I have this code (from async_read_until boost documentation): boost::asio::streambuf b; void handler(const boost::system::error_code& e, std::size_t size) { if (!e) { std::istream is(&b); std::string line; std::getline(is, line); // ... } } boost::asio::async_read_until(s, b, "\r\n", handler); But I obtain this error on Ubuntu 11.04 (boost 1.45.0): boost/asio/impl/read_until.hpp|388|*error: request for member ‘async_read_some’* in ‘((boost::asio::detail::read_until_delim_op<boost::asio::basic_stream_socket<boost::asio::ip::tcp>*, std::allocator<char>, void (*)(const boost::system::error_code&, unsigned int)>*)this)->boost::asio::detail::read_until_delim_op<boost::asio::basic_stream_socket<boost::asio::ip::tcp>*, std::allocator<char>, void (*)(const boost::system::error_code&, unsigned int)>::stream_’, which is of non-class type ‘boost::asio::basic_stream_socketboost::asio::ip::tcp*’ I Included in my project: libpthread libboost_system -- View this message in context: http://boost.2283326.n4.nabble.com/async-read-some-not-found-tp3732368p37323... Sent from the Boost - Users mailing list archive at Nabble.com.