Queue using singly-linked list

Queue.h

//
//  Queue.h
//  Data Structures
//
//  Created by Salvador Guerrero on 3/15/16.
//  Copyright © 2016 ByteApps. All rights reserved.
//

/*
 * Queue using singly-linked list
 *
 * A samples can be found at: https://github.com/ObjSal/Data-Structures
 */

#include "List.h"

#ifndef Queue_h
#define Queue_h

typedef struct list Queue;

void enqueue(Queue **queue, item_type item)
{
    list_insert(queue, item);
}

/*
 * not performant at all, don't use in production, just for the demo.
 */

Queue* _dequeue(Queue *queue_head,  Queue *queue)
{
    if (queue == NULL) return NULL;

    if (queue->next)
    {
        return _dequeue(queue_head, queue->next);
    }

    Queue *predecessor_node = list_predecessor(queue_head, queue->item);

    if (predecessor_node)
    {
        predecessor_node->next = NULL;
    }

    return queue;
}

Queue* dequeue(Queue *queue)
{
    return _dequeue(queue, queue);
}

#endif /* Queue_h */