CS35 Stack ADT

#pragma once
/* Copyright (c) 2018
   Swarthmore College Computer Science Department, Swarthmore PA
   A. Danner, M. Gagne, J. Brody, Z. Palmer, A. Soni, L. Meeden
   Distributed as course material for Spring 2018
   CPSC 035: Data Structures and Algorithms
 */
 
/**
 * The Stack is a pure virtual (abstract) interface of a stack.  Stack
 * implementations should inherit from and implement this interface.
 * @tparam The type of elements stored in this stack.
 */
template <typename T>
class Stack {
public:
    virtual ~Stack() { };

    /**
     * Adds an element to this stack.
     * @param element The element to add to the stack.
     */
    virtual void push(T item) = 0;

    /**
     * Removes the top element from the stack.
     * @return The element that was removed.
     * @throws runtime_error If the stack is empty.
     */
    virtual T pop() = 0;

    /**
     * Determines the size of the stack.
     * @return The number of elements in the stack.
     */
    virtual int getSize() = 0;

    /**
     * Determines whether the stack is empty.
     * @return true if the stack is empty; false otherwise.
     */
    virtual bool isEmpty() = 0;

    /**
     * Retrieves the top element of this stack (without removing it).
     * @return The top element of this stack.
     * @throws runtime_error If the stack is empty.
     */
    virtual T getTop() = 0;

    // You can safely ignore the following code.  This eliminates some default
    // class routines, preventing you from using them accidentally.
    // Specifically, we are disabling the use of the copy constructor and the
    // copy assignment operator.  You can read more here:
    //   http://www.cplusplus.com/articles/y8hv0pDG/
public:
    Stack() { }
private:
    Stack(const Stack& other) = delete;
    Stack& operator=(const Stack& other) = delete;
};