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1 | // (C) Copyright 2008 CodeRage, LLC (turkanis at coderage dot com) |
2 | // (C) Copyright 2003-2007 Jonathan Turkanis | |
3 | // Distributed under the Boost Software License, Version 1.0. (See accompanying | |
4 | // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt.) | |
5 | ||
6 | // See http://www.boost.org/libs/iostreams for documentation. | |
7 | ||
8 | // Thanks to Gareth Sylvester-Bradley for the Dinkumware versions of the | |
9 | // positioning functions. | |
10 | ||
11 | #ifndef BOOST_IOSTREAMS_POSITIONING_HPP_INCLUDED | |
12 | #define BOOST_IOSTREAMS_POSITIONING_HPP_INCLUDED | |
13 | ||
14 | #if defined(_MSC_VER) | |
15 | # pragma once | |
16 | #endif | |
17 | ||
18 | #include <boost/config.hpp> | |
19 | #include <boost/cstdint.hpp> | |
20 | #include <boost/integer_traits.hpp> | |
21 | #include <boost/iostreams/detail/config/codecvt.hpp> // mbstate_t. | |
22 | #include <boost/iostreams/detail/config/fpos.hpp> | |
23 | #include <boost/iostreams/detail/ios.hpp> // streamoff, streampos. | |
24 | ||
25 | // Must come last. | |
26 | #include <boost/iostreams/detail/config/disable_warnings.hpp> | |
27 | ||
28 | #ifdef BOOST_NO_STDC_NAMESPACE | |
29 | namespace std { using ::fpos_t; } | |
30 | #endif | |
31 | ||
32 | namespace boost { namespace iostreams { | |
33 | ||
34 | //------------------Definition of stream_offset-------------------------------// | |
35 | ||
36 | typedef boost::intmax_t stream_offset; | |
37 | ||
38 | //------------------Definition of stream_offset_to_streamoff------------------// | |
39 | ||
40 | inline std::streamoff stream_offset_to_streamoff(stream_offset off) | |
41 | { return static_cast<stream_offset>(off); } | |
42 | ||
43 | //------------------Definition of offset_to_position--------------------------// | |
44 | ||
45 | # ifndef BOOST_IOSTREAMS_HAS_DINKUMWARE_FPOS | |
46 | ||
47 | inline std::streampos offset_to_position(stream_offset off) { return off; } | |
48 | ||
49 | # else // # ifndef BOOST_IOSTREAMS_HAS_DINKUMWARE_FPOS | |
50 | ||
51 | inline std::streampos offset_to_position(stream_offset off) | |
52 | { return std::streampos(std::mbstate_t(), off); } | |
53 | ||
54 | # endif // # ifndef BOOST_IOSTREAMS_HAS_DINKUMWARE_FPOS | |
55 | ||
56 | //------------------Definition of position_to_offset--------------------------// | |
57 | ||
58 | // Hande custom pos_type's | |
59 | template<typename PosType> | |
60 | inline stream_offset position_to_offset(PosType pos) | |
61 | { return std::streamoff(pos); } | |
62 | ||
63 | # ifndef BOOST_IOSTREAMS_HAS_DINKUMWARE_FPOS | |
64 | ||
65 | inline stream_offset position_to_offset(std::streampos pos) { return pos; } | |
66 | ||
67 | # else // # ifndef BOOST_IOSTREAMS_HAS_DINKUMWARE_FPOS | |
68 | ||
69 | // In the Dinkumware standard library, a std::streampos consists of two stream | |
70 | // offsets -- _Fpos, of type std::fpos_t, and _Myoff, of type std::streamoff -- | |
71 | // together with a conversion state. A std::streampos is converted to a | |
72 | // boost::iostreams::stream_offset by extracting the two stream offsets and | |
73 | // summing them. The value of _Fpos can be extracted using the implementation- | |
74 | // defined member functions seekpos() or get_fpos_t(), depending on the | |
75 | // Dinkumware version. The value of _Myoff cannot be extracted directly, but can | |
76 | // be calculated as the difference between the result of converting the | |
77 | // std::fpos to a std::streamoff and the result of converting the member _Fpos | |
78 | // to a long. The latter operation is accomplished with the macro BOOST_IOSTREAMS_FPOSOFF, | |
79 | // which works correctly on platforms where std::fpos_t is an integral type and | |
80 | // platforms where it is a struct | |
81 | ||
82 | // Converts a std::fpos_t to a stream_offset | |
83 | inline stream_offset fpos_t_to_offset(std::fpos_t pos) | |
84 | { | |
85 | # if defined(_POSIX_) || (_INTEGRAL_MAX_BITS >= 64) || defined(__IBMCPP__) | |
86 | return pos; | |
87 | # else | |
88 | return BOOST_IOSTREAMS_FPOSOFF(pos); | |
89 | # endif | |
90 | } | |
91 | ||
92 | // Extracts the member _Fpos from a std::fpos | |
93 | inline std::fpos_t streampos_to_fpos_t(std::streampos pos) | |
94 | { | |
95 | # if defined (_CPPLIB_VER) || defined(__IBMCPP__) | |
96 | return pos.seekpos(); | |
97 | # else | |
98 | return pos.get_fpos_t(); | |
99 | # endif | |
100 | } | |
101 | ||
102 | inline stream_offset position_to_offset(std::streampos pos) | |
103 | { | |
104 | return fpos_t_to_offset(streampos_to_fpos_t(pos)) + | |
105 | static_cast<stream_offset>( | |
106 | static_cast<std::streamoff>(pos) - | |
107 | BOOST_IOSTREAMS_FPOSOFF(streampos_to_fpos_t(pos)) | |
108 | ); | |
109 | } | |
110 | ||
111 | # endif // # ifndef BOOST_IOSTREAMS_HAS_DINKUMWARE_FPOS | |
112 | ||
113 | } } // End namespaces iostreams, boost. | |
114 | ||
115 | #include <boost/iostreams/detail/config/enable_warnings.hpp> | |
116 | ||
117 | #endif // #ifndef BOOST_IOSTREAMS_POSITIONING_HPP_INCLUDED |