Chris@16: // (C) Copyright 2008 CodeRage, LLC (turkanis at coderage dot com)
Chris@16: // (C) Copyright 2003-2007 Jonathan Turkanis
Chris@16: // Distributed under the Boost Software License, Version 1.0. (See accompanying
Chris@16: // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt.)
Chris@16: 
Chris@16: // See http://www.boost.org/libs/iostreams for documentation.
Chris@16: 
Chris@16: // 
Chris@16: // Contains metafunctions char_type_of, category_of and mode_of used for
Chris@16: // deducing the i/o category and i/o mode of a model of Filter or Device.
Chris@16: //
Chris@16: // Also contains several utility metafunctions, functions and macros.
Chris@16: //
Chris@16: 
Chris@16: #ifndef BOOST_IOSTREAMS_IO_TRAITS_HPP_INCLUDED
Chris@16: #define BOOST_IOSTREAMS_IO_TRAITS_HPP_INCLUDED
Chris@16: 
Chris@16: #if defined(_MSC_VER) && (_MSC_VER >= 1020)
Chris@16: # pragma once
Chris@16: #endif              
Chris@16: 
Chris@16: #include <iosfwd>            // stream types, char_traits.
Chris@16: #include <boost/config.hpp>  // partial spec, deduced typename.
Chris@16: #include <boost/detail/workaround.hpp>
Chris@16: #include <boost/iostreams/categories.hpp>
Chris@16: #include <boost/iostreams/detail/bool_trait_def.hpp> 
Chris@16: #include <boost/iostreams/detail/config/wide_streams.hpp>
Chris@16: #include <boost/iostreams/detail/is_iterator_range.hpp>    
Chris@16: #include <boost/iostreams/detail/select.hpp>        
Chris@16: #include <boost/iostreams/detail/select_by_size.hpp>      
Chris@16: #include <boost/iostreams/detail/wrap_unwrap.hpp>       
Chris@16: #include <boost/iostreams/traits_fwd.hpp> 
Chris@16: #include <boost/mpl/bool.hpp>   
Chris@16: #include <boost/mpl/eval_if.hpp>
Chris@16: #include <boost/mpl/identity.hpp>      
Chris@16: #include <boost/mpl/int.hpp>  
Chris@16: #include <boost/mpl/or.hpp>                 
Chris@16: #if !BOOST_WORKAROUND(BOOST_MSVC, <= 1300)
Chris@16: # include <boost/range/iterator_range.hpp>
Chris@16: # include <boost/range/value_type.hpp>
Chris@16: #endif // #if BOOST_WORKAROUND(BOOST_MSVC, <= 1300)
Chris@16: #include <boost/ref.hpp>
Chris@16: #include <boost/type_traits/is_convertible.hpp>
Chris@16: 
Chris@16: // Must come last.
Chris@16: #include <boost/iostreams/detail/config/disable_warnings.hpp>
Chris@16: 
Chris@16: namespace boost { namespace iostreams {
Chris@16: 
Chris@16: //----------Definitions of predicates for streams and stream buffers----------//
Chris@16: 
Chris@16: #ifndef BOOST_IOSTREAMS_NO_STREAM_TEMPLATES //--------------------------------//
Chris@16: 
Chris@16: BOOST_IOSTREAMS_BOOL_TRAIT_DEF(is_istream, std::basic_istream, 2)
Chris@16: BOOST_IOSTREAMS_BOOL_TRAIT_DEF(is_ostream, std::basic_ostream, 2)
Chris@16: BOOST_IOSTREAMS_BOOL_TRAIT_DEF(is_iostream, std::basic_iostream, 2)
Chris@16: BOOST_IOSTREAMS_BOOL_TRAIT_DEF(is_streambuf, std::basic_streambuf, 2)
Chris@16: BOOST_IOSTREAMS_BOOL_TRAIT_DEF(is_ifstream, std::basic_ifstream, 2)
Chris@16: BOOST_IOSTREAMS_BOOL_TRAIT_DEF(is_ofstream, std::basic_ofstream, 2)
Chris@16: BOOST_IOSTREAMS_BOOL_TRAIT_DEF(is_fstream, std::basic_fstream, 2)
Chris@16: BOOST_IOSTREAMS_BOOL_TRAIT_DEF(is_filebuf, std::basic_filebuf, 2)
Chris@16: BOOST_IOSTREAMS_BOOL_TRAIT_DEF(is_istringstream, std::basic_istringstream, 3)
Chris@16: BOOST_IOSTREAMS_BOOL_TRAIT_DEF(is_ostringstream, std::basic_ostringstream, 3)
Chris@16: BOOST_IOSTREAMS_BOOL_TRAIT_DEF(is_stringstream, std::basic_stringstream, 3)
Chris@16: BOOST_IOSTREAMS_BOOL_TRAIT_DEF(is_stringbuf, std::basic_stringbuf, 3)
Chris@16: 
