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/* Copyright (C) 2002
* Housemarque Oy
* http://www.housemarque.com
*
* Permission to copy, use, modify, sell and distribute this software is
* granted provided this copyright notice appears in all copies. This
* software is provided "as is" without express or implied warranty, and
* with no claim as to its suitability for any purpose.
*
* See http://www.boost.org for most recent version.
*/
/* This is a trivial example of using BOOST_PP_WHILE() that simply
* counts down from N to 0 ultimately expanding to a 0.
*/
#include <boost/preprocessor/dec.hpp>
#include <boost/preprocessor/while.hpp>
#define COUNT_DOWN(N) BOOST_PP_WHILE(COUNT_DOWN_C,COUNT_DOWN_F,N)
/* Above is the macro we are implementing using BOOST_PP_WHILE(). */
#define COUNT_DOWN_C(D,N) N
/* Above is the condition. It expands to the current N. */
#define COUNT_DOWN_F(D,N) BOOST_PP_DEC(N)
/* Above is the iteration macro. It decrements N. */
enum { x = COUNT_DOWN(50) };
/* The above expands to 0. */
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