Chris@16: // (C) Copyright 2008 CodeRage, LLC (turkanis at coderage dot com)
Chris@16: // (C) Copyright 2003-2007 Jonathan Turkanis
Chris@16: // Distributed under the Boost Software License, Version 1.0. (See accompanying
Chris@16: // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt.)
Chris@16: 
Chris@16: // See http://www.boost.org/libs/iostreams for documentation.
Chris@16: 
Chris@16: #ifndef BOOST_IOSTREAMS_SEEK_HPP_INCLUDED
Chris@16: #define BOOST_IOSTREAMS_SEEK_HPP_INCLUDED
Chris@16: 
Chris@16: #if defined(_MSC_VER) && (_MSC_VER >= 1020)
Chris@16: # pragma once
Chris@16: #endif
Chris@16: 
Chris@16: #include <boost/config.hpp>  // DEDUCED_TYPENAME, MSVC.
Chris@16: #include <boost/integer_traits.hpp>
Chris@16: #include <boost/iostreams/categories.hpp>
Chris@16: #include <boost/iostreams/detail/dispatch.hpp>
Chris@16: #include <boost/iostreams/detail/ios.hpp>       // streamsize, seekdir, openmode.
Chris@16: #include <boost/iostreams/detail/streambuf.hpp>
Chris@16: #include <boost/iostreams/detail/wrap_unwrap.hpp>
Chris@16: #include <boost/iostreams/operations_fwd.hpp>
Chris@16: #include <boost/iostreams/positioning.hpp>
Chris@16: #include <boost/mpl/if.hpp>
Chris@16: 
Chris@16: // Must come last.
Chris@16: #include <boost/iostreams/detail/config/disable_warnings.hpp>
Chris@16: 
Chris@16: namespace boost { namespace iostreams {
Chris@16: 
Chris@16: namespace detail {
Chris@16: 
Chris@16: template<typename T>
Chris@16: struct seek_device_impl;
Chris@16: 
Chris@16: template<typename T>
Chris@16: struct seek_filter_impl;
Chris@16: 
Chris@16: } // End namespace detail.
Chris@16: 
Chris@16: template<typename T>
Chris@16: inline std::streampos
Chris@16: seek( T& t, stream_offset off, BOOST_IOS::seekdir way,
Chris@16:       BOOST_IOS::openmode which = BOOST_IOS::in | BOOST_IOS::out )
Chris@16: { 
Chris@16:     using namespace detail;
Chris@16:     return seek_device_impl<T>::seek(detail::unwrap(t), off, way, which); 
Chris@16: }
Chris@16: 
Chris@16: template<typename T, typename Device>
Chris@16: inline std::streampos
Chris@16: seek( T& t, Device& dev, stream_offset off, BOOST_IOS::seekdir way,
Chris@16:       BOOST_IOS::openmode which = BOOST_IOS::in | BOOST_IOS::out )
Chris@16: { 
Chris@16:     using namespace detail;
Chris@16:     return seek_filter_impl<T>::seek(detail::unwrap(t), dev, off, way, which);
Chris@16: }
Chris@16: 
Chris@16: namespace detail {
Chris@16: 
Chris@16: //------------------Definition of seek_device_impl----------------------------//
Chris@16: 
Chris@16: template<typename T>
Chris@16: struct seek_device_impl
Chris@16:     : mpl::if_<
Chris@16:           is_custom<T>,
Chris@16:           operations<T>,
Chris@16:           seek_device_impl<
Chris@16:               BOOST_DEDUCED_TYPENAME
Chris@16:               dispatch<
Chris@16:                   T, iostream_tag, istream_tag, ostream_tag,
Chris@16:                   streambuf_tag, two_head, any_tag
Chris@16:               >::type
Chris@16:           >
Chris@16:       >::type
Chris@16:     { };
Chris@16: 
Chris@16: struct seek_impl_basic_ios {
Chris@16:     template<typename T>
Chris@16:     static std::streampos seek( T& t, stream_offset off,
Chris@16:                                 BOOST_IOS::seekdir way,
Chris@16:                                 BOOST_IOS::openmode which )
Chris@16:     {
Chris@16:         if ( way == BOOST_IOS::beg &&
Chris@16:              ( off < integer_traits<std::streamoff>::const_min ||
Chris@16:                off > integer_traits<std::streamoff>::const_max ) )
Chris@16:         {
Chris@16:             return t.rdbuf()->pubseekpos(offset_to_position(off));
Chris@16:         } else {
Chris@16:             return t.rdbuf()->pubseekoff(off, way, which);
Chris@16:         }
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: template<>
Chris@16: struct seek_device_impl<iostream_tag> : seek_impl_basic_ios { };
Chris@16: 
Chris@16: template<>
Chris@16: struct seek_device_impl<istream_tag> : seek_impl_basic_ios { };
Chris@16: 
Chris@16: template<>
Chris@16: struct seek_device_impl<ostream_tag> : seek_impl_basic_ios { };
Chris@16: 
Chris@16: template<>
Chris@16: struct seek_device_impl<streambuf_tag> {
Chris@16:     template<typename T>
Chris@16:     static std::streampos seek( T& t, stream_offset off,
Chris@16:                                 BOOST_IOS::seekdir way,
Chris@16:                                 BOOST_IOS::openmode which )
Chris@16:     {
Chris@16:         if ( way == BOOST_IOS::beg &&
Chris@16:              ( off < integer_traits<std::streamoff>::const_min ||
Chris@16:                off > integer_traits<std::streamoff>::const_max ) )
Chris@16:         {
Chris@16:             return t.BOOST_IOSTREAMS_PUBSEEKPOS(offset_to_position(off));
Chris@16:         } else {
Chris@16:             return t.BOOST_IOSTREAMS_PUBSEEKOFF(off, way, which);
Chris@16:         }
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: template<>
Chris@16: struct seek_device_impl<two_head> {
Chris@16:     template<typename T>
Chris@16:     static std::streampos seek( T& t, stream_offset off,
Chris@16:                                 BOOST_IOS::seekdir way,
Chris@16:                                 BOOST_IOS::openmode which )
Chris@16:     { return t.seek(off, way, which); }
Chris@16: };
Chris@16: 
Chris@16: template<>
Chris@16: struct seek_device_impl<any_tag> {
Chris@16:     template<typename T>
Chris@16:     static std::streampos seek( T& t, stream_offset off,
Chris@16:                                 BOOST_IOS::seekdir way,
Chris@16:                                 BOOST_IOS::openmode )
Chris@16:     { return t.seek(off, way); }
Chris@16: };
Chris@16: 
Chris@16: //------------------Definition of seek_filter_impl----------------------------//
Chris@16: 
Chris@16: template<typename T>
Chris@16: struct seek_filter_impl
Chris@16:     : mpl::if_<
Chris@16:           is_custom<T>,
Chris@16:           operations<T>,
Chris@16:           seek_filter_impl<
Chris@16:               BOOST_DEDUCED_TYPENAME
Chris@16:               dispatch<T, two_head, any_tag>::type
Chris@16:           >
Chris@16:       >::type
Chris@16:     { };
Chris@16: 
Chris@16: template<>
Chris@16: struct seek_filter_impl<two_head> {
Chris@16:     template<typename T, typename Device>
Chris@16:     static std::streampos seek( T& t, Device& d,
Chris@16:                                 stream_offset off,
Chris@16:                                 BOOST_IOS::seekdir way,
Chris@16:                                 BOOST_IOS::openmode which )
Chris@16:     { return t.seek(d, off, way, which); }
Chris@16: };
Chris@16: 
Chris@16: template<>
Chris@16: struct seek_filter_impl<any_tag> {
Chris@16:     template<typename T, typename Device>
Chris@16:     static std::streampos seek( T& t, Device& d,
Chris@16:                                 stream_offset off,
Chris@16:                                 BOOST_IOS::seekdir way,
Chris@16:                                 BOOST_IOS::openmode )
Chris@16:     { return t.seek(d, off, way); }
Chris@16: };
Chris@16: 
Chris@16: } // End namespace detail.
Chris@16: 
Chris@16: } } // End namespaces iostreams, boost.
Chris@16: 
Chris@16: #include <boost/iostreams/detail/config/enable_warnings.hpp>
Chris@16: 
Chris@16: #endif // #ifndef BOOST_IOSTREAMS_SEEK_HPP_INCLUDED