boost/iostreams/close.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_CLOSE_HPP_INCLUDED
   9 #define BOOST_IOSTREAMS_CLOSE_HPP_INCLUDED
  10
  11 #if defined(_MSC_VER) && (_MSC_VER >= 1020)
  12 # pragma once
  13 #endif
  14
  15 #include <boost/config.hpp>  // DEDUCED_TYPENAME, MSVC.
  16 #include <boost/detail/workaround.hpp>
  17 #include <boost/iostreams/categories.hpp>
  18 #include <boost/iostreams/flush.hpp>
  19 #include <boost/iostreams/detail/adapter/non_blocking_adapter.hpp>
  20 #include <boost/iostreams/detail/ios.hpp> // BOOST_IOS
  21 #include <boost/iostreams/detail/select.hpp>
  22 #include <boost/iostreams/detail/wrap_unwrap.hpp>
  23 #include <boost/iostreams/operations_fwd.hpp>
  24 #include <boost/iostreams/traits.hpp>
  25 #include <boost/mpl/identity.hpp>
  26 #include <boost/mpl/if.hpp>
  27 #include <boost/type_traits/is_convertible.hpp>
  28 #include <boost/type_traits/is_integral.hpp>
  29 #include <boost/type_traits/remove_cv.hpp>
  30 #include <boost/type_traits/remove_reference.hpp>
  31
  32 // Must come last.
  33 #include <boost/iostreams/detail/config/disable_warnings.hpp>
  34
  35 namespace boost { namespace iostreams {
  36
  37 template<typename T>
  38 void close(T& t);
  39
  40 template<typename T>
  41 void close(T& t, BOOST_IOS::openmode which);
  42
  43 template<typename T, typename Sink>
  44 void close(T& t, Sink& snk, BOOST_IOS::openmode which);
  45
  46 namespace detail {
  47
  48 template<typename T>
  49 void close_all(T& t)
  50 {
  51     try {
  52         boost::iostreams::close(t, BOOST_IOS::in);
  53     } catch (...) {
  54         try {
  55             boost::iostreams::close(t, BOOST_IOS::out);
  56         } catch (...) { }
  57         throw;
  58     }
  59     boost::iostreams::close(t, BOOST_IOS::out);
  60 }
  61
  62 template<typename T, typename Sink>
  63 void close_all(T& t, Sink& snk)
  64 {
  65     try {
  66         boost::iostreams::close(t, snk, BOOST_IOS::in);
  67     } catch (...) {
  68         try {
  69             boost::iostreams::close(t, snk, BOOST_IOS::out);
  70         } catch (...) { }
  71         throw;
  72     }
  73     boost::iostreams::close(t, snk, BOOST_IOS::out);
  74 }
  75
  76 } // End namespaces detail.
  77
  78 } } // End namespaces iostreams, boost.
  79
  80 #if BOOST_WORKAROUND(BOOST_MSVC, < 1300) //-----------------------------------//
  81 # include <boost/iostreams/detail/vc6/close.hpp>
  82 #else // #if BOOST_WORKAROUND(BOOST_MSVC, < 1300) //--------------------------//
  83
  84 namespace boost { namespace iostreams {
  85
  86 namespace detail {
  87
  88 template<typename T>
  89 struct close_impl;
  90
  91 } // End namespace detail.
