Chris@16: /* Copyright 2003-2008 Joaquin M Lopez Munoz.
Chris@16:  * Distributed under the Boost Software License, Version 1.0.
Chris@16:  * (See accompanying file LICENSE_1_0.txt or copy at
Chris@16:  * http://www.boost.org/LICENSE_1_0.txt)
Chris@16:  *
Chris@16:  * See http://www.boost.org/libs/multi_index for library home page.
Chris@16:  */
Chris@16: 
Chris@16: #ifndef BOOST_MULTI_INDEX_DETAIL_HEADER_HOLDER_HPP
Chris@16: #define BOOST_MULTI_INDEX_DETAIL_HEADER_HOLDER_HPP
Chris@16: 
Chris@101: #if defined(_MSC_VER)
Chris@16: #pragma once
Chris@16: #endif
Chris@16: 
Chris@16: #include <boost/noncopyable.hpp>
Chris@16: 
Chris@16: namespace boost{
Chris@16: 
Chris@16: namespace multi_index{
Chris@16: 
Chris@16: namespace detail{
Chris@16: 
Chris@16: /* A utility class used to hold a pointer to the header node.
Chris@16:  * The base from member idiom is used because index classes, which are
Chris@16:  * superclasses of multi_index_container, need this header in construction
Chris@16:  * time. The allocation is made by the allocator of the multi_index_container
Chris@16:  * class --hence, this allocator needs also be stored resorting
Chris@16:  * to the base from member trick.
Chris@16:  */
Chris@16: 
Chris@16: template<typename NodeTypePtr,typename Final>
Chris@16: struct header_holder:private noncopyable
Chris@16: {
Chris@16:   header_holder():member(final().allocate_node()){}
Chris@16:   ~header_holder(){final().deallocate_node(&*member);}
Chris@16: 
Chris@16:   NodeTypePtr member;
Chris@16: 
Chris@16: private:
Chris@16:   Final& final(){return *static_cast<Final*>(this);}
Chris@16: };
Chris@16: 
Chris@16: } /* namespace multi_index::detail */
Chris@16: 
Chris@16: } /* namespace multi_index */
Chris@16: 
Chris@16: } /* namespace boost */
Chris@16: 
Chris@16: #endif