #include <boost/iostreams/detail/is_iterator_range.hpp>
  28 #include <boost/iostreams/detail/select.hpp>
  29 #include <boost/iostreams/detail/wrap_unwrap.hpp>
  30 #include <boost/iostreams/device/array.hpp>
  31 #include <boost/iostreams/traits.hpp>
  32 #include <boost/mpl/and.hpp>
  33 #include <boost/mpl/bool.hpp> // true_.
  34 #include <boost/mpl/if.hpp>
  35 #if !BOOST_WORKAROUND(BOOST_MSVC, <= 1300)
  36 # include <boost/range/iterator_range.hpp>
  37 #endif // #if BOOST_WORKAROUND(BOOST_MSVC, <= 1300)
  38 #include <boost/type_traits/is_array.hpp>
  39
  40 // Must come last.
  41 #include <boost/iostreams/detail/config/disable_warnings.hpp> // VC7.1 C4224.
  42
  43 namespace boost { namespace iostreams { namespace detail {
  44
  45 //------------------Definition of resolve-------------------------------------//
  46
  47 #ifndef BOOST_IOSTREAMS_BROKEN_OVERLOAD_RESOLUTION //-------------------------//
  48
  49 template<typename Mode, typename Ch, typename T>
  50 struct resolve_traits {
  51     typedef typename
  52             mpl::if_<
  53                 boost::detail::is_incrementable<T>,
  54                 output_iterator_adapter<Mode, Ch, T>,
  55                 const T&
  56             >::type type;
  57 };
  58
  59 # ifndef BOOST_IOSTREAMS_NO_STREAM_TEMPLATES //-------------------------------//
  60
  61 template<typename Mode, typename Ch, typename T>
  62 typename resolve_traits<Mode, Ch, T>::type
  63 resolve( const T& t
  64          BOOST_IOSTREAMS_DISABLE_IF_STREAM(T)
  65
  66          // I suspect that the compilers which require this workaround may
  67          // be correct, but I'm not sure why :(
  68          #if BOOST_WORKAROUND(BOOST_INTEL_CXX_VERSION, BOOST_TESTED_AT(810)) ||\
  69              BOOST_WORKAROUND(__MWERKS__, BOOST_TESTED_AT(0x3205)) || \
  70              BOOST_WORKAROUND(BOOST_IOSTREAMS_GCC, BOOST_TESTED_AT(400)) \
  71              /**/
  72          , typename disable_if< is_iterator_range<T> >::type* = 0
  73          #endif
  74          )
  75 {
  76     typedef typename resolve_traits<Mode, Ch, T>::type return_type;
  77     return return_type(t);
  78 }
  79
  80 template<typename Mode, typename Ch, typename Tr>
  81 mode_adapter< Mode, std::basic_streambuf<Ch, Tr> >
  82 resolve(std::basic_streambuf<Ch, Tr>& sb)
  83 { return mode_adapter< Mode, std::basic_streambuf<Ch, Tr> >(wrap(sb)); }
  84
  85 template<typename Mode, typename Ch, typename Tr>
  86 mode_adapter< Mode, std::basic_istream<Ch, Tr> >
  87 resolve(std::basic_istream<Ch, Tr>& is)
  88 { return mode_adapter< Mode, std::basic_istream<Ch, Tr> >(wrap(is)); }
  89
  90 template<typename Mode, typename Ch, typename Tr>
  91 mode_adapter< Mode, std::basic_ostream<Ch, Tr> >
  92 resolve(std::basic_ostream<Ch, Tr>& os)
  93 { return mode_adapter< Mode, std::basic_ostream<Ch, Tr> >(wrap(os)); }
  94
  95 template<typename Mode, typename Ch, typename Tr>
  96 mode_adapter< Mode, std::basic_iostream<Ch, Tr> >
  97 resolve(std::basic_iostream<Ch, Tr>& io)
  98 { return mode_adapter< Mode, std::basic_iostream<Ch, Tr> >(wrap(io)); }
  99
 100 template<typename Mode, typename Ch, std::size_t N>
 101 array_adapter<Mode, Ch> resolve(Ch (&array)[N])
 102 { return array_adapter<Mode, Ch>(array); }
 103
 104 #  if !BOOST_WORKAROUND(BOOST_MSVC, <= 1300)
 105     template<typename Mode, typename Ch, typename Iter>
 106     range_adapter< Mode, boost::iterator_range<Iter> >
 107     resolve(const boost::iterator_range<Iter>& rng)
 108     { return range_adapter< Mode, boost::iterator_range<Iter> >(rng); }
 109 #  endif // #if BOOST_WORKAROUND(BOOST_MSVC, <= 1300)
 110
 111 # else // # ifndef BOOST_IOSTREAMS_NO_STREAM_TEMPLATES //---------------------//
 112
 113 template<typename Mode, typename Ch, typename T>
 114 typename resolve_traits<Mode, Ch, T>::type
 115 resolve( const T& t
 116          BOOST_IOSTREAMS_DISABLE_IF_STREAM(T)
 117          #if defined(__GNUC__)
 118          , typename disable_if< is_iterator_range<T> >::type* = 0
 119          #endif
 120          )
 121 {
 122     typedef typename resolve_traits<Mode, Ch, T>::type return_type;
 123     return return_type(t);
 124 }
 125
 126 template<typename Mode, typename Ch>
