Re: [boost] PP: MSVC BOOST_PP_REPEAT + BOOST_PP_SEQ_ELEM bug

From: Paul Mensonides (pmenso57_at_[hidden])
Date: 2003-04-11 22:54:12

Aleksey Gurtovoy wrote:
> Paul Mensonides wrote:
>>> #include "boost/preprocessor/repeat.hpp"
>>> #include "boost/preprocessor/seq/elem.hpp"
>>>
>>> #define b( x, y ) x y
>>> #define BODY( unused, n, tuple ) tuple
>>>
>>> #define SOMETHING( arity, params ) \
>>>     BOOST_PP_REPEAT( \
>>>           arity \
>>>         , BODY \
>>>         , ( a, BOOST_PP_SEQ_ELEM(0, params), c ) \
>>>         ) \
>>> /**/
>>>
>>> SOMETHING( 5, (b)(d) )
>>
>> Do the parts work independently?
>>
>> BOOST_PP_SEQ_ELEM(0, (b)(c)) -> b
>>
>> BOOST_PP_REPEAT(5, BODY, (a, b, c)) -> (a, b, c) (a, b, c) // etc.
>
> Yep, they do - that's why I named it "BOOST_PP_REPEAT +
> BOOST_PP_SEQ_ELEM bug".

That is what I figured, but I wanted to make sure that the (a, b, c) wasn't
causing a problem--which it shouldn't be anyway.  I'll look at this later when I
have time to install VC6 on my other computer.  VC has a really annoying problem
with expansion order, and that is likely causing this problem.

Paul Mensonides