template2.cpp

#include <iostream>
#include <vector>
#include <cstdlib>
#include <string>
#include <stdexcept>

using namespace std;

template <class T>
class Stack {
private:
	vector<T> elems;     // elements 

public:
	void push(T const&);  // push element 
	void pop();               // pop element 
	T top() const;            // return top element 
	bool empty() const{       // return true if empty.
		return elems.empty();
	}
};

template <class T>
void Stack<T>::push(T const& elem)
{
	// append copy of passed element 
	elems.push_back(elem);
}

template <class T>
void Stack<T>::pop()
{
	if (elems.empty()) {
		throw out_of_range("Stack<>::pop(): empty stack");
	}
	// remove last element 
	elems.pop_back();
}

template <class T>
T Stack<T>::top() const
{
	if (elems.empty()) {
		throw out_of_range("Stack<>::top(): empty stack");
	}
	// return copy of last element 
	return elems.back();
}

int main()
{
	try {
		Stack<int>         intStack;  // stack of ints 
		Stack<string> stringStack;    // stack of strings 

		// manipulate int stack 
		intStack.push(7);
		intStack.push(14);
		cout << intStack.top() << endl;

		// manipulate string stack 
		stringStack.push("hello");
		stringStack.push("frog");
		cout << stringStack.top() << std::endl;
		stringStack.pop();
		cout << stringStack.top() << std::endl;
		stringStack.pop();
		cout << stringStack.top() << std::endl;
		stringStack.pop();
	}
	catch (exception const& ex) {
		cerr << "Exception: " << ex.what() << endl;
		return -1;
	}
}