  92
  93 template<typename T>
  94 void close(T& t) { detail::close_all(t); }
  95
  96 template<typename T>
  97 void close(T& t, BOOST_IOS::openmode which)
  98 {
  99 #ifdef BOOST_IOSTREAMS_STRICT
 100     assert(which == BOOST_IOS::in || which == BOOST_IOS::out);
 101 #else
 102         if (which == (BOOST_IOS::in | BOOST_IOS::out)) {
 103                 detail::close_all(t);
 104                 return;
 105         }
 106 #endif
 107     detail::close_impl<T>::close(detail::unwrap(t), which);
 108 }
 109
 110 template<typename T, typename Sink>
 111 void close(T& t, Sink& snk, BOOST_IOS::openmode which)
 112 {
 113 #ifdef BOOST_IOSTREAMS_STRICT
 114     assert(which == BOOST_IOS::in || which == BOOST_IOS::out);
 115 #else
 116         if (which == (BOOST_IOS::in | BOOST_IOS::out)) {
 117                 detail::close_all(t, snk);
 118                 return;
 119         }
 120 #endif
 121     detail::close_impl<T>::close(detail::unwrap(t), snk, which);
 122 }
 123
 124 namespace detail {
 125
 126 //------------------Definition of close_impl----------------------------------//
 127
 128 struct close_boost_stream { };
 129 struct close_filtering_stream { };
 130
 131 template<typename T>
 132 struct close_tag {
 133     typedef typename category_of<T>::type             category;
 134     typedef typename detail::unwrapped_type<T>::type  unwrapped;
 135     typedef typename
 136             iostreams::select<
 137                 mpl::not_< is_convertible<category, closable_tag> >,
 138                 any_tag,
 139                 mpl::or_<
 140                     is_boost_stream<unwrapped>,
 141                     is_boost_stream_buffer<unwrapped>
 142                 >,
 143                 close_boost_stream,
 144                 mpl::or_<
 145                     is_filtering_stream<unwrapped>,
 146                     is_filtering_streambuf<unwrapped>
 147                 >,
 148                 close_filtering_stream,
 149                 mpl::or_<
 150                     is_convertible<category, two_sequence>,
 151                     is_convertible<category, dual_use>
 152                 >,
 153                 two_sequence,
 154                 else_,
 155                 closable_tag
 156             >::type type;
 157 };
 158
 159 template<typename T>
 160 struct close_impl
 161     : mpl::if_<
 162           is_custom<T>,
 163           operations<T>,
 164           close_impl<BOOST_DEDUCED_TYPENAME close_tag<T>::type>
 165       >::type
 166     { };
 167
 168 template<>
 169 struct close_impl<any_tag> {
 170     template<typename T>
 171     static void close(T& t, BOOST_IOS::openmode which)
 172     {
 173         if (which == BOOST_IOS::out)
 174             iostreams::flush(t);
 175     }
 176
 177     template<typename T, typename Sink>
 178     static void close(T& t, Sink& snk, BOOST_IOS::openmode which)
 179     {
 180         if (which == BOOST_IOS::out) {
 181             non_blocking_adapter<Sink> nb(snk);
 182             iostreams::flush(t, nb);
 183         }
 184     }
 185 };
 186
 187 template<>
 188 struct close_impl<close_boost_stream> {
 189     template<typename T>
 190     static void close(T& t)
 191     {
 192         t.close();
 193     }
 194     template<typename T>
 195     static void close(T& t, BOOST_IOS::openmode which)
 196     {
 197         if (which == BOOST_IOS::out)
 198             t.close();
 199     }
 200 };
 201
 202 template<>
 203 struct close_impl<close_filtering_stream> {
 204     template<typename T>
 205     static void close(T& t, BOOST_IOS::openmode which)
 206     {
 207         typedef typename category_of<T>::type category;
 208         const bool in =  is_convertible<category, input>::value &&
 209                         !is_convertible<category, output>::value;
 210         if (in == (which == BOOST_IOS::in) && t.is_complete())
 211             t.pop();
 212     }
 213 };
 214
 215 #include <boost/iostreams/detail/config/disable_warnings.hpp> // Borland.
 216 template<>
 217 struct close_impl<closable_tag> {
 218     template<typename T>
 219     static void close(T& t, BOOST_IOS::openmode which)
 220     {
 221         typedef typename category_of<T>::type category;
 222         const bool in =  is_convertible<category, input>::value &&
 223                         !is_convertible<category, output>::value;
 224         if (in == (which == BOOST_IOS::in))
 225             t.close();
 226     }
 227     template<typename T, typename Sink>
 228     static void close(T& t, Sink& snk, BOOST_IOS::openmode which)
 229     {
 230         typedef typename category_of<T>::type category;
 231         const bool in =  is_convertible<category, input>::value &&
 232                         !is_convertible<category, output>::value;
 233         if (in == (which == BOOST_IOS::in)) {
 234             non_blocking_adapter<Sink> nb(snk);
 235             t.close(nb);
 236         }
 237     }
 238 };
 239
 240 template<>
 241 struct close_impl<two_sequence> {
 242     template<typename T>
 243     static void close(T& t, BOOST_IOS::openmode which) { t.close(which); }
 244     template<typename T, typename Sink>
 245     static void close(T& t, Sink& snk, BOOST_IOS::openmode which)
 246     {
 247         non_blocking_adapter<Sink> nb(snk);
 248         t.close(nb, which);
 249     }
 250 };
 251
 252 } // End namespace detail.
 253
 254 } } // End namespaces iostreams, boost.
 255
 256 #endif // #if BOOST_WORKAROUND(BOOST_MSVC, < 1300) //-------------------------//
 257
 258 #include <boost/iostreams/detail/config/enable_warnings.hpp>
 259
 260 #endif // #ifndef BOOST_IOSTREAMS_CLOSE_HPP_INCLUDED