sl@0: // (C) Copyright Jonathan Turkanis 2003.
sl@0: // Distributed under the Boost Software License, Version 1.0. (See accompanying
sl@0: // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt.)
sl@0: 
sl@0: // See http://www.boost.org/libs/iostreams for documentation.
sl@0: 
sl@0: #ifndef BOOST_IOSTREAMS_SEEK_HPP_INCLUDED
sl@0: #define BOOST_IOSTREAMS_SEEK_HPP_INCLUDED
sl@0: 
sl@0: #if defined(_MSC_VER) && (_MSC_VER >= 1020)
sl@0: # pragma once
sl@0: #endif
sl@0: 
sl@0: #include <boost/config.hpp>  // DEDUCED_TYPENAME, MSVC.
sl@0: #include <boost/integer_traits.hpp>
sl@0: #include <boost/iostreams/categories.hpp>
sl@0: #include <boost/iostreams/detail/dispatch.hpp>
sl@0: #include <boost/iostreams/detail/ios.hpp>       // streamsize, seekdir, openmode.
sl@0: #include <boost/iostreams/detail/streambuf.hpp>
sl@0: #include <boost/iostreams/detail/wrap_unwrap.hpp>
sl@0: #include <boost/iostreams/operations_fwd.hpp>
sl@0: #include <boost/iostreams/positioning.hpp>
sl@0: #include <boost/mpl/if.hpp>
sl@0: 
sl@0: // Must come last.
sl@0: #include <boost/iostreams/detail/config/disable_warnings.hpp>
sl@0: 
sl@0: namespace boost { namespace iostreams {
sl@0: 
sl@0: namespace detail {
sl@0: 
sl@0: template<typename T>
sl@0: struct seek_device_impl;
sl@0: 
sl@0: template<typename T>
sl@0: struct seek_filter_impl;
sl@0: 
sl@0: } // End namespace detail.
sl@0: 
sl@0: template<typename T>
sl@0: inline std::streampos
sl@0: seek( T& t, stream_offset off, BOOST_IOS::seekdir way,
sl@0:       BOOST_IOS::openmode which = BOOST_IOS::in | BOOST_IOS::out )
sl@0: { 
sl@0:     using namespace detail;
sl@0:     return seek_device_impl<T>::seek(detail::unwrap(t), off, way, which); 
sl@0: }
sl@0: 
sl@0: template<typename T, typename Device>
sl@0: inline std::streampos
sl@0: seek( T& t, Device& dev, stream_offset off, BOOST_IOS::seekdir way,
sl@0:       BOOST_IOS::openmode which = BOOST_IOS::in | BOOST_IOS::out )
sl@0: { 
sl@0:     using namespace detail;
sl@0:     return seek_filter_impl<T>::seek(detail::unwrap(t), dev, off, way, which);
sl@0: }
sl@0: 
sl@0: namespace detail {
sl@0: 
sl@0: //------------------Definition of seek_device_impl----------------------------//
sl@0: 
sl@0: template<typename T>
sl@0: struct seek_device_impl
sl@0:     : mpl::if_<
sl@0:           is_custom<T>,
sl@0:           operations<T>,
sl@0:           seek_device_impl<
sl@0:               BOOST_DEDUCED_TYPENAME
sl@0:               dispatch<
sl@0:                   T, iostream_tag, istream_tag, ostream_tag,
sl@0:                   streambuf_tag, two_head, any_tag
sl@0:               >::type
sl@0:           >
sl@0:       >::type
sl@0:     { };
sl@0: 
sl@0: struct seek_impl_basic_ios {
sl@0:     template<typename T>
sl@0:     static std::streampos seek( T& t, stream_offset off,
sl@0:                                 BOOST_IOS::seekdir way,
sl@0:                                 BOOST_IOS::openmode which )
sl@0:     {
sl@0:         if ( way == BOOST_IOS::beg &&
sl@0:              ( off < integer_traits<std::streamoff>::const_min ||
sl@0:                off > integer_traits<std::streamoff>::const_max ) )
sl@0:         {
sl@0:             return t.rdbuf()->pubseekpos(offset_to_position(off));
sl@0:         } else {
