Dear All: In the following codes, I feed the container with B*, however I user the member of  B as the index. Can somebody explain to me how this work out?  And It  seems that if smart pointers are feeded into the container, it still works out. #include <boost/config.hpp> /* keep it first to prevent nasty warns in MSVC */ #include <boost/multi_index_container.hpp> #include <boost/multi_index/ordered_index.hpp> #include <boost/multi_index/member.hpp> #include <iostream> using namespace boost::multi_index; class B { public:     int idx; }; typedef boost::multi_index_container<     B*,     indexed_by<         ordered_unique<             BOOST_MULTI_INDEX_MEMBER(B, int, idx)         >     >

Container;

int main() {     Container container;     B* p1 = new B;     B* p2 = new B;     p1->idx = 2;     p2->idx = 1;     container.insert(p1);     container.insert(p2);     Container::iterator iter;     for(iter=container.begin();iter!=container.end();iter++)     {         B* tmp = (*iter);         std::cout << tmp->idx << std::endl;     }     return 0; } 好玩贺卡等你发，邮箱贺卡全新上线！ ___________________________________________________________ 好玩贺卡等你发，邮箱贺卡全新上线！ http://card.mail.cn.yahoo.com/