The BOOST_PP_IDENTITY macro expands to its argument when invoked.

Usage

BOOST_PP_IDENTITY(item)()

Arguments

item
The result of the expansion.

Remarks

This macro is designed to be used with BOOST_PP_IF and BOOST_PP_IIF when only one of the clauses needs to be invoked.

See Also

Requirements

Header:  <boost/preprocessor/facilities/identity.hpp>

Sample Code

#include <boost/preprocessor/control/if.hpp>
#include <boost/preprocessor/facilities/empty.hpp>
#include <boost/preprocessor/facilities/identity.hpp>

#define MACRO(n) BOOST_PP_IF(n, BOOST_PP_IDENTITY(x), BOOST_PP_EMPTY)()

MACRO(0) // expands to nothing
MACRO(1) // expands to x
© 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)