[29] | 1 | // (C) Copyright Jonathan Turkanis 2003. |
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| 2 | // Distributed under the Boost Software License, Version 1.0. (See accompanying |
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| 3 | // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt.) |
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| 4 | |
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| 5 | // See http://www.boost.org/libs/iostreams for documentation. |
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| 6 | |
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| 7 | // Contains: The function template copy, which reads data from a Source |
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| 8 | // and writes it to a Sink until the end of the sequence is reached, returning |
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| 9 | // the number of characters transfered. |
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| 10 | |
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| 11 | // The implementation is complicated by the need to handle smart adapters |
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| 12 | // and direct devices. |
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| 13 | |
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| 14 | #ifndef BOOST_IOSTREAMS_COPY_HPP_INCLUDED |
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| 15 | #define BOOST_IOSTREAMS_COPY_HPP_INCLUDED |
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| 16 | |
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| 17 | #if defined(_MSC_VER) && (_MSC_VER >= 1020) |
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| 18 | # pragma once |
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| 19 | #endif |
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| 20 | |
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| 21 | #include <algorithm> // copy. |
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| 22 | #include <utility> // pair. |
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| 23 | #include <boost/detail/workaround.hpp> |
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| 24 | #include <boost/iostreams/chain.hpp> |
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| 25 | #include <boost/iostreams/constants.hpp> |
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| 26 | #include <boost/iostreams/detail/adapter/non_blocking_adapter.hpp> |
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| 27 | #include <boost/iostreams/detail/buffer.hpp> |
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| 28 | #include <boost/iostreams/detail/closer.hpp> |
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| 29 | #include <boost/iostreams/detail/enable_if_stream.hpp> |
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| 30 | #include <boost/iostreams/detail/ios.hpp> // failure, streamsize. |
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| 31 | #include <boost/iostreams/detail/resolve.hpp> |
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| 32 | #include <boost/iostreams/detail/wrap_unwrap.hpp> |
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| 33 | #include <boost/iostreams/operations.hpp> // read, write, close. |
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| 34 | #include <boost/iostreams/pipeline.hpp> |
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| 35 | #include <boost/static_assert.hpp> |
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| 36 | #include <boost/type_traits/is_same.hpp> |
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| 37 | |
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| 38 | namespace boost { namespace iostreams { |
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| 39 | |
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| 40 | namespace detail { |
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| 41 | |
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| 42 | template<typename Source, typename Sink> |
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| 43 | std::streamsize copy_impl( Source& src, Sink& snk, |
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| 44 | std::streamsize /* buffer_size */, |
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| 45 | mpl::true_, mpl::true_ ) |
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| 46 | { // Copy from a direct Source to a direct Sink. |
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| 47 | using namespace std; |
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| 48 | typedef typename char_type_of<Source>::type char_type; |
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| 49 | typedef pair<char_type*, char_type*> pair_type; |
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| 50 | pair_type p1 = iostreams::input_sequence(src); |
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| 51 | pair_type p2 = iostreams::output_sequence(snk); |
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| 52 | if (p1.second - p1.first < p2.second - p2.first) { |
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| 53 | std::copy(p1.first, p1.second, p2.first); |
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| 54 | return static_cast<streamsize>(p1.second - p1.first); |
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| 55 | } else { |
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| 56 | throw BOOST_IOSTREAMS_FAILURE("destination too small"); |
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| 57 | } |
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| 58 | } |
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| 59 | |
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| 60 | template<typename Source, typename Sink> |
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| 61 | std::streamsize copy_impl( Source& src, Sink& snk, |
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| 62 | std::streamsize /* buffer_size */, |
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| 63 | mpl::true_, mpl::false_ ) |
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| 64 | { // Copy from a direct Source to an indirect Sink. |
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| 65 | using namespace std; |
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| 66 | typedef typename char_type_of<Source>::type char_type; |
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| 67 | typedef pair<char_type*, char_type*> pair_type; |
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| 68 | pair_type p = iostreams::input_sequence(src); |
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| 69 | std::streamsize size, total; |
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| 70 | for ( total = 0, size = static_cast<streamsize>(p.second - p.first); |
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| 71 | total < size; ) |
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| 72 | { |
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| 73 | std::streamsize amt = |
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| 74 | iostreams::write(snk, p.first + total, size - total); |
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| 75 | total += amt; |
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| 76 | } |
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| 77 | return size; |
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| 78 | } |
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| 79 | |
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| 80 | template<typename Source, typename Sink> |
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| 81 | std::streamsize copy_impl( Source& src, Sink& snk, |
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| 82 | std::streamsize buffer_size, |
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| 83 | mpl::false_, mpl::true_ ) |
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| 84 | { // Copy from an indirect Source to a direct Sink. |
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| 85 | using namespace std; |
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| 86 | typedef typename char_type_of<Source>::type char_type; |
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| 87 | typedef pair<char_type*, char_type*> pair_type; |
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| 88 | detail::basic_buffer<char_type> buf(buffer_size); |
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| 89 | pair_type p = snk.output_sequence(); |
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| 90 | streamsize total = 0; |
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| 91 | bool done = false; |
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| 92 | while (!done) { |
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| 93 | streamsize amt; |
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| 94 | done = (amt = iostreams::read(src, buf.data(), buffer_size)) == -1; |
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| 95 | std::copy(buf.data(), buf.data() + amt, p.first + total); |
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| 96 | if (amt != -1) |
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| 97 | total += amt; |
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| 98 | } |
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| 99 | return total; |
