Signals and slots are used for communication between objects. Compiling it sucks (less now), running it typically doesn't. An overview of Qts signals and slots inter-object communication mechanism. The beauty of moc is that it front loads a lot of the magic. Having dabbled with Qt off and on for decades I wasn't surprised.
You're surprised signals are fairly low overhead (and that's fine) and and wondered if anyone actually thought they were performant. I wonder who thought signals were fast to begin with? Insofar as other overhead sensitive environments go, Trolltech ported Qt (including the signal/slot paradigm) to a realtime OS (QNX) and features it prominently in safety critical contexts (e.g. It's actually pretty difficult to structure something such that a signals/slots become a performance bottleneck. That's what Trolltech recommended and almost certainly what the current crop of ioslaves do today (okay I lied, it looks like there are dedicated socket classes that provide their own signals these days). But I know little about Qt, I have a few questions here. QObject Model, moc, parent-child object memory management etc. Also, the QObject system has a lot of nice features, e.g. The signal/slot, state machine in Qt looks very good to my situation. What context am I missing? You're talking about network I/O as being a bad use case for signals/slots and I've pointed out that I (along with other KDE folks) wrote code using signals/slots to handle incoming network data. While looking for some event framework for c++, I found Qt.