Chris@16: #else // #ifndef BOOST_IOSTREAMS_NO_STREAM_TEMPLATES //-----------------------//
Chris@16: 
Chris@16: BOOST_IOSTREAMS_BOOL_TRAIT_DEF(is_istream, std::istream, 0)
Chris@16: BOOST_IOSTREAMS_BOOL_TRAIT_DEF(is_ostream, std::ostream, 0)
Chris@16: BOOST_IOSTREAMS_BOOL_TRAIT_DEF(is_iostream, std::iostream, 0)
Chris@16: BOOST_IOSTREAMS_BOOL_TRAIT_DEF(is_streambuf, std::streambuf, 0)
Chris@16: 
Chris@16: #endif // #ifndef BOOST_IOSTREAMS_NO_STREAM_TEMPLATES //----------------------//
Chris@16: 
Chris@16: template<typename T>
Chris@16: struct is_std_io
Chris@16:     : mpl::or_< is_istream<T>, is_ostream<T>, is_streambuf<T> >
Chris@16:     { };
Chris@16: 
Chris@16: template<typename T>
Chris@16: struct is_std_file_device
Chris@16:     : mpl::or_< 
Chris@16:           is_ifstream<T>, 
Chris@16:           is_ofstream<T>, 
Chris@16:           is_fstream<T>, 
Chris@16:           is_filebuf<T>
Chris@16:       >
Chris@16:     { };
Chris@16: 
Chris@16: template<typename T>
Chris@16: struct is_std_string_device
Chris@16:     : mpl::or_< 
Chris@16:           is_istringstream<T>, 
Chris@16:           is_ostringstream<T>, 
Chris@16:           is_stringstream<T>, 
Chris@16:           is_stringbuf<T>
Chris@16:       >
Chris@16:     { };
Chris@16: 
Chris@16: template<typename Device, typename Tr, typename Alloc>
Chris@16: struct stream;
Chris@16: 
Chris@16: template<typename T, typename Tr, typename Alloc, typename Mode>
Chris@16: class stream_buffer;
Chris@16: 
Chris@16: template< typename Mode, typename Ch, typename Tr, 
Chris@16:           typename Alloc, typename Access >
Chris@16: class filtering_stream;
Chris@16: 
Chris@16: template< typename Mode, typename Ch, typename Tr, 
Chris@16:           typename Alloc, typename Access >
Chris@16: class wfiltering_stream;
Chris@16: 
Chris@16: template< typename Mode, typename Ch, typename Tr, 
Chris@16:           typename Alloc, typename Access >
Chris@16: class filtering_streambuf;
Chris@16: 
Chris@16: template< typename Mode, typename Ch, typename Tr, 
Chris@16:           typename Alloc, typename Access >
Chris@16: class filtering_wstreambuf;
Chris@16: 
Chris@16: namespace detail {
Chris@16: 
Chris@16: template<typename T, typename Tr>
Chris@16: class linked_streambuf;
Chris@16: 
Chris@16: BOOST_IOSTREAMS_BOOL_TRAIT_DEF( is_boost_stream,
Chris@16:                                 boost::iostreams::stream,
Chris@16:                                 3 )
Chris@16: BOOST_IOSTREAMS_BOOL_TRAIT_DEF( is_boost_stream_buffer,
Chris@16:                                 boost::iostreams::stream_buffer,
Chris@16:                                 4 )
Chris@16: BOOST_IOSTREAMS_BOOL_TRAIT_DEF( is_filtering_stream_impl,
Chris@16:                                 boost::iostreams::filtering_stream,
Chris@16:                                 5 )
Chris@16: BOOST_IOSTREAMS_BOOL_TRAIT_DEF( is_filtering_wstream_impl,
Chris@16:                                 boost::iostreams::wfiltering_stream,
Chris@16:                                 5 )
Chris@16: BOOST_IOSTREAMS_BOOL_TRAIT_DEF( is_filtering_streambuf_impl,
Chris@16:                                 boost::iostreams::filtering_streambuf,
Chris@16:                                 5 )
Chris@16: BOOST_IOSTREAMS_BOOL_TRAIT_DEF( is_filtering_wstreambuf_impl,
Chris@16:                                 boost::iostreams::filtering_wstreambuf,
Chris@16:                                 5 )
Chris@16: BOOST_IOSTREAMS_BOOL_TRAIT_DEF(is_linked, linked_streambuf, 2)
Chris@16: 
Chris@16: template<typename T>
Chris@16: struct is_filtering_stream
