Dears I have question. Why there are problems to connect function that returns auto_ptr to the signal? Below there is a code which won't compile i line where is comment. Regards. #include <iostream> #include <boost/signals.hpp> #include <boost/shared_ptr.hpp> #include <boost/bind.hpp> #include <memory> #include <vector> #include <iterator> #include <algorithm> class some_class { public: ::std::vector <int> func1() { using ::std::vector; typedef vector <int> Res; Res res (2); res.at(0) = 13; res.at(1) = 14; return res; } ::boost::shared_ptr < ::std::vector <int> > func2() { using ::std::vector; using ::boost::shared_ptr; typedef shared_ptr < vector <int> > Res; Res res (new vector<int> (2)); res->at(0) = 23; res->at(1) = 24; return res; } ::std::auto_ptr < ::std::vector <int> > func3() { using ::std::vector; using ::std::auto_ptr; typedef auto_ptr < vector <int> > Res; Res res (new vector<int> (2)); res->at(0) = 33; res->at(1) = 34; return res; } }; int main() { using ::boost::signal; using ::std::vector; using ::std::auto_ptr; using ::boost::shared_ptr; using ::boost::bind; some_class sc; signal < vector <int> (void) > sig1; signal < shared_ptr < vector <int> > (void) > sig2; signal < auto_ptr < vector <int> > (void) > sig3; sig1.connect (bind (&some_class::func1,&sc)); vector <int> ret1 (sig1()); ::std::copy (ret1.begin(), ret1.end(), ::std::ostream_iterator<int> (::std::cout, "\n")); sig2.connect (bind (&some_class::func2,&sc)); vector <int> ret2 (*sig2()); ::std::copy (ret2.begin(), ret2.end(), ::std::ostream_iterator<int> (::std::cout, "\n")); sig3.connect (bind (&some_class::func3,&sc)); //sig3(); // <- ERROR } -- |\/\/| Seweryn Habdank-Wojewódzki \/\/