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// (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.
#ifndef BOOST_IOSTREAMS_SEEK_HPP_INCLUDED
#define BOOST_IOSTREAMS_SEEK_HPP_INCLUDED
#if defined(_MSC_VER)
# pragma once
#endif
#include <boost/config.hpp> // DEDUCED_TYPENAME, MSVC.
#include <boost/integer_traits.hpp>
#include <boost/iostreams/categories.hpp>
#include <boost/iostreams/detail/dispatch.hpp>
#include <boost/iostreams/detail/ios.hpp> // streamsize, seekdir, openmode.
#include <boost/iostreams/detail/streambuf.hpp>
#include <boost/iostreams/detail/wrap_unwrap.hpp>
#include <boost/iostreams/operations_fwd.hpp>
#include <boost/iostreams/positioning.hpp>
#include <boost/mpl/if.hpp>
// Must come last.
#include <boost/iostreams/detail/config/disable_warnings.hpp>
namespace boost { namespace iostreams {
namespace detail {
template<typename T>
struct seek_device_impl;
template<typename T>
struct seek_filter_impl;
} // End namespace detail.
template<typename T>
inline std::streampos
seek( T& t, stream_offset off, BOOST_IOS::seekdir way,
BOOST_IOS::openmode which = BOOST_IOS::in | BOOST_IOS::out )
{
using namespace detail;
return seek_device_impl<T>::seek(detail::unwrap(t), off, way, which);
}
template<typename T, typename Device>
inline std::streampos
seek( T& t, Device& dev, stream_offset off, BOOST_IOS::seekdir way,
BOOST_IOS::openmode which = BOOST_IOS::in | BOOST_IOS::out )
{
using namespace detail;
return seek_filter_impl<T>::seek(detail::unwrap(t), dev, off, way, which);
}
namespace detail {
//------------------Definition of seek_device_impl----------------------------//
template<typename T>
struct seek_device_impl
: mpl::if_<
is_custom<T>,
operations<T>,
seek_device_impl<
BOOST_DEDUCED_TYPENAME
dispatch<
T, iostream_tag, istream_tag, ostream_tag,
streambuf_tag, two_head, any_tag
>::type
>
>::type
{ };
struct seek_impl_basic_ios {
template<typename T>
static std::streampos seek( T& t, stream_offset off,
BOOST_IOS::seekdir way,
BOOST_IOS::openmode which )
{
if ( way == BOOST_IOS::beg &&
( off < integer_traits<std::streamoff>::const_min ||
off > integer_traits<std::streamoff>::const_max ) )
{
return t.rdbuf()->pubseekpos(offset_to_position(off));
} else {
return t.rdbuf()->pubseekoff(off, way, which);
}
}
};
template<>
struct seek_device_impl<iostream_tag> : seek_impl_basic_ios { };
template<>
struct seek_device_impl<istream_tag> : seek_impl_basic_ios { };
template<>
struct seek_device_impl<ostream_tag> : seek_impl_basic_ios { };
template<>
struct seek_device_impl<streambuf_tag> {
template<typename T>
static std::streampos seek( T& t, stream_offset off,
BOOST_IOS::seekdir way,
BOOST_IOS::openmode which )
{
if ( way == BOOST_IOS::beg &&
( off < integer_traits<std::streamoff>::const_min ||
off > integer_traits<std::streamoff>::const_max ) )
{
return t.BOOST_IOSTREAMS_PUBSEEKPOS(offset_to_position(off));
} else {
return t.BOOST_IOSTREAMS_PUBSEEKOFF(off, way, which);
}
}
};
template<>
struct seek_device_impl<two_head> {
template<typename T>
static std::streampos seek( T& t, stream_offset off,
BOOST_IOS::seekdir way,
BOOST_IOS::openmode which )
{ return t.seek(off, way, which); }
};
template<>
struct seek_device_impl<any_tag> {
template<typename T>
static std::streampos seek( T& t, stream_offset off,
BOOST_IOS::seekdir way,
BOOST_IOS::openmode )
{ return t.seek(off, way); }
};
//------------------Definition of seek_filter_impl----------------------------//
template<typename T>
struct seek_filter_impl
: mpl::if_<
is_custom<T>,
operations<T>,
seek_filter_impl<
BOOST_DEDUCED_TYPENAME
dispatch<T, two_head, any_tag>::type
>
>::type
{ };
template<>
struct seek_filter_impl<two_head> {
template<typename T, typename Device>
static std::streampos seek( T& t, Device& d,
stream_offset off,
BOOST_IOS::seekdir way,
BOOST_IOS::openmode which )
{ return t.seek(d, off, way, which); }
};
template<>
struct seek_filter_impl<any_tag> {
template<typename T, typename Device>
static std::streampos seek( T& t, Device& d,
stream_offset off,
BOOST_IOS::seekdir way,
BOOST_IOS::openmode )
{ return t.seek(d, off, way); }
};
} // End namespace detail.
} } // End namespaces iostreams, boost.
#include <boost/iostreams/detail/config/enable_warnings.hpp>
#endif // #ifndef BOOST_IOSTREAMS_SEEK_HPP_INCLUDED
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