Chris@16:     : mpl::or_<
Chris@16:           is_filtering_stream_impl<T>,
Chris@16:           is_filtering_wstream_impl<T>
Chris@16:       >
Chris@16:     { };
Chris@16: 
Chris@16: template<typename T>
Chris@16: struct is_filtering_streambuf
Chris@16:     : mpl::or_<
Chris@16:           is_filtering_streambuf_impl<T>,
Chris@16:           is_filtering_wstreambuf_impl<T>
Chris@16:       >
Chris@16:     { };
Chris@16: 
Chris@16: template<typename T>
Chris@16: struct is_boost
Chris@16:     : mpl::or_<
Chris@16:           is_boost_stream<T>, 
Chris@16:           is_boost_stream_buffer<T>, 
Chris@16:           is_filtering_stream<T>, 
Chris@16:           is_filtering_streambuf<T>
Chris@16:       >
Chris@16:     { };
Chris@16: 
Chris@16: } // End namespace detail.
Chris@16:                     
Chris@16: //------------------Definitions of char_type_of-------------------------------//
Chris@16: 
Chris@16: namespace detail {
Chris@16: 
Chris@16: template<typename T>
Chris@16: struct member_char_type { typedef typename T::char_type type; };
Chris@16: 
Chris@16: } // End namespace detail.
Chris@16: 
Chris@16: #ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION //---------------------------//
Chris@16: # ifndef BOOST_IOSTREAMS_NO_STREAM_TEMPLATES //-------------------------------//
Chris@16: 
Chris@16: template<typename T>
Chris@16: struct char_type_of 
Chris@16:     : detail::member_char_type<
Chris@16:           typename detail::unwrapped_type<T>::type
Chris@16:       > 
Chris@16:     { };
Chris@16: 
Chris@16: # else // # ifndef BOOST_IOSTREAMS_NO_STREAM_TEMPLATES //---------------------//
Chris@16: 
Chris@16: template<typename T>
Chris@16: struct char_type_of {
Chris@16:     typedef typename detail::unwrapped_type<T>::type U;
Chris@16:     typedef typename 
Chris@16:             mpl::eval_if<
Chris@16:                 is_std_io<U>,
Chris@16:                 mpl::identity<char>,
Chris@16:                 detail::member_char_type<U>
Chris@16:             >::type type;
Chris@16: };
Chris@16: 
Chris@16: # endif // # ifndef BOOST_IOSTREAMS_NO_STREAM_TEMPLATES //--------------------//
Chris@16: 
Chris@16: template<typename Iter>
Chris@16: struct char_type_of< iterator_range<Iter> > {
Chris@16:     typedef typename iterator_value<Iter>::type type;
Chris@16: };
Chris@16: 
Chris@16: #else // #ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION //------------------//
Chris@16: 
Chris@16: template<typename T>
Chris@16: struct char_type_of {
Chris@16:     template<typename U>
Chris@16:     struct get_value_type {
Chris@16:         #if !BOOST_WORKAROUND(BOOST_MSVC, <= 1300)
Chris@16:             typedef typename range_value<U>::type type;
Chris@16:         #endif // #if BOOST_WORKAROUND(BOOST_MSVC, <= 1300)
Chris@16:     };
Chris@16:     typedef typename 
Chris@16:             mpl::eval_if<
Chris@16:                 is_iterator_range<T>,
Chris@16:                 get_value_type<T>,
Chris@16:                 detail::member_char_type<
Chris@16:                     BOOST_DEDUCED_TYPENAME detail::unwrapped_type<T>::type
Chris@16:                 >
Chris@16:             >::type type;
Chris@16: };
Chris@16: 
Chris@16: #endif // #ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION //-----------------//
Chris@16: 
Chris@16: //------------------Definitions of category_of--------------------------------//
Chris@16: 
Chris@16: namespace detail {
Chris@16: 
Chris@16: template<typename T>
Chris@16: struct member_category { typedef typename T::category type; };
Chris@16: 
Chris@16: } // End namespace detail.
