Question

I have some code which creates a synchronised queue which I use in a data gathering class to report it’s data. The method which creates queues is kicking up a warning:

Queue^% DataGatherer::AddOutputQueue()
{
    Queue^ outputQueue = Queue::Synchronized(gcnew Queue);
    AddOutputQueue(outputQueue);
    return outputQueue;
}

1>.\DataGatherer.cpp(21) : warning C4172: returning address of local variable or temporary

Is this a warning I should be worried about or am I safe in this case and it’s just the compiler getting confused about Queue::Synchronized returning a Queue^? The code appears to run fine, but warnings make me nervous 😉

Answer 1

Queue^% indicates a handle being passed by reference. However, the handle inside the func is a local variable which can’t be passed by reference since it’s potentially destroyed when the func finishes. Remove the % from the return type and you are fine.

Edit: It doesn’t mean anything your code seems to work. It can stop doing so any minute.