BOOST_PP_TUPLE_EAT

The BOOST_PP_TUPLE_EAT macro expands to a macro that eats a tuple.

The size argument must be the actual size of the tuple in the non-variadic version.

For the variadic version ^(v) the size may be left out completely so that the macro can be invoked as BOOST_PP_TUPLE_EAT(); you may get a warning from some compilers, but the functionality will still work. If you specify a size in the variadic version, it will be ignored, but the warning from some compilers will not occur.

Header:  <boost/preprocessor/tuple/eat.hpp>

#include <boost/preprocessor/control/if.hpp>
#include <boost/preprocessor/tuple/eat.hpp>

#define OP(a, b) (a b)

#define MACRO(n) BOOST_PP_IF(n, OP, BOOST_PP_TUPLE_EAT(2))(1, 2)

// or for the variadic version (v)

#define MACRO(n) BOOST_PP_IF(n, OP, BOOST_PP_TUPLE_EAT())(1, 2)

MACRO(0) // expands to nothing
MACRO(1) // expands to (1, 2)

© Copyright Housemarque Oy 2002
© Copyright Paul Mensonides 2002
© Copyright Edward Diener 2011,2013

Распространяется в соответствии с лицензией Boost Software License, Version 1.0. (См. сопроводительный файл)LICENSE_1_0.txtили копия наwww.boost.org/LICENSE_1_0.txt