queue.h

#ifndef QUEUE_H
#define QUEUE_H

#include <exception>
#include <memory>

class Queue
{
private:
	const int maxSize;
	int numValues;
    std::unique_ptr<char[]> queue;

public:
	class Full: public std::exception
	{
	public:
		virtual const char* what() const throw();
	};

	class Empty: public std::exception
	{
	public:
		virtual const char* what() const throw();
	};

	/** Initialise the queue, maxSize is the maximum number of
		values that can be stored in the queue at any time **/
	Queue( const int _maxSize );

	~Queue();

	/** Returns the number of values currently stored in the
		queue **/
	int num_items() const;

	/** Add value to the front of the queue, raises Queue::Full
		exception is queue is full **/
	void push( char value );

	/** Returns the value currently stored at the front of the
		queue, raises Queue::Empty exception is queue is
		empty **/
	char front() const;

	/** Returns the value currently stored at the back of the
		queue, raises Queue.Empty exception if the queue is
		empty **/
	char back() const;

	/** Removes and returns the value currently stored at the
		front of the queue, raises Queue::Empty exception is queue
		is empty **/
	char pop();
};

#endif