Added thirdparty: boost library

thirdparty/include/boost/multi_index/detail/invalidate_iterators.hpp

@@ -0,0 +1,44 @@
+/* Copyright 2003-2021 Joaquin M Lopez Munoz.
+ * 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/multi_index for library home page.
+ */
+
+#ifndef BOOST_MULTI_INDEX_DETAIL_INVALIDATE_ITERATORS_HPP
+#define BOOST_MULTI_INDEX_DETAIL_INVALIDATE_ITERATORS_HPP
+
+#if defined(_MSC_VER)
+#pragma once
+#endif
+
+namespace boost{
+
+namespace multi_index{
+
+namespace detail{
+
+/* invalidate_iterators mimics the interface of index_access_sequence (see
+ * index_access_sequence.hpp) but returns dummy indices whose iterator type
+ * won't ever match those of the source: the net effect is that safe iterator
+ * transfer resolves to iterator invalidation, so backbone function invocation
+ * extract_(x,invalidate_iterators()) is used in extraction scenarios other
+ * than merging.
+ */
+
+struct invalidate_iterators
+{
+  typedef void iterator;
+
+  invalidate_iterators& get(){return *this;}
+  invalidate_iterators& next(){return *this;}
+};
+
+} /* namespace multi_index::detail */
+
+} /* namespace multi_index */
+
+} /* namespace boost */
+
+#endif