Imported Upstream version 1.49.0upstream/1.49.0

1 files changed, 180 insertions, 0 deletions

diff --git a/boost/iostreams/seek.hpp b/boost/iostreams/seek.hpp
new file mode 100644
index 0000000000..efa3c7daf0
--- /dev/null
+++ b/boost/iostreams/seek.hpp
@@ -0,0 +1,180 @@
+// (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