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copied!<p>(I had to use an own answer to write code-blocks - sorry!) </p> <p>The <code>composite_key</code> with <code>used_time</code> and <code>parts</code> (as Kirill V. Lyadvinsky suggested) is basically what I've already implemented. I want to get rid of the lexicographical compare of the <code>parts</code>-vector.</p> <p>Suppose I've stored the needed_demand somehow then I could write a simple function, which returns the correct index within a random-access data-structure like that: </p> <pre><code>int get_index(intermediate_result &input_result) const { int ret_value = 0; int index_part = 1; for(int i=0;i<needed_demand.size();++i) { ret_value += input_result.get_part(i) * index_part; index_part *= (needed_demand.get_part(i) + 1); } } </code></pre> <p>Obviously this can be implemented more efficiently and this is not the only possible index ordering for the needed demand. But let's suppose this function exists as a member-function of <code>intermediate_result</code>! Is it possible to write something like this to prevent <code>lexicographical_compare</code> ?</p> <pre><code>indexed_by< random_access< >, ordered_unique< composite_key< intermediate_result, member<intermediate_result, int, &intermediate_result::used_time>, const_mem_fun<intermediate_result,int,&intermediate_result::get_index> > > > </code></pre> <p>If this is possible and I initialized the multi-index with all possible <code>parts</code>-vectors (i.e. in my comment above I would've pushed 24 empty maps in my data-structure), does this find the right entry for a given <code>intermediate_result</code> in constant time (after computing the correct index with <code>get_index</code>) ?<br> I have to ask this, because I don't quite see, how the <code>random_access<></code> index is linked with the <code>ordered_unique<></code> index..</p> <p>But thank you for your answers so far!!</p>

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