stack.h

#ifndef STACK_H
#define STACK_H

#include <exception>
#include <memory>

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

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

    ~Stack();

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

    /** Add value to the top of the stack, raises Stack::Full
        exception if stack is full */
    void push( char value );

    /** Returns the value currently stored at the top of the
        stack, raises Stack::Empty exception if stack is
        empty */
    char top();

    /** Removes and returns the value currently stored at the
        top of the stack, raises Stack::Empty exception if stack
        is empty */
    char pop();
};

#endif