The input stream was not closed properly. Somebody is trying to read from it, but the stream can't give anything by some reason.
The output stream was not closed properly. Somebody is trying to write into it, but it can't receive the data by some reason.
Abstract. If you want to catch simply all stream interruptions.
If you have some good reason to not use assert(0).<br/> In other words, if you really think you need a recoverable assert(0).<br/> Be careful. See <a href="https://forum.dlang.org/post/mailman.1239.1490287548.31550.digitalmars-d@puremagic.com" target="_blank">the discussion</a>.
Abstract. Just a base to differ the user things from the system things.