1 // (C) Copyright Jonathan Turkanis 2003.

     2 // Distributed under the Boost Software License, Version 1.0. (See accompanying

     3 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt.)

     4 

     5 // See http://www.boost.org/libs/iostreams for documentation.

     6 

     7 // Thanks to Gareth Sylvester-Bradley for the Dinkumware versions of the

     8 // positioning functions.

     9 

    10 #ifndef BOOST_IOSTREAMS_POSITIONING_HPP_INCLUDED

    11 #define BOOST_IOSTREAMS_POSITIONING_HPP_INCLUDED

    12 

    13 #if defined(_MSC_VER) && (_MSC_VER >= 1020)

    14 # pragma once

    15 #endif

    16 

    17 #include <boost/config.hpp>

    18 #include <boost/cstdint.hpp>

    19 #include <boost/integer_traits.hpp>

    20 #include <boost/iostreams/detail/config/codecvt.hpp> // mbstate_t.

    21 #include <boost/iostreams/detail/ios.hpp> // streamoff, streampos.

    22 

    23 // Must come last.

    24 #include <boost/iostreams/detail/config/disable_warnings.hpp> 

    25 

    26 #ifdef BOOST_NO_STDC_NAMESPACE

    27 namespace std { using ::fpos_t; }

    28 #endif

    29 

    30 namespace boost { namespace iostreams {

    31 

    32 typedef boost::intmax_t stream_offset;

    33 

    34 inline std::streamoff stream_offset_to_streamoff(stream_offset off)

    35 { return static_cast<stream_offset>(off); }

    36 

    37 template<typename PosType> // Hande custom pos_type's.

    38 inline stream_offset position_to_offset(PosType pos)

    39 { return std::streamoff(pos); }

    40 

    41 #if ((defined(_YVALS) && !defined(__IBMCPP__)) || defined(_CPPLIB_VER)) && \

    42      !defined(__SGI_STL_PORT) && !defined(_STLPORT_VERSION) \

    43      && !defined(__QNX__) \

    44    /**/

    45 

    46         /* Dinkumware */

    47 

    48 inline std::streampos offset_to_position(stream_offset off)

    49 {

    50     // Use implementation-specific constructor.

    51     return std::streampos(std::mbstate_t(), off);

    52 }

    53 

    54 inline stream_offset fpos_t_to_offset(std::fpos_t pos)

    55 { // Helper function.

    56 #if defined(_POSIX_) || (_INTEGRAL_MAX_BITS >= 64)

    57     return pos;

    58 #else

    59     return _FPOSOFF(pos);

    60 #endif

    61 }

    62 

    63 # if defined(_CPPLIB_VER) //--------------------------------------------------//

    64 

    65         /* Recent Dinkumware */

    66 

    67 inline stream_offset position_to_offset(std::streampos pos)

    68 {

    69     // Use implementation-specific member function seekpos().

    70     return fpos_t_to_offset(pos.seekpos()) +

    71            stream_offset(std::streamoff(pos)) -

    72            stream_offset(std::streamoff(pos.seekpos()));

    73 }

    74 

    75 # else // # if defined(_CPPLIB_VER) //----------------------------------------//

    76 

    77         /* Old Dinkumware */

    78 

    79 inline stream_offset position_to_offset(std::streampos pos)

    80 {

    81     // use implementation-specific member function get_fpos_t().

    82     return fpos_t_to_offset(pos.get_fpos_t()) +

    83            stream_offset(std::streamoff(pos)) -

    84            stream_offset(std::streamoff(pos.get_fpos_t()));

    85 }

    86 

    87 # endif // # if defined(_CPPLIB_VER) //---------------------------------------//

    88 #else // Dinkumware //--------------------------------------------------------//

    89 

    90         /* Non-Dinkumware */

    91 

    92 inline std::streampos offset_to_position(stream_offset off) { return off; }

    93 

    94 inline stream_offset position_to_offset(std::streampos pos) { return pos; }

    95 

    96 #endif // Dinkumware //-------------------------------------------------------//

    97 

    98 } } // End namespaces iostreams, boost.

    99 

   100 #include <boost/iostreams/detail/config/enable_warnings.hpp> 

   101 

   102 #endif // #ifndef BOOST_IOSTREAMS_POSITIONING_HPP_INCLUDED