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| 100 | } |
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| 101 | |
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| 102 | template<typename Source, typename Sink> |
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| 103 | std::streamsize copy_impl( Source& src, Sink& snk, |
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| 104 | std::streamsize buffer_size, |
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| 105 | mpl::false_, mpl::false_ ) |
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| 106 | { // Copy from an indirect Source to a indirect Sink. This algorithm |
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| 107 | // can be improved by eliminating the non_blocking_adapter. |
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| 108 | typedef typename char_type_of<Source>::type char_type; |
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| 109 | detail::basic_buffer<char_type> buf(buffer_size); |
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| 110 | non_blocking_adapter<Sink> nb(snk); |
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| 111 | std::streamsize total = 0; |
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| 112 | bool done = false; |
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| 113 | while (!done) { |
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| 114 | std::streamsize amt; |
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| 115 | done = (amt = iostreams::read(src, buf.data(), buffer_size)) == -1; |
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| 116 | if (amt != -1) { |
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| 117 | iostreams::write(nb, buf.data(), amt); |
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| 118 | total += amt; |
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| 119 | } |
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| 120 | } |
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| 121 | return total; |
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| 122 | } |
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| 123 | |
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| 124 | template<typename Source, typename Sink> |
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| 125 | std::streamsize copy_impl(Source src, Sink snk, std::streamsize buffer_size) |
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| 126 | { |
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| 127 | using namespace std; |
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| 128 | typedef typename char_type_of<Source>::type src_char; |
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| 129 | typedef typename char_type_of<Sink>::type snk_char; |
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| 130 | BOOST_STATIC_ASSERT((is_same<src_char, snk_char>::value)); |
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| 131 | bool nothrow = false; |
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| 132 | external_closer<Source> close_source(src, BOOST_IOS::in, nothrow); |
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| 133 | external_closer<Sink> close_sink(snk, BOOST_IOS::out, nothrow); |
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| 134 | streamsize result = |
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| 135 | copy_impl( src, snk, buffer_size, |
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| 136 | is_direct<Source>(), is_direct<Sink>() ); |
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| 137 | return result; |
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| 138 | } |
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| 139 | |
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| 140 | } // End namespace detail. |
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| 141 | |
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| 142 | //------------------Definition of copy----------------------------------------// |
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| 143 | |
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| 144 | template<typename Source, typename Sink> |
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| 145 | std::streamsize |
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| 146 | copy( const Source& src, const Sink& snk, |
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| 147 | std::streamsize buffer_size = default_device_buffer_size |
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| 148 | BOOST_IOSTREAMS_DISABLE_IF_STREAM(Source) |
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| 149 | BOOST_IOSTREAMS_DISABLE_IF_STREAM(Sink) ) |
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| 150 | { |
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| 151 | typedef typename char_type_of<Source>::type char_type; |
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| 152 | return detail::copy_impl( detail::resolve<input, char_type>(src), |
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| 153 | detail::resolve<output, char_type>(snk), |
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| 154 | buffer_size ); |
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| 155 | } |
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| 156 | |
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| 157 | #if !BOOST_WORKAROUND(BOOST_MSVC, <= 1300) //---------------------------------// |
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| 158 | |
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| 159 | template<typename Source, typename Sink> |
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| 160 | std::streamsize |
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| 161 | copy( Source& src, const Sink& snk, |
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| 162 | std::streamsize buffer_size = default_device_buffer_size |
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| 163 | BOOST_IOSTREAMS_ENABLE_IF_STREAM(Source) |
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| 164 | BOOST_IOSTREAMS_DISABLE_IF_STREAM(Sink) ) |
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| 165 | { |
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| 166 | typedef typename char_type_of<Source>::type char_type; |
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| 167 | return detail::copy_impl( detail::wrap(src), |
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| 168 | detail::resolve<output, char_type>(snk), |
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| 169 | buffer_size ); |
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| 170 | } |
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| 171 | |
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| 172 | template<typename Source, typename Sink> |
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| 173 | std::streamsize |
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| 174 | copy( const Source& src, Sink& snk, |
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| 175 | std::streamsize buffer_size = default_device_buffer_size |
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| 176 | BOOST_IOSTREAMS_DISABLE_IF_STREAM(Source) |
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| 177 | BOOST_IOSTREAMS_ENABLE_IF_STREAM(Sink) ) |
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| 178 | { |
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| 179 | typedef typename char_type_of<Source>::type char_type; |
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| 180 | return detail::copy_impl( detail::resolve<input, char_type>(src), |
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| 181 | detail::wrap(snk), buffer_size); |
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| 182 | } |
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| 183 | |
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| 184 | template<typename Source, typename Sink> |
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| 185 | std::streamsize |
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| 186 | copy( Source& src, Sink& snk, |
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| 187 | std::streamsize buffer_size = default_device_buffer_size |
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| 188 | BOOST_IOSTREAMS_ENABLE_IF_STREAM(Source) |
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| 189 | BOOST_IOSTREAMS_ENABLE_IF_STREAM(Sink) ) |
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| 190 | { |
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| 191 | return detail::copy_impl(detail::wrap(src), detail::wrap(snk), buffer_size); |
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| 192 | } |
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| 193 | |
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| 194 | #endif // #if !BOOST_WORKAROUND(BOOST_MSVC, <= 1300) //-----------------------// |
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| 195 | |
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| 196 | } } // End namespaces iostreams, boost. |
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| 197 | |
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| 198 | #endif // #ifndef BOOST_IOSTREAMS_COPY_HPP_INCLUDED |
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