sl@0:             return t.rdbuf()->pubseekoff(off, way, which);
sl@0:         }
sl@0:     }
sl@0: };
sl@0: 
sl@0: template<>
sl@0: struct seek_device_impl<iostream_tag> : seek_impl_basic_ios { };
sl@0: 
sl@0: template<>
sl@0: struct seek_device_impl<istream_tag> : seek_impl_basic_ios { };
sl@0: 
sl@0: template<>
sl@0: struct seek_device_impl<ostream_tag> : seek_impl_basic_ios { };
sl@0: 
sl@0: template<>
sl@0: struct seek_device_impl<streambuf_tag> {
sl@0:     template<typename T>
sl@0:     static std::streampos seek( T& t, stream_offset off,
sl@0:                                 BOOST_IOS::seekdir way,
sl@0:                                 BOOST_IOS::openmode which )
sl@0:     {
sl@0:         if ( way == BOOST_IOS::beg &&
sl@0:              ( off < integer_traits<std::streamoff>::const_min ||
sl@0:                off > integer_traits<std::streamoff>::const_max ) )
sl@0:         {
sl@0:             return t.BOOST_IOSTREAMS_PUBSEEKPOS(offset_to_position(off));
sl@0:         } else {
sl@0:             return t.BOOST_IOSTREAMS_PUBSEEKOFF(off, way, which);
sl@0:         }
sl@0:     }
sl@0: };
sl@0: 
sl@0: template<>
sl@0: struct seek_device_impl<two_head> {
sl@0:     template<typename T>
sl@0:     static std::streampos seek( T& t, stream_offset off,
sl@0:                                 BOOST_IOS::seekdir way,
sl@0:                                 BOOST_IOS::openmode which )
sl@0:     { return t.seek(off, way, which); }
sl@0: };
sl@0: 
sl@0: template<>
sl@0: struct seek_device_impl<any_tag> {
sl@0:     template<typename T>
sl@0:     static std::streampos seek( T& t, stream_offset off,
sl@0:                                 BOOST_IOS::seekdir way,
sl@0:                                 BOOST_IOS::openmode )
sl@0:     { return t.seek(off, way); }
sl@0: };
sl@0: 
sl@0: //------------------Definition of seek_filter_impl----------------------------//
sl@0: 
sl@0: template<typename T>
sl@0: struct seek_filter_impl
sl@0:     : mpl::if_<
sl@0:           is_custom<T>,
sl@0:           operations<T>,
sl@0:           seek_filter_impl<
sl@0:               BOOST_DEDUCED_TYPENAME
sl@0:               dispatch<T, two_head, any_tag>::type
sl@0:           >
sl@0:       >::type
sl@0:     { };
sl@0: 
sl@0: template<>
sl@0: struct seek_filter_impl<two_head> {
sl@0:     template<typename T, typename Device>
sl@0:     static std::streampos seek( T& t, Device& d,
sl@0:                                 stream_offset off,
sl@0:                                 BOOST_IOS::seekdir way,
sl@0:                                 BOOST_IOS::openmode which )
sl@0:     { return t.seek(d, off, way, which); }
sl@0: };
sl@0: 
sl@0: template<>
sl@0: struct seek_filter_impl<any_tag> {
sl@0:     template<typename T, typename Device>
sl@0:     static std::streampos seek( T& t, Device& d,
sl@0:                                 stream_offset off,
sl@0:                                 BOOST_IOS::seekdir way,
sl@0:                                 BOOST_IOS::openmode )
sl@0:     { return t.seek(d, off, way); }
sl@0: };
sl@0: 
sl@0: } // End namespace detail.
sl@0: 
sl@0: } } // End namespaces iostreams, boost.
sl@0: 
sl@0: #include <boost/iostreams/detail/config/enable_warnings.hpp>
sl@0: 
sl@0: #endif // #ifndef BOOST_IOSTREAMS_SEEK_HPP_INCLUDED