I'm using Objective-C/C++ and I have an Objective-C class that is a wrapper for a C++ class, are there any special concerns I need to be aware of in order to use fast app switching?
It is my understanding that the iPhone will auto-magically save state for Objective-C objects, but I'm not sure if I need to do any special work to enable support for C++ objects. My C++ class does not have any virtual functions.
By fast app switching you mean multitasking?
There's nothing additional you need to do - iOS 4 will handle the task suspension and resume transparently, unless you need to perform background tasks, regardless of whether you're using objective c++ or just plain objective c.