//%2003////////////////////////////////////////////////////////////////////////
//
// Copyright (c) 2000, 2001, 2002  BMC Software, Hewlett-Packard Development
// Company, L. P., IBM Corp., The Open Group, Tivoli Systems.
// Copyright (c) 2003 BMC Software; Hewlett-Packard Development Company, L. P.;
// IBM Corp.; EMC Corporation, The Open Group.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to
// deal in the Software without restriction, including without limitation the
// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
// sell copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
// 
// THE ABOVE COPYRIGHT NOTICE AND THIS PERMISSION NOTICE SHALL BE INCLUDED IN
// ALL COPIES OR SUBSTANTIAL PORTIONS OF THE SOFTWARE. THE SOFTWARE IS PROVIDED
// "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT
// LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
// ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
//==============================================================================
//
// Author: Mike Brasher (mbrasher@bmc.com)
//
// Modified By:
//
//%/////////////////////////////////////////////////////////////////////////////

#ifndef Pegasus_Stack_h
#define Pegasus_Stack_h

#include <Pegasus/Common/Config.h>
#include <Pegasus/Common/ArrayInternal.h>
#include <Pegasus/Common/String.h>
#include <Pegasus/Common/InternalException.h>

PEGASUS_NAMESPACE_BEGIN

/** The Stack class provides a simple stack implementation.
    This class provides a stack implementation which is based on the Array<>
    template class.
*/
template<class T>
class Stack
{
public:

    /** Default constructor. */
    Stack() { }

    /** Copy constructor. */
    Stack(const Stack<T>& x) : _rep(x._rep) { }

    /** This constructor was added to provide a fast way of creating a stack
	with a single element on it. This constructor is necessary to realize
	the return-value compiler optimization which permits objects used in
	return/constructor expressions to be initialized only once.

	Notice that this constructor is explicit to avoid implicit 
	initialization of a stack with the type of T.
	which 
    */
    PEGASUS_EXPLICIT Stack(const T& x) { _rep.append(x); }

    /** Destructor. */
    ~Stack() { }

    /** Assignment operator. */
    Stack<T>& operator=(const Stack<T>& x) { _rep = x._rep; return *this; }

    /** Returns size of stack. */
    Uint32 size() const { return _rep.size(); }

    /** Tests whether stack is empty. */
    Boolean isEmpty() const { return _rep.size() == 0; }

    /** Pushes entry onto the stack. */
    void push(const T& x) { _rep.append(x); }

    /** Returns reference to the top element on the stack.
	@return reference to top element on stack.
	@exception throws StackUnderflow if stack is empty.
    */
    T& top();

    /** Const version of top() method.
    */
    const T& top() const { return ((Stack<T>*)this)->top(); }

    /** Pops top entry from stack. */
    void pop();

    /** Provides indexing for stack. */
    T& operator[](Uint32 i) { return _rep[i]; }

    /** Const version of indxing operator. */
    const T& operator[](Uint32 i) const { return _rep[i]; }
    
    void reserveCapacity(Uint32 capacity) { _rep.reserveCapacity(capacity); }

private:

    Array<T> _rep;
};

template<class T>
T& Stack<T>::top()
{
    if (isEmpty())
	throw StackUnderflow();

    return _rep[_rep.size() - 1];
}

template<class T>
void Stack<T>::pop()
{
    if (isEmpty())
	throw StackUnderflow();

    _rep.remove(_rep.size() - 1);
}

PEGASUS_NAMESPACE_END

#endif /* Pegasus_Stack_h */
