boost/iostreams/detail/adapter/mode_adapter.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_MODE_ADAPTER_HPP_INCLUDED
   9 #define BOOST_IOSTREAMS_DETAIL_MODE_ADAPTER_HPP_INCLUDED
  10
  11 #if defined(_MSC_VER) && (_MSC_VER >= 1020)
  12 # pragma once
  13 #endif
  14
  15 // Contains the definition of the class template mode_adapter, which allows
  16 // a filter or device to function as if it has a different i/o mode than that
  17 // deduced by the metafunction mode_of.
  18
  19 #include <boost/config.hpp>                // BOOST_MSVC.
  20 #include <boost/detail/workaround.hpp>
  21 #include <boost/iostreams/categories.hpp>
  22 #include <boost/iostreams/detail/ios.hpp>  // openmode, seekdir, int types.
  23 #include <boost/iostreams/traits.hpp>
  24 #include <boost/iostreams/operations.hpp>
  25 #include <boost/mpl/if.hpp>
  26
  27 namespace boost { namespace iostreams { namespace detail {
  28
  29 template<typename Mode, typename T>
  30 class mode_adapter {
  31 private:
  32     struct empty_base { };
  33 public:
  34     typedef typename wrapped_type<T>::type  component_type;
  35     typedef typename char_type_of<T>::type  char_type;
  36     struct category
  37         : Mode,
  38           device_tag,
  39           mpl::if_<is_filter<T>, filter_tag, device_tag>,
  40           mpl::if_<is_filter<T>, multichar_tag, empty_base>,
  41           #if !BOOST_WORKAROUND(BOOST_MSVC, < 1300)
  42               closable_tag, // VC6 can't see member close()!
  43           #endif
  44           localizable_tag
  45         { };
  46     explicit mode_adapter(const component_type& t) : t_(t) { }
  47
  48         // Device member functions.
  49
  50     std::streamsize read(char_type* s, std::streamsize n);
  51     std::streamsize write(const char_type* s, std::streamsize n);
  52     std::streampos seek( stream_offset off, BOOST_IOS::seekdir way,
  53                          BOOST_IOS::openmode which =
  54                              BOOST_IOS::in | BOOST_IOS::out );
  55 #if !BOOST_WORKAROUND(BOOST_MSVC, < 1300)
  56     void close();
  57     void close(BOOST_IOS::openmode which);
  58 #endif
  59
  60         // Filter member functions.
  61
  62     template<typename Source>
  63     std::streamsize read(Source& src, char_type* s, std::streamsize n)
  64     { return iostreams::read(t_, src, s, n); }
  65
  66     template<typename Sink>
  67     std::streamsize write(Sink& snk, const char_type* s, std::streamsize n)
  68     { return iostreams::write(t_, snk, s, n); }
  69
  70     template<typename Device>
  71     std::streampos seek(Device& dev, stream_offset off, BOOST_IOS::seekdir way)
  72     { return iostreams::seek(t_, dev, off, way); }
  73
  74     template<typename Device>
  75     std::streampos seek( Device& dev, stream_offset off,
  76                          BOOST_IOS::seekdir way, BOOST_IOS::openmode which  )
  77     { return iostreams::seek(t_, dev, off, way, which); }
  78
  79     template<typename Device>
  80     void close(Device& dev)
  81     { detail::close_all(t_, dev); }
  82
  83     template<typename Device>
  84     void close(Device& dev, BOOST_IOS::openmode which)
  85     { iostreams::close(t_, dev, which); }
  86
  87     template<typename Locale>
  88     void imbue(const Locale& loc)
  89     { iostreams::imbue(t_, loc); }
  90 private:
  91     component_type t_;
  92 };
  93
  94 //------------------Implementation of mode_adapter----------------------------//
  95
  96 template<typename Mode, typename T>
  97 std::streamsize mode_adapter<Mode, T>::read
  98     (char_type* s, std::streamsize n)
  99 { return boost::iostreams::read(t_, s, n); }
 100
 101 template<typename Mode, typename T>
 102 std::streamsize mode_adapter<Mode, T>::write
 103     (const char_type* s, std::streamsize n)
 104 { return boost::iostreams::write(t_, s, n); }
 105
 106 template<typename Mode, typename T>
 107 std::streampos mode_adapter<Mode, T>::seek
 108     (stream_offset off, BOOST_IOS::seekdir way, BOOST_IOS::openmode which)
 109 { return boost::iostreams::seek(t_, off, way, which); }
 110
 111 #if !BOOST_WORKAROUND(BOOST_MSVC, < 1300)
 112     template<typename Mode, typename T>
 113     void mode_adapter<Mode, T>::close()
 114     { detail::close_all(t_); }
 115
 116     template<typename Mode, typename T>
 117     void mode_adapter<Mode, T>::close(BOOST_IOS::openmode which)
 118     { iostreams::close(t_, which); }
 119 #endif
 120
 121 } } } // End namespaces detail, iostreams, boost.
 122
 123 #endif // #ifndef BOOST_IOSTREAMS_DETAIL_MODE_ADAPTER_HPP_INCLUDED //-----//