On Tue, 18 Mar 2003 18:46:42 +0000
Glynn Clements
Not if you want to support multiple callbacks for each event. In that case, you need to be able to identify a specific callback, which gets us back to the issue of equality of function types.
Unfortunately, the easiest solution (require the application to provide a FunPtr, as that's what's going to be passed to the lower levels) is also the ugliest.
I am perhaps missing the point. In my view, if you want to simulate multiple callbacks with just one, you can create the FunPtr in the callback registration, and keep it into a closure you give back to unregister the callback. Of course, the multiple callback is just an interface, and toolkits wich support multiple callbacks natively will not go trough this mess. What do toolkits think about this? :) What toolkits implement one callback, and what multiple ones? -- Scopriti essere umano e in quanto tale persona banale e non speciale a cui Dio concede gesti assai banali. D'ora in poi quello sei tu. [Marlene Kuntz]