118 lines
4.1 KiB
C++
118 lines
4.1 KiB
C++
// (C) Copyright 2008 CodeRage, LLC (turkanis at coderage dot com)
|
|
// (C) Copyright 2003-2007 Jonathan Turkanis
|
|
// Distributed under the Boost Software License, Version 1.0. (See accompanying
|
|
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt.)
|
|
|
|
// See http://www.boost.org/libs/iostreams for documentation.
|
|
|
|
// Thanks to Gareth Sylvester-Bradley for the Dinkumware versions of the
|
|
// positioning functions.
|
|
|
|
#ifndef BOOST_IOSTREAMS_POSITIONING_HPP_INCLUDED
|
|
#define BOOST_IOSTREAMS_POSITIONING_HPP_INCLUDED
|
|
|
|
#if defined(_MSC_VER)
|
|
# pragma once
|
|
#endif
|
|
|
|
#include <boost/config.hpp>
|
|
#include <boost/cstdint.hpp>
|
|
#include <boost/integer_traits.hpp>
|
|
#include <boost/iostreams/detail/config/codecvt.hpp> // mbstate_t.
|
|
#include <boost/iostreams/detail/config/fpos.hpp>
|
|
#include <boost/iostreams/detail/ios.hpp> // streamoff, streampos.
|
|
|
|
// Must come last.
|
|
#include <boost/iostreams/detail/config/disable_warnings.hpp>
|
|
|
|
#ifdef BOOST_NO_STDC_NAMESPACE
|
|
namespace std { using ::fpos_t; }
|
|
#endif
|
|
|
|
namespace boost { namespace iostreams {
|
|
|
|
//------------------Definition of stream_offset-------------------------------//
|
|
|
|
typedef boost::intmax_t stream_offset;
|
|
|
|
//------------------Definition of stream_offset_to_streamoff------------------//
|
|
|
|
inline std::streamoff stream_offset_to_streamoff(stream_offset off)
|
|
{ return static_cast<stream_offset>(off); }
|
|
|
|
//------------------Definition of offset_to_position--------------------------//
|
|
|
|
# ifndef BOOST_IOSTREAMS_HAS_DINKUMWARE_FPOS
|
|
|
|
inline std::streampos offset_to_position(stream_offset off) { return off; }
|
|
|
|
# else // # ifndef BOOST_IOSTREAMS_HAS_DINKUMWARE_FPOS
|
|
|
|
inline std::streampos offset_to_position(stream_offset off)
|
|
{ return std::streampos(std::mbstate_t(), off); }
|
|
|
|
# endif // # ifndef BOOST_IOSTREAMS_HAS_DINKUMWARE_FPOS
|
|
|
|
//------------------Definition of position_to_offset--------------------------//
|
|
|
|
// Hande custom pos_type's
|
|
template<typename PosType>
|
|
inline stream_offset position_to_offset(PosType pos)
|
|
{ return std::streamoff(pos); }
|
|
|
|
# ifndef BOOST_IOSTREAMS_HAS_DINKUMWARE_FPOS
|
|
|
|
inline stream_offset position_to_offset(std::streampos pos) { return pos; }
|
|
|
|
# else // # ifndef BOOST_IOSTREAMS_HAS_DINKUMWARE_FPOS
|
|
|
|
// In the Dinkumware standard library, a std::streampos consists of two stream
|
|
// offsets -- _Fpos, of type std::fpos_t, and _Myoff, of type std::streamoff --
|
|
// together with a conversion state. A std::streampos is converted to a
|
|
// boost::iostreams::stream_offset by extracting the two stream offsets and
|
|
// summing them. The value of _Fpos can be extracted using the implementation-
|
|
// defined member functions seekpos() or get_fpos_t(), depending on the
|
|
// Dinkumware version. The value of _Myoff cannot be extracted directly, but can
|
|
// be calculated as the difference between the result of converting the
|
|
// std::fpos to a std::streamoff and the result of converting the member _Fpos
|
|
// to a long. The latter operation is accomplished with the macro BOOST_IOSTREAMS_FPOSOFF,
|
|
// which works correctly on platforms where std::fpos_t is an integral type and
|
|
// platforms where it is a struct
|
|
|
|
// Converts a std::fpos_t to a stream_offset
|
|
inline stream_offset fpos_t_to_offset(std::fpos_t pos)
|
|
{
|
|
# if defined(_POSIX_) || (_INTEGRAL_MAX_BITS >= 64) || defined(__IBMCPP__)
|
|
return pos;
|
|
# else
|
|
return BOOST_IOSTREAMS_FPOSOFF(pos);
|
|
# endif
|
|
}
|
|
|
|
// Extracts the member _Fpos from a std::fpos
|
|
inline std::fpos_t streampos_to_fpos_t(std::streampos pos)
|
|
{
|
|
# if defined (_CPPLIB_VER) || defined(__IBMCPP__)
|
|
return pos.seekpos();
|
|
# else
|
|
return pos.get_fpos_t();
|
|
# endif
|
|
}
|
|
|
|
inline stream_offset position_to_offset(std::streampos pos)
|
|
{
|
|
return fpos_t_to_offset(streampos_to_fpos_t(pos)) +
|
|
static_cast<stream_offset>(
|
|
static_cast<std::streamoff>(pos) -
|
|
BOOST_IOSTREAMS_FPOSOFF(streampos_to_fpos_t(pos))
|
|
);
|
|
}
|
|
|
|
# endif // # ifndef BOOST_IOSTREAMS_HAS_DINKUMWARE_FPOS
|
|
|
|
} } // End namespaces iostreams, boost.
|
|
|
|
#include <boost/iostreams/detail/config/enable_warnings.hpp>
|
|
|
|
#endif // #ifndef BOOST_IOSTREAMS_POSITIONING_HPP_INCLUDED
|