boost/iostreams/write.hpp

0001 // (C) Copyright 2008 CodeRage, LLC (turkanis at coderage dot com)
0002 // (C) Copyright 2003-2007 Jonathan Turkanis
0003 // Distributed under the Boost Software License, Version 1.0. (See accompanying
0004 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt.)
0005
0006 // See http://www.boost.org/libs/iostreams for documentation.
0007
0008 #ifndef BOOST_IOSTREAMS_WRITE_HPP_INCLUDED
0009 #define BOOST_IOSTREAMS_WRITE_HPP_INCLUDED
0010
0011 #if defined(_MSC_VER)
0012 # pragma once
0013 #endif
0014
0015 #include <boost/config.hpp>  // DEDUCED_TYPENAME, MSVC.
0016 #include <boost/detail/workaround.hpp>
0017 #include <boost/iostreams/categories.hpp>
0018 #include <boost/iostreams/detail/char_traits.hpp>
0019 #include <boost/iostreams/detail/dispatch.hpp>
0020 #include <boost/iostreams/detail/ios.hpp>  // streamsize.
0021 #include <boost/iostreams/detail/streambuf.hpp>
0022 #include <boost/iostreams/detail/wrap_unwrap.hpp>
0023 #include <boost/iostreams/operations_fwd.hpp>
0024 #include <boost/iostreams/traits.hpp>
0025 #include <boost/mpl/if.hpp>
0026
0027 // Must come last.
0028 #include <boost/iostreams/detail/config/disable_warnings.hpp>
0029
0030 namespace boost { namespace iostreams {
0031
0032 namespace detail {
0033
0034 template<typename T>
0035 struct write_device_impl;
0036
0037 template<typename T>
0038 struct write_filter_impl;
0039
0040 } // End namespace detail.
0041
0042 template<typename T>
0043 bool put(T& t, typename char_type_of<T>::type c)
0044 { return detail::write_device_impl<T>::put(detail::unwrap(t), c); }
0045
0046 template<typename T>
0047 inline std::streamsize write
0048     (T& t, const typename char_type_of<T>::type* s, std::streamsize n)
0049 { return detail::write_device_impl<T>::write(detail::unwrap(t), s, n); }
0050
0051 template<typename T, typename Sink>
0052 inline std::streamsize
0053 write( T& t, Sink& snk, const typename char_type_of<T>::type* s,
0054        std::streamsize n )
0055 { return detail::write_filter_impl<T>::write(detail::unwrap(t), snk, s, n); }
0056
0057 namespace detail {
0058
0059 //------------------Definition of write_device_impl---------------------------//
0060
0061 template<typename T>
0062 struct write_device_impl
0063     : mpl::if_<
0064           is_custom<T>,
0065           operations<T>,
0066           write_device_impl<
0067               BOOST_DEDUCED_TYPENAME
0068               dispatch<
0069                   T, ostream_tag, streambuf_tag, output
0070               >::type
0071           >
0072       >::type
0073     { };
0074
0075 template<>
0076 struct write_device_impl<ostream_tag> {
0077     template<typename T>
0078     static bool put(T& t, typename char_type_of<T>::type c)
0079     {
0080         typedef typename char_type_of<T>::type          char_type;
0081         typedef BOOST_IOSTREAMS_CHAR_TRAITS(char_type)  traits_type;
0082         return !traits_type::eq_int_type( t.rdbuf()->sputc(c),
0083                                           traits_type::eof() );
0084     }
0085
0086     template<typename T>
0087     static std::streamsize write
0088         (T& t, const typename char_type_of<T>::type* s, std::streamsize n)
0089     { return t.rdbuf()->sputn(s, n); }
0090 };
0091
0092 template<>
0093 struct write_device_impl<streambuf_tag> {
0094     template<typename T>
0095     static bool put(T& t, typename char_type_of<T>::type c)
0096     {
0097         typedef typename char_type_of<T>::type          char_type;
0098         typedef BOOST_IOSTREAMS_CHAR_TRAITS(char_type)  traits_type;
0099         return !traits_type::eq_int_type(t.sputc(c), traits_type::eof());
0100     }
0101
0102     template<typename T>
0103     static std::streamsize write
0104         (T& t, const typename char_type_of<T>::type* s, std::streamsize n)
0105     { return t.sputn(s, n); }
0106 };
0107
0108 template<>
0109 struct write_device_impl<output> {
0110     template<typename T>
0111     static bool put(T& t, typename char_type_of<T>::type c)
0112     { return t.write(&c, 1) == 1; }
0113
0114     template<typename T>
0115     static std::streamsize
0116     write(T& t, const typename char_type_of<T>::type* s, std::streamsize n)
0117     { return t.write(s, n); }
0118 };
0119
0120 //------------------Definition of write_filter_impl---------------------------//
0121
0122 template<typename T>
0123 struct write_filter_impl
0124     : mpl::if_<
0125           is_custom<T>,
0126           operations<T>,
0127           write_filter_impl<
0128               BOOST_DEDUCED_TYPENAME
0129               dispatch<
0130                   T, multichar_tag, any_tag
0131               >::type
0132           >
0133       >::type
0134     { };
0135
0136 template<>
0137 struct write_filter_impl<multichar_tag> {
0138     template<typename T, typename Sink>
0139     static std::streamsize
0140     write( T& t, Sink& snk, const typename char_type_of<T>::type* s,
0141            std::streamsize n )
0142     { return t.write(snk, s, n); }
0143 };
0144
0145 template<>
0146 struct write_filter_impl<any_tag> {
0147     template<typename T, typename Sink>
0148     static std::streamsize
0149     write( T& t, Sink& snk, const typename char_type_of<T>::type* s,
0150            std::streamsize n )
0151     {
0152         for (std::streamsize off = 0; off < n; ++off)
0153             if (!t.put(snk, s[off]))
0154                 return off;
0155         return n;
0156     }
0157 };
0158
0159 } // End namespace detail.
0160
0161 } } // End namespaces iostreams, boost.
0162
0163 #include <boost/iostreams/detail/config/enable_warnings.hpp>
0164
0165 #endif // #ifndef BOOST_IOSTREAMS_WRITE_HPP_INCLUDED