Re: [Boost-users] [asio] serial_port::async_read_some() and scalablebuffers

So, in other words there is no way of doing this without using a completion condition? There's no simple function that will just fill up the read buffer with all of the data it can obtain?

No. But you can do as follows: 1) start an async. read with the condition transfer_at_least(1) 2) in the handler check socket.available() and perform synchronous read of this amount of data