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POboost multi_index_container changing keys -> incorret state of container
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  1. POboost multi_index_container changing keys -> incorret state of container
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    copied!<p>Supposed we have a multi index container:</p> <pre><code>#include &lt;iostream&gt; #include &lt;boost/multi_index_container.hpp&gt; #include &lt;boost/multi_index/hashed_index.hpp&gt; #include &lt;boost/multi_index/random_access_index.hpp&gt; #include &lt;boost/multi_index/tag.hpp&gt; #include &lt;boost/multi_index/key_extractors.hpp&gt; struct A{ A(int i){id=i;} int id; }; typedef boost::multi_index::multi_index_container&lt; A * , boost::multi_index::indexed_by&lt; boost::multi_index::random_access&lt; boost::multi_index::tag&lt;by_insertion&gt; &gt;, // this index represents insertion order boost::multi_index::hashed_unique&lt; boost::multi_index::tag&lt;by_id&gt;, boost::multi_index::member&lt;A, int, &amp;A::id&gt; &gt; &gt; &gt; MapType; MapType map; map.get&lt;1&gt;().insert(new A(1)); map.get&lt;1&gt;().insert(new A(2)); (*map.get&lt;1&gt;().find(1))-&gt;id=4; // HERE IF I CHANGE THE KEY, I CAN NOT FIND either key=4 or 1 MapType::nth_index&lt;1&gt;::type::iterator it = map.get&lt;1&gt;().find(4); if(it != map.get&lt;1&gt;().end() ){ std::cout &lt;&lt; "FOUND A:" &lt;&lt; *it &lt;&lt; std::endl; } // DOES NOT WORK?? WHY CANT I FIND the ELement with Key 4? </code></pre> <p>The problem is now that i probably set up the <code>boost::multi_index::member&lt;A, int, &amp;A::a&gt;</code> wrongly because when I change some key. I cannot find the element with key = 4?</p> <p>Whats wrongly used here? Any help really appreciated!</p>
 

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