The BOOST_PP_LIST_TRANSFORM macro transforms each element in a list according to a supplied transformation.

Usage

BOOST_PP_LIST_TRANSFORM(op, data, list)

Arguments

op
A ternary predicate of the form op(d, data, elem).  This transformation is expanded by BOOST_PP_LIST_TRANSFORM for each element in list with the next available BOOST_PP_WHILE iteration, the auxiliary data, and the current element in list
data
Auxiliary data passed to pred.
list
The list to be transformed.

Remarks

This macro expands op for each element in list.  It builds a new list out of the results of each call.  If, for example, list is (a, (b, (c, BOOST_PP_NIL))), this macro expands to...
(op(d, data, a), (op(d, data, b), (op(d, data, c), BOOST_PP_NIL)))
Previously, this macro could not be used inside BOOST_PP_WHILE.  There is no longer any such restriction.  It is more efficient, however, to use BOOST_PP_LIST_TRANSFORM_D in such a situation.

See Also

Requirements

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

Sample Code

#include <boost/preprocessor/arithmetic/dec.hpp>
#include <boost/preprocessor/list/transform.hpp>

#define LIST (1, (3, (2, (5, BOOST_PP_NIL))))

#define OP(d, data, elem) BOOST_PP_DEC(elem)

BOOST_PP_LIST_TRANSFORM(OP, 3, LIST)
   // expands to (0, (2, (1, (4, BOOST_PP_NIL))))

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)