/*---------------------------------------------------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     |
    \\  /    A nd           | Copyright (C) 1991-2008 OpenCFD Ltd.
     \\/     M anipulation  |
-------------------------------------------------------------------------------
License
    This file is part of OpenFOAM.

    OpenFOAM is free software; you can redistribute it and/or modify it
    under the terms of the GNU General Public License as published by the
    Free Software Foundation; either version 2 of the License, or (at your
    option) any later version.

    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    for more details.

    You should have received a copy of the GNU General Public License
    along with OpenFOAM; if not, write to the Free Software Foundation,
    Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA

Class
    Foam::FIFOStack

Description
    A FIFO stack based on a singly-linked list.
    Operations are push(), pop(), top(), bottom() and empty().

SourceFiles
    FIFOStack.C

\*---------------------------------------------------------------------------*/

#ifndef FIFOStack_H
#define FIFOStack_H

#include "SLList.H"

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

namespace Foam
{

/*---------------------------------------------------------------------------*\
                           Class FIFOStack Declaration
\*---------------------------------------------------------------------------*/

template<class T>
class FIFOStack
:
    public SLList<T>
{

public:

    // Constructors

        //- Construct null
        FIFOStack()
        {}

        //- Construct given initial T
        FIFOStack(T a)
        :
            SLList<T>(a)
        {}

        //- Construct from Istream
        FIFOStack(Istream& is)
        :
            SLList<T>(is)
        {}


    // Member Functions

        // Access

            //- Return a copy of the top element
            T top() const
            {
                return this->last();
            }

            //- Return a copy of the bottom element
            T bottom() const
            {
                return this->first();
            }


        // Check

            //- Is the stack empty
            bool empty() const
            {
                return this->size() == 0;
            }


        // Edit

            //- Push an element onto the stack
            void push(const T& a)
            {
                this->append(a);
            }

            //- Pop the bottom element off the stack
            T pop()
            {
                return this->removeHead();
            }
};


// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

} // End namespace Foam

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

#endif

// ************************************************************************* //