Hi all, I have to store pointer of type (let's say) "employee" in a multi-index-container: struct employee { employee(int id):id(id){} int id; }; Further I have to check if every id is unique: employee* e0 = new employee(1); employee* e1 = e0; employee* e2 = new employee(1); employee* e3 = new employee(2); my_multi_index_conatiner.insert(e0); // OK my_multi_index_conatiner.insert(e1); // BAD my_multi_index_conatiner.insert(e2); // BAD my_multi_index_conatiner.insert(e0); // OK Can someone tell me how a typedef of a multi_index_container fullfilling prerequisities above looks? Or is a multi_index_container not the right tool? I've tried with a method in struct employee which returns the this-pointer. But this-pointer is const const and useless for my problem. Thanks in advance!