Chris@16: 
Chris@16: template<typename T>
Chris@16: struct category_of {
Chris@16:     template<typename U>
Chris@16:     struct member_category { 
Chris@16:         typedef typename U::category type; 
Chris@16:     };
Chris@16:     typedef typename detail::unwrapped_type<T>::type U;
Chris@16:     typedef typename  
Chris@16:             mpl::eval_if<
Chris@16:                 mpl::and_<
Chris@16:                     is_std_io<U>,
Chris@16:                     mpl::not_< detail::is_boost<U> >
Chris@16:                 >,
Chris@16:                 iostreams::select<  // Disambiguation for Tru64
Chris@16:                     is_filebuf<U>,        filebuf_tag,
Chris@16:                     is_ifstream<U>,       ifstream_tag,
Chris@16:                     is_ofstream<U>,       ofstream_tag,
Chris@16:                     is_fstream<U>,        fstream_tag,
Chris@16:                     is_stringbuf<U>,      stringbuf_tag,
Chris@16:                     is_istringstream<U>,  istringstream_tag,
Chris@16:                     is_ostringstream<U>,  ostringstream_tag,
Chris@16:                     is_stringstream<U>,   stringstream_tag,
Chris@16:                     is_streambuf<U>,      generic_streambuf_tag,
Chris@16:                     is_iostream<U>,       generic_iostream_tag,
Chris@16:                     is_istream<U>,        generic_istream_tag, 
Chris@16:                     is_ostream<U>,        generic_ostream_tag
Chris@16:                 >,
Chris@16:                 detail::member_category<U>
Chris@16:             >::type type;
Chris@16: };
Chris@16: 
Chris@16: // Partial specialization for reference wrappers
Chris@16: #ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION //---------------------------//
Chris@16: 
Chris@16: template<typename T>
Chris@16: struct category_of< reference_wrapper<T> >
Chris@16:     : category_of<T>
Chris@16:     { };
Chris@16: 
Chris@16: #endif // #ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION //-----------------//
Chris@16: 
Chris@16: //------------------Definition of get_category--------------------------------//
Chris@16: 
Chris@16: // 
Chris@16: // Returns an object of type category_of<T>::type.
