// (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 |