Code Fragment: Stack

/**
 * Interface for a stack: A collection of objects that are inserted
 * and removed according to the last-in first-out principle.
 */
template <typename Object>
class Stack {
public:
 /**
  * Returns number of objects in the stack.
  */
  int size() const;
 /** 
  * Returns true if the stack is empty, false otherwise.
  */
  bool isEmpty() const;
 /** 
  * Returns the top object in the stack.
  * Throws StackEmptyException if the stack is empty. 
  */
  Object& top() throw(StackEmptyException); 
 /**
  * Inserts an object at the top of the stack.
  */
  void push(const Object& obj); 
 /** 
  * Removes and returns the top object from the stack.  
  * Throws StackEmptyException if the stack is empty.
  */
  Object pop() throw(StackEmptyException);
};