Peter Dimov wrote:
You don't need tracking for the above example; bind( slot, _2, _1 ) stores a copy of slot. Signals currently need tracking because they're noncopyable and are bound using ref(). A copyable signal does not, regardless of the semantics of the copy (deep, shallow, or something in between - deep for the signal, shallow for the contained slots).
How would such a copy behave regarding connect() and disconnect()? Neither should affect the original signal, so this would be either a deep copy or an implementation with copy on write semantics. I already don't like the fact that there is no distinction between control over connections and control over invocation. Every entity that is allowed to connect to a signal can also emit it, unless you provide a separate connect() yourself and hide the actual signal. In that case only the signal's owner can connect it to another signal and the whole tracking idea becomes somewhat uninteresting. Is a shared signal (in the sense of a shared_ptr) common practice? Regards Timmo Stange