Thread: debug assertion failed: deque iterator not dereferencable

code compiles and works if i dont have my cout statement. but when i try to cout the front and top element of queue it compiles but has that debug error

Code:

void wordTest(string search, string temp, int i)
{
	string word;
	set<string> myset;
	set<string>::iterator iter;
	//string temp;
	Stack<string> object;
	queue<Stack<string>> myqueue;

	ifstream infile;
	infile.open("words.txt");

	while (infile >> word)
	{
		myset.insert(word);
	}

		//cout << search << endl;
		iter = myset.find(search);
	
		if (iter != myset.end())
		{
			//Stack<string> object;
			object.push(temp);
			object.push(search);			
			myqueue.push(object);
		}
	

	//object.printStack(cout);


	cout << myqueue.front().top();

	
	infile.close();
}