/*
 * This is a simple stack template class based on the standard list.
 */
#ifndef _lstack_h_
#define _lstack_h_

#include <list>

using namespace std;

/*
 * This template class implements a standard stack.
 */
template <typename T>
class Stack {
public:
	// Push an item onto the stack.
	void push(const T & item)
	{
		m_data.push_back(item);
	}

	// Pop an item from the stack.  Return T() if the stack is empty.
	T pop()
	{
		if(m_data.empty()) {
			return T();
		} else {
			T ret = m_data.back();
			m_data.pop_back();
			return ret;
		}
	}

	// An alternate pop which returns through the argument list when the
	// stack is non-empty (and returns true), but just returns false if
	// the stack is empty.  This can also be more efficient if T is large,
	// and will work when T has no empty-argument constructor.
	bool pop(T &ret)
	{
		if(m_data.empty()) {
			return false;
		} else {
			ret = m_data.back();
			m_data.pop_back();
			return true;
		}
	}

	// Tell if the stack is empty
	bool empty() { return m_data.empty(); }

	// Number of items on the stack.
	int size() { return m_data.size(); }
private:
	list<T> m_data;
};

#endif /* _lstack_h_ */