Boost.Asio is a phenomenal framework that will allow you to write portable, scalable, and efficient asynchronous I/O code.
Unfortunately, the framework leverages some interesting design patterns and is not well documented beyond simple examples and tutorials. So when I saw a book written on Boost.Asio, I leapt at the chance to read it.
My initial reactions were quiet negative. The book is an expanded, fluffed up version of the official Asio examples and documents. There are a lot of gaps in the book as the authors shift from synchronous to asynchronous, and vice versa.
If you are an experienced Asio user, you won’t benefit from this book.
In any event, I would recommend watching Christopher Kohlhoff’s BoostCon presentation regardless: