Files
preprocessor/example/repeat_2d.c

74 lines
2.0 KiB
C
Raw Normal View History

2002-01-30 19:53:52 +00:00
/* 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 example implements a generalized macro for 2D repetition using
* the simple repetition primitives of the preprocessor library.
*/
#include <boost/preprocessor/repeat.hpp>
/** Repeats the macro M(X,Y,P) for X = [0,W[ and Y = [0,H[.
In other words, expands to the sequence:
<PRE>\verbatim
M( 0, 0, P) M( 1, 0, P) ... M(W-1, 0, P)
M( 0, 1, P) M( 1, 1, P) ... M(W-1, 1, P)
... ... ... ...
M( 0,H-1, P) M( 1,H-1, P) ... M(W-1,H-1, P)
\endverbatim</PRE>
2002-06-07 13:04:18 +00:00
Uses BOOST_PP_REPEAT().
2002-01-30 19:53:52 +00:00
*/
#define REPEAT_2D(W,H,M,P)\
2002-06-07 13:04:18 +00:00
/* Here we can simply use BOOST_PP_REPEAT(), because\
* it implements automatic recursion.\
2002-01-30 19:53:52 +00:00
*/\
2002-06-07 13:04:18 +00:00
BOOST_PP_REPEAT\
2002-01-30 19:53:52 +00:00
( H\
, REPEAT_2D_ROW\
, (W,M,P)\
)
#ifndef DOXYGEN_SHOULD_SKIP_THIS
#define REPEAT_2D_ROW(Y,WMP)\
BOOST_PP_REPEAT\
( BOOST_PP_TUPLE_ELEM(3,0,WMP)\
, REPEAT_2D_ELEM\
, (Y, BOOST_PP_TUPLE_ELEM(3,1,WMP), BOOST_PP_TUPLE_ELEM(3,2,WMP))\
)
#define REPEAT_2D_ELEM(X,YMP)\
BOOST_PP_TUPLE_ELEM(3,1,YMP)\
( X\
, BOOST_PP_TUPLE_ELEM(3,0,YMP)\
, BOOST_PP_TUPLE_ELEM(3,2,YMP)\
)
#endif
#include <boost/preprocessor/logical/or.hpp>
#include <boost/preprocessor/comma_if.hpp>
#include <boost/preprocessor/list/cat.hpp>
#include <boost/preprocessor/tuple/to_list.hpp>
/* Here we use the above macro to generate something. */
#define ELEM(X,Y,E) BOOST_PP_COMMA_IF(BOOST_PP_OR(X,Y)) BOOST_PP_LIST_CAT(BOOST_PP_TUPLE_TO_LIST(5,(E,_,X,_,Y)))
enum { REPEAT_2D(3,4,ELEM,elem) };
/* The above expands to:
*
* enum { elem_0_0, elem_1_0, elem_2_0,
* elem_0_1, elem_1_1, elem_2_1,
* elem_0_2, elem_1_2, elem_2_2,
* elem_0_3, elem_1_3, elem_2_3 };
*/