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