当队列不为空时，queue.front（）上的“ deque迭代器不可解除”

Question

I am sure this question gets asked a lot - in fact i found 10+ answers while googling the problem. But all of them pointed out not to call queue.front() when the queue is empty.

I have the following code:

std::queue<Message*> MessageQ;    //declaring  the queue
//...
MessageQ.push(Msg);  //filling the Queue
//...
if (!MessageQ.empty())
{
    Message* ToReturn = MessageQ.front();
    MessageQ.pop();
    return ToReturn;
}
return 0;

and i get the "deque iterator not dereferencable" error at the .front() line.

what other problems might trigger such an error when using queue.front()?

I even tried commenting the front line out - the message gets popped like it should.

Thanks for your time.

Answer 1

I'm sorry, it was a dumb mistake on my part. I had a memset() somewhere in the constructor, which overwrote the queue with the data of an empty stack, as i changed the type this afternoon.

Lesson learned, and thanks for Your answers!