Chris@16: // (C) Copyright 2008 CodeRage, LLC (turkanis at coderage dot com)
Chris@16: // (C) Copyright 2005-2007 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: #ifndef BOOST_IOSTREAMS_READ_HPP_INCLUDED
Chris@16: #define BOOST_IOSTREAMS_READ_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 <boost/config.hpp>  // DEDUCED_TYPENAME, MSVC.
Chris@16: #include <boost/detail/workaround.hpp>
Chris@16: #include <boost/iostreams/char_traits.hpp>
Chris@16: #include <boost/iostreams/detail/char_traits.hpp>
Chris@16: #include <boost/iostreams/detail/dispatch.hpp>
Chris@16: #include <boost/iostreams/detail/ios.hpp>  // streamsize.
Chris@16: #include <boost/iostreams/detail/streambuf.hpp>
Chris@16: #include <boost/iostreams/detail/wrap_unwrap.hpp>
Chris@16: #include <boost/iostreams/operations_fwd.hpp>
Chris@16: #include <boost/mpl/if.hpp>
Chris@16: 
Chris@16: // Must come last.
Chris@16: #include <boost/iostreams/detail/config/disable_warnings.hpp>
Chris@16: 
Chris@16: #if BOOST_WORKAROUND(BOOST_MSVC, < 1300) //-----------------------------------//
Chris@16: # include <boost/iostreams/detail/vc6/read.hpp>
Chris@16: #else // #if BOOST_WORKAROUND(BOOST_MSVC, < 1300) //--------------------------//
Chris@16: 
Chris@16: namespace boost { namespace iostreams {
Chris@16: 
Chris@16: namespace detail {
Chris@16: 
Chris@16: template<typename T>
Chris@16: struct read_device_impl;
Chris@16: 
Chris@16: template<typename T>
Chris@16: struct read_filter_impl;
Chris@16: 
Chris@16: } // End namespace detail.
Chris@16: 
Chris@16: template<typename T>
Chris@16: typename int_type_of<T>::type get(T& t)
Chris@16: { return detail::read_device_impl<T>::get(detail::unwrap(t)); }
Chris@16: 
Chris@16: template<typename T>
Chris@16: inline std::streamsize
Chris@16: read(T& t, typename char_type_of<T>::type* s, std::streamsize n)
Chris@16: { return detail::read_device_impl<T>::read(detail::unwrap(t), s, n); }
Chris@16: 
Chris@16: template<typename T, typename Source>
Chris@16: std::streamsize
Chris@16: read(T& t, Source& src, typename char_type_of<T>::type* s, std::streamsize n)
Chris@16: { return detail::read_filter_impl<T>::read(detail::unwrap(t), src, s, n); }
Chris@16: 
Chris@16: template<typename T>
Chris@16: bool putback(T& t, typename char_type_of<T>::type c)
Chris@16: { return detail::read_device_impl<T>::putback(detail::unwrap(t), c); }
Chris@16: 
Chris@16: //----------------------------------------------------------------------------//
Chris@16: 
Chris@16: namespace detail {
Chris@16: 
Chris@16: // Helper function for adding -1 as EOF indicator.
Chris@16: inline std::streamsize check_eof(std::streamsize n) { return n != 0 ? n : -1; }
Chris@16: 
Chris@16: // Helper templates for reading from streambufs.
Chris@16: template<bool IsLinked>
Chris@16: struct true_eof_impl;
Chris@16: 
Chris@16: template<>
Chris@16: struct true_eof_impl<true> {
Chris@16:     template<typename T>
Chris@16:     static bool true_eof(T& t) { return t.true_eof(); }
Chris@16: };
Chris@16: 
Chris@16: template<>
Chris@16: struct true_eof_impl<false> {
Chris@16:     template<typename T>
Chris@16:     static bool true_eof(T&) { return true; }
Chris@16: };
Chris@16: 
Chris@16: template<typename T>
Chris@16: inline bool true_eof(T& t)
Chris@16: {
Chris@16:     const bool linked = is_linked<T>::value;
Chris@16:     return true_eof_impl<linked>::true_eof(t);
Chris@16: }
Chris@16: 
Chris@16: //------------------Definition of read_device_impl----------------------------//
Chris@16: 
Chris@16: template<typename T>
Chris@16: struct read_device_impl
Chris@16:     : mpl::if_<
Chris@16:           detail::is_custom<T>,
Chris@16:           operations<T>,
Chris@16:           read_device_impl<
Chris@16:               BOOST_DEDUCED_TYPENAME
Chris@16:               detail::dispatch<
Chris@16:                   T, istream_tag, streambuf_tag, input
Chris@16:               >::type
Chris@16:           >
Chris@16:       >::type
Chris@16:     { };
Chris@16: 
Chris@16: template<>
Chris@16: struct read_device_impl<istream_tag> {
Chris@16:     template<typename T>
Chris@16:     static typename int_type_of<T>::type get(T& t)
Chris@16:     { return t.get(); }
Chris@16: 
Chris@16:     template<typename T>
Chris@16:     static std::streamsize
Chris@16:     read(T& t, typename char_type_of<T>::type* s, std::streamsize n)
Chris@16:     { return check_eof(t.rdbuf()->sgetn(s, n)); }
Chris@16: 
Chris@16:     template<typename T>
Chris@16:     static bool putback(T& t, typename char_type_of<T>::type c)
Chris@16:     {
Chris@16:         typedef typename char_type_of<T>::type          char_type;
Chris@16:         typedef BOOST_IOSTREAMS_CHAR_TRAITS(char_type)  traits_type;
Chris@16:         return !traits_type::eq_int_type( t.rdbuf()->sputbackc(c),
Chris@16:                                           traits_type::eof() );
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: template<>
Chris@16: struct read_device_impl<streambuf_tag> {
Chris@16:     template<typename T>
Chris@16:     static typename int_type_of<T>::type
Chris@16:     get(T& t)
Chris@16:     {   // gcc 2.95 needs namespace qualification for char_traits.