Chris@16: // 
Chris@16: template<typename T>
Chris@16: inline typename category_of<T>::type get_category(const T&) 
Chris@16: { typedef typename category_of<T>::type category; return category(); }
Chris@16: 
Chris@16: //------------------Definition of int_type_of---------------------------------//
Chris@16: 
Chris@16: template<typename T>
Chris@16: struct int_type_of { 
Chris@16: #ifndef BOOST_IOSTREAMS_NO_STREAM_TEMPLATES
Chris@16:     typedef std::char_traits<
Chris@16:                 BOOST_DEDUCED_TYPENAME char_type_of<T>::type
Chris@16:             > traits_type;      
Chris@16:     typedef typename traits_type::int_type type; 
Chris@16: #else  
Chris@16:     typedef int                            type; 
Chris@16: #endif
Chris@16: };
Chris@16: 
Chris@16: //------------------Definition of mode_of-------------------------------------//
Chris@16: 
Chris@16: namespace detail {
Chris@16: 
Chris@16: template<int N> struct io_mode_impl;
Chris@16: 
Chris@16: #define BOOST_IOSTREAMS_MODE_HELPER(tag_, id_) \
Chris@16:     case_<id_> io_mode_impl_helper(tag_); \
Chris@16:     template<> struct io_mode_impl<id_> { typedef tag_ type; }; \
Chris@16:     /**/
Chris@16: BOOST_IOSTREAMS_MODE_HELPER(input, 1)
Chris@16: BOOST_IOSTREAMS_MODE_HELPER(output, 2)
Chris@16: BOOST_IOSTREAMS_MODE_HELPER(bidirectional, 3)
Chris@16: BOOST_IOSTREAMS_MODE_HELPER(input_seekable, 4)
Chris@16: BOOST_IOSTREAMS_MODE_HELPER(output_seekable, 5)
Chris@16: BOOST_IOSTREAMS_MODE_HELPER(seekable, 6)
Chris@16: BOOST_IOSTREAMS_MODE_HELPER(dual_seekable, 7)
Chris@16: BOOST_IOSTREAMS_MODE_HELPER(bidirectional_seekable, 8)
Chris@16: BOOST_IOSTREAMS_MODE_HELPER(dual_use, 9)
Chris@16: #undef BOOST_IOSTREAMS_MODE_HELPER
Chris@16: 
Chris@16: template<typename T>
Chris@16: struct io_mode_id {
Chris@16:     typedef typename category_of<T>::type category;
Chris@16:     BOOST_SELECT_BY_SIZE(int, value, detail::io_mode_impl_helper(category()));
Chris@16: };
Chris@16: 
Chris@16: } // End namespace detail.
Chris@16: 
Chris@16: template<typename T> // Borland 5.6.4 requires this circumlocution.
Chris@16: struct mode_of : detail::io_mode_impl< detail::io_mode_id<T>::value > { };
Chris@16: 
Chris@16: // Partial specialization for reference wrappers
Chris@16: #ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION //---------------------------//
Chris@16: 
Chris@16: template<typename T>
Chris@16: struct mode_of< reference_wrapper<T> >
Chris@16:     : mode_of<T>
Chris@16:     { };
Chris@16: 
Chris@16: #endif // #ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION //-----------------//
Chris@16:                     
Chris@16: //------------------Definition of is_device, is_filter and is_direct----------//
Chris@16: 
Chris@16: namespace detail {
Chris@16: 
Chris@16: template<typename T, typename Tag>
Chris@16: struct has_trait_impl {
Chris@16:     typedef typename category_of<T>::type category;
Chris@16:     BOOST_STATIC_CONSTANT(bool, value = (is_convertible<category, Tag>::value));
Chris@16: };
Chris@16: 
Chris@16: template<typename T, typename Tag>
Chris@16: struct has_trait 
Chris@16:     : mpl::bool_<has_trait_impl<T, Tag>::value>
Chris@16:     { }; 
Chris@16: 
Chris@16: } // End namespace detail.
Chris@16: 
Chris@16: template<typename T>
Chris@16: struct is_device : detail::has_trait<T, device_tag> { };
Chris@16: 
Chris@16: template<typename T>
Chris@16: struct is_filter : detail::has_trait<T, filter_tag> { };
Chris@16: 
Chris@16: template<typename T>
Chris@16: struct is_direct : detail::has_trait<T, direct_tag> { };
Chris@16:                     
Chris@16: //------------------Definition of BOOST_IOSTREAMS_STREAMBUF_TYPEDEFS----------//
Chris@16: 
Chris@16: #define BOOST_IOSTREAMS_STREAMBUF_TYPEDEFS(Tr) \
Chris@16:     typedef Tr                              traits_type; \
Chris@16:     typedef typename traits_type::int_type  int_type; \
Chris@16:     typedef typename traits_type::off_type  off_type; \
Chris@16:     typedef typename traits_type::pos_type  pos_type; \
Chris@16:     /**/
Chris@16: 
Chris@16: } } // End namespaces iostreams, boost.
Chris@16: 
Chris@16: #include <boost/iostreams/detail/config/enable_warnings.hpp>
Chris@16: 
Chris@16: #endif // #ifndef BOOST_IOSTREAMS_IO_TRAITS_HPP_INCLUDED