pub fn return_popped(&mut self, element: T) {
        let popped_index = self.next_expected_idx - 1;
        self.elements.insert(popped_index, element);
        self.next_expected_idx = popped_index;
    }
/// Returns a previously popped element to the front of the queue.
Returns a previously popped element to the front of the queue.
Returns a previously popped element to the front of the queue .
pub fn return_popped(&mut self, element: T) {
        let popped_index = self.next_expected_idx - 1;
        self.elements.insert(popped_index, element);
        self.next_expected_idx = popped_index;
    }
pub fn return_popped ( & mut self , element : T ) { let popped_index = self . next_expected_idx - 1 ; self . elements . insert ( popped_index , element ) ; self . next_expected_idx = popped_index ; }
Returns a previously popped element to the front of the queue.
Returns a previously popped element to the front of the queue .
&mut self
element
T