sl@0: // (C) Copyright Jonathan Turkanis 2005.
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: #ifndef BOOST_IOSTREAMS_READ_HPP_INCLUDED
sl@0: #define BOOST_IOSTREAMS_READ_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>  // DEDUCED_TYPENAME, MSVC.
sl@0: #include <boost/detail/workaround.hpp>
sl@0: #include <boost/iostreams/char_traits.hpp>
sl@0: #include <boost/iostreams/detail/char_traits.hpp>
sl@0: #include <boost/iostreams/detail/dispatch.hpp>
sl@0: #include <boost/iostreams/detail/ios.hpp>  // streamsize.
sl@0: #include <boost/iostreams/detail/streambuf.hpp>
sl@0: #include <boost/iostreams/detail/wrap_unwrap.hpp>
sl@0: #include <boost/iostreams/operations_fwd.hpp>
sl@0: #include <boost/mpl/if.hpp>
sl@0: 
sl@0: // Must come last.
sl@0: #include <boost/iostreams/detail/config/disable_warnings.hpp>
sl@0: 
sl@0: #if BOOST_WORKAROUND(BOOST_MSVC, < 1300) //-----------------------------------//
sl@0: # include <boost/iostreams/detail/vc6/read.hpp>
sl@0: #else // #if BOOST_WORKAROUND(BOOST_MSVC, < 1300) //--------------------------//
sl@0: 
sl@0: namespace boost { namespace iostreams {
sl@0: 
sl@0: namespace detail {
sl@0: 
sl@0: template<typename T>
sl@0: struct read_device_impl;
sl@0: 
sl@0: template<typename T>
sl@0: struct read_filter_impl;
sl@0: 
sl@0: } // End namespace detail.
sl@0: 
sl@0: template<typename T>
sl@0: typename int_type_of<T>::type get(T& t)
sl@0: { return detail::read_device_impl<T>::get(detail::unwrap(t)); }
sl@0: 
sl@0: template<typename T>
sl@0: inline std::streamsize
sl@0: read(T& t, typename char_type_of<T>::type* s, std::streamsize n)
sl@0: { return detail::read_device_impl<T>::read(detail::unwrap(t), s, n); }
sl@0: 
sl@0: template<typename T, typename Source>
sl@0: std::streamsize
sl@0: read(T& t, Source& src, typename char_type_of<T>::type* s, std::streamsize n)
sl@0: { return detail::read_filter_impl<T>::read(detail::unwrap(t), src, s, n); }
sl@0: 
sl@0: template<typename T>
sl@0: bool putback(T& t, typename char_type_of<T>::type c)
sl@0: { return detail::read_device_impl<T>::putback(detail::unwrap(t), c); }
sl@0: 
sl@0: //----------------------------------------------------------------------------//
sl@0: 
sl@0: namespace detail {
sl@0: 
sl@0: // Helper function for adding -1 as EOF indicator.
sl@0: inline std::streamsize check_eof(std::streamsize n) { return n != 0 ? n : -1; }
sl@0: 
sl@0: // Helper templates for reading from streambufs.
sl@0: template<bool IsLinked>
sl@0: struct true_eof_impl;
sl@0: 
sl@0: template<>
sl@0: struct true_eof_impl<true> {
sl@0:     template<typename T>
sl@0:     static bool true_eof(T& t) { return t.true_eof(); }
sl@0: };
sl@0: 
sl@0: template<>
sl@0: struct true_eof_impl<false> {
sl@0:     template<typename T>
sl@0:     static bool true_eof(T& t) { return true; }
sl@0: };
sl@0: 
sl@0: template<typename T>
sl@0: inline bool true_eof(T& t)
sl@0: {
sl@0:     const bool linked = is_linked<T>::value;
sl@0:     return true_eof_impl<linked>::true_eof(t);
sl@0: }
sl@0: 
sl@0: //------------------Definition of read_device_impl----------------------------//
sl@0: 
sl@0: template<typename T>
sl@0: struct read_device_impl
sl@0:     : mpl::if_<
sl@0:           detail::is_custom<T>,
sl@0:           operations<T>,
sl@0:           read_device_impl<
sl@0:               BOOST_DEDUCED_TYPENAME
sl@0:               detail::dispatch<
sl@0:                   T, istream_tag, streambuf_tag, input
sl@0:               >::type
sl@0:           >
sl@0:       >::type
sl@0:     { };
sl@0: 
sl@0: template<>
sl@0: struct read_device_impl<istream_tag> {
sl@0:     template<typename T>
sl@0:     static typename int_type_of<T>::type get(T& t)
sl@0:     { return t.get(); }
sl@0: 
sl@0:     template<typename T>
sl@0:     static std::streamsize
sl@0:     read(T& t, typename char_type_of<T>::type* s, std::streamsize n)
sl@0:     { return check_eof(t.rdbuf()->sgetn(s, n)); }
sl@0: 
sl@0:     template<typename T>
sl@0:     static bool putback(T& t, typename char_type_of<T>::type c)
sl@0:     {
sl@0:         typedef typename char_type_of<T>::type          char_type;
sl@0:         typedef BOOST_IOSTREAMS_CHAR_TRAITS(char_type)  traits_type;
sl@0:         return !traits_type::eq_int_type( t.rdbuf()->sputbackc(c),
sl@0:                                           traits_type::eof() );
sl@0:     }
sl@0: };
sl@0: 
sl@0: template<>
sl@0: struct read_device_impl<streambuf_tag> {
sl@0:     template<typename T>
sl@0:     static typename int_type_of<T>::type
sl@0:     get(T& t)
sl@0:     {   // gcc 2.95 needs namespace qualification for char_traits.
