I'm trying to compile the asio Daytime.3 tutorial source from http://asio.sourceforge.net/boost_asio_0_3_7/libs/asio/doc/tutorial/tutdayti... and I'm getting an type error in an arg passed from asio to winsock. I'm going to try to grok the code in win_iocp_socket_service.hpp to understand the problem, but it's my first look at asio internals. (The tutorial builds correctly on Linux, not surprising as it's a windows specific binding.) Any help or pointers are appreciated: cl -c -nologo -EHsc -GR -Zc:forScope -MT -I/Boost/include/boost-1_33_1/ Daytime3-1.cpp -FoDaytime3-1.obj Daytime3-1.cpp Please define _WIN32_WINNT or _WIN32_WINDOWS appropriately Assuming _WIN32_WINNT=0x0500 (i.e. Windows 2000 target) \Boost\include\boost-1_33_1\boost\asio\detail\win_iocp_socket_service.hpp(527) : error C2664: 'WSASend' : cannot convert parameter 6 from 'boost::asio::detail::handler_ptr<Alloc_Traits>::pointer_type' to 'LPWSAOVERLAPPED' with [ Alloc_Traits=alloc_traits ] Types pointed to are unrelated; conversion requires reinterpret_cast, C-style cast or function-style cast \Boost\include\boost-1_33_1\boost\asio\stream_socket_service.hpp(222) : see reference to function template instantiation 'void boost::asio::detail::win_iocp_socket_service<Protocol>::async_send<Const_Buffers,Handler>(boost::asio::detail::win_iocp_socket_service<Protocol>::implementation_type &,const Const_Buffers &,boost::asio::socket_base::message_flags,Handler)' being compiled with [ Protocol=boost::asio::ip::tcp, Const_Buffers=boost::asio::const_buffer_container_1, Handler=boost::asio::detail::write_handler<boost::asio::ip::tcp::socket,boost::asio::const_buffer_container_1,boost::asio::detail::transfer_all_t,boost::_bi::bind_t<void,boost::_mfi::mf2<void,tcp_connection,const boost::asio::error &,size_t>,boost::_bi::list3<boost::_bi::list_av_3<boost::shared_ptr<tcp_connection>,boost::arg<1>,boost::arg<2>>::B1,boost::_bi::list_av_3<boost::shared_ptr<tcp_connection>,boost::arg<1>,boost::arg<2>>::B2,boost::_bi::list_av_3<boost::shared_ptr<tcp_connection>,boost::arg<1>,boost::arg<2>>::B3>>> ] \Boost\include\boost-1_33_1\boost\asio\basic_stream_socket.hpp(611) : see reference to function template instantiation 'void boost::asio::stream_socket_service<Protocol>::async_send<Const_Buffers,Handler>(boost::asio::stream_socket_service<Protocol>::implementation_type &,const Const_Buffers &,boost::asio::socket_base::message_flags,Handler)' being compiled with [ Protocol=boost::asio::ip::tcp, Const_Buffers=boost::asio::const_buffer_container_1, Handler=boost::asio::detail::write_handler<boost::asio::ip::tcp::socket,boost::asio::const_buffer_container_1,boost::asio::detail::transfer_all_t,boost::_bi::bind_t<void,boost::_mfi::mf2<void,tcp_connection,const boost::asio::error &,size_t>,boost::_bi::list3<boost::_bi::list_av_3<boost::shared_ptr<tcp_connection>,boost::arg<1>,boost::arg<2>>::B1,boost::_bi::list_av_3<boost::shared_ptr<tcp_connection>,boost::arg<1>,boost::arg<2>>::B2,boost::_bi::list_av_3<boost::shared_ptr<tcp_connection>,boost::arg<1>,boost::arg<2>>::B3>>> ] \Boost\include\boost-1_33_1\boost\asio\impl\write.ipp(167) : see reference to function template instantiation 'void boost::asio::basic_stream_socket<Protocol>::async_write_some<Const_Buffers,boost::asio::detail::write_handler<Async_Write_Stream,Const_Buffers,Completion_Condition,Handler>>(const Const_Buffers &,boost::asio::detail::write_handler<Async_Write_Stream,Const_Buffers,Completion_Condition,Handler>)' being compiled with [ Protocol=boost::asio::ip::tcp, Const_Buffers=boost::asio::const_buffer_container_1, Async_Write_Stream=boost::asio::ip::tcp::socket, Completion_Condition=boost::asio::detail::transfer_all_t, Handler=boost::_bi::bind_t<void,boost::_mfi::mf2<void,tcp_connection,const boost::asio::error &,size_t>,boost::_bi::list3<boost::_bi::list_av_3<boost::shared_ptr<tcp_connection>,boost::arg<1>,boost::arg<2>>::B1,boost::_bi::list_av_3<boost::shared_ptr<tcp_connection>,boost::arg<1>,boost::arg<2>>::B2,boost::_bi::list_av_3<boost::shared_ptr<tcp_connection>,boost::arg<1>,boost::arg<2>>::B3>> ] \Boost\include\boost-1_33_1\boost\asio\impl\write.ipp(174) : see reference to function template instantiation 'void boost::asio::async_write<Async_Write_Stream,Const_Buffers,boost::asio::detail::transfer_all_t,Handler>(Async_Write_Stream &,const Const_Buffers &,Completion_Condition,Handler)' being compiled with [ Async_Write_Stream=boost::asio::ip::tcp::socket, Const_Buffers=boost::asio::const_buffer_container_1, Handler=boost::_bi::bind_t<void,boost::_mfi::mf2<void,tcp_connection,const boost::asio::error &,size_t>,boost::_bi::list3<boost::_bi::list_av_3<boost::shared_ptr<tcp_connection>,boost::arg<1>,boost::arg<2>>::B1,boost::_bi::list_av_3<boost::shared_ptr<tcp_connection>,boost::arg<1>,boost::arg<2>>::B2,boost::_bi::list_av_3<boost::shared_ptr<tcp_connection>,boost::arg<1>,boost::arg<2>>::B3>>, Completion_Condition=boost::asio::detail::transfer_all_t ] Daytime3-1.cpp(41) : see reference to function template instantiation 'void boost::asio::async_write<boost::asio::ip::tcp::socket,boost::asio::const_buffer_container_1,boost::_bi::bind_t<R,F,L>>(Async_Write_Stream &,const Const_Buffers &,Handler)' being compiled with [ R=void, F=boost::_mfi::mf2<void,tcp_connection,const boost::asio::error &,size_t>, L=boost::_bi::list3<boost::_bi::list_av_3<boost::shared_ptr<tcp_connection>,boost::arg<1>,boost::arg<2>>::B1,boost::_bi::list_av_3<boost::shared_ptr<tcp_connection>,boost::arg<1>,boost::arg<2>>::B2,boost::_bi::list_av_3<boost::shared_ptr<tcp_connection>,boost::arg<1>,boost::arg<2>>::B3>, Async_Write_Stream=boost::asio::ip::tcp::socket, Const_Buffers=boost::asio::const_buffer_container_1, Handler=boost::_bi::bind_t<void,boost::_mfi::mf2<void,tcp_connection,const boost::asio::error &,size_t>,boost::_bi::list3<boost::_bi::list_av_3<boost::shared_ptr<tcp_connection>,boost::arg<1>,boost::arg<2>>::B1,boost::_bi::list_av_3<boost::shared_ptr<tcp_connection>,boost::arg<1>,boost::arg<2>>::B2,boost::_bi::list_av_3<boost::shared_ptr<tcp_connection>,boost::arg<1>,boost::arg<2>>::B3>>