Imported Upstream version 1.57.0upstream/1.57.0

1 files changed, 65 insertions, 0 deletions

diff --git a/boost/intrusive/detail/default_header_holder.hpp b/boost/intrusive/detail/default_header_holder.hpp
new file mode 100644
index 0000000000..c471691640
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+++ b/boost/intrusive/detail/default_header_holder.hpp
@@ -0,0 +1,65 @@
+/////////////////////////////////////////////////////////////////////////////
+//
+// (C) Copyright Ion Gaztanaga  2014-2014
+//
+// 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/intrusive for documentation.
+//
+/////////////////////////////////////////////////////////////////////////////
+
+#ifndef BOOST_INTRUSIVE_DETAIL_DEFAULT_HEADER_HOLDER_HPP
+#define BOOST_INTRUSIVE_DETAIL_DEFAULT_HEADER_HOLDER_HPP
+
+#if defined(_MSC_VER)
+#  pragma once
+#endif
+
+#include <boost/intrusive/pointer_traits.hpp>
+#include <boost/intrusive/detail/to_raw_pointer.hpp>
+
+namespace boost {
+namespace intrusive {
+namespace detail {
+
+// trivial header node holder
+template < typename NodeTraits >
+struct default_header_holder : public NodeTraits::node
+{
+    typedef NodeTraits node_traits;
+    typedef typename node_traits::node node;
+    typedef typename node_traits::node_ptr node_ptr;
+    typedef typename node_traits::const_node_ptr const_node_ptr;
+
+    default_header_holder() : node() {}
+
+    const_node_ptr get_node() const
+    { return pointer_traits< const_node_ptr >::pointer_to(*static_cast< const node* >(this)); }
+
+    node_ptr get_node()
+    { return pointer_traits< node_ptr >::pointer_to(*static_cast< node* >(this)); }
+
+    // (unsafe) downcast used to implement container-from-iterator
+    static default_header_holder* get_holder(const node_ptr &p)
+    { return static_cast< default_header_holder* >(boost::intrusive::detail::to_raw_pointer(p)); }
+};
+
+// type function producing the header node holder
+template < typename Value_Traits, typename HeaderHolder >
+struct get_header_holder_type
+{
+    typedef HeaderHolder type;
+};
+template < typename Value_Traits >
+struct get_header_holder_type< Value_Traits, void >
+{
+    typedef default_header_holder< typename Value_Traits::node_traits > type;
+};
+
+} //namespace detail
+} //namespace intrusive
+} //namespace boost
+
+#endif //BOOST_INTRUSIVE_DETAIL_DEFAULT_HEADER_HOLDER_HPP