boost/iostreams/stream.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_STREAM_HPP_INCLUDED
   9 #define BOOST_IOSTREAMS_STREAM_HPP_INCLUDED
  10
  11 #if defined(_MSC_VER) && (_MSC_VER >= 1020)
  12 # pragma once
  13 #endif
  14
  15 #include <boost/iostreams/constants.hpp>
  16 #include <boost/iostreams/detail/char_traits.hpp>
  17 #include <boost/iostreams/detail/config/overload_resolution.hpp>
  18 #include <boost/iostreams/detail/forward.hpp>
  19 #include <boost/iostreams/detail/iostream.hpp>  // standard streams.
  20 #include <boost/iostreams/detail/select.hpp>
  21 #include <boost/iostreams/stream_buffer.hpp>
  22 #include <boost/mpl/and.hpp>
  23 #include <boost/type_traits/is_convertible.hpp>
  24 #include <boost/utility/base_from_member.hpp>
  25
  26 namespace boost { namespace iostreams { namespace detail {
  27
  28 template<typename Device, typename Tr>
  29 struct stream_traits {
  30     typedef typename char_type_of<Device>::type                char_type;
  31     typedef Tr                                                 traits_type;
  32     typedef typename category_of<Device>::type                 mode;
  33     typedef typename
  34             iostreams::select< // Dismbiguation required for Tru64.
  35                 mpl::and_<
  36                     is_convertible<mode, input>,
  37                     is_convertible<mode, output>
  38                 >,
  39                 BOOST_IOSTREAMS_BASIC_IOSTREAM(char_type, traits_type),
  40                 is_convertible<mode, input>,
  41                 BOOST_IOSTREAMS_BASIC_ISTREAM(char_type, traits_type),
  42                 else_,
  43                 BOOST_IOSTREAMS_BASIC_OSTREAM(char_type, traits_type)
  44             >::type stream_type;
  45     typedef typename
  46             iostreams::select< // Dismbiguation required for Tru64.
  47                 mpl::and_<
  48                     is_convertible<mode, input>,
  49                     is_convertible<mode, output>
  50                 >,
  51                 iostream_tag,
  52                 is_convertible<mode, input>,
  53                 istream_tag,
  54                 else_,
  55                 ostream_tag
  56             >::type stream_tag;
  57 };
  58
  59 // By encapsulating initialization in a base, we can define the macro
  60 // BOOST_IOSTREAMS_DEFINE_FORWARDING_FUNCTIONS to generate constuctors
  61 // without base member initializer lists.
  62 template< typename Device,
  63           typename Tr =
  64               BOOST_IOSTREAMS_CHAR_TRAITS(
  65                   BOOST_DEDUCED_TYPENAME char_type_of<Device>::type
  66               ),
  67           typename Alloc =
  68               std::allocator<
  69                   BOOST_DEDUCED_TYPENAME char_type_of<Device>::type
  70               >,
  71           typename Base = // VC6 Workaround.
  72               BOOST_DEDUCED_TYPENAME
  73               detail::stream_traits<Device, Tr>::stream_type >
  74 class stream_base
  75     : protected base_from_member< stream_buffer<Device, Tr, Alloc> >,
  76       public Base
  77 {
  78 private:
  79     typedef base_from_member< stream_buffer<Device, Tr, Alloc> >  pbase_type;
  80     typedef typename stream_traits<Device, Tr>::stream_type       stream_type;
  81 protected:
  82     using pbase_type::member; // Avoid warning about 'this' in initializer list.
  83 public:
  84     stream_base() : pbase_type(), stream_type(&member) { }
  85 };
  86
  87 } } } // End namespaces detail, iostreams, boost.
  88
  89 #ifdef BOOST_IOSTREAMS_BROKEN_OVERLOAD_RESOLUTION
  90 # include <boost/iostreams/detail/broken_overload_resolution/stream.hpp>
  91 #else
  92
  93 namespace boost { namespace iostreams {
  94
  95 //
  96 // Template name: stream.
  97 // Description: A iostream which reads from and writes to an instance of a
  98 //      designated device type.
  99 // Template paramters:
 100 //      Device - A device type.
 101 //      Alloc - The allocator type.
 102 //
 103 template< typename Device,
 104           typename Tr =
 105               BOOST_IOSTREAMS_CHAR_TRAITS(
 106                   BOOST_DEDUCED_TYPENAME char_type_of<Device>::type
 107               ),
 108           typename Alloc =
 109               std::allocator<
 110                   BOOST_DEDUCED_TYPENAME char_type_of<Device>::type
 111               > >
 112 struct stream : detail::stream_base<Device, Tr, Alloc> {
 113 public:
 114     typedef typename char_type_of<Device>::type  char_type;
 115     struct category
 116         : mode_of<Device>::type,
 117           closable_tag,
 118           detail::stream_traits<Device, Tr>::stream_tag
 119         { };
 120     BOOST_IOSTREAMS_STREAMBUF_TYPEDEFS(Tr)
 121 private:
 122     typedef typename
 123             detail::stream_traits<
 124                 Device, Tr
 125             >::stream_type                       stream_type;
 126 public:
 127     stream() { }
 128     BOOST_IOSTREAMS_FORWARD( stream, open_impl, Device,
 129                              BOOST_IOSTREAMS_PUSH_PARAMS,
 130                              BOOST_IOSTREAMS_PUSH_ARGS )
 131     bool is_open() const { return this->member.is_open(); }
 132     void close() { this->member.close(); }
 133     bool auto_close() const { return this->member.auto_close(); }
 134     void set_auto_close(bool close) { this->member.set_auto_close(close); }
 135     bool strict_sync() { return this->member.strict_sync(); }
 136     Device& operator*() { return *this->member; }
 137     Device* operator->() { return &*this->member; }
 138     Device* component() { return this->member.component(); }
 139 private:
 140     void open_impl(const Device& dev BOOST_IOSTREAMS_PUSH_PARAMS()) // For forwarding.
 141     {
 142         this->clear();
 143         this->member.open(dev BOOST_IOSTREAMS_PUSH_ARGS());
 144     }
 145 };
 146
 147 } } // End namespaces iostreams, boost.
 148
 149 #endif // #ifdef BOOST_IOSTREAMS_BROKEN_OVERLOAD_RESOLUTION
 150
 151 #endif // #ifndef BOOST_IOSTREAMS_stream_HPP_INCLUDED