I'm trying to figure out how to use the boost.lambda library, and I'm having some issues, probably stupid ones, but still, issues. In the following code I want to remove all obects from m_devices that only have 1 remaining reference (unique() returns true). Yes, I know that this would be pretty easy, using regular function pointers, and the like, however, I'm trying to learn this library. What am I doing wrong? I would also appreciate any pointers for using boost.lambda Whenever I compile the following code on VS2005 I get the following errors: Warning 1 warning C4512: 'boost::lambda::identity<T>' : assignment operator could not be generated c:\program files (x86)\boost\boost_1_34_0\boost\lambda\detail\lambda_functor_base.hpp 43 Warning 2 warning C4512: 'boost::lambda::lambda_functor<T>' : assignment operator could not be generated c:\program files (x86)\boost\boost_1_34_0\boost\lambda\detail\lambda_functors.hpp 204 Warning 3 warning C4512: 'boost::lambda::identity<T>' : assignment operator could not be generated c:\program files (x86)\boost\boost_1_34_0\boost\lambda\detail\lambda_functor_base.hpp 43 Warning 4 warning C4512: 'boost::lambda::lambda_functor<T>' : assignment operator could not be generated c:\program files (x86)\boost\boost_1_34_0\boost\lambda\detail\lambda_functors.hpp 204 Error 5 error C2451: conditional expression of type 'boost::lambda::detail::member_pointer_caller<RET,A,B>' is illegal c:\program files (x86)\microsoft visual studio 8\vc\include\algorithm 87 Error 6 error C2675: unary '!' : 'boost::lambda::detail::member_pointer_caller<RET,A,B>' does not define this operator or a conversion to a type acceptable to the predefined operator c:\program files (x86)\microsoft visual studio 8\vc\include\algorithm 1240 Error 7 error C2582: 'operator =' function is unavailable in 'std::pair<_Ty1,_Ty2>' c:\program files (x86)\microsoft visual studio 8\vc\include\algorithm 1241 My code for the class I'm having trouble with follows: #pragma once #include <string> #include <map> #include <boost/shared_ptr.hpp> #include "SocketDevice.h" namespace Socket { class SocketFactory { public: SocketFactory(std::string Host, std::string Port); virtual ~SocketFactory(void); protected: std::pair<std::string, std::string> m_dest; boost::shared_ptr<SocketDevice> m_device; static std::map<std::pair<std::string, std::string>, boost::shared_ptr<SocketDevice>> m_devices; private: void RemoveUnreferencedSockets(void); }; }; #include "SocketFactory.h" #include <boost/lambda/lambda.hpp> #include <boost/bind.hpp> Socket::SocketFactory::~SocketFactory(void) { } void Socket::SocketFactory::RemoveUnreferencedSockets(void) { std::remove_if(Socket::SocketFactory::m_devices.begin(), Socket::SocketFactory::m_devices.end(), boost::lambda::_1 ->* &std::pair<std::pair<std::string, std::string>, boost::shared_ptr<SocketDevice> >::second ->* &boost::shared_ptr<SocketDevice>::unique); }