#ifndef queue_cxx
#define queue_cxx

#include "listNode2.h"
#include "queue.h"

typedef bool boolean ;

template <class T>
queue<T>::queue(void){
  front = NULL ;
}//end of constructor

template <class T>
queue<T>::~queue(void){
  node<T> * temp = front ;
  while(front != NULL){
    delete temp ;
    temp = front ;
    front = front->link() ;
  }//while
}//end of destructor

template <class T>
boolean queue<T>::isEmpty(void){
  return front == NULL ;
}//end of isEmpty

template <class T>
void queue<T>::enqueue(const T & item){
  if(front == NULL){
    front = new node<T>(item, NULL) ;
  }else{ 
    node<T> * prev = front ;
    while(prev->link() != NULL)
      prev = prev->link() ;
    node<T> * new_node = new node<T>(item,NULL) ;
    prev->set_link(new_node) ;
  }//else
}//end of enqueue

template <class T>
T queue<T>::dequeue(void){
  if(front == NULL){
    cerr << "Tried to dequeue from an empty"
         << " queue." << endl ;
    exit(EXIT_FAILURE) ;
  }else{
    node<T> * temp = front ;
    T data = temp->data() ;
    front = front->link() ;
    delete temp ;
    return data ;
  }//else
}//end of dequeue

#endif