The BOOST_PP_LIST_FOR_EACH_PRODUCT macro repeats a macro for each cartesian product of several lists.

Usage

BOOST_PP_LIST_FOR_EACH_PRODUCT(macro, size, tuple)

Arguments

macro
The binary macro of the form macro(r, product).  This macro is expanded by BOOST_PP_FOR_EACH_PRODUCT with each cartesian product in tuple.  It is expanded with the next available BOOST_PP_FOR repetition and a tuple containing a cartesian product.  This tuple will have size elements.
size
The size of tuple.
tuple
A tuple of lists from which cartesian products are obtained.

Remarks

This macro is a repetition construct.  If two lists are (a, (b, (c, BOOST_PP_NIL))) and (x, (y, (z, BOOST_PP_NIL))), this macro will produce the following sequence:
macro(r, (a, x)) macro(r, (a, y)) macro(r, (a, z))
macro(r, (b, x)) macro(r, (b, y)) macro(r, (b, z))
macro(r, (c, x)) macro(r, (c, y)) macro(r, (c, z))
Previously, this macro could not be used inside BOOST_PP_FOR.  There is no longer any such restriction.  It is more efficient, however, to use BOOST_PP_LIST_FOR_EACH_PRODUCT_R in such a situation.

See Also

Requirements

Header:  <boost/preprocessor/list/for_each_product.hpp>

Sample Code

#include <boost/preprocessor/list/for_each_product.hpp>

#define L1 (a, (b, (c, BOOST_PP_NIL)))
#define L2 (x, (y, (z, BOOST_PP_NIL)))

#define MACRO(r, product) product

BOOST_PP_LIST_FOR_EACH_PRODUCT(MACRO, 2, (L1, L2))
   // expands to (a, x) (a, y) (a, z) (b, x) (b, y) (b, z) (c, x) (c, y) (c, z)

© Copyright Housemarque Oy 2002
© Copyright Paul Mensonides 2002

Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at www.boost.org/LICENSE_1_0.txt)