Thorsten Ottosen wrote:
The return type already serves a dual purpose: it can store a character or an EOF indication. Unfortunately, with non-blocking or async i/o there are now three possible results of a call to get:
1. A character is successfully retrieved. 2. The end of the stream has been reached. 3. No characters are currently available, but more may be available later.
isn't this a job for boost::optional<int> ?
Actually, template<typename Source> int get(Source&); should really be template<typename Source> optional<char> get(Source&); so maybe I should use optional< optional<char> > ;-) Seriously, I think the trouble with this suggestion is that EOF and EAGAIN really deserve equal treatment, whereas with optional<int>, the former would be represented as part of the int and the latter would be represented as the absence of an int. If use optional<int> (which I don't dismiss), there will be lots of tests like if (c && c.get() != EOF) where otherwise you would have if (c.good()) Jonathan