You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and dots ('.'), can be up to 35 characters long. Letters must be lowercase.
180 lines
5.4 KiB
180 lines
5.4 KiB
// (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) && (_MSC_VER >= 1020) |
|
# 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
|
|
|