Chris@16:         typedef typename char_type_of<T>::type     char_type;
Chris@16:         typedef iostreams::char_traits<char_type>  traits_type;
Chris@16:         typename int_type_of<T>::type c;
Chris@16:         return !traits_type::is_eof(c = t.sbumpc()) ||
Chris@16:                 detail::true_eof(t)
Chris@16:                     ?
Chris@16:                 c : traits_type::would_block();
Chris@16:     }
Chris@16: 
Chris@16:     template<typename T>
Chris@16:     static std::streamsize
Chris@16:     read(T& t, typename char_type_of<T>::type* s, std::streamsize n)
Chris@16:     {
Chris@16:         std::streamsize amt;
Chris@16:         return (amt = t.sgetn(s, n)) != 0 ?
Chris@16:             amt :
Chris@16:             detail::true_eof(t) ?
Chris@16:                 -1 :
Chris@16:                 0;
Chris@16:     }
Chris@16: 
Chris@16:     template<typename T>
Chris@16:     static bool putback(T& t, typename char_type_of<T>::type c)
Chris@16:     {   // gcc 2.95 needs namespace qualification for char_traits.
Chris@16:         typedef typename char_type_of<T>::type     char_type;
Chris@16:         typedef iostreams::char_traits<char_type>  traits_type;
Chris@16:         return !traits_type::is_eof(t.sputbackc(c));
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: template<>
Chris@16: struct read_device_impl<input> {
Chris@16:     template<typename T>
Chris@16:     static typename int_type_of<T>::type
Chris@16:     get(T& t)
Chris@16:     {   // gcc 2.95 needs namespace qualification for char_traits.
Chris@16:         typedef typename char_type_of<T>::type     char_type;
Chris@16:         typedef iostreams::char_traits<char_type>  traits_type;
Chris@16:         char_type c;
Chris@16:         std::streamsize amt;
Chris@16:         return (amt = t.read(&c, 1)) == 1 ?
Chris@16:             traits_type::to_int_type(c) :
Chris@16:             amt == -1 ?
Chris@16:                 traits_type::eof() :
Chris@16:                 traits_type::would_block();
Chris@16:     }
Chris@16: 
Chris@16:     template<typename T>
Chris@16:     static std::streamsize
Chris@16:     read(T& t, typename char_type_of<T>::type* s, std::streamsize n)
Chris@16:     { return t.read(s, n); }
Chris@16: 
Chris@16:     template<typename T>
Chris@16:     static bool putback(T& t, typename char_type_of<T>::type c)
Chris@16:     {   // T must be Peekable.
Chris@16:         return t.putback(c);
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: //------------------Definition of read_filter_impl----------------------------//
Chris@16: 
Chris@16: template<typename T>
Chris@16: struct read_filter_impl
Chris@16:     : mpl::if_<
Chris@16:           detail::is_custom<T>,
Chris@16:           operations<T>,
Chris@16:           read_filter_impl<
Chris@16:               BOOST_DEDUCED_TYPENAME
Chris@16:               detail::dispatch<
Chris@16:                   T, multichar_tag, any_tag
Chris@16:               >::type
Chris@16:           >
Chris@16:       >::type
Chris@16:     { };
Chris@16: 
Chris@16: template<>
Chris@16: struct read_filter_impl<multichar_tag> {
Chris@16:     template<typename T, typename Source>
Chris@16:     static std::streamsize read
Chris@16:        (T& t, Source& src, typename char_type_of<T>::type* s, std::streamsize n)
Chris@16:     { return t.read(src, s, n); }
Chris@16: };
Chris@16: 
Chris@16: template<>
Chris@16: struct read_filter_impl<any_tag> {
Chris@16:     template<typename T, typename Source>
Chris@16:     static std::streamsize read
Chris@16:        (T& t, Source& src, typename char_type_of<T>::type* s, std::streamsize n)
Chris@16:     {   // gcc 2.95 needs namespace qualification for char_traits.
Chris@16:         typedef typename char_type_of<T>::type     char_type;
Chris@16:         typedef iostreams::char_traits<char_type>  traits_type;
Chris@16:         for (std::streamsize off = 0; off < n; ++off) {
Chris@16:             typename traits_type::int_type c = t.get(src);
Chris@16:             if (traits_type::is_eof(c))
Chris@16:                 return check_eof(off);
Chris@16:             if (traits_type::would_block(c))
Chris@16:                 return off;
Chris@16:             s[off] = traits_type::to_char_type(c);
Chris@16:         }
Chris@16:         return n;
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: } // End namespace detail.
Chris@16: 
Chris@16: } } // End namespaces iostreams, boost.
Chris@16: 
Chris@16: #endif // #if BOOST_WORKAROUND(BOOST_MSVC, < 1300) //-------------------------//
Chris@16: 
Chris@16: #include <boost/iostreams/detail/config/enable_warnings.hpp>
Chris@16: 
Chris@16: #endif // #ifndef BOOST_IOSTREAMS_READ_HPP_INCLUDED