181 lines
5.5 KiB
C++
Executable File
181 lines
5.5 KiB
C++
Executable File
// (C) Copyright 2008 CodeRage, LLC (turkanis at coderage dot com)
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// (C) Copyright 2003-2007 Jonathan Turkanis
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// Distributed under the Boost Software License, Version 1.0. (See accompanying
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// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt.)
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// See http://www.boost.org/libs/iostreams for documentation.
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#ifndef BOOST_IOSTREAMS_SEEK_HPP_INCLUDED
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#define BOOST_IOSTREAMS_SEEK_HPP_INCLUDED
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#if defined(_MSC_VER)
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# pragma once
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#endif
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#include <boost/config.hpp> // DEDUCED_TYPENAME, MSVC.
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#include <boost/integer_traits.hpp>
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#include <boost/iostreams/categories.hpp>
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#include <boost/iostreams/detail/dispatch.hpp>
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#include <boost/iostreams/detail/ios.hpp> // streamsize, seekdir, openmode.
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#include <boost/iostreams/detail/streambuf.hpp>
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#include <boost/iostreams/detail/wrap_unwrap.hpp>
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#include <boost/iostreams/operations_fwd.hpp>
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#include <boost/iostreams/positioning.hpp>
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#include <boost/mpl/if.hpp>
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// Must come last.
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#include <boost/iostreams/detail/config/disable_warnings.hpp>
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namespace boost { namespace iostreams {
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namespace detail {
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template<typename T>
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struct seek_device_impl;
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template<typename T>
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struct seek_filter_impl;
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} // End namespace detail.
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template<typename T>
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inline std::streampos
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seek( T& t, stream_offset off, BOOST_IOS::seekdir way,
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BOOST_IOS::openmode which = BOOST_IOS::in | BOOST_IOS::out )
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{
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using namespace detail;
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return seek_device_impl<T>::seek(detail::unwrap(t), off, way, which);
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}
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template<typename T, typename Device>
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inline std::streampos
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seek( T& t, Device& dev, stream_offset off, BOOST_IOS::seekdir way,
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BOOST_IOS::openmode which = BOOST_IOS::in | BOOST_IOS::out )
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{
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using namespace detail;
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return seek_filter_impl<T>::seek(detail::unwrap(t), dev, off, way, which);
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}
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namespace detail {
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//------------------Definition of seek_device_impl----------------------------//
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template<typename T>
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struct seek_device_impl
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: mpl::if_<
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is_custom<T>,
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operations<T>,
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seek_device_impl<
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BOOST_DEDUCED_TYPENAME
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dispatch<
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T, iostream_tag, istream_tag, ostream_tag,
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streambuf_tag, two_head, any_tag
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>::type
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>
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>::type
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{ };
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struct seek_impl_basic_ios {
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template<typename T>
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static std::streampos seek( T& t, stream_offset off,
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BOOST_IOS::seekdir way,
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BOOST_IOS::openmode which )
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{
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if ( way == BOOST_IOS::beg &&
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( off < integer_traits<std::streamoff>::const_min ||
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off > integer_traits<std::streamoff>::const_max ) )
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{
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return t.rdbuf()->pubseekpos(offset_to_position(off));
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} else {
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return t.rdbuf()->pubseekoff(off, way, which);
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}
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}
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};
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template<>
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struct seek_device_impl<iostream_tag> : seek_impl_basic_ios { };
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template<>
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struct seek_device_impl<istream_tag> : seek_impl_basic_ios { };
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template<>
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struct seek_device_impl<ostream_tag> : seek_impl_basic_ios { };
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template<>
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struct seek_device_impl<streambuf_tag> {
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template<typename T>
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static std::streampos seek( T& t, stream_offset off,
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BOOST_IOS::seekdir way,
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BOOST_IOS::openmode which )
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{
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if ( way == BOOST_IOS::beg &&
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( off < integer_traits<std::streamoff>::const_min ||
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off > integer_traits<std::streamoff>::const_max ) )
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{
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return t.BOOST_IOSTREAMS_PUBSEEKPOS(offset_to_position(off));
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} else {
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return t.BOOST_IOSTREAMS_PUBSEEKOFF(off, way, which);
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}
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}
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};
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template<>
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struct seek_device_impl<two_head> {
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template<typename T>
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static std::streampos seek( T& t, stream_offset off,
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BOOST_IOS::seekdir way,
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BOOST_IOS::openmode which )
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{ return t.seek(off, way, which); }
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};
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template<>
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struct seek_device_impl<any_tag> {
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template<typename T>
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static std::streampos seek( T& t, stream_offset off,
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BOOST_IOS::seekdir way,
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BOOST_IOS::openmode )
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{ return t.seek(off, way); }
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};
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//------------------Definition of seek_filter_impl----------------------------//
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template<typename T>
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struct seek_filter_impl
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: mpl::if_<
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is_custom<T>,
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operations<T>,
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seek_filter_impl<
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BOOST_DEDUCED_TYPENAME
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dispatch<T, two_head, any_tag>::type
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>
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>::type
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{ };
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template<>
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struct seek_filter_impl<two_head> {
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template<typename T, typename Device>
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static std::streampos seek( T& t, Device& d,
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stream_offset off,
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BOOST_IOS::seekdir way,
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BOOST_IOS::openmode which )
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{ return t.seek(d, off, way, which); }
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};
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template<>
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struct seek_filter_impl<any_tag> {
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template<typename T, typename Device>
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static std::streampos seek( T& t, Device& d,
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stream_offset off,
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BOOST_IOS::seekdir way,
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BOOST_IOS::openmode )
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{ return t.seek(d, off, way); }
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};
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} // End namespace detail.
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} } // End namespaces iostreams, boost.
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#include <boost/iostreams/detail/config/enable_warnings.hpp>
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#endif // #ifndef BOOST_IOSTREAMS_SEEK_HPP_INCLUDED
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