The following code example is taken from the book
The C++ Standard Library - A Tutorial and Reference
by Nicolai M. Josuttis, Addison-Wesley, 1999
© Copyright Nicolai M. Josuttis 1999
/* ************************************************************
* Stack.hpp
* - safer and more convenient stack class
* ************************************************************/
#ifndef STACK_HPP
#define STACK_HPP
#include <deque>
#include <exception>
template <class T>
class Stack {
protected:
std::deque<T> c; // container for the elements
public:
/* exception class for pop() and top() with empty stack
*/
class ReadEmptyStack : public std::exception {
public:
virtual const char* what() const throw() {
return "read empty stack";
}
};
// number of elements
typename std::deque<T>::size_type size() const {
return c.size();
}
// is stack empty?
bool empty() const {
return c.empty();
}
// push element into the stack
void push (const T& elem) {
c.push_back(elem);
}
// pop element out of the stack and return its value
T pop () {
if (c.empty()) {
throw ReadEmptyStack();
}
T elem(c.back());
c.pop_back();
return elem;
}
// return value of next element
T& top () {
if (c.empty()) {
throw ReadEmptyStack();
}
return c.back();
}
};
#endif /* STACK_HPP */