multi_index/detail/invalidate_iterators.hpp

0001 /* Copyright 2003-2021 Joaquin M Lopez Munoz.
0002  * Distributed under the Boost Software License, Version 1.0.
0003  * (See accompanying file LICENSE_1_0.txt or copy at
0004  * http://www.boost.org/LICENSE_1_0.txt)
0005  *
0006  * See http://www.boost.org/libs/multi_index for library home page.
0007  */
0008
0009 #ifndef BOOST_MULTI_INDEX_DETAIL_INVALIDATE_ITERATORS_HPP
0010 #define BOOST_MULTI_INDEX_DETAIL_INVALIDATE_ITERATORS_HPP
0011
0012 #if defined(_MSC_VER)
0013 #pragma once
0014 #endif
0015
0016 namespace boost{
0017
0018 namespace multi_index{
0019
0020 namespace detail{
0021
0022 /* invalidate_iterators mimics the interface of index_access_sequence (see
0023  * index_access_sequence.hpp) but returns dummy indices whose iterator type
0024  * won't ever match those of the source: the net effect is that safe iterator
0025  * transfer resolves to iterator invalidation, so backbone function invocation
0026  * extract_(x,invalidate_iterators()) is used in extraction scenarios other
0027  * than merging.
0028  */
0029
0030 struct invalidate_iterators
0031 {
0032   typedef void iterator;
0033
0034   invalidate_iterators& get(){return *this;}
0035   invalidate_iterators& next(){return *this;}
0036 };
0037
0038 } /* namespace multi_index::detail */
0039
0040 } /* namespace multi_index */
0041
0042 } /* namespace boost */
0043
0044 #endif