ceph/src/boost/libs/iostreams/include/boost/iostreams/filtering_stream.hpp

   1 // (C) Copyright 2008 CodeRage, LLC (turkanis at coderage dot com)
   2 // (C) Copyright 2004-2007 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_FILTER_STREAM_HPP_INCLUDED
   9 #define BOOST_IOSTREAMS_FILTER_STREAM_HPP_INCLUDED
  10
  11 #if defined(_MSC_VER)
  12 # pragma once
  13 #endif
  14
  15 #include <memory>                                     // allocator.
  16 #include <boost/iostreams/detail/access_control.hpp>
  17 #include <boost/iostreams/detail/char_traits.hpp>
  18 #include <boost/iostreams/detail/iostream.hpp>        // standard streams.
  19 #include <boost/iostreams/detail/push.hpp>
  20 #include <boost/iostreams/detail/select.hpp>
  21 #include <boost/iostreams/detail/streambuf.hpp>       // pubsync.
  22 #include <boost/iostreams/filtering_streambuf.hpp>
  23 #include <boost/mpl/and.hpp>
  24 #include <boost/mpl/bool.hpp>
  25 #include <boost/static_assert.hpp>
  26 #include <boost/type_traits/is_convertible.hpp>
  27
  28 // Must come last.
  29 #include <boost/iostreams/detail/config/disable_warnings.hpp>  // MSVC.
  30
  31 namespace boost { namespace iostreams {
  32
  33 //--------------Definition of filtered_istream--------------------------------//
  34
  35 namespace detail {
  36
  37 template<typename Mode, typename Ch, typename Tr>
  38 struct filtering_stream_traits {
  39     typedef typename
  40             iostreams::select<  // Disambiguation for Tru64
  41                 mpl::and_<
  42                     is_convertible<Mode, input>,
  43                     is_convertible<Mode, output>
  44                 >,
  45                 BOOST_IOSTREAMS_BASIC_IOSTREAM(Ch, Tr),
  46                 is_convertible<Mode, input>,
  47                 BOOST_IOSTREAMS_BASIC_ISTREAM(Ch, Tr),
  48                 else_,
  49                 BOOST_IOSTREAMS_BASIC_OSTREAM(Ch, Tr)
  50             >::type stream_type;
  51     typedef typename
  52             iostreams::select< // Dismbiguation required for Tru64.
  53                 mpl::and_<
  54                     is_convertible<Mode, input>,
  55                     is_convertible<Mode, output>
  56                 >,
  57                 iostream_tag,
  58                 is_convertible<Mode, input>,
  59                 istream_tag,
  60                 else_,
  61                 ostream_tag
  62             >::type stream_tag;
  63 };
  64
  65 template<typename Chain, typename Access>
  66 class filtering_stream_base
  67     : public access_control<
  68                  boost::iostreams::detail::chain_client<Chain>,
  69                  Access
  70              >,
  71       public filtering_stream_traits<
  72                  typename Chain::mode,
  73                  typename Chain::char_type,
  74                  typename Chain::traits_type
  75              >::stream_type
  76 {
  77 public:
  78     typedef Chain                                         chain_type;
  79     typedef access_control<
  80                  boost::iostreams::detail::chain_client<Chain>,
  81                  Access
  82              >                                            client_type;
  83 protected:
  84     typedef typename
  85             filtering_stream_traits<
  86                  typename Chain::mode,
  87                  typename Chain::char_type,
  88                  typename Chain::traits_type
  89             >::stream_type                                stream_type;
  90     filtering_stream_base() : stream_type(0) { this->set_chain(&chain_); }
  91 private:
  92     void notify() { this->rdbuf(chain_.empty() ? 0 : &chain_.front()); }
  93     Chain chain_;
  94 };
  95
  96 } // End namespace detail.
  97
  98 //
  99 // Macro: BOOST_IOSTREAMS_DEFINE_FILTER_STREAM(name_, chain_type_, default_char_)
 100 // Description: Defines a template derived from std::basic_streambuf which uses
 101 //      a chain to perform i/o. The template has the following parameters:
 102 //      Mode - the i/o mode.
 103 //      Ch - The character type.
 104 //      Tr - The character traits type.
 105 //      Alloc - The allocator type.
 106 //      Access - Indicates accessibility of the chain interface; must be either
 107 //          public_ or protected_; defaults to public_.
 108 // Macro parameters:
 109 //      name_ - The name of the template to be defined.
 110 //      chain_type_ - The name of the chain template.
 111 //      default_char_ - The default value for the char template parameter.
 112 //
 113 #define BOOST_IOSTREAMS_DEFINE_FILTER_STREAM(name_, chain_type_, default_char_) \
 114     template< typename Mode, \
 115               typename Ch = default_char_, \
 116               typename Tr = BOOST_IOSTREAMS_CHAR_TRAITS(Ch), \
 117               typename Alloc = std::allocator<Ch>, \
 118               typename Access = public_ > \
 119     class name_ \
 120         : public boost::iostreams::detail::filtering_stream_base< \
 121                      chain_type_<Mode, Ch, Tr, Alloc>, Access \
 122                  > \
 123     { \
 124     public: \
 125         typedef Ch                                char_type; \
 126         struct category \
 127             : Mode, \
 128               closable_tag, \
 129               detail::filtering_stream_traits<Mode, Ch, Tr>::stream_tag \
 130             { }; \
 131         BOOST_IOSTREAMS_STREAMBUF_TYPEDEFS(Tr) \
 132         typedef Mode                              mode; \
 133         typedef chain_type_<Mode, Ch, Tr, Alloc>  chain_type; \
 134         name_() { } \
 135         BOOST_IOSTREAMS_DEFINE_PUSH_CONSTRUCTOR(name_, mode, Ch, push_impl) \
 136         ~name_() { \
 137             if (this->is_complete()) \
 138                  this->rdbuf()->BOOST_IOSTREAMS_PUBSYNC(); \
 139         } \
 140     private: \
 141         typedef access_control< \
 142                     boost::iostreams::detail::chain_client< \
 143                         chain_type_<Mode, Ch, Tr, Alloc> \
 144                     >, \
 145                     Access \
 146                 > client_type; \
 147         template<typename T> \
 148         void push_impl(const T& t BOOST_IOSTREAMS_PUSH_PARAMS()) \
 149         { client_type::push(t BOOST_IOSTREAMS_PUSH_ARGS()); } \
 150     }; \
 151     /**/
 152 BOOST_IOSTREAMS_DEFINE_FILTER_STREAM(filtering_stream, boost::iostreams::chain, char)
 153 BOOST_IOSTREAMS_DEFINE_FILTER_STREAM(wfiltering_stream, boost::iostreams::chain, wchar_t)
 154
 155 typedef filtering_stream<input>    filtering_istream;
 156 typedef filtering_stream<output>   filtering_ostream;
 157 typedef wfiltering_stream<input>   filtering_wistream;
 158 typedef wfiltering_stream<output>  filtering_wostream;
 159
 160 //----------------------------------------------------------------------------//
 161
 162 } } // End namespace iostreams, boost
 163
 164 #include <boost/iostreams/detail/config/enable_warnings.hpp> // MSVC
 165
 166 #endif // #ifndef BOOST_IOSTREAMS_FILTER_STREAM_HPP_INCLUDED