sl@0:         typedef typename char_type_of<T>::type     char_type;
sl@0:         typedef iostreams::char_traits<char_type>  traits_type;
sl@0:         typename int_type_of<T>::type c;
sl@0:         return !traits_type::is_eof(c = t.sbumpc()) ||
sl@0:                 detail::true_eof(t)
sl@0:                     ?
sl@0:                 c : traits_type::would_block();
sl@0:     }
sl@0: 
sl@0:     template<typename T>
sl@0:     static std::streamsize
sl@0:     read(T& t, typename char_type_of<T>::type* s, std::streamsize n)
sl@0:     {
sl@0:         std::streamsize amt;
sl@0:         return (amt = t.sgetn(s, n)) != 0 ?
sl@0:             amt :
sl@0:             detail::true_eof(t) ?
sl@0:                 -1 :
sl@0:                 0;
sl@0:     }
sl@0: 
sl@0:     template<typename T>
sl@0:     static bool putback(T& t, typename char_type_of<T>::type c)
sl@0:     {   // gcc 2.95 needs namespace qualification for char_traits.
sl@0:         typedef typename char_type_of<T>::type     char_type;
sl@0:         typedef iostreams::char_traits<char_type>  traits_type;
sl@0:         return !traits_type::is_eof(t.sputbackc(c));
sl@0:     }
sl@0: };
sl@0: 
sl@0: template<>
sl@0: struct read_device_impl<input> {
sl@0:     template<typename T>
sl@0:     static typename int_type_of<T>::type
sl@0:     get(T& t)
sl@0:     {   // gcc 2.95 needs namespace qualification for char_traits.
sl@0:         typedef typename char_type_of<T>::type     char_type;
sl@0:         typedef iostreams::char_traits<char_type>  traits_type;
sl@0:         char_type c;
sl@0:         std::streamsize amt;
sl@0:         return (amt = t.read(&c, 1)) == 1 ?
sl@0:             traits_type::to_int_type(c) :
sl@0:             amt == -1 ?
sl@0:                 traits_type::eof() :
sl@0:                 traits_type::would_block();
sl@0:     }
sl@0: 
sl@0:     template<typename T>
sl@0:     static std::streamsize
sl@0:     read(T& t, typename char_type_of<T>::type* s, std::streamsize n)
sl@0:     { return t.read(s, n); }
sl@0: 
sl@0:     template<typename T>
sl@0:     static bool putback(T& t, typename char_type_of<T>::type c)
sl@0:     {   // T must be Peekable.
sl@0:         return t.putback(c);
sl@0:     }
sl@0: };
sl@0: 
sl@0: //------------------Definition of read_filter_impl----------------------------//
sl@0: 
sl@0: template<typename T>
sl@0: struct read_filter_impl
sl@0:     : mpl::if_<
sl@0:           detail::is_custom<T>,
sl@0:           operations<T>,
sl@0:           read_filter_impl<
sl@0:               BOOST_DEDUCED_TYPENAME
sl@0:               detail::dispatch<
sl@0:                   T, multichar_tag, any_tag
sl@0:               >::type
sl@0:           >
sl@0:       >::type
sl@0:     { };
sl@0: 
sl@0: template<>
sl@0: struct read_filter_impl<multichar_tag> {
sl@0:     template<typename T, typename Source>
sl@0:     static std::streamsize read
sl@0:        (T& t, Source& src, typename char_type_of<T>::type* s, std::streamsize n)
sl@0:     { return t.read(src, s, n); }
sl@0: };
sl@0: 
sl@0: template<>
sl@0: struct read_filter_impl<any_tag> {
sl@0:     template<typename T, typename Source>
sl@0:     static std::streamsize read
sl@0:        (T& t, Source& src, typename char_type_of<T>::type* s, std::streamsize n)
sl@0:     {   // gcc 2.95 needs namespace qualification for char_traits.
sl@0:         typedef typename char_type_of<T>::type     char_type;
sl@0:         typedef iostreams::char_traits<char_type>  traits_type;
sl@0:         for (std::streamsize off = 0; off < n; ++off) {
sl@0:             typename traits_type::int_type c = t.get(src);
sl@0:             if (traits_type::is_eof(c))
sl@0:                 return check_eof(off);
sl@0:             if (traits_type::would_block(c))
sl@0:                 return off;
sl@0:             s[off] = traits_type::to_char_type(c);
sl@0:         }
sl@0:         return n;
sl@0:     }
sl@0: };
sl@0: 
sl@0: } // End namespace detail.
sl@0: 
sl@0: } } // End namespaces iostreams, boost.
sl@0: 
sl@0: #endif // #if BOOST_WORKAROUND(BOOST_MSVC, < 1300) //-------------------------//
sl@0: 
sl@0: #include <boost/iostreams/detail/config/enable_warnings.hpp>
sl@0: 
sl@0: #endif // #ifndef BOOST_IOSTREAMS_READ_HPP_INCLUDED