Hello, Ok, this is what I'm trying to do: I want to define some base class A which has a container with elements it needs to sort. I want to be flexible with the comparison function, so the base class A will define an abstract comparison function which will be implemented by derived classes. Since std::sort () expects function objects, after a lot of asking around I found out I needed to use boost::bind. However, trying almost all different types of combinations and looking up all kind of manuals, I'm pretty much clueless... Here's the test-case code: --- #include <algorithm> #include <string> #include <vector> #include class A { public: virtual bool sort (std::string const * const & a, std::string const * const & b) const = 0; void func () { // std::sort ( _elements.begin(), _elements.end(), boost::mem_fn ( A::sort) ); std::sort ( _elements.begin(), _elements.end(), boost::bind ( A::sort, this, _1, _2 ) ); } private: std::vector < std::string * > _elements; }; class B : public A { public: virtual bool sort (std::string const * const & a, std::string const * const & b) const { return true; } }; class C : public A { public: virtual bool sort (std::string const * const & a, std::string const * const & b) const { return false; } }; --- I hope the code makes it a bit more clear as to what I'm trying to do... I follow examples listed at threads like http://blog.gmane.org/gmane.comp.lib.boost.user/day=20050617 , and well, this is almost a literate copy of some recommendations but it doesn't work: -- sort.cpp: In member function ‘void A::func()’: sort.cpp:13: error: no matching function for call to ‘bind(<unknown type>, A* const, boost::arg<1>&, boost::arg<2>&)’ /usr/local/include/boost/bind.hpp:1416: note: candidates are: boost::_bi::bind_t::type> boost::bind(F, A1, A2, A3) [with F = bool (A::*)(const std::string* const&, const std::string* const&)const, A1 = A*, A2 = boost::arg<1>, A3 = boost::arg<2>] /usr/local/include/boost/bind/bind_mf_cc.hpp:78: note: boost::_bi::bind_t, typename boost::_bi::list_av_3::type> boost::bind(R (T::*)(B1, B2)const, A1, A2, A3) [with R = bool, T = A, B1 = const std::string* const&, B2 = const std::string* const&, A1 = A*, A2 = boost::arg<1>, A3 = boost::arg<2>] -- and well, the error is cryptic enough for me to not quite understand what I'm doing wrong... any suggestions ? Thanks in advance! Regards, Leon Mergen