Re: [boost] BOOST_PP_ENUM_PARAMS can't be nested inside BOOST_PP_IF?

Arkadiy Vertleyb wrote:

Hi,

The following code:

#include <boost/preprocessor/control/if.hpp> #include <boost/preprocessor/enum_params.hpp> BOOST_PP_ENUM_PARAMS(3, p) BOOST_PP_IF(1, BOOST_PP_ENUM_PARAMS(3, p), blah)

results in the following text (vc71, main CVS):

p0 , p1 , p2 p0

and a warning:

to many parameters for BOOST_PP_IIF_1.

What's wrong?

"Being lazy" solves the problem: #include <boost/preprocessor/control/if.hpp> #include <boost/preprocessor/enum_params.hpp> #include <boost/preprocessor/tuple/eat.hpp> BOOST_PP_ENUM_PARAMS(3, p) BOOST_PP_IF(1, BOOST_PP_ENUM_PARAMS, blah BOOST_PP_TUPLE_EAT(2))(3,p) Note: - BOOST_PP_IF does not get disabled - lazy invocation => no repetition in the "else-case". Regards, Tobias