sl@0: // (C) Copyright Jonathan Turkanis 2003.
sl@0: // Distributed under the Boost Software License, Version 1.0. (See accompanying
sl@0: // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt.)
sl@0: 
sl@0: // See http://www.boost.org/libs/iostreams for documentation.
sl@0: 
sl@0: // To do: add support for random-access.
sl@0: 
sl@0: #ifndef BOOST_IOSTREAMS_COMBINE_HPP_INCLUDED
sl@0: #define BOOST_IOSTREAMS_COMBINE_HPP_INCLUDED
sl@0: 
sl@0: #if defined(_MSC_VER) && (_MSC_VER >= 1020)
sl@0: # pragma once
sl@0: #endif              
sl@0: 
sl@0: #include <boost/config.hpp> // NO_STD_LOCALE, DEDUCED_TYPENAME.
sl@0: #ifndef BOOST_NO_STD_LOCALE
sl@0: # include <locale>
sl@0: #endif
sl@0: #include <boost/iostreams/detail/ios.hpp>   
sl@0: #include <boost/iostreams/detail/wrap_unwrap.hpp>       
sl@0: #include <boost/iostreams/traits.hpp>         
sl@0: #include <boost/iostreams/operations.hpp>        
sl@0: #include <boost/mpl/if.hpp>    
sl@0: #include <boost/static_assert.hpp>  
sl@0: #include <boost/type_traits/is_convertible.hpp>
sl@0: #include <boost/type_traits/is_same.hpp> 
sl@0: 
sl@0: namespace boost { namespace iostreams {
sl@0: 
sl@0: namespace detail {
sl@0: 
sl@0: //
sl@0: // Template name: combined_device.
sl@0: // Description: Model of Device defined in terms of a Source/Sink pair.
sl@0: // Template paramters:
sl@0: //      Source - A model of Source, with the same char_type and traits_type
sl@0: //          as Sink.
sl@0: //      Sink - A model of Sink, with the same char_type and traits_type
sl@0: //          as Source.
sl@0: //
sl@0: template<typename Source, typename Sink>
sl@0: class combined_device {
sl@0: public:
sl@0:     typedef typename char_type_of<Source>::type char_type;
sl@0:     struct category
sl@0:         : bidirectional, 
sl@0:           device_tag, 
sl@0:           closable_tag, 
sl@0:           localizable_tag
sl@0:         { };
sl@0:     combined_device(const Source& src, const Sink& snk);
sl@0:     std::streamsize read(char_type* s, std::streamsize n);
sl@0:     std::streamsize write(const char_type* s, std::streamsize n);
sl@0:     void close(BOOST_IOS::openmode);
sl@0:     #ifndef BOOST_NO_STD_LOCALE
sl@0:         void imbue(const std::locale& loc);
sl@0:     #endif
sl@0: private:
sl@0:     typedef typename char_type_of<Sink>::type sink_char_type;
sl@0:     BOOST_STATIC_ASSERT((is_same<char_type, sink_char_type>::value));
sl@0:     Source  src_;
sl@0:     Sink    sink_;
sl@0: };
sl@0: 
sl@0: //
sl@0: // Template name: combined_filter.
sl@0: // Description: Model of Device defined in terms of a Source/Sink pair.
sl@0: // Template paramters:
sl@0: //      InputFilter - A model of InputFilter, with the same char_type as 
sl@0: //          OutputFilter.
sl@0: //      OutputFilter - A model of OutputFilter, with the same char_type as 
sl@0: //          InputFilter.
sl@0: //
sl@0: template<typename InputFilter, typename OutputFilter>
sl@0: class combined_filter {
sl@0: private:
sl@0:     typedef typename category_of<InputFilter>::type    in_category;
sl@0:     typedef typename category_of<OutputFilter>::type   out_category;
sl@0: public:
sl@0:     typedef typename char_type_of<InputFilter>::type   char_type;
sl@0:     struct category 
sl@0:         : multichar_bidirectional_filter_tag,
sl@0:           closable_tag, 
sl@0:           localizable_tag
sl@0:         { };
sl@0:     combined_filter(const InputFilter& in, const OutputFilter& out);
sl@0: 
sl@0:     template<typename Source>
sl@0:     std::streamsize read(Source& src, char_type* s, std::streamsize n)
sl@0:     { return boost::iostreams::read(in_, src, s, n); }
sl@0: 
sl@0:     template<typename Sink>
sl@0:     std::streamsize write(Sink& snk, const char_type* s, std::streamsize n)
sl@0:     { return boost::iostreams::write(out_, snk, s, n); }
sl@0: 
sl@0:     template<typename Sink>
sl@0:     void close(Sink& snk, BOOST_IOS::openmode which)
sl@0:         {
sl@0:             if (which & BOOST_IOS::in)
sl@0:                 iostreams::close(in_, snk, which);
sl@0:             if (which & BOOST_IOS::out)
sl@0:                 iostreams::close(out_, snk, which);
sl@0:         }
sl@0:     #ifndef BOOST_NO_STD_LOCALE
sl@0:         void imbue(const std::locale& loc);
sl@0:     #endif
sl@0: private:
sl@0:     typedef typename char_type_of<OutputFilter>::type  output_char_type;
sl@0:     BOOST_STATIC_ASSERT((is_same<char_type, output_char_type>::value));
sl@0:     InputFilter   in_;
sl@0:     OutputFilter  out_;
sl@0: };
sl@0: 
sl@0: template<typename In, typename Out>
sl@0: struct combination_traits 
sl@0:     : mpl::if_<
sl@0:           is_device<In>,
sl@0:           combined_device<
sl@0:               typename wrapped_type<In>::type,
sl@0:               typename wrapped_type<Out>::type
sl@0:           >,
sl@0:           combined_filter<
sl@0:               typename wrapped_type<In>::type,
sl@0:               typename wrapped_type<Out>::type
sl@0:           >
sl@0:       >
sl@0:     { };
sl@0: 
sl@0: } // End namespace detail.