 127 mode_adapter<Mode, std::streambuf>
 128 resolve(std::streambuf& sb)
 129 { return mode_adapter<Mode, std::streambuf>(wrap(sb)); }
 130
 131 template<typename Mode, typename Ch>
 132 mode_adapter<Mode, std::istream>
 133 resolve(std::istream& is)
 134 { return mode_adapter<Mode, std::istream>(wrap(is)); }
 135
 136 template<typename Mode, typename Ch>
 137 mode_adapter<Mode, std::ostream>
 138 resolve(std::ostream& os)
 139 { return mode_adapter<Mode, std::ostream>(wrap(os)); }
 140
 141 template<typename Mode, typename Ch>
 142 mode_adapter<Mode, std::iostream>
 143 resolve(std::iostream& io)
 144 { return mode_adapter<Mode, std::iostream>(wrap(io)); }
 145
 146 template<typename Mode, typename Ch, std::size_t N>
 147 array_adapter<Mode, Ch> resolve(Ch (&array)[N])
 148 { return array_adapter<Mode, Ch>(array); }
 149
 150 template<typename Mode, typename Ch, typename Iter>
 151 range_adapter< Mode, boost::iterator_range<Iter> >
 152 resolve(const boost::iterator_range<Iter>& rng)
 153 { return range_adapter< Mode, boost::iterator_range<Iter> >(rng); }
 154
 155 # endif // # ifndef BOOST_IOSTREAMS_NO_STREAM_TEMPLATES //--------------------//
 156 #else // #ifndef BOOST_IOSTREAMS_BROKEN_OVERLOAD_RESOLUTION //----------------//
 157
 158 template<typename Mode, typename Ch, typename T>
 159 struct resolve_traits {
 160     // Note: test for is_iterator_range must come before test for output
 161     // iterator.
 162     typedef typename
 163             iostreams::select<  // Disambiguation for Tru64.
 164                 is_std_io<T>,
 165                 mode_adapter<Mode, T>,
 166                 is_iterator_range<T>,
 167                 range_adapter<Mode, T>,
 168                 is_dereferenceable<T>,
 169                 output_iterator_adapter<Mode, Ch, T>,
 170                 is_array<T>,
 171                 array_adapter<Mode, T>,
 172                 else_,
 173                 #if !BOOST_WORKAROUND(__BORLANDC__, < 0x600)
 174                     const T&
 175                 #else
 176                     T
 177                 #endif
 178             >::type type;
 179 };
 180
 181 template<typename Mode, typename Ch, typename T>
 182 typename resolve_traits<Mode, Ch, T>::type
 183 resolve(const T& t, mpl::true_)
 184 {   // Bad overload resolution.
 185     typedef typename resolve_traits<Mode, Ch, T>::type return_type;
 186     return return_type(wrap(const_cast<T&>(t)));
 187 }
 188
 189 template<typename Mode, typename Ch, typename T>
 190 typename resolve_traits<Mode, Ch, T>::type
 191 resolve(const T& t, mpl::false_)
 192 {
 193     typedef typename resolve_traits<Mode, Ch, T>::type return_type;
 194     return return_type(t);
 195 }
 196
 197 template<typename Mode, typename Ch, typename T>
 198 typename resolve_traits<Mode, Ch, T>::type
 199 resolve(const T& t BOOST_IOSTREAMS_DISABLE_IF_STREAM(T))
 200 { return resolve<Mode, Ch>(t, is_std_io<T>()); }
 201
 202 # if !BOOST_WORKAROUND(__BORLANDC__, < 0x600) && \
 203      !BOOST_WORKAROUND(BOOST_MSVC, <= 1300) && \
 204      !defined(__GNUC__) // ---------------------------------------------------//
 205
 206 template<typename Mode, typename Ch, typename T>
 207 typename resolve_traits<Mode, Ch, T>::type
 208 resolve(T& t, mpl::true_)
 209 {
 210     typedef typename resolve_traits<Mode, Ch, T>::type return_type;
 211     return return_type(wrap(t));
 212 }
 213
 214 template<typename Mode, typename Ch, typename T>
 215 typename resolve_traits<Mode, Ch, T>::type
 216 resolve(T& t, mpl::false_)
 217 {
 218     typedef typename resolve_traits<Mode, Ch, T>::type return_type;
 219     return return_type(t);
 220 }
 221
 222 template<typename Mode, typename Ch, typename T>
 223 typename resolve_traits<Mode, Ch, T>::type
 224 resolve(T& t BOOST_IOSTREAMS_ENABLE_IF_STREAM(T))
 225 { return resolve<Mode, Ch>(t, is_std_io<T>()); }
 226
 227 # endif // Borland 5.x, VC6-7.0 or GCC 2.9x //--------------------------------//
 228 #endif // #ifndef BOOST_IOSTREAMS_BROKEN_OVERLOAD_RESOLUTION //---------------//
 229
 230 } } } // End namespaces detail, iostreams, boost.
 231
 232 #include <boost/iostreams/detail/config/enable_warnings.hpp> // VC7.1 4224.
 233
 234 #endif // BOOST_IOSTREAMS_DETAIL_RESOLVE_HPP_INCLUDED