sl@0: 
sl@0: template<typename In, typename Out>
sl@0: struct combination : detail::combination_traits<In, Out>::type {
sl@0:     typedef typename detail::combination_traits<In, Out>::type  base_type;
sl@0:     typedef typename detail::wrapped_type<In>::type          in_type;
sl@0:     typedef typename detail::wrapped_type<Out>::type         out_type;
sl@0:     combination(const in_type& in, const out_type& out)
sl@0:         : base_type(in, out) { }
sl@0: };
sl@0: 
sl@0: namespace detail {
sl@0: 
sl@0: // Workaround for VC6 ETI bug.
sl@0: template<typename In, typename Out>
sl@0: struct combine_traits {
sl@0:     typedef combination<
sl@0:                 BOOST_DEDUCED_TYPENAME detail::unwrapped_type<In>::type, 
sl@0:                 BOOST_DEDUCED_TYPENAME detail::unwrapped_type<Out>::type
sl@0:             > type;
sl@0: };
sl@0: 
sl@0: } // End namespace detail.
sl@0: 
sl@0: //
sl@0: // Template name: combine.
sl@0: // Description: Takes a Source/Sink pair or InputFilter/OutputFilter pair and
sl@0: //      returns a Reource or Filter which performs input using the first member
sl@0: //      of the pair and output using the second member of the pair.
sl@0: // Template paramters:
sl@0: //      In - A model of Source or InputFilter, with the same char_type as Out.
sl@0: //      Out - A model of Sink or OutputFilter, with the same char_type as In.
sl@0: //
sl@0: template<typename In, typename Out>
sl@0: typename detail::combine_traits<In, Out>::type
sl@0: combine(const In& in, const Out& out) 
sl@0: { 
sl@0:     typedef typename detail::combine_traits<In, Out>::type return_type;
sl@0:     return return_type(in, out); 
sl@0: }
sl@0: 
sl@0: //----------------------------------------------------------------------------//
sl@0: 
sl@0: namespace detail {
sl@0: 
sl@0: //--------------Implementation of combined_device-----------------------------//
sl@0: 
sl@0: template<typename Source, typename Sink>
sl@0: inline combined_device<Source, Sink>::combined_device
sl@0:     (const Source& src, const Sink& snk)
sl@0:     : src_(src), sink_(snk) { }
sl@0: 
sl@0: template<typename Source, typename Sink>
sl@0: inline std::streamsize
sl@0: combined_device<Source, Sink>::read(char_type* s, std::streamsize n)
sl@0: { return iostreams::read(src_, s, n); }
sl@0: 
sl@0: template<typename Source, typename Sink>
sl@0: inline std::streamsize
sl@0: combined_device<Source, Sink>::write(const char_type* s, std::streamsize n)
sl@0: { return iostreams::write(sink_, s, n); }
sl@0: 
sl@0: template<typename Source, typename Sink>
sl@0: inline void
sl@0: combined_device<Source, Sink>::close(BOOST_IOS::openmode which)
sl@0: { 
sl@0:     if (which & BOOST_IOS::in)
sl@0:         iostreams::close(src_, which); 
sl@0:     if (which & BOOST_IOS::out)
sl@0:         iostreams::close(sink_, which); 
sl@0: }
sl@0: 
sl@0: #ifndef BOOST_NO_STD_LOCALE
sl@0:     template<typename Source, typename Sink>
sl@0:     void combined_device<Source, Sink>::imbue(const std::locale& loc)
sl@0:     {
sl@0:         iostreams::imbue(src_, loc);
sl@0:         iostreams::imbue(sink_, loc);
sl@0:     }
sl@0: #endif
sl@0: 
sl@0: //--------------Implementation of filter_pair---------------------------------//
sl@0: 
sl@0: template<typename InputFilter, typename OutputFilter>
sl@0: inline combined_filter<InputFilter, OutputFilter>::combined_filter
sl@0:     (const InputFilter& in, const OutputFilter& out) : in_(in), out_(out)
sl@0:     { }
sl@0: 
sl@0: #ifndef BOOST_NO_STD_LOCALE
sl@0:     template<typename InputFilter, typename OutputFilter>
sl@0:     void combined_filter<InputFilter, OutputFilter>::imbue
sl@0:         (const std::locale& loc)
sl@0:     {
sl@0:         iostreams::imbue(in_, loc);
sl@0:         iostreams::imbue(out_, loc);
sl@0:     }
sl@0: #endif
sl@0: 
sl@0: 
sl@0: } // End namespace detail.
sl@0: 
sl@0: } } // End namespaces iostreams, boost.
sl@0: 
sl@0: #endif // #ifndef BOOST_IOSTREAMS_COMBINE_HPP_INCLUDED